JP2005265690A - Accuracy determination system, accuracy determination device and server device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an accuracy determination system capable of determining accuracy of a positioning result using a GPS satellite, highly accurately without requiring detailed altitude information. <P>SOLUTION: A CPU of a navigation device acquires topographic coordinate data on a plurality of spots existing around the present position coordinate P of a vehicle from a topographic database in a server device and stores it in a RAM. The CPU selects topographic coordinate data fit to the traveling direction of the vehicle from the topographic coordinate data stored in the RAM, determines a determination reference plane PS of a polygon wherein spots D1, D2, D3 shown by the topographic coordinate data are vertexes, and calculates a plane PB passing the line L of intersection between a plane PA and the determination reference plane PS and vertical to the plane PA and the distance d in the altitude direction (z-direction) of the position coordinate P. When the distance d is below a threshold Th1 determined based on a DOP value, the CPU determines to be normal because the accuracy of the GPS positioning result is high. When the distance d is over the threshold Th1, the CPU determines to be abnormal because the accuracy of the GPS positioning result is low. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an accuracy determination system, an accuracy determination device, and a server device that determine the accuracy of position coordinates calculated based on reception results of satellite signals transmitted from GPS satellites.

  Conventionally, a satellite signal transmitted from a GPS satellite is received, and the distance between the GPS satellite and its own position is measured based on the reception result (orbit information and time information of the satellite included in the satellite signal). There is known a GPS receiver that calculates its own position coordinates. This type of GPS receiver captures four or more GPS satellites, and receives and analyzes the satellite signals transmitted from these GPS satellites. The three-dimensional coordinates consisting of are calculated (three-dimensional positioning).

  By the way, it is known that in positioning using a GPS satellite, an error occurs due to an influence of a reflected wave generated by reflecting a satellite signal to a high-rise building or the like. The GPS receiver calculates the distance between each GPS satellite and its own position based on the position of the GPS satellite and the reception time of the satellite signal, but the distance is measured based on the reception result of the reflected wave. As a result, a measurement error corresponding to the distance of the propagation path extended by reflection occurs. FIG. 16 is a diagram showing the GPS receiver 11 that receives reflected waves.

  For this reason, in the conventional apparatus, the altitude information is obtained from the map database including the altitude information, the accuracy of the positioning result by the GPS satellite is determined, and if the accuracy is low, the positioning is performed by another method. It was.

  For example, the vehicular GPS navigation device described in Patent Document 1 calculates its own position (latitude, longitude, altitude) based on the reception result of a satellite signal from a GPS satellite, and the latitude / longitude of the calculation results. If the altitude information corresponding to the latitude / longitude is obtained from the map database using the information, and there is a discrepancy between the altitude of the current location indicated by the altitude information and the altitude calculated based on the reception result, the GPS Since the accuracy of the positioning result using the satellite is low, the normal GPS positioning is stopped.

In addition, as a GPS receiver that performs positioning using altitude information included in a map database, there is known another apparatus that improves the accuracy of two-dimensional positioning using altitude information in a map database (for example, Patent Document 2). , 3).
JP-A-6-50766 Japanese Patent Laid-Open No. 4-166781 JP-A-62-261087

  However, as in the vehicle GPS navigation device described in Patent Document 1, the altitude of the current location estimated from the altitude information provided in the map database is simply compared with the altitude calculated based on the reception result of the satellite signal. When determining the accuracy of positioning results using GPS satellites, the altitude information of each point must be stored densely in the map database, and a large-capacity storage medium must be installed in the device. There was a problem of not becoming.

  In addition, when the altitude at which the vehicle can exist or the distance that the vehicle can move per unit time is regarded as an appropriate range, and a value exceeding the range is calculated as the positioning result, the above-mentioned vehicle If the GPS navigation apparatus is configured, the above problem can be solved without storing detailed altitude information in the map database. However, when such a method is adopted, there is a problem that accuracy of accuracy determination deteriorates.

  The present invention has been made in view of such a problem, and does not require detailed altitude information, and the accuracy determination system and the accuracy determination device capable of determining the accuracy of a positioning result using a GPS satellite with high accuracy, and its It aims at providing the server apparatus used for an accuracy determination system.

  In order to achieve this object, the invention according to claim 1 calculates the position coordinates of the present location in the three-dimensional coordinate system by the position calculation means based on the reception result of the reception means for receiving the satellite signal from the GPS satellite. A moving body is an accuracy determination system that determines the accuracy of coordinates calculated by the position calculation means, and includes a terrain storage means, a data acquisition means, a deviation value calculation means, and an accuracy determination means. . The three-dimensional coordinate system is a three-dimensional coordinate system including coordinates representing altitude (for example, a three-dimensional coordinate system including latitude, longitude, and altitude).

  The terrain storage means in this accuracy determination system stores terrain coordinate data for each predetermined point, and the terrain coordinate data represents the position coordinates of the ground surface at the point in the three-dimensional coordinate system. Yes. The data acquisition means acquires, from the terrain storage means, terrain coordinate data of a plurality of points existing around the coordinates calculated by the position calculation means.

  The deviation value calculation means is calculated by the position calculation means based on a polygonal configuration surface having each point around the coordinates calculated by the position calculation means represented by the topographic coordinate data acquired by the data acquisition means as a reference. A shift value related to the positional shift of coordinates is calculated. The accuracy determination means determines the accuracy of the coordinates calculated by the position calculation means based on the deviation value calculated by the deviation value calculation means.

  According to this accuracy determination system, the accuracy of coordinates calculated by the position calculation means is determined with reference to the polygonal configuration surface having the point represented by the terrain coordinate data at the apex, so only the point where the terrain coordinate data exists exists. In addition, the accuracy of the coordinates calculated by the position calculating means can be determined at other points (within the polygonal region connecting the points where the terrain coordinate data exists).

  In a route along which a moving body such as a vehicle moves, it is normal that the terrain changes smoothly. Therefore, the ground surface is represented almost accurately by the polygon. Therefore, according to the present invention, it is possible to accurately determine the accuracy of the coordinates calculated by the position calculation means without storing altitude information (the terrain coordinate data here) in the terrain storage means densely. .

  That is, according to the present invention, the accuracy of positioning results using GPS satellites can be determined with high accuracy without requiring detailed altitude information. For example, positioning using GPS satellites or vehicles In a system that identifies the current location in a plurality of modes, such as positioning (estimated navigation) using various built-in sensors, it is possible to appropriately switch modes.

  The deviation value calculating means is the moving direction of the moving object based on the topographic coordinate data acquired by the data acquiring means and the determination result of the direction determining means for determining the moving direction of the moving object. From the intersection line L of the plane PA parallel to the altitude direction including the straight line passing through the coordinate P0 calculated by the position calculation means at the first time and the polygonal component surface. It may be configured to calculate the distance to the coordinates calculated by the calculation means at the second time point as the deviation value.

  In addition, the deviation value calculating means includes a plane PA parallel to the altitude direction including a straight line parallel to the moving direction of the moving body and including the straight line passing through the coordinates P0 calculated by the position calculating means at the first time point, and The distance from the plane PB passing through the intersection line L with the polygonal configuration plane and perpendicular to the plane PA parallel to the altitude direction to the coordinates calculated by the position calculation means at the second time point It is more preferable that the calculation is performed as a deviation value. Note that the second time point may be the same time point as the first time point or may be a different time point.

  As the above-mentioned deviation value regarding the positional deviation, the altitude direction distance from the coordinates calculated by the position calculating means to the polygonal construction surface may be adopted, but the deviation value is calculated in this way. Then, when the inclination of the polygon (the amount of altitude displacement relative to the amount of latitude / longitude displacement) is large, the coordinates of the current location obtained as a result of positioning are slightly different from the coordinates other than the altitude coordinates (latitude / longitude coordinates). Even if there is a serious positioning error, the above-mentioned deviation value will fluctuate excessively. For this reason, if the distance in the altitude direction from the coordinates calculated by the position calculation means to the polygonal construction surface is used as the deviation value, the accuracy of the coordinates calculated by the position calculation means may not be determined with high accuracy. .

  On the other hand, assuming a vehicle that travels on a road such as an automobile as a moving body, it is reasonable to assume that the vehicle is traveling on a horizontal road at least in a direction perpendicular to the moving direction of the vehicle. is there.

  Therefore, as described in claim 2, the distance from the intersection line L to the coordinates calculated by the position calculating means (the distance in the altitude direction may be the shortest distance), or the plane passing through the intersection line L From the plane PB perpendicular to the plane PA parallel to the altitude direction (that is, the plane PB passing through the intersection line L and perpendicular to the intersection line L), the position calculating means If the distance to the calculated coordinates (the distance in the altitude direction or the shortest distance may be used) is adopted as the deviation value, the coordinates calculated by the position calculation means and the current location of the moving object are calculated based on the deviation value. The difference from the true coordinates can be expressed almost correctly, and the accuracy of the coordinates calculated by the position calculating means can be accurately determined.

  In addition, in the accuracy determination system, when the deviation value is less than the threshold, the accuracy of the coordinates calculated by the position calculation unit is determined to be high, and when the deviation value is greater than or equal to the threshold, the coordinates of the coordinates calculated by the position calculation unit are determined. The accuracy determination means may be configured to determine that the accuracy is low. According to the accuracy determination system of the third aspect configured as described above, the accuracy of coordinates can be determined easily and with high accuracy.

  Further, in positioning using GPS satellites, the accuracy of positioning changes depending on the arrangement state of the GPS satellites to be captured. Therefore, in the accuracy determination system according to claim 3, the threshold is set to DOP ( It may be determined based on the (Dilution Of Precision) value.

  That is, the accuracy determination system includes a DOP value calculating unit that calculates a DOP value based on the arrangement state of a GPS satellite that is a transmission source of a satellite signal used when the position calculating unit calculates coordinates, and the DOP value. It is preferable to provide threshold value determining means for determining the threshold value used by the accuracy determination means when determining the accuracy of coordinates based on the DOP value calculated by the calculation means. According to the accuracy determination system according to claim 4 configured as described above, the threshold value is determined based on the DOP value. Therefore, the error based on the satellite arrangement is not misunderstood by the influence of the multipath. Abnormalities in GPS positioning can be detected with high sensitivity.

  In the above, the accuracy determination system capable of determining the accuracy of the positioning result using the GPS satellite with high accuracy without the dense topographic coordinate data has been described. In addition to the calculation means, when it is configured to include an inclination angle detecting means for detecting the inclination angle of itself (moving body) and a moving speed detecting means for detecting the moving speed of itself (moving body) The accuracy determination system may be configured as described in claim 5.

  The accuracy determination system according to claim 5 includes a movement amount calculation unit that calculates a movement amount of the moving body in an altitude direction per unit time based on detection results of the inclination angle detection unit and the movement speed detection unit, and a position Displacement amount calculating means for calculating the displacement amount in the altitude direction per unit time of the coordinates calculated by the calculating means, and the movement amount calculated by the movement amount calculating means and the displacement by the comparison determining means The displacement amount calculated by the amount calculating means is compared, and the accuracy of the coordinates calculated by the position calculating means is determined. Note that the movement amount calculation means and the displacement amount calculation means calculate the movement amount or displacement amount in the altitude direction and compare them with each other because the position coordinate calculation error caused by the reflected wave is a three-dimensional coordinate. This is because it appears greatly in the coordinates of altitude.

  In this accuracy determination system, the displacement amount in the altitude direction where a positioning error is likely to appear is compared with the displacement amount calculated based on the detection result of each detection means built in the moving body (for example, the displacement amount and the displacement amount). Therefore, the accuracy of the coordinates calculated by the position calculation means is determined, so that the accuracy of the coordinates can be determined with high accuracy without using the above-described altitude information and topographic coordinate data.

  However, the accuracy determination using the comparison determination unit is affected by the detection error of each of the detection units, so that the accuracy of the determination may be deteriorated compared to the accuracy determination using the accuracy determination unit. Therefore, the invention described in claim 5 is preferably used in combination with the accuracy determination system described in claims 1 to 4.

  The accuracy determination system according to claim 6 is the accuracy determination system according to claims 1 to 4, wherein the movement amount calculation unit, the displacement amount calculation unit, the comparison determination unit, and a predetermined condition are satisfied. Switching means for prohibiting the operation of the accuracy determination means and selectively operating the comparison determination means. According to this accuracy determination system, the defects of the accuracy determination means and the comparison determination means can be complemented each other.

  For example, if the moving body is present in an area where the terrain coordinate data is not stored in the terrain storage means, the terrain coordinate data can be obtained by configuring the switching means so that the comparison determination means determines the accuracy of the coordinates. Even if a moving body exists in a non-existing area, the accuracy of coordinates calculated by the position calculating means can be determined. In addition, the terrain coordinate data to be stored in the terrain storage means by storing the terrain coordinate data of the area in the terrain storage means only in areas where sufficient accuracy cannot be obtained by the accuracy determination by the comparison determination means. The total amount of can be reduced.

  In addition, when the terrain storage means is provided in an external server device and each of the other means is mounted on a mobile object, the server device is accessed wirelessly from the data acquisition means provided in the mobile object, and the terrain coordinates Data will be acquired, but if the accuracy determination system is configured to acquire the terrain coordinate data from the terrain storage means wirelessly, the terrain coordinate data will be temporarily acquired from the terrain storage means due to the deterioration of the communication environment May not be possible. In such a case, since the accuracy of the coordinates cannot be determined by the accuracy determination means, the switching means may be configured as described in claim 7.

  The switching means in the accuracy determination system according to claim 7 operates the accuracy determination means when the data acquisition means succeeds in acquiring the terrain coordinate data, and causes the accuracy determination means to operate when the data acquisition means fails to acquire the terrain coordinate data. Instead, the comparison determination unit is selectively operated. According to this accuracy determination system, when the terrain coordinate data cannot be acquired from the terrain storage means, the accuracy of the coordinates can be determined by the comparison determination means, so that the position calculation means can always calculate stably. It is possible to determine the accuracy of coordinates.

  Note that the accuracy determination system according to claim 6 may be provided with comprehensive determination means according to claim 8 instead of the switching means. In the accuracy determination system according to the eighth aspect, the comprehensive determination unit comprehensively determines the accuracy of the coordinates calculated by the position calculation unit using the determination results of the accuracy determination unit and the comparison determination unit. In the accuracy determination system according to claim 8 configured as described above, the accuracy of the coordinates calculated by the position calculation means is determined by a plurality of methods, and the accuracy of the coordinates is determined again based on the results. The accuracy of the coordinates calculated by the position calculating means can be determined with high accuracy.

  Further, as described in claim 9, the comparison determination unit determines that the difference between the movement amount calculated by the movement amount calculation unit and the displacement amount calculated by the displacement amount calculation unit is less than a predetermined threshold. It is preferable that the accuracy of the coordinates calculated by the calculation unit is determined to be high, and the accuracy of the coordinates calculated by the position calculation unit is determined to be low when the difference is equal to or greater than a threshold value. In this way, with a simple configuration, it is possible to determine the accuracy of coordinates based on the movement amount calculated by the movement amount calculation unit and the displacement amount calculated by the displacement amount calculation unit.

  Although the accuracy determination system of the present invention has been described above, the accuracy determination system includes a accuracy determination device and a server that stores terrain coordinate data in which the position coordinates of the ground surface are represented in a three-dimensional coordinate system for each predetermined point. And a device. The accuracy determination apparatus according to claim 10, wherein communication means capable of communicating with the server device, and terrain coordinate data of a plurality of points existing around the coordinates calculated by the position calculation means from the server device via the communication means. An accuracy determination apparatus comprising: a data acquisition unit that performs the above-described deviation value calculation unit, and the accuracy determination unit. According to the present invention, the accuracy determination system can be configured without providing the terrain storage means in the accuracy determination device, and the accuracy determination device can be manufactured at low cost.

  In addition, according to the present invention, since the accuracy of coordinates is determined based on the polygonal configuration surface, the server device and the accuracy determination device are compared with conventional devices that require altitude information for each determination point. The amount of communication can be reduced, and network resources can be used effectively. The accuracy determination apparatus may include the movement amount calculation means, the displacement amount calculation means, the comparison determination means, and the switching means (or comprehensive determination means).

  In addition, the server device according to claim 11 includes a communication unit capable of communicating with the accuracy determination device, and the terrain storage unit, and when the communication unit receives a request signal for terrain coordinate data from the accuracy determination device, The transmission control means reads out the terrain coordinate data of a plurality of points existing around the coordinates calculated by the position calculation means of the moving object to be determined by the accuracy determination device from the terrain storage means, and reads the data to the communication means. The terrain coordinate data is transmitted to the accuracy determination device. If this server apparatus and the said accuracy determination apparatus are used, the accuracy determination system of this invention mentioned above can be comprised.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is an explanatory diagram showing the configuration of an accuracy determination system 1 to which the present invention is applied. The accuracy determination system 1 according to the present embodiment includes a vehicle 3 as a moving body and a center 7 including the server device 5 of the present invention. The center 7 and the vehicle 3 can communicate bidirectionally via a cellular network 9. Has been.

  FIG. 2 is a block diagram illustrating a configuration of the navigation device 10 included in the vehicle 3 and the server device 5 included in the center 7. As shown in FIG. 2, the navigation device 10 receives a satellite signal transmitted from the GPS satellite 2 and calculates a three-dimensional coordinate (specifically, latitude / longitude / altitude) of the current location. A wireless communication device 13 that can wirelessly communicate with the server device 5 via the cellular network 9, a tilt sensor 15, a gyroscope 17, a vehicle speed sensor 19 that detects the moving speed Vs of the vehicle 3, and the user Operation switch group 21 for inputting various commands to the device, a map data input device 23, a display device 25 for displaying various information (such as a map), a speaker 27 for performing audio output, and the navigation And a navigation control circuit 30 that performs overall control of each part of the apparatus 10.

  The GPS receiver 11 includes a receiver 11a that receives a satellite signal (a so-called GPS signal) transmitted from the GPS satellite 2, and a calculator 11b that calculates the current position of the vehicle 3 based on the reception result of the receiver 11a. . Specifically, the calculation unit 11b calculates the position coordinates P = (x, y, z) of the current location in a three-dimensional coordinate system including latitude, longitude, and altitude based on the reception result of the reception unit 11a. This calculated value is input to the navigation control circuit 30. FIG. 3 is an explanatory diagram showing a three-dimensional coordinate system used in this embodiment. In the following, latitude is assigned to the x coordinate, longitude is assigned to the y coordinate, altitude is assigned to the z coordinate, and the three-dimensional coordinate is expressed by the xyz coordinate.

  On the other hand, the inclination sensor 15 detects the inclination angle Θ (see FIG. 11) of the road surface. The inclination sensor 15 detects, for example, the inclination angle of the vehicle 3, that is, the inclination angle Θ of the road surface on which the vehicle 3 travels, using the fact that the pendulum is directed in the vertical direction. In addition, the gyroscope 17 detects the moving direction (traveling direction) of the vehicle 3 based on the force during the rotational motion applied to the vehicle 3.

  The map data input unit 23 inputs map matching data for position correction, road data representing road connections, and the like from a storage medium storing them to the navigation control circuit 30. Examples of the storage medium include a CD-ROM, a DVD, and a hard disk. In addition, the display device 25 is a color display device including a liquid crystal display or the like, and displays the current position of the vehicle 3, a map image, and the like on the screen based on the video signal input from the navigation control circuit 30. The speaker 27 reproduces a voice signal input from the navigation control circuit 30 and is used when voice guidance is provided for a route to the destination.

  In addition, the navigation control circuit 30 includes a CPU 31, a ROM 33, a RAM 35, and the like, and performs various processes including processes described later by executing a program stored in the ROM 33 by the CPU 31. The navigation control circuit 30 includes coordinates P representing the current position of the vehicle 3 obtained from the GPS receiver 11, a speed vector V indicating the moving direction of the vehicle 3, output values of the inclination sensor 15, the gyroscope 17, and the vehicle speed sensor 19. Based on the above, the current position is specified, and a mark representing the current position of the vehicle 3 is displayed on the display device 25 together with the map image. The current position is specified by a method such as GPS navigation or dead reckoning according to the reception status of the GPS signal.

  On the other hand, the server device 5 includes a CPU 51 that performs overall control of the device, a ROM 53 that stores programs, a RAM 55 that temporarily stores various data during program execution, and an external device mounted on the vehicle 3 via the cellular network 9. A wireless communication device 57 capable of communicating with the wireless communication device 13, and a terrain database (DB) 59 for storing terrain coordinate data in which the position of the ground surface is represented by latitude, longitude, and altitude for each predetermined point. . The terrain coordinate data is provided to the navigation device 10 via the cellular network 9 in response to a request from the navigation device 10. Hereinafter, a point where the terrain coordinate data exists in the terrain database 59 is expressed as a “data existence point”.

  FIG. 4 is an explanatory diagram showing a mode of data transmission / reception between the navigation device 10 and the server device 5. Although details will be described later, the navigation device 10 is configured to send a request signal for the terrain coordinate data to the server device 5 as necessary, and in addition to the request command, the current position coordinate P of the vehicle 3 and the movement A request signal storing information indicating the direction (specifically, the velocity vector V) is transmitted to the server device 5.

  When the server device 5 receives the request signal from the navigation device 10, the server device 5 moves around the current position coordinate P based on the current position coordinate P of the vehicle 3 and the information (velocity vector V) indicating the moving direction included in the request signal. The terrain coordinate data of the existing data location is selected, the selected terrain coordinate data is stored in the response signal, and the response signal is transmitted to the navigation device 10. The navigation device 10 determines the accuracy of the GPS positioning result, that is, the current position coordinate P obtained from the GPS receiver 11 based on the topographic coordinate data obtained from the server device 5.

  FIG. 5 is a flowchart showing the positioning accuracy determination process executed by the CPU 31 of the navigation device 10. When the positioning accuracy determination process is executed, the CPU 31 causes the GPS receiver 11 to perform positioning multiple times, and acquires the position coordinates of the vehicle 3 for a predetermined period from the GPS receiver 11 (S110). Thereafter, the CPU 31 calculates the velocity vector V = (Vx, Vy, Vz) of the vehicle 3 in the three-dimensional coordinate system based on the acquired position coordinates of the predetermined period (S120).

  When the processing in S120 is completed, the CPU 31 determines whether or not the terrain coordinate data around the current position necessary for determining the determination reference plane PS (see FIG. 3) exists in the RAM 35 (S130). Here, the terrain coordinate data around the current position necessary for the determination of the determination reference plane PS is stored in the RAM 35 by determining whether or not the terrain coordinate data within a predetermined range with respect to the current position of the vehicle 3 is the specified number or more. What is necessary is just to judge whether it exists.

  If it is determined in S130 that the terrain coordinate data necessary for determining the determination reference plane PS does not exist (No in S130), the CPU 31 accesses the server device 5 of the center 7 and requests the terrain coordinate data (S140). Specifically, the CPU 31 stores, in addition to the request command, a request signal that stores the latest position coordinates P of the vehicle 3 acquired from the GPS receiver 11 and a velocity vector V as information representing the moving direction of the vehicle 3. Transmit to device 5.

  Thereafter, the CPU 31 waits for a response signal to be received by the wireless communication device 13 (150). If the wireless communication device 13 receives a response signal from the server device 5 within a predetermined period, the CPU 31 determines Yes in S150. Then, the terrain coordinate data included in the response signal received from the server device 5 via the wireless communication device 13 is stored in the RAM 35 (S160).

  After the process in S160 is completed or when the determination is Yes in S130, the CPU 31 moves the process to S170 and determines the determination reference plane PS shown in FIG. Specifically, the CPU 31 uses the terrain coordinate data existing around the current position coordinate P of the vehicle 3 from the plurality of terrain coordinate data stored in the RAM 35 based on the current position coordinate P and the velocity vector V of the vehicle 3. Then, a predetermined number (three in the present embodiment) of topographic coordinate data on the traveling direction side of the vehicle 3 is selected, and a polygonal configuration surface having a point represented by the selected topographic coordinate data as a vertex is determined as a determination reference plane PS. To decide.

  FIG. 6 is an explanatory diagram showing a method for determining the determination reference plane PS. As shown in FIG. 6, the CPU 31 determines the terrain coordinate data around the current position coordinate P of the vehicle 3, the determined determination reference plane PS surrounds the current position coordinate P of the vehicle 3, and further determines the determination reference from the current position coordinate P. The surface PS is selected so that the distance to the edge on the traveling direction side of the vehicle 3 is a predetermined value or more, and the surface connecting the data existence points of the topographic coordinate data is determined as the determination reference surface PS. Note that “surrounding the current position coordinate P” means that the xy coordinate of the coordinate P falls within the projection of the determination reference plane PS onto the xy plane (that is, the z coordinate is not evaluated).

  The determination method of the determination reference plane PS will be described in detail. In FIG. 6A, the traveling direction of the vehicle 3 is directed to the upper side of the page, so that the CPU 31 determines the point surrounding the current position coordinate P of the vehicle 3. Of the topographic coordinate data D [1], D [2], D [3], and D [4], D [1], D [2], and D [3] are selected to form the determination reference plane PS. To do. In FIG. 6B, since the traveling direction of the vehicle 3 is directed to the lower right side of the page, the CPU 31 determines the terrain coordinate data D [1], D [2] of the point surrounding the current position coordinate P of the vehicle 3. ], D [3], D [4], D [1], D [2], D [4] are selected to form the determination reference plane PS.

  After the determination reference plane PS is determined, the CPU 31 sets the initial determination flag F to F = 1 (S175), and thereafter causes the GPS receiver 11 to perform positioning again, so that the current position coordinate P of the latest vehicle 3 is obtained. Obtain (S180). Thereafter, the CPU 31 determines whether or not the current position coordinate P of the latest vehicle 3 acquired in S180 is present on the determination reference plane PS determined in S170 (S190), and the latest current position acquired in S180. If it is determined that the coordinate P does not exist on the determination reference plane PS, the process proceeds to S120. On the other hand, when the CPU 31 determines that the current position coordinate P exists on the determination reference plane PS (Yes in S190), the CPU 31 proceeds to S200 and executes the first determination process shown in FIG. FIG. 7 is a flowchart showing the first determination process executed by the CPU 31.

  When the first determination process is executed, the CPU 31 determines whether or not the initial determination flag F is F = 1 (S205). If it is determined that F = 1 (Yes in S205), the CPU 31 sets F = 0. Later (S207), the current speed vector V of the vehicle 3 is calculated (S210). Note that the speed vector V may be calculated based on the current position coordinates P of the latest vehicle 3 and the position coordinates of several past ones, or output values of the gyroscope 17 and the vehicle speed sensor 19. May be calculated based on

  When the processing in S210 is completed, the CPU 31 calculates the DOP value at the time of positioning based on the arrangement state of the source GPS satellite of the satellite signal used when the GPS receiver 11 performed positioning in S180, and the DOP value Is multiplied by a coefficient α to determine a threshold Th1 (Th1 = α · (DOP value)) (S220).

  Thereafter, the CPU 31 shifts the processing to S230, and the current position coordinates P = (Px, Py, Pz) of the latest vehicle 3 obtained in S180 and the velocity vector V = (Vx, Vy, Vz) and an intersection line L between the plane PA and the determination reference plane PS (in FIG. 3, the intersection points of the edge of the determination reference plane PS and the intersection line L are represented by Ra and Rb). A plane PB that is a plane perpendicular to the plane PA is obtained. The plane PA is a plane parallel to the altitude direction (z direction) and parallel to the velocity vector V and passing through the current position coordinates P = (Px, Py, Pz) of the latest vehicle 3. Specifically, the plane PA is expressed by the following equation.

(Vy, −Vx, 0) · (x, y, z) = Px · Vy + Py · (−Vx)
In addition, the plane PB is represented by the following expression when the normal vector of the determination reference plane PS is (Nx, Ny, Nz).

(Vx, Vy, W) * (x, y, z) = Px * Vx + Py * Vy + Pz * W
W = {(Vx) ² + (Vy) ² } · Nz / (Vx · Nx + Vy · Ny)
When the process in S230 is completed, the CPU 31 obtains a distance d from the plane PB to the current position coordinate P of the vehicle 3, and stores the distance d in the RAM 35 (S240). FIG. 8 is an explanatory diagram showing the distance d from the plane PB to the current position coordinate P of the vehicle 3. In FIG. 8, in a coordinate system in which the xy plane is the horizontal axis and the z axis is the vertical axis, an intersection line between the plane PB and the plane PA is represented by a line segment RaRb.

  As shown in FIG. 8, the distance d is a distance in the altitude direction (z direction) from the plane PB to the current position coordinate P. Specifically, when the coordinate P of the distance d calculation target is P = (x, y, z), the distance d is calculated as follows.

d = | {(Px−x) · Vx + (Py−y) · Vy
+ Pz · W} / W−z |
After calculating the distance d in this way, the CPU 31 determines whether or not the calculated distance d is less than the threshold Th1 (S250). If it is determined that the distance d is less than the threshold Th1 (that is, d <Th1) (Yes in S250), a normal determination indicating that the GPS positioning result is normal is made (S260), and the determination value K1 is set to K1. = 0 is set, and the first determination process is terminated.

  On the other hand, if it is determined that the distance d is greater than or equal to the threshold Th1 (No in S250), the CPU 31 makes an abnormality determination indicating that the GPS positioning result is abnormal (S270), and sets the determination value K1 as follows. Calculate (S280).

K1 = β1 · (Th1-d)
That is, in S280, a value obtained by multiplying the difference between the calculated distance d and the threshold value Th1 by the positive coefficient β1 is calculated as the determination value K1. When the calculation of the determination value K1 ends, the CPU 31 ends the first determination process.

  In addition, if the CPU 31 determines No in S205 (that is, if F = 0 is determined in S205), the CPU 31 calculates the current speed vector V of the vehicle 3 (S293), and changes the speed vector V in the xy direction. Based on the amount (that is, the difference from the past speed vector), it is determined whether there is any change in the traveling direction of the vehicle 3 (S297).

  Specifically, in S297, it is determined whether or not the amount of change in the xy direction of the velocity vector V is greater than or equal to a predetermined amount. If it is determined that the amount of change in the xy direction is equal to or greater than the predetermined amount (Yes in S297), the process proceeds to S220, and the above-described calculation of the threshold Th1 and the derivation of the plane PB are performed.

  On the other hand, if it is determined that the amount of change is less than the predetermined amount (No in S297), the process proceeds to S240, and the distance d is calculated without changing the plane PB. In S297, the traveling direction is determined based on the amount of change in the xy direction of the velocity vector V. For example, based on the output value of the gyroscope 17, there is no change in the traveling direction of the vehicle 3. You may judge.

When this first determination process ends, the CPU 31 executes a second determination process in S300. FIG. 9 is a flowchart showing the second determination process executed by the CPU 31.
When the second determination process is executed, the CPU 31 determines whether or not the number of times the distance d is calculated in the first determination process is two or more, and the calculation result (distance d) is stored in the RAM 35 two or more (S310). ), If it is determined that it is not stored (No in S310), the second determination process is terminated. On the other hand, if it is determined that two or more are stored (Yes in S310), the change in the distance d per unit time based on the calculation results d (t) and d (t-1) of the distance d for the past two times. The amount Δd is calculated (S320).

Δd = | d (t) −d (t−1) |
Thereafter, the CPU 31 determines whether or not the change amount Δd is less than a predetermined threshold value Th2 (S330). If the CPU 31 determines that the change amount Δd is less than the threshold value Th2 (that is, Δd <Th2) (Yes in S330), GPS is performed. A normal determination indicating that the positioning result is normal is made (S340), K2 = 0 is set as the determination value K2, and the second determination process is terminated.

  On the other hand, when determining that the change amount Δd is equal to or greater than the threshold Th2 (No in S330), the CPU 31 makes an abnormality determination indicating that the GPS positioning result is abnormal (S350), and sets the determination value K2 as follows. (S360). The coefficient β2 is a positive coefficient.

K2 = β2 · (Th2−Δd)
When the determination value K2 is calculated in this way, the CPU 31 ends the second determination process, and executes the third determination process in S400. FIG. 10 is a flowchart showing the third determination process executed by the CPU 31.

  When the third determination process is executed, the CPU 31 performs the past two GPS positioning results, that is, the position coordinates P (t) = (x (t), y () of the vehicle 3 acquired from the GPS receiver 11 over the past two times. t), z (t)), P (t-1) = (x (t-1), y (t-1), z (t-1)) based on the altitude direction (z direction) The movement amount Δz per unit time of 3 is calculated (S410).

Δz = z (t) −z (t−1)
Thereafter, the CPU 31 acquires the road surface inclination angle Θ from the inclination sensor 15 (S420), and acquires the moving speed Vs of the vehicle 3 from the vehicle speed sensor 19 (S430). Then, based on the moving speed Vs and the inclination angle Θ obtained from the inclination sensor 15, the amount of movement ΔH in the altitude direction per unit time of the vehicle 3 is calculated (S440).

ΔH = Vs · sinΘ
FIG. 11 is an explanatory view showing the vehicle 3 that travels on the road surface at the inclination angle Θ at the speed Vs. After calculating ΔH in this way, the CPU 31 calculates a difference δ between the movement amount Δz obtained based on the GPS positioning result and the movement amount ΔH obtained based on the detection results of the sensors 15 and 19 (S450). .

δ = | Δz−ΔH |
After calculating the difference δ, the CPU 31 determines whether or not the difference δ is less than a predetermined threshold Th3 (S460), and determines that the difference δ is less than the threshold Th3 (that is, δ <Th3) (S460). Yes), a normal determination indicating that the GPS positioning result is normal is made (S470), the determination value K3 is set to K3 = 0, and the third determination process is terminated.

  On the other hand, when the CPU 31 determines that the difference δ is equal to or greater than the threshold Th3 (No in S460), the CPU 31 makes an abnormality determination indicating that the GPS positioning result is abnormal (S480), and calculates the determination value K3 as follows. (S490). The coefficient β3 is a positive coefficient.

K3 = β3 · (Th3-δ)
When the determination value K3 is calculated in this way, the CPU 31 ends the third determination process. FIG. 12 is a graph showing a change in Δz when the GPS positioning result shows an abnormality due to the influence of multipath. When the GPS positioning result shows an abnormality due to the influence of the multipath, Δz greatly fluctuates with respect to the movement amount ΔH obtained by the sensor, as shown on the right side of the graph of FIG. In the third determination process, the presence or absence of such a phenomenon is detected by determining whether the difference between ΔH and Δz is less than the threshold Th3.

  When the third determination process is completed, the CPU 31 executes a comprehensive determination process in subsequent S500. FIG. 13 is a flowchart showing the comprehensive determination process executed by the CPU 31.

  When the comprehensive determination process is executed, the CPU 31 determines whether or not the GPS positioning results are all determined to be normal in the first to third determination processes (S510), and determines that all are determined to be normal (S510). Yes), after determining the accuracy of the GPS positioning result to the “high” level (S515), the process proceeds to S550.

  On the other hand, if the CPU 31 determines that all the GPS positioning results are not normally determined in the first to third determination processes (No in S510), the CPU 31 determines whether there are two or more normal determinations in S520. . If it is determined that two or more have been determined to be normal, the accuracy of the GPS positioning result is determined to be “middle-up” level (S525), and the process proceeds to S550.

  If the CPU 31 determines in S520 that there are less than two normal determinations, the CPU 31 proceeds to S530 and determines whether there are one or more normal determinations. If it is determined that there is one or more normal determinations (S530), the accuracy of the GPS positioning result is determined to be “intermediate / lower” level (S535), and then the process proceeds to S550. In addition, if the CPU 31 determines that the normality determination is 0 in S530 (No in S530), the CPU 31 determines the accuracy of the GPS positioning result to the “low” level (S540), and then moves the process to S550.

  After shifting to S550, the CPU 31 determines whether or not the first and second determination processes are executed before this comprehensive determination process. In the comprehensive determination process executed in S500, “Yes” is determined here. On the other hand, it is determined No in the comprehensive determination process executed in S640 described later.

If it is determined Yes in S550, the CPU 31 calculates a determination value K related to the accuracy of the GPS positioning result as follows (S560).
K = (K1 + K2 + K3) / 3
After that, the CPU 31 determines that the information indicates the level of accuracy determined in any of S515, S525, S535, and S540 (that is, any level of “high”, “middle upper”, “middle lower”, and “low”). The value K is stored in the RAM 35 as a comprehensive determination result (S590). On the other hand, if it is determined No in S550, the CPU 31 sets the determination value K related to the accuracy of the GPS positioning result to K = K3 (S570), and then executes the above-described processing of S590 to perform the comprehensive determination processing. finish.

  When the comprehensive determination process in S500 ends, the CPU 31 determines whether or not a predetermined time has elapsed (S610). If it is determined that the predetermined time has elapsed (Yes in S610), the process proceeds to S180. On the other hand, if it is determined that the predetermined time has not elapsed (No in S610), the process proceeds to S620, and it is determined whether an end command for the positioning accuracy determination process is input from another task (S620). If it is determined that the end command has been input (Yes in S620), the positioning accuracy determination process is terminated. If it is determined that the end command has not been input (No in S620), the process proceeds to S610, where Wait until time has passed.

  In addition, if the CPU 31 determines that it has not been able to receive the response signal from the server device 5 even though it has waited for a predetermined period of time to receive the response signal in S150 (No in S150), it proceeds to S630. Then, the third determination process described above is executed, and then the comprehensive determination process is executed (S640). Before the comprehensive determination process executed in S640, the first and second determination processes are not executed, and only the third determination process is executed. Therefore, in S510, the normal determination is made in the third determination process. Yes, otherwise, No. If it is determined No in S510, there are no normal determinations, so that it is determined No in S520 and S530. Also in S550, it is determined No as described above, and the process of S570 is executed.

  That is, when the normal determination is made in the third determination process (S630), the CPU 31 determines the accuracy of the GPS positioning result to “high” level in the comprehensive determination process in S640, and sets the determination value K = 0. On the other hand, when the abnormality determination is made in the third determination process (S630), the accuracy of the GPS positioning result is determined to be “low” level, and the determination value K = K3 is set.

  When the comprehensive determination process in S640 is completed, the CPU 31 determines whether or not a predetermined time has elapsed in S650, and when determining that it has elapsed (Yes in S650), the CPU 31 proceeds to S120. On the other hand, if it is determined in S650 that the predetermined time has not elapsed, it is determined whether an end command for the positioning accuracy determination process is input from another task (S660), and it is determined that the end command is input. Then (Yes in S660), the positioning accuracy determination process ends. On the other hand, if it is determined that the end command has not been input (No in S660), the process proceeds to S650 and waits until a predetermined time elapses.

  Although the positioning accuracy determination process has been described above, the comprehensive determination result (accuracy level and determination value K) obtained by the positioning accuracy determination process is used in the switching process executed by the CPU 31 as follows. FIG. 14 is a flowchart showing a positioning method switching process executed by the CPU 31.

  When the CPU 31 executes the switching process, in S710, the CPU 31 acquires the overall determination result (accuracy level and determination value K) from the positioning accuracy determination process task, and the accuracy of the GPS positioning result obtained in the overall determination process is obtained. It is determined whether the level is “high” (S720). If it is determined that the level of accuracy is the “high” level, the process proceeds to S730, the position of the vehicle is specified by GPS navigation (GPS navigation on), and the switching process ends.

  On the other hand, if the CPU 31 determines in S720 that the accuracy level is not the “high” level, the CPU 31 proceeds to S740 and determines whether the accuracy of the GPS positioning result obtained in the comprehensive determination processing is the “low” level. Judge whether or not. If it is determined that the level of accuracy is the “low” level (Yes in S740), the process proceeds to S750 so that the vehicle position is not specified by GPS navigation (GPS navigation off), and various sensors are set. The vehicle position is specified by the estimated navigation used. Thereafter, the switching process ends.

  If it is determined in S740 that the accuracy level is not the “low” level (No in S740), the CPU 31 moves the process to S760, and based on the accuracy level and the determination value K, the vehicle position by GPS navigation is determined. Turn on / off the identification. Specifically, even if the accuracy level is “middle and upper”, if the determination value takes a large negative value, the GPS navigation is switched to the estimated navigation, and the accuracy level is “middle and lower”. When the determination value takes a value close to 0, the vehicle position is specified by GPS navigation. When the process in S760 is completed, the CPU 31 ends the switching process. This switching process is performed every time the comprehensive determination process is executed.

  Although the various processes executed by the CPU 31 have been described above, the server device 5 that provides the topographic coordinate data to the navigation device 10 provides the topographic coordinate data as follows. FIG. 15 is a flowchart showing data transmission processing executed by the CPU 51 of the server device 5.

  After executing the data transmission process, the CPU 51 of the server device 5 stands by until a request signal for topographic coordinate data is transmitted from the navigation device 10 in S810. When the request signal for the terrain coordinate data is received via the wireless communication device 57, the process proceeds to S820, where the current position of the vehicle 3 is based on the current position coordinate P and the velocity vector V of the vehicle 3 included in the request signal. The terrain coordinate data to be transmitted to be transmitted to the vehicle 3 is selected from the terrain coordinate data of a plurality of points existing around.

  At this time, since it is preferable from the viewpoint of effective use of network resources that the amount of topographic coordinate data to be transmitted is as small as possible, the determination reference plane PS is configured in accordance with the determination method of the determination reference plane PS in the navigation device 10. The minimum terrain coordinate data necessary for the transmission is determined as a transmission target.

  Specifically, as shown in FIG. 6A, when the traveling direction of the vehicle 3 is directed upward, the terrain coordinate data D [1], D [ 2], D [3], and D [4], D [1], D [2], and D [3] are selected as transmission targets. Further, as shown in FIG. 6B, when the traveling direction of the vehicle 3 is directed to the lower right side, the terrain coordinate data D [1], D [2] of the point surrounding the current position coordinate P of the vehicle 3 , D [3], D [4], D [1], D [2], D [4] are selected as transmission targets.

  When the terrain coordinate data to be transmitted is selected in this way, the CPU 51 reads the selected terrain coordinate data to be transmitted from the terrain database 59 (S830), and a response signal storing a group of these terrain coordinate data to be transmitted. Is transmitted to the wireless communication device 57 using the navigation device 10 as a transmission destination (S840). Thereafter, the CPU 51 ends the data transmission process.

  The accuracy determination system 1 of the present embodiment has been described above. According to the accuracy determination system 1, the calculation unit 11b of the GPS receiver 11 receives the reception result of the reception unit 11a that receives the satellite signal from the GPS satellite 2. Based on the above, a position coordinate P of the current location in a three-dimensional coordinate system composed of latitude, longitude, and altitude is calculated. Further, the CPU 31 of the navigation device 10 performs the processing from S140 to S160, from the terrain database 59 storing the terrain coordinate data, as a wireless communication device 57 as communication means on the server device 5 side and as communication means on the navigation device 10 side. The terrain coordinate data of a plurality of points existing around the current position coordinate P of the vehicle 3 is acquired via the wireless communication device 13.

  In addition, the CPU 31 selects terrain coordinate data suitable for the traveling direction of the vehicle 3 indicated by the speed vector V from the terrain coordinate data, and a polygonal determination reference plane whose vertex is the point indicated by the terrain coordinate data. PS is determined, and a distance d related to the positional deviation of the position coordinate P calculated by the calculation unit 11b is calculated using the determination reference plane PS as a reference. Specifically, the distance d in the altitude direction (z direction) from the plane PB passing through the intersection line L of the plane PA and the determination reference plane PS and perpendicular to the plane PA to the position coordinate P is calculated (S240). If the distance d is less than the threshold value Th1 determined based on the DOP value in S220, the CPU 31 determines that the GPS positioning result has high accuracy in the first determination process (S260), and the distance d is the threshold value Th1. If it is above, it is determined that the accuracy of the GPS positioning result is low, and abnormality determination is performed in the first determination process (S270).

  Thus, in the accuracy determination system 1 of the present embodiment, the accuracy of the coordinates P calculated by the GPS receiver 11 is determined using the determination reference plane PS, so that not only the point where the topographic coordinate data exists but also other points. The accuracy of the GPS positioning result can also be determined at points (regions of the determination reference plane PS connecting points where terrain coordinate data exists). In particular, in the present embodiment, the determination reference plane PS can represent the ground surface of the area almost accurately and is horizontal in a direction perpendicular to the intersection line L extending along the direction of the xy component of the speed vector V of the vehicle 3. The plane PB can accurately represent the road on which the vehicle 3 is traveling. Therefore, the accuracy of the GPS positioning result (ie, the accuracy of the GPS positioning result (ie, the terrain coordinate data here) is not required. The accuracy of the position coordinates P of the vehicle 3 calculated by the GPS receiver 11 can be determined.

  Therefore, according to the present embodiment, the GPS navigation can be appropriately turned on / off by the switching process executed by the CPU 31, and the vehicle position can be accurately identified using the GPS navigation or the estimated navigation.

  Further, in the accuracy determination system 1 of the present embodiment, the threshold Th1 is determined based on the DOP value obtained when the GPS receiver 11 performs positioning in S180. It is possible to suppress an error and an error from being caused, and to detect abnormalities in GPS positioning due to multipath with high sensitivity. Further, in the accuracy determination system 1 of the present embodiment, if the topographic coordinate data is successfully received (Yes in S150), the first determination process is executed, and if reception of the topographic coordinate data fails (No in S150), the first The third determination process (S630) is selectively executed without executing the determination process (that is, prohibiting the operation of the first determination process).

  In the third determination process, the movement amount ΔH in the altitude direction per unit time of the vehicle 3 is calculated based on the output values of the inclination sensor 15 as the inclination angle detection means and the vehicle speed sensor 19 as the movement speed detection means. In addition to calculating (S440), a moving amount (displacement amount) Δz in the altitude direction per unit time of the current position coordinate P calculated by the GPS receiver 11 is calculated (S410), and the difference δ is obtained. (S450). If the difference δ is less than the threshold Th3, the accuracy of the GPS positioning result is high, and normal determination is performed in the third determination process (S470). If the difference δ is greater than or equal to the threshold Th3, the accuracy of the GPS positioning result is low. In the third determination process, abnormality determination (S480) is performed.

  For this reason, in the accuracy determination system 1 of the present embodiment, the accuracy of the GPS positioning result can be determined without acquiring the terrain coordinate data from the terrain database 59, and the radio communication device 57 of the server device 5 and the navigation device 10 can be determined. Even when data transmission / reception to / from the wireless communication device 13 is impossible, it is possible to continuously determine the accuracy of the GPS positioning result based on the output value of the sensor.

  In this embodiment, when the topographic coordinate data can be acquired from the server device 5, not only the first determination process but also the second determination process and the third determination process are executed to comprehensively determine the accuracy of the GPS positioning result. I tried to do it. Specifically, the number of times determined to be normal in each determination process is used for final accuracy determination, and if the normal determination is made in all the determination processes, the GPS positioning result (that is, the GPS receiver 11). The accuracy of the position coordinate P) calculated by is determined as “high”, and if abnormality determination is made in all determination processes, the accuracy of the GPS positioning result is determined as “low”. In the accuracy determination system 1 of the present embodiment, the accuracy of the coordinate P calculated by the GPS receiver 11 is determined by a plurality of methods as described above, and the accuracy of the coordinate P is finally determined based on the result. The accuracy of the coordinates calculated by the receiving device 11 can be determined with high accuracy.

  In addition, in this embodiment, since the terrain database 59 for storing the terrain coordinate data is arranged in the center 7, it is not necessary to provide the terrain database 59 in the navigation device 10, and the navigation device 10 can be manufactured at low cost. The accuracy determination system 1 can be constructed at a low cost.

  The receiving unit of the present invention corresponds to the receiving unit 11a of the present embodiment, and the position calculating unit of the present invention corresponds to the calculating unit 11b. The terrain storage means corresponds to the terrain database 59, and the data acquisition means corresponds to the processing of S140 to S160 executed by the CPU 31. In addition, the deviation value calculation means corresponds to the processing of the CPU 31 (S240) for calculating the distance d as the deviation value of the present invention, and the accuracy determination means corresponds to the processing of S250 to S270 executed by the CPU 31. The direction determination means of the present invention is realized by the processing of S210 and S293 in which the CPU 31 calculates the velocity vector V based on the time change of the coordinates P output from the GPS receiver 11.

  Further, the “polygonal component plane” in the present invention corresponds to a triangular determination reference plane PS having points D1, D2 and D3 represented by the topographic coordinate data, and “a straight line parallel to the moving direction of the moving object”. The plane parallel to the altitude direction including the straight line passing through the coordinates calculated by the position calculation means at the first time corresponds to the plane PA. Further, the DOP value calculation means and the threshold value determination means are realized by the processing of S220 executed by the CPU 31.

  In addition, the inclination angle detection means corresponds to the inclination sensor 15, and the moving speed detection means corresponds to the vehicle speed sensor 19. Further, the movement amount calculating means is realized by the processing of S440 executed by the CPU 31, and the displacement amount calculating means is realized by the processing of S410 executed by the CPU 31. The comparison determination unit is realized by the processing of S460 to S480 executed by the CPU 31.

  The switching means executes the first determination process when the CPU 31 succeeds in acquiring the terrain coordinate data (Yes in S150), and executes the first determination process when the acquisition of the terrain coordinate data fails (No in S150). This is realized by an operation of selectively executing only the third determination process among the first to third determination processes. In addition, the comprehensive determination means is realized by the processing of S500 executed by the CPU 31. Further, the transmission control means of the server device is realized by a data transmission process executed by the CPU 51.

The accuracy determination system of the present invention is not limited to the above-described embodiment, and can take various forms.
In the above embodiment, the distance d between the position coordinate P of the vehicle 3 calculated by the GPS receiver 11 and the plane PB is obtained to determine whether or not the GPS positioning result is normal. Since the GPS positioning error is small in latitude / longitude coordinates (x coordinate / y coordinate) and large in altitude coordinates (z coordinate), for example, the position of the vehicle 3 calculated by the GPS receiver 11 is used instead of the distance d. A distance d ′ between the coordinate P and the intersection line L may be obtained to determine whether or not the GPS positioning result is normal. That is, the first determination process may be configured such that the distance d ′ between the intersection line L and the position coordinate P is obtained in S240 and compared with the threshold Th1.

  If the latitude / longitude coordinates calculated by the positioning by the GPS receiver 11 are expressed approximately correctly, the distance d ′ between the intersection line L and the position coordinates P can be obtained even if the distance d between the plane PB and the position coordinates P is obtained. Even if it is obtained, substantially the same value (d≈d ′) can be obtained, so that the accuracy of the GPS positioning result can be determined with high accuracy as in the above embodiment.

It is explanatory drawing showing the structure of the accuracy determination system 1 to which this invention was applied. 3 is a block diagram illustrating configurations of a navigation device 10 and a server device 5. FIG. It is explanatory drawing showing the structure of a three-dimensional coordinate system. It is explanatory drawing which showed the aspect of data transmission / reception. 4 is a flowchart showing a positioning accuracy determination process executed by a CPU 31 of the navigation device 10. It is explanatory drawing which showed the determination method of determination reference plane PS. It is a flowchart showing the 1st determination process which CPU31 performs. FIG. 6 is an explanatory diagram showing a distance d from a plane PB to a position coordinate P of the vehicle 3. It is a flowchart showing the 2nd determination process which CPU31 performs. It is a flowchart showing the 3rd determination process which CPU31 performs. It is explanatory drawing which showed the vehicle 3 which drive | works the road surface of inclination | tilt angle (theta) at the speed Vs. It is a graph which shows the time change of movement amount (DELTA) z when the result of GPS positioning shows abnormality by the influence of a multipath. It is a flowchart showing the comprehensive determination process which CPU31 performs. It is a flowchart showing the switching process which CPU31 performs. 4 is a flowchart showing a data transmission process executed by a CPU 51 of the server device 5. It is explanatory drawing which showed the GPS receiver 11 which receives a reflected wave.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Accuracy determination system, 2 ... GPS satellite, 3 ... Vehicle, 5 ... Server apparatus, 7 ... Center, 9 ... Cellular network, 10 ... Navigation apparatus, 11 ... GPS receiver, 11a ... Receiver, 11b ... Calculation part, DESCRIPTION OF SYMBOLS 13 ... Wireless communication apparatus, 15 ... Tilt sensor, 17 ... Gyroscope, 19 ... Vehicle speed sensor, 21 ... Operation switch group, 23 ... Map data input device, 25 ... Display apparatus, 27 ... Speaker, 30 ... Navigation control circuit, 31 ... CPU, 33 ... ROM, 35 ... RAM, 51 ... CPU, 53 ... ROM, 55 ... RAM, 57 ... wireless communication device, 59 ... terrain database

Claims (11)

A moving body comprising: receiving means for receiving a satellite signal transmitted from a GPS satellite; and position calculating means for calculating position coordinates of a current location in a three-dimensional coordinate system including altitude based on a reception result of the receiving means, Is an accuracy determination system for determining the accuracy of the coordinates calculated by the position calculation means,
Terrain storage means for storing, for each predetermined point, terrain coordinate data in which the position coordinates of the ground surface are represented in the three-dimensional coordinate system;
Data acquisition means for acquiring, from the terrain storage means, the terrain coordinate data of a plurality of points existing around the coordinates calculated by the position calculation means;
The position of the coordinates calculated by the position calculating means with reference to a polygonal construction surface having each point around the coordinates calculated by the position calculating means represented by the topographic coordinate data acquired by the data acquiring means as a reference. A deviation value calculating means for calculating a deviation value related to the deviation;
Accuracy determination means for determining the accuracy of the coordinates calculated by the position calculation means based on the deviation value calculated by the deviation value calculation means;
An accuracy determination system comprising: Direction determining means for determining a moving direction of the moving body;
With
The deviation value calculating means is a straight line parallel to the moving direction of the moving body based on the terrain coordinate data acquired by the data acquiring means and the determination result of the direction determining means. The plane parallel to the altitude direction including the straight line passing through the coordinates calculated at the time point 1 and the polygonal plane, or the plane perpendicular to the plane parallel to the altitude direction through the intersection line The accuracy determination system according to claim 1, wherein a distance from the surface to the coordinates calculated by the position calculation unit at a second time is calculated as the deviation value.   The accuracy determination means determines that the accuracy of the coordinates calculated by the position calculation means is high when the deviation value is less than a predetermined threshold, and the position when the deviation value is equal to or greater than the threshold. The accuracy determination system according to claim 1, wherein the accuracy of the coordinates calculated by the calculation unit is determined to be low. A DOP value calculating means for calculating a DOP (Dilution Of Precision) value based on an arrangement state of a GPS satellite that is a transmission source of the satellite signal used when the position calculating means calculates the coordinates;
Based on the DOP value calculated by the DOP value calculating means, threshold determining means for determining the threshold used by the accuracy determining means when determining the accuracy of the coordinates;
The accuracy determination system according to claim 3, further comprising: A moving body comprising: receiving means for receiving a satellite signal transmitted from a GPS satellite; and position calculating means for calculating position coordinates of a current location in a three-dimensional coordinate system including altitude based on a reception result of the receiving means, Is an accuracy determination system for determining the accuracy of the coordinates calculated by the position calculation means,
In the moving body,
An inclination angle detecting means for detecting an inclination angle of the moving body;
A moving speed detecting means for detecting a moving speed of the moving body;
Is provided,
The system
Based on the detection results of the tilt angle detecting means and the moving speed detecting means, a moving amount calculating means for calculating the moving amount of the moving body in the altitude direction per unit time;
Based on the calculation result of the position calculating means, a displacement amount calculating means for calculating a displacement amount in the altitude direction per unit time of the coordinates calculated by the position calculating means;
The movement amount calculated by the movement amount calculation unit is compared with the displacement amount calculated by the displacement amount calculation unit, and the accuracy of the coordinates calculated by the position calculation unit is determined based on the comparison result. Comparison judgment means;
An accuracy determination system comprising: In the moving body,
An inclination angle detecting means for detecting an inclination angle of the moving body;
A moving speed detecting means for detecting a moving speed of the moving body;
Is provided,
The system
Based on the detection results of the tilt angle detecting means and the moving speed detecting means, a moving amount calculating means for calculating the moving amount of the moving body in the altitude direction per unit time;
Based on the calculation result of the position calculating means, a displacement amount calculating means for calculating a displacement amount in the altitude direction per unit time of the coordinates calculated by the position calculating means;
The movement amount calculated by the movement amount calculation unit is compared with the displacement amount calculated by the displacement amount calculation unit, and the accuracy of the coordinates calculated by the position calculation unit is determined based on the comparison result. Comparison judgment means;
Switching means for prohibiting the operation of the accuracy determination means and operating the comparison determination means when a predetermined condition is satisfied;
The accuracy determination system according to any one of claims 1 to 4, further comprising:   The switching unit operates the accuracy determination unit when the data acquisition unit succeeds in acquiring the topographic coordinate data, and replaces the accuracy determination unit when the data acquisition unit fails to acquire the topographic coordinate data. The accuracy determination system according to claim 6, wherein the comparison determination unit is selectively operated. In the moving body,
An inclination angle detecting means for detecting an inclination angle of the moving body;
A moving speed detecting means for detecting a moving speed of the moving body;
Is provided,
The system
Based on the detection results of the tilt angle detecting means and the moving speed detecting means, a moving amount calculating means for calculating the moving amount of the moving body in the altitude direction per unit time;
Based on the calculation result of the position calculating means, a displacement amount calculating means for calculating a displacement amount in the altitude direction per unit time of the coordinates calculated by the position calculating means;
The movement amount calculated by the movement amount calculation unit is compared with the displacement amount calculated by the displacement amount calculation unit, and the accuracy of the coordinates calculated by the position calculation unit is determined based on the comparison result. Comparison judgment means;
Comprehensive determination means for determining the accuracy of the coordinates calculated by the position calculation means using the determination results of the accuracy determination means and the comparison determination means;
The accuracy determination system according to any one of claims 1 to 4, further comprising:   The comparison determination unit is configured to calculate the position calculation unit when the difference between the movement amount calculated by the movement amount calculation unit and the displacement amount calculated by the displacement amount calculation unit is less than a predetermined threshold. The accuracy of the coordinates is determined to be high, and if the difference is equal to or greater than the threshold, the accuracy of the coordinates calculated by the position calculation unit is determined to be low. The accuracy judgment system described in 1. A moving body comprising: receiving means for receiving a satellite signal transmitted from a GPS satellite; and position calculating means for calculating position coordinates of a current location in a three-dimensional coordinate system including altitude based on a reception result of the receiving means, Is an accuracy determination device for determining the accuracy of the coordinates calculated by the position calculation means,
Communication means capable of communicating with a server device that stores terrain coordinate data in which position coordinates of the ground surface are represented in the three-dimensional coordinate system for each predetermined point;
Data acquisition means for acquiring, from the server device, the topographic coordinate data of a plurality of points existing around the coordinates calculated by the position calculation means, via the communication means;
The position of the coordinates calculated by the position calculating means with reference to a polygonal construction surface having each point around the coordinates calculated by the position calculating means represented by the topographic coordinate data acquired by the data acquiring means as a reference. A deviation value calculating means for calculating a deviation value related to the deviation;
Accuracy determination means for determining the accuracy of the coordinates calculated by the position calculation means based on the deviation value calculated by the deviation value calculation means;
An accuracy determination apparatus comprising: Communication means capable of communicating with the accuracy determination device according to claim 10;
Terrain storage means for storing terrain coordinate data represented by a three-dimensional coordinate system in which the position coordinates of the ground surface include altitude for each predetermined point;
When the communication means receives a request signal for the terrain coordinate data from the accuracy determination device, the terrain at a plurality of points existing around the coordinates calculated by the position calculation means of the moving object to be determined by the accuracy determination device. Coordinate data is read from the terrain storage means, and the communication control means causes the communication means to transmit the read terrain coordinate data to the accuracy determination device;
A server device comprising: