JP5886150B2 - Vehicle speed detection device and program for vehicle speed detection device - Google Patents

Description

  The present invention relates to a vehicle speed detection device that calculates and outputs a vehicle speed of a vehicle body equipped with a work device based on a satellite signal from a positioning satellite, for example.

  Conventionally, as a fertilizer application device that applies fertilizer to the field, in order to uniformize the fertilizer amount per unit area of fertilizer to be applied to the field, the fertilizer amount is set to the traveling speed (vehicle speed) of the riding management machine equipped with the fertilizer device. There is one that performs fertilization in conjunction. Although there are various methods for detecting the vehicle speed, Patent Document 1 discloses a technique for detecting the traveling vehicle speed of a passenger management machine equipped with a fertilizer application device using a signal from GPS.

  In Patent Document 1, when the vehicle speed based on the speed information from the GPS and the vehicle speed based on the vehicle speed pulse of the vehicle speed sensor that detects the rotation speed of the wheel provided on the vehicle body cannot be obtained from the GPS, The vehicle speed from the vehicle speed sensor is output to the fertilizer application device. In particular, in Patent Document 1, the slip rate is included in the vehicle speed when determining the vehicle speed.

JP 2010-187558 A

  In Patent Document 1, when the vehicle body slips in the field during the operation of the fertilizer, a difference occurs between the vehicle speed obtained from the vehicle speed sensor that detects the rotation speed of the wheel and the actual vehicle speed. The vehicle speed is corrected by adding the slip ratio to the vehicle speed obtained from the sensor. However, even when the vehicle speed is corrected using the slip ratio, it may be difficult to match the corrected vehicle speed with the actual vehicle speed of the fertilizer application, and stable fertilization work even if Patent Document 1 is used. It was difficult to do.

  Therefore, in view of the above problems, the present invention can input an appropriate vehicle speed according to the working state of the working device to the working device by determining the vehicle speed to be output to the working device according to the slip ratio of the vehicle body. An object of the present invention is to provide a vehicle speed detection device and a program for the vehicle speed detection device.

The technical means of the present invention for solving this technical problem is characterized by the following points.
A vehicle speed detection device according to the present invention receives a satellite signal from a positioning satellite and calculates a first vehicle speed of the vehicle body based on a reception unit attached to a vehicle body provided with a working device and a satellite signal received by the reception unit. A first vehicle speed calculation unit, a second vehicle speed calculation unit that calculates a second vehicle speed based on the number of wheel rotations detected by a vehicle speed detection unit provided in the vehicle body, and a first vehicle speed calculation unit that is calculated by the both vehicle speed calculation units. A slip calculation unit that calculates a slip ratio based on one vehicle speed and the second vehicle speed, and an output of either the first vehicle speed or the second vehicle speed is determined based on the slip ratio calculated by the slip calculation unit. When the satellite signal is determined to be unstable based on the calculation result of the slip ratio calculated by the main vehicle speed output determination unit and the slip calculation unit, the second vehicle speed obtained by the second vehicle speed calculation unit To output vehicle speed Characterized in that it comprises a driven pulley speed output determining unit for a constant, the vehicle speed output section for outputting a speed determined by the main speed output determination unit or said driven pulley speed output determining unit.

Before SL main speed output determination unit, when the slip ratio is not greater than the predetermined threshold value is determined on the vehicle speed and outputs a second vehicle speed which has been determined by the second vehicle speed calculating section is larger than the slip rate threshold In some cases, the first vehicle speed calculated by the first vehicle speed calculation unit is determined as the vehicle speed to be output .

Program in the vehicle speed detection device of the present invention is a program embedded in the vehicle speed detection device for calculating the vehicle body speed based on the satellite signals from the attached and positioning satellites to the vehicle body provided with a working device, the vehicle speed A detecting device calculates a first vehicle speed of the vehicle body based on the satellite signal, a slip rate based on the first vehicle speed, and a second vehicle speed detected by a vehicle speed detector provided on the vehicle body. And when the satellite signal is determined to be unstable based on the result of the slip ratio calculation, the step of determining the vehicle speed to output the second vehicle speed, and the satellite signal based on the result of the slip ratio calculation. Is determined to be stable, it is determined whether or not the slip ratio is greater than a predetermined threshold, and if the slip ratio is greater than the threshold, the first Determining the vehicle speed and outputting the speed, characterized in that to execute the steps of outputting the first vehicle speed or the second speed is determined by the step.

The present invention has the following effects.
According to the first aspect of the invention, it is possible to input an appropriate vehicle speed to the working device in accordance with the working state of the vehicle body (farm field state, traveling state). For example, the actual vehicle speed (ground speed) can be detected based on the first vehicle speed when the farm field is a soft field that easily slips or during high-speed work where a slip is likely to occur. On the other hand, when the farm is a hard farm where slip is unlikely to occur or during low-speed work, the accurate ground speed can be detected by the second vehicle speed.

  According to the second aspect of the present invention, when the vehicle body is traveling while slipping, the first vehicle speed that can detect the accurate vehicle speed even in the slip state can be input to the working device, and the vehicle body hardly slips. When the vehicle is traveling in the second position, the second vehicle speed that is not affected by the positioning satellite can be input to the work device. In other words, whether or not the vehicle body slips, the vehicle speed of the vehicle body is stably input to the work device, so that the work device can smoothly perform work linked to the vehicle speed.

According to the third aspect of the present invention, when the satellite signal is unstable, work by the work device is performed using the second vehicle speed that can be obtained without being affected by the positioning satellite at all instead of the first vehicle speed. It can be performed.
According to the invention of claim 4, when the satellite signal is unstable, the work by the work device is performed using the second vehicle speed that can be obtained without being affected by the positioning satellite at all instead of the first vehicle speed. It can be performed. Further, even if the slip ratio calculation value is affected by an external radio wave (electromagnetic wave or the like) during the calculation of the slip ratio, it can be dealt with by the second vehicle speed.

  According to the fifth aspect of the present invention, the first vehicle speed of the vehicle body is calculated based on the satellite signal, and the slip ratio is based on the first vehicle speed and the second vehicle speed detected by the vehicle speed detection unit provided on the vehicle body. Since the program calculates the output of either the first vehicle speed or the second vehicle speed based on the slip ratio, the vehicle body is set to an appropriate vehicle speed according to the work state of the vehicle body (farm field state, running state). Can be entered. For example, the actual vehicle speed (ground speed) can be detected based on the first vehicle speed when the farm field is a soft field that easily slips or during high-speed work where a slip is likely to occur. On the other hand, when the farm is a hard farm where slip is unlikely to occur or during low-speed work, the accurate ground speed can be detected by the second vehicle speed.

It is a control block diagram at the time of mounting the vehicle speed detection apparatus in 1st Embodiment to a tractor. It is a flowchart from vehicle speed calculation to vehicle speed output. It is a modification of the flowchart of FIG. It is a control block diagram at the time of mounting the vehicle speed detection apparatus in 2nd Embodiment on a tractor. It is a flowchart from the vehicle speed calculation to the vehicle speed output in the same embodiment. It is the whole figure which connected the fertilizer application to the tractor.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The vehicle speed detection device of the present invention detects the vehicle speed of a vehicle body equipped with a work device using a satellite positioning system (Global Positioning System, Galileo, GLONASS, etc.). The vehicle speed detection device is attached to a vehicle body (for example, a tractor) that pulls a working device such as a fertilizer application device or a medicine spraying device, and can calculate the speed (vehicle speed) of the moving vehicle body.

FIG. 1 is a control block diagram when the vehicle speed detection device is mounted on a tractor (vehicle body) equipped with a work device. FIG. 6 shows an overall view of the tractor. Hereinafter, the case where the vehicle speed detection device is mounted on the tractor will be described as an example.
As shown in FIG. 6, the tractor 1 is configured by mounting an engine 3 and a transmission 4 on a traveling vehicle (traveling vehicle body) 2 having wheels on the front and rear. A control device 5 is mounted on the tractor 1. This control device 5 is based on an operation signal when an operation tool installed around the driver's seat 6 is operated, detection signals of various sensors mounted on the traveling vehicle body 2, and the like. Control.

For example, the control device 5 operates a three-point link mechanism 7 provided at the rear portion of the traveling vehicle 2 based on an operation signal of the operating tool, or controls the engine speed based on an accelerator pedal sensor. In addition, the control apparatus 2 should just be what controls the working system and traveling system of the tractor 1, and a control system is not limited.
Further, the tractor 1 is provided with a vehicle speed detection unit (vehicle speed sensor) 8 that detects the vehicle speed of the tractor 1 based on data from the traveling vehicle 2 (for example, the rotational speed of the axle).

  A vehicle speed detection device 13 for determining the vehicle speed of the tractor based on the satellite signal from the positioning satellite 15 is detachable around the driver seat 6 of the tractor 1 or on the top plate of the cabin 14 surrounding the driver seat 6 of the tractor 1. Is provided. The three-point link mechanism 7, which is the rear part of the tractor 1, is equipped with a fertilizer application device 9 that operates in conjunction with the vehicle speed obtained by the vehicle speed detection device 13 and supplies fertilizer to the field. The fertilizer application device 9 has wheels and travels by towing the tractor 1.

As shown in FIG. 1, the control device 10 of the fertilizer application device 9 includes an input unit (interface) 11 that inputs a vehicle speed, and a fertilization amount calculation unit 12 that calculates a fertilization amount according to the vehicle speed input to the input unit 11. I have. The input unit 11 is a connection port to which a harness or the like is connected. When the harness of the vehicle speed detection device 13 is connected, the vehicle speed obtained by the vehicle speed detection device 13 is input.
The fertilization amount calculation unit 12 increases the fertilization amount discharged to the outside from the fertilizer application device 9 when the vehicle speed is fast so that the amount per unit area is uniform, and decreases the fertilization amount when the vehicle speed is slow. The fertilizer amount linked to the vehicle speed is calculated. According to the fertilizer application device 9, the fertilizer application amount can be calculated by the fertilizer application amount calculator 12 in accordance with the vehicle speed input to the input unit 11, and the calculated fertilizer application amount can be supplied to the field.

  As shown in FIG. 1, the vehicle speed detection device 13 includes a reception unit 20, a first vehicle speed calculation unit 21 a, a second vehicle speed calculation unit 21 b, a vehicle speed input unit 22, a slip calculation unit 23, and a slip rate determination unit 29. And a main vehicle speed output determination unit 24 and a vehicle speed output unit 25. The receiving unit 20, the first vehicle speed calculation unit 21a, the second vehicle speed calculation unit 21b, the vehicle speed input unit 22, the slip calculation unit 23, the main vehicle speed output determination unit 24, and the vehicle speed output unit 25 may be electronic components such as semiconductors or the vehicle speed detection. The program is configured to operate the device 13, and these are stored in the housing 26.

  The receiving unit 20 receives a satellite signal from the positioning satellite 15. The first vehicle speed calculation unit 21 a calculates the first vehicle speed of the tractor 1 based on the satellite signal received by the reception unit 20. Specifically, the first vehicle speed calculation unit 21a obtains the distance between the receiving unit 20 and the positioning satellite 15 based on the carrier phase (carrier phase method) of the satellite signal transmitted from the positioning satellite 15, and calculates the distance from the distance. The position of the receiving unit 20 is calculated. Then, the first vehicle speed calculation unit 21 a converts the distance when the position of the reception unit 20 changes within a predetermined time into a speed, and uses the converted value as the first vehicle speed of the tractor 1.

When the positioning satellite 15 is a GPS satellite, the fundamental frequency f ₀ of the satellite signal transmitted from the positioning satellite 15 is 1575.42 MHz, and the wavelength of the carrier wave L1 is about 19 cm. Since the first vehicle speed calculation unit 21a obtains the position of the tractor 1 using the carrier wave phase of the satellite signal, the position of the tractor 1 is theoretically equal to or less than 1.9 cm corresponding to one-tenth of the wavelength. It can be obtained with high accuracy and position detection with high resolution can be performed. Since the first vehicle speed calculation unit 21a uses the position and time of the tractor 1 with high resolution, the resolution of the vehicle speed can detect the speed of the tractor 1 in units of 1 cm / sec to 0.036 km / h. it can. That is, the first vehicle speed calculation unit 21a can obtain a highly accurate vehicle speed with a resolution of 0.036 km / h.

The first speed calculation unit 21a calculates the first vehicle speed of the tractor 1 based on the carrier phase of the satellite signal. However, the Doppler shift (Doppler shift method) when the reception unit 20 receives the satellite signal is used. Based on this, the first vehicle speed of the tractor 1 may be calculated.
In the case of the Doppler shift method, the first vehicle speed calculation unit 21a, for example, shifts between the frequency of the satellite signal transmitted by the positioning satellite 15 and the frequency of the satellite signal when the reception unit 20 receives the satellite signal (Doppler shift value). ) And the position of the receiving unit 20 is calculated based on the satellite signal. The first vehicle speed calculation unit 21a converts the distance when the position of the reception unit 20 changes within a predetermined time into a speed, and uses the converted value as the first vehicle speed of the tractor 1. As described above, when the position of the tractor 1 is obtained based on the Doppler shift method, although the position accuracy of the tractor 1 is lower than that when the carrier phase is used, the environmental performance is excellent and the signal from the satellite is stable. The vehicle speed can be detected stably.

The second vehicle speed calculation unit 21 b calculates the second vehicle speed based on the number of wheel rotations detected by the vehicle speed detection unit (vehicle speed sensor) 8. Since the second vehicle speed calculation unit 21b obtains the second vehicle speed from the number of rotations of wheels and the like, when the tractor 1 slips, the actual vehicle speed (ground speed) of the tractor 1 becomes a different value.
The slip calculation unit 23 calculates the tractor slip ratio based on the first vehicle speed obtained based on the satellite signal of the positioning satellite 15 and the second vehicle speed detected on the tractor side. For example, the slip calculation unit 23 obtains the slip rate by the slip ratio = 1− [calculation result of the first vehicle speed calculation unit (first vehicle speed) ÷ calculation result of the second vehicle speed calculation unit (second vehicle speed)]. The first vehicle speed and the second vehicle speed employed for calculating the slip ratio may be average values obtained by averaging the calculation results of a predetermined time.

  The slip ratio determination unit 29 determines the magnitude of the slip ratio calculated by the slip calculation unit 23. The slip ratio determination unit 29 includes a threshold value for determining the magnitude of the slip ratio. Here, when the calculated value of the first vehicle speed obtained from the satellite signal and the calculated value of the second vehicle speed obtained from the vehicle speed sensor 8 match, almost no slip is generated in the tractor 1. (The slip ratio is small) and these calculated values (first vehicle speed, second vehicle speed) are considered to be the same as the actual vehicle speed (ground speed) of the tractor 1.

  On the other hand, when the calculated value of the first vehicle speed obtained from the satellite signal and the calculated value of the second vehicle speed obtained from the vehicle speed sensor 8 are greatly deviated, a large slip has occurred in the tractor 1 ( The calculated value may not be the actual vehicle speed of the tractor 1. Of the two calculated values of the first vehicle speed and the second vehicle speed, the calculated value of the first vehicle speed is obtained based on the satellite signal. Since the calculated value is obtained directly from the traveling vehicle of the tractor 1, there is an influence due to the slip of the tractor 1.

The main vehicle speed output determination unit 24 determines the output of either the first vehicle speed or the second vehicle speed based on the magnitude of the slip determined by the slip ratio determination unit 29.
When the slip ratio is larger than the threshold value, the main vehicle speed output determining unit 24 uses the first satellite signal of the positioning satellite 15 that is not affected by slip in order to obtain the vehicle speed of the tractor 1 properly even when the tractor 1 slips. The vehicle speed is determined as the vehicle speed to be output to the outside. Further, when the slip ratio is smaller than the threshold value, it is considered that both the first vehicle speed and the second vehicle speed can be applied. However, unlike the first vehicle speed, the second vehicle speed is different from the first vehicle speed. Since it is not affected by the environment, in order to obtain the vehicle speed of the tractor 1 stably, the main vehicle speed output determination unit 24 determines the second vehicle speed by the vehicle speed sensor 8 as the vehicle speed to be output to the outside.

The vehicle speed output unit 25 includes an output terminal that outputs a vehicle speed, electronic components, and the like, and outputs the vehicle speed (first vehicle speed or second vehicle speed) determined by the main vehicle speed output determination unit 24. For example, the vehicle speed can be output to the fertilizer application 9 by connecting the output terminal of the vehicle speed output unit 25 and the input unit 11 of the fertilizer application 9 with a harness.
The vehicle speed output unit 25 may output the vehicle speed wirelessly. For example,
The vehicle speed output unit 25 may be configured by a transceiver equipped with a function capable of performing short-range wireless communication (such as WiFi (R), Bluetooth (R), and ZigBee (R)). In this case, what is necessary is just to comprise the input part by the side of the fertilizer applicator 9 which inputs a vehicle speed with the transmitter / receiver which can perform short-distance wireless communication.

  The vehicle speed detection device 13 includes a receiving unit 20, a first vehicle speed calculation unit 21a, a second vehicle speed detection unit 21b, a vehicle speed input unit 22, a slip calculation unit 23, a main vehicle speed output determination unit 24, and a vehicle speed output unit 25. A satellite determination unit 27a and a slave vehicle speed output determination unit 28a are provided. The satellite determination unit 27a and the slave vehicle speed output determination unit 28a are configured by a program stored in the vehicle speed detection device 13 or the like.

  The satellite determination unit 27a determines the degree of stability of the positioning satellite 15 (the degree of instability of the satellite signal). For example, when the calculation result of the first vehicle speed obtained by the first vehicle speed calculation unit 21a is not appropriate and the calculation result is not reliable (the calculation result is infinite, minus, incomputable due to rank drop, physical Is greater than the vehicle speed upper limit), the satellite determination unit 27a determines that the satellite signal is unstable based on the calculation result of the first vehicle speed, and otherwise determines that the satellite signal is stable. To do.

  When the satellite determination unit 27a determines that the satellite signal is unstable, the slave vehicle speed output determination unit 28a determines the vehicle speed to output the second vehicle speed obtained by the second vehicle speed calculation unit 21b. That is, when the satellite signal is unstable, the slave vehicle speed output determination unit 28a replaces the main vehicle speed output determination unit 24 that determines the vehicle speed to be output according to the slip ratio as the first vehicle speed or the second vehicle speed. The vehicle speed at which the second vehicle speed is output is determined.

FIG. 2 shows a flowchart from vehicle speed calculation to vehicle speed output. A program for executing the vehicle speed detection device 13 will be described with reference to FIG. In the description of FIG. 2, it is assumed that the positioning satellite 15 is GPS for convenience of description.
As shown in FIG. 2, in S1, when the vehicle speed detection device 13 is turned on by turning on the ignition key of the tractor 1 or the like, the vehicle speed calculation unit 21 is activated and the reception unit 20 starts receiving satellite signals. (S1: Start positioning). Further, the rotational speed of the axle from the vehicle speed sensor 8 is input to the vehicle speed input unit 22 (S2: vehicle speed sensor input). When the rotational speed of the axle is input, the second vehicle speed calculation unit 21b calculates the second vehicle speed (S3: second vehicle speed calculation). The first vehicle speed calculation unit 21 calculates the first vehicle speed based on the satellite signal (S4: first vehicle speed calculation).

  Next, the satellite determination unit 27a determines the degree of stability of the satellite signal based on the calculation result of the first vehicle speed (S5). Here, when the calculation result of the first vehicle speed is appropriate and reliable and the satellite signal is not unstable (S5, yes), the satellite determination unit 27a performs the process to calculate the slip ratio by the slip calculation unit 23. Proceed. On the other hand, when the first vehicle speed is not reliable and the satellite signal is unstable (No in S5), the satellite determination unit 27a proceeds to the determination of the second vehicle speed by the slave vehicle speed output determination unit 28a (S8: Second vehicle speed set). That is, in S8, the vehicle speed output determination unit 28 determines the second vehicle speed obtained by the second vehicle speed calculation unit 21b when the satellite signal is unstable due to the calculation result of the first vehicle speed calculated by the first vehicle speed calculation unit 21a. Is determined as the vehicle speed.

The slip calculation unit 23 obtains a slip ratio from the first vehicle speed and the second vehicle speed (S6: slip ratio calculation).
When the calculation of the slip ratio is completed, the slip ratio determination unit 29 compares the obtained slip ratio with a threshold value, and when the slip ratio is smaller than the threshold value (S7, yes), the second speed by the main vehicle speed output determination unit 24 is set. The process proceeds to the determination of the vehicle speed (S8: second vehicle speed set). That is, in S8, the main vehicle speed output determination unit 24 determines the vehicle speed to output the second vehicle speed obtained by the second vehicle speed calculation unit 21b when the slip ratio is equal to or less than the threshold value.

On the other hand, when the slip ratio is larger than the threshold value (S7, No), the slip ratio determination unit 29 advances the process to the determination of the first vehicle speed by the main vehicle speed output determination unit 24 (S9: first vehicle speed set). That is, in S9, the main vehicle speed output determination unit 24 determines the vehicle speed to output the first vehicle speed obtained by the first vehicle speed calculation unit 21a when the slip ratio is larger than the threshold value.
In addition, the threshold for determining the magnitude of the slip ratio is a slip ratio that may affect the work on the work device side as “large: over threshold”, and the slip ratio that does not affect the work on the work device side. “Small: Within threshold”. For example, in practice, the threshold of the slip ratio is preferably set to −3 to + 3%.

The vehicle speed output unit 25 outputs the first vehicle speed or the second vehicle speed to the fertilizer application device 9 (S10: vehicle speed output). When the first vehicle speed or the second vehicle speed is output, the process returns to the vehicle speed sensor input.
As described above, according to the present invention, the vehicle speed detection device 13 includes the first vehicle speed calculation unit 21a that calculates the first vehicle speed, the second vehicle speed calculation unit 21b that calculates the second vehicle speed, the first vehicle speed, and the second vehicle speed. Since the slip calculation unit 23 that calculates the slip ratio based on the output of the first vehicle speed and the second vehicle speed is determined based on the slip ratio, the working state of the tractor and fertilizer application ( The vehicle speed can be appropriately output according to the field state and the traveling state. For example, the first vehicle speed obtained from the satellite signal can be set as the actual vehicle speed of the tractor when the field is a soft field where the slip easily occurs or during high-speed work where a slip is likely to occur. In addition, when the farm is in a hard field where slip is unlikely to occur or during low speed work where slip is not likely to occur, the second vehicle speed obtained by the vehicle speed sensor can be set as the actual vehicle speed of the tractor.

Further, since the vehicle speed detection device 13 includes the slave vehicle speed output determination unit 28a, when the satellite signal is unstable, the vehicle speed detection device 13 calculates the second vehicle speed instead of the first vehicle speed calculated by the first vehicle speed calculation unit 21a. Therefore, the vehicle speed can be continuously and stably input to the work device.
In the embodiment described above, the degree of instability of the satellite signal is determined based on the calculation result of the first vehicle speed. However, the degree of instability of the satellite signal based on the reception status of the satellite signal received by the receiving unit 20. May be judged. For example, when the satellite signal received by the receiving unit 20 is interrupted or when the receiving unit 20 has a low reception sensitivity of the satellite signal and the vehicle speed cannot be calculated, the satellite determination unit 27a receives the satellite signal for calculating the vehicle speed. When the reception condition cannot be obtained, it is determined that the satellite signal is unstable. Otherwise, it is determined that the satellite signal is stable. The slave vehicle speed output determining unit 28a outputs the second vehicle speed obtained by the second vehicle speed calculating unit 21b when the satellite signal is unstable due to the reception status of the satellite signal received by the receiver unit 20. The flow from the vehicle speed calculation to the vehicle speed output in this case is as shown in FIG. In addition, S1-S7, S9, and S10 of FIG. 3 are the same as that of FIG.

In S11, if the receiving unit 20 can only obtain satellite signals of less than four positioning satellites after starting positioning, or even if satellite signals from four or more positioning satellites can be received, When the accuracy reduction rate (DOP), the horizontal accuracy reduction rate (HDOP), and the vertical accuracy reduction rate (VDOP) are large and the first vehicle speed cannot be calculated using the satellite signal, the satellite determination unit 27 a It is judged that it is not stable (S11, No). Subsequent to the processing of “No” in S11, when the processing proceeds to the processing of the second vehicle speed set in S8, the slave vehicle speed output determination unit 28 determines the vehicle speed to output the second vehicle speed obtained by the second vehicle speed calculation unit 21b. . In the modified example of FIG. 3, the vehicle speed to be output to the work device 9 can be selected according to the reception status of the satellite signal in the receiving unit 20.
[Second Embodiment]
The second embodiment includes a vehicle speed detection device 13 that determines whether or not a satellite signal is unstable using a calculation result of the slip ratio after calculating the slip ratio.

  As shown in FIG. 4, the vehicle speed detection device 13 includes a reception unit 20, a first vehicle speed calculation unit 21 a, a second vehicle speed calculation unit 21 b, a vehicle speed input unit 22, a slip calculation unit 23, and a slip rate determination unit 29. And a main vehicle speed output determination unit 24, a vehicle speed output unit 25, a satellite determination unit 27b, and a slave vehicle speed output determination unit 28b. The first vehicle speed calculation unit 21a, the second vehicle speed calculation unit 21b, the vehicle speed input unit 22, the slip calculation unit 23, the slip rate determination unit 29, the main vehicle speed output determination unit 24, and the vehicle speed output unit 25 are the same as in the first embodiment. Since there is, explanation is omitted.

  The satellite determination unit 27b determines the degree of stability of the positioning satellite 15 based on the calculation result of the slip ratio. For example, when the calculation result of the slip ratio obtained by the slip calculation unit 23 is not appropriate and the calculation result is not reliable (the calculation result is infinite, exceeds 100%, and cannot be calculated), the calculation result of the slip ratio is Based on this, the satellite determination unit 27b determines that the satellite signal is unstable, and otherwise determines that the satellite signal is stable.

When the satellite determination unit 27b determines that the satellite signal is unstable, the slave vehicle speed output determination unit 28b determines the vehicle speed to output the second vehicle speed obtained by the second vehicle speed calculation unit 21b.
The flow from the vehicle speed calculation to the vehicle speed output when the satellite determination unit 27b and the slave vehicle speed output determination unit 28b are provided in the vehicle speed detection device 13 is as shown in FIG. 5 are the same as those in FIG. 2.

  In S12, after the slip ratio is calculated, when the slip ratio calculation result is not appropriate at the same time when the slip ratio is determined or before the slip ratio is determined, the satellite determination unit 27b It is determined that the vehicle is unstable (S12, no), and the process proceeds to the determination of the second vehicle speed by the slave vehicle speed output determination unit 28b (S8: second vehicle speed set). In S8, the main vehicle speed output determination unit 24 determines the vehicle speed to output the second vehicle speed obtained by the second vehicle speed calculation unit 21b. On the other hand, when the calculation result of the slip ratio is appropriate, the satellite determination unit 27b determines that the satellite signal is stable, and otherwise determines that the satellite signal is stable (S12, yes), Proceed to the slip ratio determination by the slip ratio determination unit 29. As described above, in the second embodiment, even after the slip ratio is calculated, it is determined that the satellite signal is unstable based on the calculation result of the slip ratio. If the satellite signal is unstable, the second vehicle speed is output. can do.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims. In the above-described embodiment, the vehicle speed detection device 13 may output the vehicle speed to another work device 9 such as a medicine spraying device, or may be attached to the work device 9. That is, the vehicle speed detection device 13 may be mounted on the vehicle side or on the work device side.

  In addition to the tractor, the vehicle speed detection device 13 may be mounted on a vehicle body such as a combiner or a transplanter. Further, when the vehicle speed is output also to a vehicle body such as a tractor, a combiner, or a transplanter, the vehicle speed output unit 25 may output the vehicle speed to a vehicle communication network (such as a controller area network) provided in the vehicle body. . Thus, if the vehicle speed is output to the vehicle communication network, the vehicle speed can be input to the work device 9 and various devices mounted on the vehicle body via the vehicle communication network. The work device 9 and various devices can be operated in conjunction with the vehicle speed detected by the vehicle speed detection device 13.

DESCRIPTION OF SYMBOLS 1 Tractor 2 Traveling vehicle body 3 Engine 4 Transmission device 5 Control device 6 Driver's seat 7 Three-point link mechanism 8 Vehicle speed detection part (vehicle speed sensor)
DESCRIPTION OF SYMBOLS 9 Fertilizer 10 Control apparatus 11 Input part 12 Fertilization amount calculation part 13 Vehicle speed detection apparatus 14 Cabin 15 Positioning satellite 20 Reception part 21a First vehicle speed calculation part 21b Second vehicle speed calculation part 22 Vehicle speed input part 23 Slip calculation part 24 Main vehicle speed output Determining unit 25 Vehicle speed output unit 26 Housing 27a, 27b Satellite determination unit 28a, 28b Sub-vehicle speed output determining unit

Claims (3)

A receiver that receives a satellite signal from a positioning satellite and is attached to a vehicle body equipped with a working device;
A first vehicle speed calculation unit that calculates a first vehicle speed of the vehicle body based on a satellite signal received by the reception unit;
A second vehicle speed calculation unit that calculates a second vehicle speed based on the rotational speed of the wheel detected by the vehicle speed detection unit provided in the vehicle body;
A slip calculation unit for calculating a slip ratio based on the first vehicle speed calculated by the both vehicle speed calculation unit and the second vehicle speed;
A main vehicle speed output determination unit that determines an output of either the first vehicle speed or the second vehicle speed based on the slip ratio calculated by the slip calculation unit;
If it is determined that the satellite signal is unstable based on the slip ratio calculation result calculated by the slip calculation unit, the second vehicle speed obtained by the second vehicle speed calculation unit is determined as the vehicle speed to be output. A vehicle speed output determination unit;
A vehicle speed output unit that outputs the vehicle speed determined by the main vehicle speed output determination unit or the slave vehicle speed output determination unit;
A vehicle speed detection device comprising:   The main vehicle speed output determination unit determines the vehicle speed to output the second vehicle speed obtained by the second vehicle speed calculation unit when the slip ratio is equal to or less than a predetermined threshold, and when the slip ratio is larger than the threshold The vehicle speed detection device according to claim 1, wherein the first vehicle speed calculated by the first vehicle speed calculation unit is determined as a vehicle speed to be output. A program installed in a vehicle speed detection device that is attached to a vehicle body equipped with a working device and calculates a vehicle speed of the vehicle body based on a satellite signal from a positioning satellite,
In the vehicle speed detection device,
Calculating a first vehicle speed of the vehicle body based on the satellite signal;
Calculating a slip ratio based on the first vehicle speed and a second vehicle speed detected by a vehicle speed detector provided on the vehicle body;
If the satellite signal is determined to be unstable according to the calculation result of the slip ratio, determining the vehicle speed to output the second vehicle speed;
When it is determined that the satellite signal is stable based on the calculation result of the slip ratio, it is determined whether or not the slip ratio is larger than a predetermined threshold, and when the slip ratio is larger than the threshold, Determining the vehicle speed to output one vehicle speed;
Outputting the first vehicle speed or the second vehicle speed determined in the step;
The program of the vehicle speed detection apparatus characterized by performing this .

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