JP7091189B2 - Automatic driving system for work vehicles - Google Patents

Description

The present invention relates to an automatic traveling system for a work vehicle that automatically travels a work vehicle according to a target route by using a satellite positioning system.

Conventionally, as a vehicle that automatically travels a work vehicle according to a target route using a satellite positioning system, the work vehicle (autonomous traveling work vehicle) is set to a target route (travel route) generated according to the work site (field). When the work vehicle enters the turning area (headland turning area) on the outer edge side of the work area while reciprocating along the line, the control device activates the speed change means to change the vehicle speed of the work vehicle to the turning speed (headland turning speed). There is a work vehicle control device configured to turn the work vehicle at a turning speed in the turning region by decelerating to (see, for example, Patent Document 1).

International Publication No. 2015/147108

Normally, the target routes used when automatically traveling a work vehicle such as a tractor include a plurality of parallel routes arranged in parallel in a traveling area divided in the work area and a plurality of parallel routes arranged in parallel on the outer edge side of the traveling area. It includes a plurality of turning paths that connect the parallel paths of the above in the order of travel. Then, in each parallel path, the work vehicle turns from the work path in the work path in which the work vehicle is made to work in the work area set on the center side of the travel area and in the turning area set on the outer edge side of the travel area. It includes a non-working route that causes the working vehicle to travel in a stopped state until the route is reached.

In the work vehicle control device described in Patent Document 1, for example, when the vehicle speed of the work vehicle in the work route included in the target route is increased in order to improve the work efficiency, the work vehicle enters the turning region. The braking distance required to reduce the vehicle speed of the work vehicle to the turning speed is increased. Therefore, the turning area in the work area becomes wider and the work area becomes narrower. Since the work area is an area where the work vehicle automatically travels while working, if the work area becomes narrower, the area where the user manually drives the work vehicle in the work area becomes wider, which is a burden on the user. Becomes larger.

Therefore, it is conceivable to widen the work area in order to reduce the burden on the user, but in this case, the turning area is narrowed and the vehicle speed of the work vehicle is changed to the turning speed after the work vehicle enters the turning area. The braking distance required to reduce the speed is reduced. Therefore, the vehicle speed of the work vehicle in the work area becomes slow, which leads to a decrease in work efficiency. Further, if the vehicle speed of the work vehicle in the work path is increased while widening the work area, the vehicle speed of the work vehicle is set to the turning speed from the time when the work vehicle enters the turning area until the start of turning (headland turning). Can no longer be lowered. As a result, there is a risk that the work vehicle may protrude from the work area during turning and come into contact with other objects such as ridges.

In view of this situation, the main problem of the present invention is to increase the vehicle speed of the work vehicle in the work area and improve the work efficiency while widening the work area in the work area.

The first characteristic configuration of the present invention is in an automatic traveling system for a work vehicle.
A vehicle speed control unit that controls the vehicle speed of the work vehicle,
A storage unit that stores a target route generated according to the traveling area divided in the work area, and a storage unit.
It has an automatic travel control unit that automatically travels the work vehicle according to the target route using a satellite positioning system.
The target route includes a plurality of parallel routes arranged in parallel in the traveling region, and a plurality of turning routes arranged at the outer edge of the traveling region and connecting the plurality of parallel routes in the traveling order. Ori,
The automatic traveling control unit measures the separation distance from the work vehicle to the outer peripheral edge of the work site in the traveling direction of the work vehicle when the work vehicle is automatically traveling on the parallel route. Has a part,
The vehicle speed control unit has a vehicle speed limiting unit that limits the vehicle speed of the work vehicle according to the separation distance.

According to this configuration, when the work vehicle is automatically traveling on a parallel route, the separation distance measured by the separation distance measuring unit is measured by the vehicle speed limiting unit regardless of the work area or turning area set in the work area. Limit the vehicle speed of the work vehicle according to the above.

Specifically, while the work vehicle traveling on the round-trip route is far away from the outer edge of the work area located in the traveling direction, the separation distance measured by the separation distance measuring unit becomes long, so that the vehicle speed limiting unit is used. , The speed limit of the work vehicle on the round-trip route is increased according to the separation distance. That is, it is possible to improve the work efficiency by increasing the vehicle speed of the work vehicle.

Then, when the work vehicle traveling on the round-trip route approaches the outer peripheral edge of the work area located in the traveling direction, the separation distance measured by the separation distance measuring unit becomes shorter, so that the vehicle speed limiting unit determines the separation distance. Therefore, the speed limit of the work vehicle in the round-trip route is slowed down so that the braking distance of the work vehicle is shorter than the separation distance. That is, regardless of the work area or turning area set in the work area, when the work vehicle approaches the outer peripheral edge of the work area, the vehicle speed limit unit sets the outer peripheral edge of the work area according to the separation distance at that time. The speed limit of the work vehicle is set so that the work vehicle can be braked and stopped in the meantime. This prevents the work vehicle from protruding from the work site when the automatic driving control unit stops the work vehicle from traveling near the outer peripheral edge of the work site according to the parallel route or when the work vehicle is turned according to the turning route. It is possible to avoid the possibility that the work vehicle may come into contact with other objects such as ridges due to the protrusion.

That is, it is possible to increase the vehicle speed of the work vehicle in the work area while widening the work area in which the work vehicle automatically travels in the work area. As a result, the burden on the user can be reduced and the work efficiency can be improved.

The second characteristic configuration of the present invention is
The target route includes a target vehicle speed when the work vehicle automatically travels on the parallel route.
The vehicle speed limiting unit calculates a comparative braking distance that is shorter than the separation distance by a set distance, and while the braking distance of the work vehicle according to the target vehicle speed is shorter than the comparative braking distance, the vehicle speed of the work vehicle. When the first vehicle speed limiting process for limiting the vehicle speed of the work vehicle is performed so that the target vehicle speed is maintained, and the braking distance of the work vehicle according to the target vehicle speed becomes the same as the comparative braking distance. A second vehicle speed limiting process is performed in which the vehicle speed of the work vehicle is reduced from the target vehicle speed in response to the decrease in the separation distance so that the braking distance of the work vehicle is maintained at the comparative braking distance.

According to this configuration, the vehicle speed limiting unit performs the first vehicle speed limiting process while the braking distance of the working vehicle according to the target vehicle speed is shorter than the comparative braking distance due to the long separation distance, thereby performing the vehicle speed of the working vehicle. To the target vehicle speed. As a result, there is a risk that fuel efficiency will deteriorate due to the unnecessarily high vehicle speed of the work vehicle, and that the work vehicle's followability to the target route will decrease when the work vehicle is automatically driven according to the target route. It can be avoided.

Then, when the separation distance is shortened and the braking distance of the work vehicle according to the target vehicle speed becomes the same as the comparative braking distance, the vehicle speed limiting unit performs the second vehicle speed limiting process to perform the braking distance of the work vehicle. However, the vehicle speed of the work vehicle is limited so that the comparative braking distance becomes shorter as the separation distance decreases. As a result, when the work vehicle approaches the outer peripheral edge of the work site or reaches a turning path, the vehicle speed of the work vehicle can be sufficiently reduced. As a result, when the automatic driving control unit stops the work vehicle from traveling near the outer peripheral edge of the work site according to the parallel route, or when the work vehicle is made to turn according to the turning route, the work vehicle protrudes from the work area and has ridges or the like. It is possible to more reliably avoid the risk of contact with other objects.

The third characteristic configuration of the present invention is
In the storage unit, the turning radius of the work vehicle, the working width of the work vehicle, the margin width set between the outer peripheral edge of the work area and the traveling region, the parallel path and the turning path. Each connection point with is memorized,
The separation distance measuring unit includes the current position of the work vehicle in the parallel path acquired by using the satellite positioning system, the connection point on the terminal side in the parallel path stored in the storage unit, and the connection point. The point is to measure the separation distance based on the turning radius of the work vehicle, the work width of the work vehicle, and the margin width.

According to this configuration, for example, the separation distance measuring unit has a turning radius of the work vehicle, half the length of the work width of the work vehicle, and a margin of the work site before the work vehicle automatically travels on the parallel route. By adding the width, the fixed separation distance from the connection point on the terminal side in the parallel path to the outer peripheral edge of the work site is calculated and stored in the storage unit. Then, while the work vehicle is automatically traveling on the parallel route, the separation distance measuring unit calculates the untraveled distance between the current position of the work vehicle and the connection point on the terminal side in the parallel route. The above-mentioned separation distance is measured by adding the above-mentioned fixed separation distance to this untraveled distance.

That is, the separation distance measuring unit determines the untraveled distance that changes according to the current position of the work vehicle in the parallel path acquired by using the satellite positioning system and the fixed separation distance that is a fixed value stored in the storage unit. The separation distance will be measured based on this. As a result, the calculation load required for measuring the separation distance can be reduced, and as a result, the separation distance can be measured quickly and accurately.

The fourth characteristic configuration of the present invention is
In the storage unit, a plurality of shape specifying points in the work area acquired by using the satellite positioning system and a shape specifying line connecting the plurality of shape specifying points to specify the shape of the work area are stored. Being done
The separation distance measuring unit is from the current position of the work vehicle in the parallel path acquired by using the satellite positioning system to the shape specifying line located on the extension line of the parallel path in the traveling direction of the work vehicle. The point is to measure the distance as the separation distance.

According to this configuration, the separation distance measuring unit can measure the separation distance relatively easily while using the shape specifying line acquired when specifying the shape of the work site by using the satellite positioning system. ..

The fifth characteristic configuration of the present invention is
The work vehicle is provided with a distance sensor that measures the distance to a distance measurement object existing in the traveling direction of the work vehicle.
The separation distance measuring unit is at a point of measuring the separation distance based on the measurement result of the distance sensor.

According to this configuration, the separation distance can be accurately measured based on the measurement result of the distance sensor without using the satellite positioning system.

The figure which shows the schematic structure of the automatic driving system for a work vehicle. Block diagram showing the schematic configuration of an automated driving system for work vehicles A diagram showing an example of a target route generated by the target route generator. Flow chart of target route generation control Explanatory drawing about measurement of separation distance by separation distance measuring part Graph showing the relationship between the separation distance and the vehicle speed Explanatory drawing about measurement of separation distance by separation distance measuring part and measurement of comparative braking distance by vehicle speed limit part Graph showing the relationship between the separation distance and the upper limit speed Flow chart of vehicle speed limit control Explanatory drawing about measurement of separation distance by separation distance measuring part in another embodiment

Hereinafter, as an example of a mode for carrying out the present invention, an embodiment in which the automatic traveling system for a work vehicle according to the present invention is applied to a tractor as an example of a work vehicle will be described with reference to the drawings.
The automatic traveling system for a work vehicle according to the present invention includes a passenger work vehicle other than a tractor, for example, a passenger grass mowing machine, a passenger rice transplanter, a combine, a wheel loader, a snowplow, and an unmanned mowing machine. It can be applied to work vehicles.

As shown in FIG. 3, the tractor 1 illustrated in this embodiment is configured to be able to automatically travel in a field A or the like, which is an example of a work site, by an automatic traveling system for a work vehicle. As shown in FIGS. 1 and 2, the automatic traveling system is an example of an automatic traveling unit 2 mounted on a tractor 1 and a wireless communication device set to enable wireless communication with the automatic traveling unit 2. 3, etc. are provided. For the mobile communication terminal 3, a tablet-type personal computer or smartphone having a multi-touch type display unit (for example, a liquid crystal panel) 4 that enables various information displays and input operations related to automatic driving may be adopted. can.

As shown in FIG. 1, the tractor 1 is connected to the rear portion of the tractor 1 via a three-point link mechanism 5 so that a rotary tiller 6 which is an example of a working device can be raised and lowered and rolled. As a result, the tractor 1 is configured to have rotary tillage specifications.
In addition, instead of the rotary tiller 6, various working devices such as a plow, a disc halo, a cultivator, a subsoiler, a sowing device, a spraying device, and a mowing device can be connected to the rear part of the tractor 1.

As shown in FIGS. 1 and 2, the tractor 1 includes driveable and steerable left and right front wheels 10, driveable left and right rear wheels 11, a cabin 13 forming a boarding-type driving unit 12, and a common rail system. The electronically controlled diesel engine (hereinafter referred to as the engine) 14, the speed change unit 15 that shifts the power from the engine 14, the all-hydraulic power steering unit 16 that steers the left and right front wheels 10, and the left and right rear wheels 11 are braked. The brake unit 17, the electro-hydraulic control type work clutch unit 19 that interrupts the transmission to the rotary cultivating device 6, the electro-hydraulic control type elevating drive unit 20 that elevates and drives the rotary cultivating device 6, and the rotary cultivating device 6 in the roll direction. The electro-hydraulic control type rolling drive unit 21, the vehicle state detection device 23 including various sensors and switches for detecting various setting states and operating states of each part in the tractor 1, the current position p0 of the tractor 1 and the like. A positioning unit 24 for measuring the current orientation and the like, an in-vehicle control unit 40 having various control units, and the like are provided.
An electronically controlled gasoline engine or the like having an electronic governor may be adopted as the engine 14. The power steering unit 16 may be an electric type including an electric motor.

The driver unit 12 includes operating levers such as an accelerator lever and a shift lever, operating pedals such as an accelerator pedal and a clutch pedal, a steering wheel 30 for manual steering shown in FIG. 1, and a passenger's steering wheel 30. It is equipped with a seat 31 and a multi-touch type liquid crystal monitor 32 that enables various information displays and input operations.

As shown in FIG. 2, the speed change unit 15 includes an electronically controlled continuously variable transmission 36 that shifts the power from the engine 14, and the power after the speed change by the continuously variable transmission 36 is used for forward and reverse. It includes an electro-hydraulic control type forward / backward switching device 37, and the like. The continuously variable transmission 36 includes an I-HMT (Integrated Hydro-static Mechanical Transmission), which is an example of a hydraulic mechanical continuously variable transmission having higher transmission efficiency than a hydrostatic continuously variable transmission (HST). Has been adopted. The forward / backward switching device 37 includes a hydraulic clutch for connecting / disconnecting forward power, a hydraulic clutch for connecting / disconnecting reverse power, and an electromagnetic valve for controlling the flow of oil with respect to them.
Instead of the I-HMT, the continuously variable transmission 36 includes an HMT (Hydraulic Mechanical Transmission), which is an example of a hydraulic mechanical continuously variable transmission, a hydrostatic continuously variable transmission, or a belt-type continuously variable transmission. A device, etc. may be adopted. Further, the speed change unit 15 is provided with an electro-hydraulic control type stepped speed change device having a plurality of hydraulic clutches for speed change and a plurality of solenoid valves for controlling the flow of oil with respect to the stepless speed change device 36 instead of the stepless speed change device 36. It may be included.

Although not shown, the brake unit 17 operates the left and right brakes that individually brake the left and right rear wheels 11 and the left and right brakes in conjunction with the depression operation of the left and right brake pedals provided in the driving unit 12. The foot brake system, the parking brake system that activates the left and right brakes in conjunction with the operation of the parking lever provided in the driver unit 12, and the brake inside the turn in conjunction with the steering of the left and right front wheels 10 over the set angle. It includes a turning brake system to operate, etc.

As shown in FIG. 2, the in-vehicle control unit 40 includes an engine control unit 41 that controls the engine 14, a vehicle speed control unit 42 that controls the vehicle speed V of the tractor 1 and forward / backward switching, and steering that controls the steering. A control unit 43, a work device control unit 44 that controls work devices such as a rotary tiller 6, a display control unit 45 that controls display and notification by a liquid crystal monitor 32, and an automatic travel control unit 46 that controls automatic driving. , And a non-volatile vehicle-mounted storage unit 47 that stores a target route for automatic driving generated according to a traveling area divided in the work area. Each control unit 41 to 46 is constructed by an electronic control unit in which a microcomputer or the like is integrated, various control programs, or the like. The control units 41 to 46 are connected to each other so as to be able to communicate with each other via a CAN (Controller Area Network).

The vehicle state detection device 23 is a general term for various sensors and switches provided in each part of the tractor 1. The vehicle state detection device 23 includes an accelerator sensor that detects the operation position of the accelerator lever, a first position sensor for shifting that detects the operation position of the shift lever, and forward / backward advance that detects the operation position of the reverser lever for forward / backward switching. A second position sensor for switching, a rotation sensor for detecting the output rotation speed of the engine 14, a vehicle speed sensor for detecting the vehicle speed V of the tractor 1, a steering angle sensor for detecting the steering angle of the front wheel 10, and the like are included. There is.

The engine control unit 41 executes engine rotation speed maintenance control that maintains the engine rotation speed at the rotation speed according to the operation position of the accelerator lever based on the detection information from the accelerator sensor and the detection information from the rotation sensor. do.

The vehicle speed control unit 42 continuously shifts the vehicle speed V of the tractor 1 to a speed according to the operation position of the shift lever based on the detection information from the first position sensor and the detection information from the vehicle speed sensor. Vehicle speed control for controlling the operation of the device 36, forward / backward switching control for switching the transmission state of the forward / backward switching device 37 based on the detection information from the second position sensor, and the like are executed. The vehicle speed control includes a deceleration stop process of decelerating the continuously variable transmission 36 to the zero speed state and stopping the running of the tractor 1 when the speed change lever is operated to the zero speed position.

The positioning unit 24 is a satellite navigation device 25 and 3 that measure the current position p0 and the current direction of the tractor 1 by using GPS (Global Positioning System) which is an example of a satellite positioning system (NSS). It has an inertial measurement unit (IMU) 26 that measures the posture and orientation of the tractor 1 with a gyroscope of the axis and acceleration sensors in three directions. Positioning methods using GPS include DGPS (Differential GPS: relative positioning method) and RTK-GPS (Real Time Kinematic GPS: interference positioning method). In this embodiment, RTK-GPS suitable for positioning of a moving body is adopted. Therefore, as shown in FIG. 1, a reference station 73 that enables positioning by RTK-GPS is installed at a known position around the field.

As shown in FIGS. 1 and 2, the tractor 1 and the reference station 73 have GPS antennas 75 and 76 for receiving radio waves transmitted from the GPS satellite 74 (see FIG. 1), and the tractor 1 and the reference station 73, respectively. Communication modules 77, 78, etc. that enable wireless communication of each information including positioning information between the antennas are provided. As a result, in the satellite navigation device 25 of the positioning unit 24, the positioning information obtained by the GPS antenna 75 on the tractor side receiving the radio wave from the GPS satellite 74 and the radio wave from the GPS satellite 74 on the base station side The current position p0 and the current direction of the tractor 1 can be measured with high accuracy based on the positioning information obtained by receiving the radio wave. Further, the positioning unit 24 has the satellite navigation device 25 and the inertial measurement unit 26 to measure the current position p0, the current direction, and the attitude angle (yaw angle, roll angle, pitch angle) of the tractor 1 with high accuracy. be able to.

In this tractor 1, the inertial measurement unit 26 of the positioning unit 24, the GPS antenna 75, and the communication module 77 are included in the antenna unit 79 shown in FIG. The antenna unit 79 is arranged at the center of the upper left and right on the front side of the cabin 13.

As shown in FIG. 2, the mobile communication terminal 3 is positioned between an electronic control unit in which a microcontroller and the like are integrated, a terminal control unit 80 having various control programs, and a communication module 77 on the tractor side. A communication module 90, etc., which enables wireless communication of each information including information is provided. The terminal control unit 80 includes a display control unit 81 that controls the operation of the display unit 4, a target route generation unit 82 that generates a target route P for automatic driving, a target route P generated by the target route generation unit 82, and the like. A non-volatile terminal storage unit 83, and the like for storing the above are included. In the terminal storage unit 83, as various information used for generating the target path P, vehicle body information such as the turning radius R of the tractor 1 and the working width W1, field information such as the shape and size of the field A, and the like. Is remembered. In the field information, in order to specify the shape and size of the field A, a plurality of shapes in the field A acquired by using the satellite positioning system when the tractor 1 is moved along the outer peripheral edge of the field A. Four corner points Ap1 to Ap4 (see FIG. 10) that serve as specific points (shape-specific coordinates), and a shape-specific line that connects the corner points Ap1 to Ap4 to specify the shape and size of the field A. AL (see FIG. 10), etc. are included.

As shown in FIGS. 3 to 4, the target route generation unit 82 includes the turning radius R and working width W1 of the tractor 1 included in the vehicle body information, the shape and size of the field A included in the field information, and the like. The target route generation control for generating the target route P is executed based on the above.
Specifically, as shown in FIG. 3, for example, in a rectangular field A, a start point p1 and an end point p2 of automatic running are set, and the working running direction of the tractor 1 is a direction along the short side of the field A. When set to, the target route generation unit 82 first positions the field A in the margin area A1 adjacent to the outer peripheral edge of the field A and inside the margin area A1 as shown in FIGS. 3 to 4. The first division process (step # 1 in FIG. 4) for dividing into the traveling area A2 is performed.
Next, the target route generation unit 82 sets the working area W1 in the traveling area A2 divided by the first division process based on the turning radius R of the tractor 1 and the working width W1 in the direction along the long side of the field A. A parallel path generation process (step # 2 in FIG. 4) for generating a plurality of parallel paths P1 arranged in parallel at regular intervals according to the distance, and a plurality of parallel paths arranged on the outer edge of each long side in the traveling region A2. A turning path generation process (step # 3 in FIG. 4) for generating a plurality of turning paths P2 connecting the parallel paths P1 of the above in the order of travel is performed.
Then, the work set in the traveling area A2 divided by the first division processing between the pair of non-working areas A2a set on the outer edge portion on each long side in the traveling area A2 and the pair of non-working areas A2a. The second division process (step # 4 in FIG. 4) for dividing into the area A2b is performed, and each parallel path P1 generated by the parallel path generation process is combined with the non-work path P1a included in the pair of non-work areas A2a. A route division process (step # 5 in FIG. 4) for dividing the work path P1b included in the work area A2b is performed.
As a result, the target route generation unit 82 can generate a target route P suitable for automatically traveling the tractor 1 in the field A shown in FIG.

In the target paths P shown in FIGS. 3, 5, and 7, each non-working path P1a and each turning path P2 are paths in which the tractor 1 automatically travels without performing tilling work, and each of the above-mentioned working paths P1b is , The tractor 1 is a route that automatically travels while performing tillage work. The start point p3 of each work path P1b is the work start point where the tractor 1 starts the tilling work, and the end point p4 of each work path P1b is the work stop point where the tractor 1 stops the tilling work. Further, each non-working path P1a has a work stop point p4 before the tractor 1 turns on the turning path P2 and a work start point p3 after the tractor 1 turns on the turning path P2. It is an alignment route for aligning in the work traveling direction of. Then, the length L1 of each non-working path P1a is determined based on the vehicle body information of the tractor 1 including the positional relationship of the rotary tilling device 6 in the tractor 1.
Further, of the connection points p5 and p6 between each parallel path P1 and each turning path P2 in the target path P, the connection point p5 on the terminal side in each parallel path P1 is the turning start point of the tractor 1, and each parallel path. The connection point p6 on the starting end side in P1 is the turning end point of the tractor 1.
Then, the start point p3 and the end point p4 of each work path P1b described above, each connection point p5 and p6 between each parallel path P1 and each turn path P2 in the target path P, and the length L1 of each non-work path P1a. , Etc. are included in the target path P stored in the terminal storage unit 83.

In the field A shown in FIGS. 3, 5, and 7, the above-mentioned margin area A1 is such that when the tractor 1 automatically travels on the outer peripheral portion of the traveling area A2, the rotary tiller 6 or the like is adjacent to the field A. This is an area secured between the outer peripheral edge of the field A and the traveling area A2 in order to prevent contact with other objects. The distance between the outer peripheral edge of the field A and the traveling area A2 in the margin area A1 is stored in the terminal storage unit 83 as the margin width W2, which is one of the field information.
Further, each of the above-mentioned non-working areas A2a is a ridge turning area for the tractor 1 to swivel and move from the current working path P1b to the next working path P1b at the ridge of the field A. Then, the distance obtained by adding the length L1 of the non-working path (alignment path) P1a described above, the turning radius R of the tractor 1, and the length W1 / 2 which is half of the working width W1 in the tractor 1 is not. The ridge turning width W3 between the margin area A1 and the working area A2b in the work area (ridge turning area) A2a, and this ridge turning width W3 is stored in the terminal storage unit 83 as one of the field information. ing.

The target route P shown in FIGS. 3, 5, and 7 is only an example, and the target route generation unit 82 responds to vehicle body information different depending on the model of the tractor 1, the type of work, and the field A. Based on field information such as the shape and size of different fields A, various target routes P suitable for them can be generated.

The target route P is stored in the terminal storage unit 83 in a state associated with vehicle body information, field information, and the like, and can be displayed on the display unit 4 of the mobile communication terminal 3. The target route P includes a first vehicle speed V1 (see FIG. 6) set as a target vehicle speed of the tractor 1 in each parallel route P3, and a second vehicle speed V2 (see FIG. 6) set as a target vehicle speed of the tractor 1 in each turning path P2b. 6), front wheel steering angle in each parallel path P1, front wheel steering angle in each turning path P2b, and the like are included.

The terminal control unit 80 transmits the vehicle body information, the field information, the target route P, etc. stored in the terminal storage unit 83 to the vehicle-mounted control unit 40 in response to the transmission request command from the vehicle-mounted control unit 40. The vehicle-mounted control unit 40 stores the received vehicle body information, field information, target route P, and the like in the vehicle-mounted storage unit 47. Regarding the transmission of the target route P, for example, the terminal control unit 80 transmits all of the target route P from the terminal storage unit 83 to the vehicle-mounted control unit 40 at once before the tractor 1 starts automatic traveling. You may do it. Further, for example, the terminal control unit 80 divides the target route P into a plurality of divided route information for each predetermined distance, and the traveling distance of the tractor 1 reaches the predetermined distance from the stage before the tractor 1 starts automatic traveling. For each, a predetermined number of division route information according to the traveling order of the tractor 1 may be sequentially transmitted from the terminal storage unit 83 to the vehicle-mounted control unit 40.

In the vehicle-mounted control unit 40, detection information from various sensors and switches included in the vehicle state detection device 23 is input to the automatic driving control unit 46 via the vehicle speed control unit 42, the steering control unit 43, and the like. ing. As a result, the automatic traveling control unit 46 can monitor various setting states in the tractor 1 and operating states of each unit.

In the state where the driving mode of the tractor 1 is switched to the automatic driving mode, the automatic driving control unit 46 starts automatic driving by operating the display unit 4 of the mobile communication terminal 3 by a user such as a passenger or an administrator outside the vehicle. Is commanded, the positioning unit 24 starts automatic traveling control for automatically traveling the tractor 1 according to the target route P while acquiring the current position p0 and the current orientation of the tractor 1.

The automatic driving control by the automatic driving control unit 46 includes automatic control processing for the engine that transmits a control command for automatic driving related to the engine 14 to the engine control unit 41, and automatic driving for switching the vehicle speed V and forward / backward movement of the tractor 1. Vehicle speed automatic control processing that transmits control commands to the vehicle speed control unit 42, steering automatic control processing that transmits control commands for automatic driving related to steering to the steering control unit 43, and automation related to work devices such as the rotary tillage device 6. It includes a work automatic control process for transmitting a travel control command to the work device control unit 44, and the like.

In the automatic engine control process, the automatic driving control unit 46 issues an engine rotation speed change command to the engine control unit 41, which instructs the engine rotation speed to be changed based on the set rotation speed included in the target path P. Send. The engine control unit 41 executes engine speed change control that automatically changes the engine speed in response to various control commands regarding the engine 14 transmitted from the automatic travel control unit 46.

In the vehicle speed automatic control process, the automatic travel control unit 46 is included in the shift operation command for instructing the shift operation of the continuously variable transmission 36 based on the target vehicle speed included in the target path P, and the target path P. A forward / backward switching command for instructing a forward / backward switching operation of the forward / backward switching device 37 based on the traveling direction of the tractor 1 and the like are transmitted to the vehicle speed control unit 42. The vehicle speed control unit 42 automatically controls the operation of the continuously variable transmission 36 in response to various control commands regarding the continuously variable transmission 36, the forward / backward switching device 37, etc. transmitted from the automatic driving control unit 46. Control, automatic forward / backward switching control that automatically controls the operation of the forward / backward switching device 37, and the like are executed. For vehicle speed control, for example, when the target vehicle speed included in the target path P is zero speed, the continuously variable transmission 36 is decelerated to a zero speed state to stop the running of the tractor 1. Etc. are included.

In the automatic steering control process, the automatic driving control unit 46 transmits a steering command for instructing steering of the left and right front wheels 10 to the steering control unit 43 based on the front wheel steering angle and the like included in the target path P. .. The steering control unit 43 controls the operation of the power steering unit 16 to steer the left and right front wheels 10 in response to the steering command transmitted from the automatic travel control unit 46, and the left and right front wheels 10 are set. When the steering is steered to an angle or more, the brake unit 17 is operated to operate the brake inside the turning, and the automatic brake turning control is executed.

In the automatic work control process, the automatic travel control unit 46 gives a work start command for instructing the rotary tiller 6 to switch to the work state based on the work start point p3 included in the target route P, and the target route. A work stop command for instructing the switching of the rotary tillage device 6 to the non-work state based on the work stop point p4 included in P is transmitted to the work device control unit 44. The working device control unit 44 controls the operation of the elevating drive unit 20 and the work clutch unit 19 in response to various control commands regarding the rotary tilling device 6 transmitted from the automatic traveling control unit 46, and controls the rotary tilling device 6. Automatic work start control that lowers to the work height and operates, automatic work stop control that stops the rotary tiller 6 and raises it to the non-work height, and the like are executed. Further, the working device control unit 44 is driven up and down based on the detection of the tilling depth sensor that detects the tilling depth by the rotary tilling device 6 in the working state in which the rotary tilling device 6 is lowered to the working height and operated. Automatic tillage maintenance control that controls the operation of the unit 20 to maintain the tillage depth by the rotary tiller 6 to the set depth, and the tilt sensor and the acceleration sensor of the inertial measurement unit 26 that detect the roll angle of the tractor 1. Based on the detection, the operation of the rolling drive unit 21 is controlled to execute the automatic roll angle maintenance control for maintaining the tilting posture in the roll direction of the rotary tilling device 6 in the set posture (for example, the horizontal posture).

That is, the above-mentioned automatic traveling unit 2 includes a power steering unit 16, a brake unit 17, a work clutch unit 19, an elevating drive unit 20, a rolling drive unit 21, a vehicle state detection device 23, a positioning unit 24, and an in-vehicle control unit 40. And the communication module 77, etc. are included. Then, when these operate properly, the tractor 1 can be automatically driven with high accuracy according to the target route P, and the rotary tilling device 6 can properly perform the tilling.

As shown in FIGS. 2, 5 and 7, when the tractor 1 is automatically traveling on the parallel path P1 by the automatic traveling control, the automatic traveling control unit 46 is from the front end of the tractor 1 in the traveling direction of the tractor 1. It has a separation distance measuring unit 46A for measuring the separation distance D1 to the outer peripheral edge of the field A. The vehicle speed control unit 42 has a vehicle speed limiting unit 42A that limits the vehicle speed V of the tractor 1 according to the separation distance D1 measured by the separation distance measuring unit 46A. The vehicle body information stored in the vehicle-mounted storage unit 47 includes the relationship between the front-rear length L2 from the front end of the tractor 1 to the mounting position of the GPS antenna 75 in the plan view of the tractor 1, the vehicle speed V of the tractor 1, and the braking distance. Includes a map to show.

As shown in FIGS. 5 and 7, the separation distance measuring unit 46A has the current position p0 of the tractor 1 in the parallel path P1 acquired by using the satellite positioning system, and the parallel path P1 stored in the in-vehicle storage unit 47. The connection point p5 on the terminal side, the turning radius R of the tractor 1, the working width W1 of the tractor 1, the margin width W2 of the field A, and the front-rear length L2 from the front end of the tractor 1 to the mounting position of the GPS antenna 75. The separation distance D1 is measured based on the above.

Specifically, the separation distance measuring unit 46A is half the length of the turning radius R of the tractor 1 and the working width W1 of the tractor 1 at the stage before the tractor 1 automatically travels on the parallel path P1 by the automatic traveling control. By adding W1 / 2 and the margin width W2 of the field A, the fixed separation distance D3 from the connection point p5 on the terminal side in the parallel path P1 to the outer peripheral edge of the field A is calculated and stored in the in-vehicle storage unit 47. .. Then, while the tractor 1 is automatically traveling on the parallel path P1 by the automatic traveling control, the separation distance measuring unit 46A is from the above-mentioned current position p0 of the tractor 1 and the connection point p5 on the terminal side in the parallel path P1. The untraveled distance D4 between them is calculated, and the above-mentioned separation distance D1 is measured by subtracting the above-mentioned front-rear length L2 from the sum of the untraveled distance D4 and the fixed separation distance D3.

That is, the separation distance measuring unit 46A has an untraveled distance D4 that changes according to the current position p0 of the tractor 1 in the parallel path P1 acquired by using the satellite positioning system, and a fixed value stored in the vehicle-mounted storage unit 47. The separation distance D1 will be measured based on the above-mentioned fixed separation distance D3 and the front-rear length L2. As a result, the calculation load required for measuring the separation distance D1 can be reduced, and as a result, the separation distance D1 can be measured quickly and accurately.

The separation distance measuring unit 46A has a front-rear length L2 from the front end of the tractor 1 to the mounting position of the GPS antenna 75 at the stage where the current position p0 of the tractor 1 in the parallel path P1 is acquired by using the satellite positioning system. Based on this, it may be configured to correct the deviation between the current position p0 of the tractor 1 and the front end position of the tractor 1.
Further, the separation distance measuring unit 46A has a turning radius R of the tractor 1 and a half length W1 / 2 of the working width W1 of the tractor 1 in the stage before the tractor 1 automatically travels on the parallel path P1 by the automatic traveling control. And the fixed separation distance D3 obtained by adding the margin width W2 of the field A minus the above-mentioned front-rear length L2 is calculated as a fixed value for measuring the separation distance and stored in the in-vehicle storage unit 47. It may be configured to cause. In this case, it is possible to further reduce the calculation load required for measuring the separation distance D1.

The vehicle speed limiting unit 42A limits the vehicle speed V of the tractor 1 according to the separation distance D1 measured by the separation distance measuring unit 46A while the tractor 1 automatically travels on the parallel path P1 by the automatic traveling control. To execute.

Explaining the control operation of the vehicle speed limiting unit 42A in the vehicle speed limiting control based on the flowchart shown in FIG. 9, the vehicle speed limiting unit 42A first, as shown in FIG. 7, first, the separation distance D1 measured by the separation distance measuring unit 46A. The braking distance calculation process (step # 10 in FIG. 9) for calculating the comparative braking distance D2, which is shorter than the separation distance D1 by the set distance D5, is performed. As shown in FIG. 7, the comparative braking distance D2 calculated here is a traveling limit in which the current position p0 of the tractor 1 is the intersection of the outer peripheral edge of the field A located in the traveling direction of the tractor 1 and the parallel path P1. It becomes shorter as it approaches the position p10, and becomes zero when the front end position of the tractor 1 reaches the travel limit position p11 that has entered the field A by the set distance D5 from the travel limit position p10.
Next, the vehicle speed limiting unit 42A sets the vehicle speed V of the tractor 1 according to the comparative braking distance D2 as the upper limit speed Vmax from the comparative braking distance D2 obtained by the braking distance calculation process and the map described above. (Step # 11 in FIG. 9) is performed. As shown in FIGS. 6 and 8, the upper limit speed Vmax set here becomes slower as the separation distance D1 becomes shorter with the automatic traveling of the tractor 1 on the parallel path P1, and the front end position of the tractor 1 is restricted. When the position p11 is reached (see FIG. 7), the speed becomes zero.
Further, the vehicle speed limiting unit 42A compares the upper limit speed Vmax set in the upper limit speed setting process with the first vehicle speed V1 which is the target vehicle speed of the tractor 1 in the parallel path P1 (step # 12 in FIG. 9). I do.
Then, as shown in FIG. 6, the braking distance of the tractor 1 according to the first vehicle speed V1 is shorter than the comparative braking distance D2 until the upper limit speed Vmax drops to the first vehicle speed V1 in the comparison process. Therefore, the vehicle speed limiting unit 42A performs the first vehicle speed limiting process (step # 13 in FIG. 9) for limiting the vehicle speed V of the tractor 1 so that the vehicle speed V of the tractor 1 is maintained at the first vehicle speed V1.
Further, as shown in FIG. 6, when the upper limit speed Vmax drops to the first vehicle speed V1 in the comparison process, the braking distance of the tractor 1 according to the first vehicle speed V1 becomes the same as the comparative braking distance D2. The vehicle speed limiting unit 42A reduces the vehicle speed V of the tractor 1 from the first vehicle speed V1 in accordance with the decrease of the separation distance D1 so that the braking distance of the tractor 1 is maintained at the comparative braking distance D2 (second vehicle speed limiting process). Step # 14) in FIG. 9 is performed.
After that, the vehicle speed limiting unit 42A performs a determination process (step # 15 in FIG. 9) for determining whether or not the tractor 1 has reached the connection point (turning start point) p5 on the terminal side in the parallel path P1.
Then, the vehicle speed limiting unit 42A continues the second vehicle speed limiting process until it is determined in the determination process that the current position p0 of the tractor 1 has reached the connection point (turning start point) p5.
Further, the vehicle speed limiting unit 42A ends the vehicle speed limiting control when it is determined in the determination process that the current position p0 of the tractor 1 has reached the connection point (turning start point) p5. As a result, as shown in FIG. 6, the vehicle speed V of the tractor 1, which has decreased according to the decrease of the separation distance D1 due to the second vehicle speed limiting process, is such that the current position p0 of the tractor 1 is the connection point (turning start point) p5. When it reaches, it stops lowering at the vehicle speed corresponding to the separation distance D1 obtained at this time.
Then, when the vehicle speed limiting unit 42A finishes the vehicle speed limiting control, the vehicle speed control unit 42 executes the vehicle speed control, and while the tractor 1 automatically travels on the turning path P2b, the vehicle speed V of the tractor 1 is turned. The second vehicle speed V2 (see FIG. 6), which is the target vehicle speed of the tractor 1 on the route P2b, is maintained. After that, as the tractor 1 moves from the turning path P2b to the parallel path P1, the vehicle speed V of the tractor 1 is changed from the second vehicle speed V2 to the first vehicle speed V1, and the vehicle speed control is terminated to limit the vehicle speed. The vehicle speed limit control by 42A is executed.

That is, when the tractor 1 starts automatic traveling on the parallel path P1, the vehicle speed limiting unit 42A is long while the separation distance D1 is long and the braking distance of the tractor 1 according to the first vehicle speed V1 is shorter than the comparative braking distance D2. Performs the first vehicle speed limiting process to limit the vehicle speed V of the tractor 1 to the first vehicle speed V1. As a result, the vehicle speed V of the tractor 1 becomes unnecessarily high, resulting in poor fuel economy and a decrease in the followability of the tractor 1 to the target route P when the tractor 1 is automatically driven according to the target route P. It is possible to avoid the possibility of doing so.

After that, when the separation distance D1 becomes shorter and the braking distance of the tractor 1 according to the first vehicle speed V1 becomes the same as the comparative braking distance D2, the vehicle speed limiting unit 42A performs the second vehicle speed limiting process, and the braking distance of the tractor 1 However, the vehicle speed V of the tractor 1 is limited so as to be maintained at the comparative braking distance D2, which becomes shorter as the separation distance D1 decreases. As a result, when the tractor 1 approaches the outer peripheral edge of the field A or reaches the turning path P2, the vehicle speed V of the tractor 1 can be sufficiently reduced. As a result, when the automatic traveling control unit 46 stops traveling of the tractor 1 near the outer peripheral edge of the field A according to the parallel path P1, or when the tractor 1 is rotated according to the turning path P2, the tractor 1 is moved to the field A. It is possible to avoid the possibility of protruding from the ridge and coming into contact with other objects such as ridges.

As shown in FIG. 1, the tractor 1 has two front and rear lidar sensors (LiDAR Sensor: Light Detection and Ranging Sensor) that measure the distance to the object to be measured in three dimensions using a laser and generate a three-dimensional image. ) 100, 101 and left and right sonar units 102 for measuring the distance to the object to be measured using ultrasonic waves.

Of the front and rear rider sensors 100 and 101, the front rider sensor 100 looks down on the front side of the tractor 1 from the diagonally upper side at the upper left and right center points on the front side of the cabin 13 in which the antenna unit 79 is arranged. It is arranged in a forward-down posture. As a result, the front rider sensor 100 is set so that the front side of the tractor 1 is the measurement range. The rear rider sensor 101 is arranged at the center of the upper left and right on the rear end side of the cabin 13 in a rear-down posture looking down on the rear side of the tractor 1 from the diagonally upper side. As a result, the rear rider sensor 101 is set so that the rear side of the tractor 1 is the measurement range.

The left and right sonar units 102 are attached to the left and right boarding / alighting steps arranged on the lower sides of the left and right sides of the cabin 13 in a left / right outward posture with a small depression angle. As a result, the left and right sonar units 102 are arranged at relatively high positions between the front wheels 10 and the rear wheels 11 in a state where the left and right outer sides of the tractor 1 are set to be the measurement range.

The front and rear rider sensors 100 and 101 and the left and right sonar units 102 are connected to the automatic traveling control unit 46 of the vehicle-mounted control unit 40 so as to be able to communicate with each other via CAN. As a result, the automatic traveling control unit 46 can monitor the surroundings of the tractor 1 based on the information from the front and rear rider sensors 100 and 101 and the left and right sonar units 102. As a result, for example, when the tractor 1 approaches another object such as a ridge adjacent to the field A, or when another object such as another work vehicle approaches the tractor 1, the automatic traveling control unit 46 sets the automatic traveling control unit 46. The situation at that time can be accurately grasped, and vehicle speed control, automatic steering control, etc. suitable for the situation at that time can be executed. As a result, it is possible to avoid the possibility that the tractor 1 comes into contact with another object.

[Another Embodiment]
Another embodiment of the present invention will be described.
It should be noted that the configurations of each of the different embodiments described below are not limited to being applied independently, but can also be applied in combination with the configurations of other other embodiments.

(1) Another typical embodiment relating to the configuration of the work vehicle 1 is as follows.
For example, the work vehicle 1 may be configured to have a semi-crawler specification in which left and right crawlers are provided instead of the left and right rear wheels 11.
For example, the work vehicle 1 may be configured to have a full crawler specification in which left and right crawlers are provided instead of the left and right front wheels 10 and the left and right rear wheels 11.
For example, the work vehicle 1 may be configured to have an electric specification provided with an electric motor instead of the engine 14.
For example, the work vehicle 1 may be configured in a hybrid specification including an engine 14 and an electric motor.

(2) As shown in FIG. 10, the separation distance measuring unit 46A identifies the current position p0 of the tractor 1 in the parallel path P1 acquired by using the satellite positioning system and the work site shape stored in the in-vehicle storage unit 47. The distance from the current position p0 of the tractor 1 to the shape specifying line AL located on the extension line of the parallel path P1 in the traveling direction of the tractor 1 is measured as the separation distance D1 based on the shape specifying line AL. It may be configured.

(3) The separation distance measuring unit 46A may be configured to measure the separation distance D1 based on the measurement result of the front rider sensor 100, which is an example of the distance sensor.
A stereo camera or the like may be adopted as the distance sensor.

1 Work vehicle 42 Vehicle speed control unit 46 Automatic travel control unit 46A Separation distance measurement unit 42A Vehicle speed limit unit 47 Storage unit 100 Distance sensor A Work area A2 Travel area Ap1 Shape specific point Ap4 Shape specific point AL Shape specific line D1 Separation distance D2 Comparison Braking distance D5 Set distance P Target route P1 Parallel route P2 Turning route R Turning radius V1 Target vehicle speed W Working width W2 Margin width p0 Current position p5 Connection point p6 Connection point

Claims (4)

A vehicle speed control unit that controls the vehicle speed of the work vehicle,
It has an automatic driving control unit that automatically drives the work vehicle according to a target route generated in a traveling area divided in the work area.
The target route includes a plurality of parallel routes arranged in parallel in the traveling region, and a plurality of turning routes arranged at the outer edge of the traveling region and connecting the plurality of parallel routes in the traveling order. Ori,
The automatic traveling control unit measures the separation distance from the work vehicle to the outer peripheral edge of the work site in the traveling direction of the work vehicle when the work vehicle is automatically traveling on the parallel route. Has a part,
The vehicle speed control unit has a vehicle speed limiting unit that limits the vehicle speed of the work vehicle according to the separation distance.
When the comparative braking distance is set to a distance shorter than the separation distance by a set distance, the vehicle speed limiting unit of the work vehicle according to a preset target vehicle speed when the work vehicle automatically travels on the parallel route. While the braking distance is shorter than the comparative braking distance, the first vehicle speed limiting process for limiting the vehicle speed of the work vehicle is performed so that the vehicle speed of the work vehicle is maintained at the target vehicle speed, and the vehicle speed is set according to the target vehicle speed. When the braking distance of the work vehicle becomes the same as the comparative braking distance, the vehicle speed of the work vehicle corresponds to the decrease of the separation distance so that the braking distance of the work vehicle is maintained at the comparative braking distance. An automatic traveling system for a work vehicle that performs a second vehicle speed limiting process that reduces the speed from the target vehicle speed . The storage unit includes the turning radius of the work vehicle, the working width of the work vehicle, the margin width set between the outer peripheral edge of the work area and the traveling area, the parallel path, and the turning path. Each connection point of is memorized,
The separation distance measuring unit includes the current position of the work vehicle in the parallel path, the connection point on the terminal side in the parallel path stored in the storage unit, the turning radius of the work vehicle, and the work. The automatic traveling system for a work vehicle according to claim 1, wherein the separation distance is measured based on the work width of the vehicle and the margin width. The storage unit stores a plurality of shape specifying points in the work area and a shape specifying line that connects the plurality of shape specifying points to specify the shape of the work area.
The separation distance measuring unit measures the distance from the current position of the work vehicle in the parallel path to the shape specifying line located on the extension line of the parallel path in the traveling direction of the work vehicle as the separation distance. Item 1. The automatic traveling system for the work vehicle according to Item 1. The work vehicle is provided with a distance sensor that measures the distance to a distance measurement object existing in the traveling direction of the work vehicle.
The automatic traveling system for a work vehicle according to claim 1, wherein the separation distance measuring unit measures the separation distance based on the measurement result of the distance sensor.

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