Control method for coupling device

Abstract

To change a position of a work device to a work vehicle.SOLUTION: In a control method of a connector (8) for connecting a work vehicle (1) to a work device (2), a control device (70) changes a connection position (P12) of the connector (8) to the work device (2), based on past traveling results of the work device (2).SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a method for controlling a coupling device that couples, for example, a work vehicle and a work implement. [Background technology]

[0002] Conventionally, a coupling device for coupling a work implement to a work vehicle such as a tractor is known from Patent Document 1. The coupling device in Patent Document 1 includes a coupling frame mounted to the rear of the tractor body so that it can be raised and lowered, and an engaging part that is provided on the upper part of the coupling frame and engages with an engaged part that is provided on the work implement. The engaging part swings around the engaged part, allowing the work implement to be coupled. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-64582 Summary of the Invention [Problem to be solved by the invention]

[0004] As shown in the coupling device of Patent Document 1, the coupling device is a device configured to couple a working implement to the rear of a tractor. The working implement can generally be raised and lowered by raising and lowering the coupling device using a lifting device provided at the rear of the tractor. However, the lifting and lowering of the lifting device is controlled by hydraulic cylinders, control valves, etc., which are provided on the tractor, and the working implement is raised and lowered only by controlling the lifting and lowering of the tractor. There is no other way to raise or lower the working implement, or to change its position.

[0005] In view of the above problems, an object of the present invention is to provide a control method for a coupling device that can change the position of a working device relative to a work vehicle. [Means for solving the problem]

[0006] The technical means of the present invention for solving this technical problem is characterized by the following points. A method for controlling a coupling device according to one aspect of the present invention includes: Method for controlling a coupling device that couples a work vehicle and a work implement And , the coupling device comprises a coupling member, a first coupling part provided at one end of the coupling member, the first coupling part having a coupling position for coupling to the work vehicle that is swingably supported by a bracket of the work vehicle, a second coupling part provided at the other end of the coupling member, the second coupling part having a coupling position for coupling to the work device that is swingably supported by a bracket of the work device, and an actuator that can change the coupling position of the second coupling part in a swing direction by swinging the coupling member around the first coupling part as an axis, Control device calculates the past travel record of the working device including the device position of the working device, and the device position of the working device is Past running records of the work equipment The actuator is controlled so that the path of the second connecting portion coincides with the path of the second connecting portion. Change the connection position of 。

[0007] before The control device determines whether the route of the driving record is appropriate, determining that the route of the travel record is appropriate when the distance between the route of the travel record and an obstacle in the field is equal to or greater than a predetermined distance; If the route of the travel record is appropriate, the device position of the working device is adjusted so as to match the route of the travel record. The second connection Change the connection position 。

[0008] When the distance between the traveled route and an obstacle in the field is less than a predetermined value, the control device , the route of the driving record is judged to be inappropriate, The second connection The connection position is changed so as to be different from the route of the travel record. At least one of the work vehicle, the work device, and the coupling device has a positioning device, and the control device calculates the device position based on the position measured by the positioning device, and adjusts the calculated device position so that it matches the route of the travel history. The second connection Change the connection position. The control device calculates the device position based on the angle of the coupling device relative to the work vehicle, and adjusts the device position so that the calculated device position matches the route of the travel history. The second connection Change the connection position.

[0009] The control device acquires a location estimation model and connection information through communication, The second connection The location of the connection point is estimated. The control device is capable of acquiring operation information of the work device from the work device via an in-vehicle network.

[0010] The coupling device includes a pair of lower links, a pair of lift rods, and a pair of lift cylinders, the pair of lower links each correspond to the connecting member, The front ends of the pair of lower links are supported so as to be swingable up and down relative to the work vehicle, and the rear ends are connected to the work device. Each of the pair of lower links is raised and lowered by driving the pair of lift cylinders. The control device extends and retracts at least one of the pair of lift rods, thereby raising and lowering the corresponding lower link of the pair of lower links, thereby changing the attitude of the work device. [Effects of the Invention]

[0011] According to the present invention, the position of the work implement relative to the work vehicle can be changed. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 2 is a control block diagram of the tractor, the coupling device, and the work device. [Figure 2] FIG. 10 is a diagram showing an example of a creation screen M1. [Figure 3] FIG. 1 is an explanatory diagram illustrating automatic driving of a tractor. [Figure 4A] FIG. 10 is a diagram illustrating an example of a coupling device. [Figure 4B] FIG. 10 is a diagram showing another example of a coupling device. [Figure 5A] FIG. 1 is a diagram showing an automatic driving situation. [Figure 5B] FIG. 10 is a diagram showing the automatic driving state during turning. [Figure 6] FIG. 10 is a diagram illustrating an example of performance data. [Figure 7] FIG. 10 is a diagram showing a state in which a tractor is towing a work implement and performing automatic traveling. [Figure 8A] FIG. 10 is a diagram illustrating an example of a driving record. [Figure 8B] FIG. 10 is a diagram showing another example of the driving record. [Figure 9A] FIG. 10 is a diagram illustrating an example of a coupling device equipped with a positioning device. [Figure 9B] FIG. 10 is a diagram illustrating another example of a coupling device equipped with a positioning device. [Figure 10] FIG. 10 is a diagram showing a modified example of the coupling device. [Figure 11] FIG. 10 is a control block diagram of a modified example of the tractor, the coupling device, and the work device. [Figure 12] FIG. 2 is a side view of the tractor. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 12 shows a state in which the work vehicle 1 is coupled with the work implement 2. First, a tractor 1, which is one of the work vehicles, will be described. As shown in FIG. 12, the tractor 1 includes a traveling body 3 having a traveling device 7, a prime mover 4, and The vehicle is equipped with a transmission 5. The traveling device 7 is a device having front wheels 7F and rear wheels 7R. The front wheels 7F may be of either a tire type or a crawler type. The rear wheels 7R may also be of either a tire type or a crawler type. The prime mover 4 is a diesel engine, an electric motor, or the like. The transmission 5 is capable of switching the propulsive force of the traveling device 7 by changing the speed, and is also capable of switching the traveling device 7 between forward and reverse. The traveling vehicle body 3 is provided with a cabin 9, and a driver's seat 10 is provided within the cabin 9.

[0014] Further, a coupling device 8 for coupling the working implement 2 is provided at the rear of the traveling body 3. The coupling device 8 is a lifting device that connects the working implement 2 to the traveling body 3 and is composed of a swing drawbar that does not lift or lower, or a three-point link mechanism, etc., that lifts or lowers the working implement 2. The working implement 2 is detachable from the coupling device 8. By coupling the working implement 2 to the coupling device 8, the working implement 2 can be towed by the traveling body 3. The working implement 2 is a trailer for transporting, a tilling implement, a fertilizer spreader for spreading fertilizer, a transplanter for planting seedlings, an irrigation device for irrigating, a pesticide spreader for spreading pesticides, a seed spreader for spreading seeds, a harvester for harvesting grass or the like, a spreader for spreading grass or the like, a grass collector for collecting grass or the like, a shaping device for shaping grass or the like, a composite device for performing multiple tasks, etc.

[0015] FIG. 1 shows a control block diagram of the tractor 1, the coupling device 8, and the work implement 2. As shown in FIG. 1, the tractor 1 is equipped with a steering device 29. The steering device 29 has a handle (steering wheel) 30, a rotating shaft (steering shaft) 31 that rotates in conjunction with the rotation of the handle 30, and an assist mechanism (power steering mechanism) 32 that assists in steering the handle 30. The assist mechanism 32 includes a hydraulic pump 33, a control valve 34 to which hydraulic oil discharged from the hydraulic pump 33 is supplied, and a steering cylinder 35 operated by the control valve 34. The control valve 34 is an electromagnetic valve that operates based on a control signal. The control valve 34 is, for example, a three-position switching valve that can be switched by moving a spool or the like. The control valve 34 can also be switched by steering the steering shaft 31. The steering cylinder 35 is connected to an arm (knuckle arm) that changes the direction of the front wheels 7F.

[0016] Therefore, when the steering wheel 30 is operated, the switching position and opening degree of the control valve 34 are switched in response to the steering wheel 30, and the steering cylinder 35 extends or contracts to the left or right in response to the switching position and opening degree of the control valve 34, thereby changing the steering direction of the front wheels 7F. Note that the above-described steering device 29 is an example, and is not limited to the above-described configuration. The tractor 1 is equipped with a positioning device 40. The positioning device 40 can detect its own position (positioning information including latitude and longitude) using a satellite positioning system (positioning satellite) such as D-GPS, GPS, GLONASS, Beidou, Galileo, or Michibiki, i.e., a global positioning system. That is, the positioning device 40 receives satellite signals (position of the positioning satellite, transmission time, correction information, etc.) transmitted from the positioning satellites, and detects the position of the tractor 1 (e.g., latitude and longitude), i.e., the work vehicle position P10, based on the satellite signals. The positioning device 40 has a receiving device 41 and an inertial measurement unit (IMU) 42. The receiving device 41 has an antenna and the like and is a device that receives satellite signals transmitted from the positioning satellites, and is attached to the traveling vehicle body 3 separately from the inertial measurement unit 42. In this embodiment, the receiving device 41 is attached to the traveling vehicle body 3, i.e., the cabin 9. The location where the receiving device 41 is attached is not limited to the embodiment.

[0017] The inertial measurement unit 42 has an acceleration sensor that detects acceleration, a gyro sensor that detects angular velocity, etc. The inertial measurement unit 42 is provided on the traveling vehicle body 3, for example, below the driver's seat 10, and can detect the roll angle, pitch angle, yaw angle, etc. of the traveling vehicle body 3. As shown in FIG. 1, the tractor 1 includes a plurality of detection devices 38, a plurality of operation members (operation devices) 39, and a control device (first control device) 60. The plurality of detection devices 38, the positioning device 40, and the first control device 60 are connected by an in-vehicle network N1, and the first control device The first control device 60 can acquire detection information detected by the multiple detection devices 38 and the work vehicle position (position information) detected by the positioning device 40. The first control device 60 can acquire operation information when the multiple operation members (operation devices) 39 are operated.

[0018] The multiple detection devices 38 are devices that detect the state of the tractor 1, and include, for example, a water temperature sensor 38a that detects the water temperature, a fuel sensor 38b that detects the remaining amount of fuel, a prime mover rotation sensor (rotation sensor) 38c that detects the rotation speed of the prime mover 4, an accelerator pedal sensor 38d that detects the amount of operation of the accelerator pedal, a steering angle sensor 38e that detects the steering angle of the steering device 29, a speed sensor 38f that detects the vehicle speed (velocity) of the traveling vehicle body 3, a PTO rotation sensor (rotation sensor) 38g that detects the rotation speed of the PTO shaft, and a battery sensor 38h that detects the voltage of a storage battery such as a battery.

[0019] The tractor 1 also has a plurality of operating members (operating devices) 39. The operating members 39 include a shuttle lever 39a for switching the traveling body 3 between forward and reverse, an ignition switch 39b for starting the prime mover 4, a PTO speed change lever 39c for setting the rotation speed of the PTO shaft, a speed change lever 39d for manually changing the speed (speed change level) of the transmission 5, and an accelerator 39e for increasing or decreasing the vehicle speed.

[0020] The first control device 60 performs various controls of the tractor 1. For example, the first control device 60 controls the engine rotation speed in accordance with the amount of operation of the accelerator pedal, controls a clutch that switches between forward and reverse provided in the transmission 5 when the traveling body 3 is switched between forward and reverse, and controls changing the gear stage of the transmission 5 when the gear stage is changed by the shift lever 39d. In addition, the first control device 60 controls the steering of the steering device 29 in accordance with the steering angle of the steering device 29 when the tractor is operated manually.

[0021] The tractor 1 is capable of automatic driving, and the automatic driving is performed based on a preset driving line L1. As shown in Figure 2, the driving line L1 for automatic driving can be displayed on a display device 50 provided on the tractor 1. 2, when a predetermined operation is performed on the display device 50, a creation screen M1 for the travel line L1 is displayed. The creation screen M1 includes a field section 65 to which position information (latitude, longitude) is assigned. Here, when a predetermined operation is performed on the display device 50, a straight section L1a for moving the tractor 1 straight and a turning section L1b can be set in the field section 65 as the travel line L1.

[0022] The automatic driving can be performed by the first control device 60. The first control device 60 has an automatic driving control unit 63 that controls the automatic driving. The automatic driving control unit 63 starts automatic driving when in automatic driving mode. As shown in FIG. 3, when the tractor 1 is performing automatic driving, if the deviation between the work vehicle position P10 and the traveling line L1 is less than a threshold value, the automatic driving control unit 63 maintains the rotation angle of the steering shaft (rotation shaft) 31. If the deviation between the work vehicle position P10 and the traveling line L1 is equal to or greater than the threshold value and the tractor 1 is located on the left side of the traveling line L1, the automatic driving control unit 63 rotates the steering shaft 31 so that the steering direction of the tractor 1 is to the right. If the deviation between the work vehicle position P10 and the traveling line L1 is equal to or greater than the threshold value and the tractor 1 is located on the right side of the traveling line L1, the automatic driving control unit 63 rotates the steering shaft 31 so that the steering direction of the tractor 1 is to the left. In the above-described embodiment, the steering angle of the steering device 29 is changed based on the deviation between the work vehicle position P10 and the traveling line L1, but if the orientation of the traveling line L1 and the orientation (vehicle body orientation) F1 of the direction of travel (traveling direction) of the tractor 1 (traveling body 3) differ, that is, if the angle θg of the vehicle body orientation F1 with respect to the traveling line L1 is equal to or greater than a threshold value, the automatic driving control unit 63 may set the steering angle so that the angle θg becomes zero (the vehicle body orientation F1 coincides with the orientation of the traveling line L1). The final steering angle in automatic steering may be set based on the steering angle calculated based on the position deviation and the steering angle calculated based on the azimuth (azimuth deviation). The setting of the steering angle in automatic steering in the above-described embodiment is an example and is not limited thereto.

[0023] 4A, the coupling device 8 is, for example, a towing hitch and includes a coupling member 8a and an actuator 8b. The coupling member 8a is a rod-shaped member that couples the tractor 1 and the working implement 2. The coupling member 8a includes a first coupling portion 8a1 and a second coupling portion 8a2. The first connecting part 8a1 is a part that connects to the tractor 1, and is swingably supported on a vertical shaft 44 that is provided on a bracket 43 that is provided at the rear of the tractor 1. For example, a through-hole that penetrates the first connecting part 8a1 in the vertical direction is formed, and the vertical shaft 44 is inserted into the through-hole to connect the first connecting part 8a1 to the rear of the tractor 1. The bracket 43 is provided on, for example, a transmission case, a differential case, etc. of the transmission 5.

[0024] The second connecting part 8a2 is a part that connects to the working device 2, and is pivotally supported so as to be swingable on a vertical shaft 46 that is provided on a bracket 45 that is provided at the front of the working device 2. For example, the second connecting part 8a2 has a through-hole that penetrates vertically, and the second connecting part 8a2 is connected to the front of the working device 2 by inserting the vertical shaft 46 into the through-hole. As shown in FIG. 4A, the actuator 8b can change the connecting position P12 of the second connecting portion 8a2. The actuator 8b is, for example, an extendable hydraulic cylinder. One end of the actuator (hydraulic cylinder) 8b is pivotally supported so as to be swingable on a bracket 47 provided on the tractor 1. The other end of the actuator (hydraulic cylinder) 8b is pivotally supported so as to be swingable on a midpoint of the connecting member 8a (the intermediate portion between the first connecting portion 8a1 and the second connecting portion 8a2). Therefore, the connecting position P12 of the second connecting portion 8a2 can be changed by extending or retracting the actuator (hydraulic cylinder) 8b.

[0025] As shown in Fig. 4B, the actuator (hydraulic cylinder) 8b may be provided between the connecting member 8a and the working device 2. As shown in Fig. 4B, one end of the actuator (hydraulic cylinder) 8b is pivotally supported so as to be swingable on a bracket 48 provided on the working device 2. The other end of the actuator (hydraulic cylinder) 48 is pivotally supported so as to be swingable on an intermediate portion of the connecting member 8a. Therefore, by extending or contracting the actuator (hydraulic cylinder) 8b, the connecting position P11 of the first connecting portion 8a1 can be changed.

[0026] 1, the coupling device 8 is provided with a control valve 55 that controls the extension and retraction of the hydraulic cylinder 8b. The control valve 55 is, for example, a three-position switchable solenoid valve. When the control valve 55 is shifted from the neutral position to one position (first position) 55a, the hydraulic cylinder 8b extends, and when the control valve 55 is shifted from the neutral position to the other position (second position) 55b, the hydraulic cylinder 8b contracts. As shown in Fig. 1, the coupling device 8 is equipped with a control device (second control device) 70. The second control device 70 is composed of a CPU, electronic and electric circuits, etc. The second control device 70 outputs a control signal to the solenoid of the control valve 55 to switch the position of the control valve 55 and control the extension and retraction of the hydraulic cylinder 8b.

[0027] The second control device 70 is connected to an in-vehicle network N1 provided on the tractor 1 side. The second control device 70 is able to acquire information on the tractor 1 side, such as detection information, work vehicle position (position information), and operation information. As shown in FIG. 1, if the work device 2 is equipped with a control device (third control device) 2a, the second control device 70 is able to acquire various information (operation information) of the work device 2 transmitted from the third control device 2a via the in-vehicle network N1.

[0028] 5A and 5B are diagrams showing the state of automatic driving. 5A and 5B, the second control device 70 controls the coupling position P12 based on the traveling line L1 when the tractor 1 is automatically driven. That is, the second control device 70 changes the coupling position P12 so that the coupling position P12 coincides with the traveling line L1 during automatic driving.

[0029] Hereinafter, the control of the coupling position P12 during automatic driving of the tractor 1 will be described in detail. When performing automatic driving, the second control device 70 acquires the driving line L1 (straight section L1a, turning section L1b) via the in-vehicle network N1 before starting automatic driving. Then, when automatic driving starts, the second control device 70 estimates the position of the connecting position P12 relative to the driving line L1, and changes the connecting position P12 so that the estimated connecting position P12 coincides with the driving line L1.

[0030] 5A, in automatic driving, if the work vehicle position P10 of the tractor 1 does not match the travel line L1 (straight section L1a), the automatic driving control unit 63 controls the tractor 1 to steer to the left so that the work vehicle position P10 of the tractor 1 matches the travel line L1 (straight section L1a). Here, if control is not performed by the second control device 70 in a situation where the work vehicle position P10 of the tractor 1 matches the travel line L1 (straight section L1a), the coupling position P12 (position of the work implement 2) may not match the travel line L1.

[0031] 5B, during automatic driving, even when the work vehicle position P10 of the tractor 1 does not match the travel line L1 (turning section L1b), the automatic driving control unit 63 controls the tractor 1 to steer to the left so that the work vehicle position P10 of the tractor 1 matches the travel line L1 (turning section L1b). Here, if control is not performed by the second control device 70, the coupling position P12 (position of the work implement 2) may not match the travel line L1. In other words, during automatic driving of the tractor 1, if control is not performed by the second control device 70, the coupling position P12 (position of the work implement 2) may not match the travel line L1.

[0032] Therefore, the second control device 70, independent of the automatic driving control unit 63, controls the hydraulic cylinder 8b to extend and retract so that the position deviation ΔK1 between the connecting position P12 (position of the work device 2) and the traveling line L1 becomes zero (so as to eliminate the position deviation ΔK1). For example, as shown in Fig. 5A, if the coupling position P12 (position of the working device 2) is deviated to the left with respect to the traveling line L1, the second control device 70 outputs a signal to the control valve 55 to contract the hydraulic cylinder 8b, thereby shifting the coupling position P12 to the right and aligning it with the traveling line L1 (straight section L1a). Also, as shown in Fig. 5B, if the coupling position P12 (position of the working device 2) is deviated to the left with respect to the traveling line L1 (swivel section L1b), the second control device 70 outputs a signal to the control valve 55 to contract the hydraulic cylinder 8b, thereby shifting the coupling position P12 to the right and bringing it closer to the traveling line L1 (swivel section L1b).

[0033] The second control device 70 estimates the position of the coupling position P12 using a model (position estimation model) that estimates the position of the coupling position P12. The position estimation model is, for example, a learned model constructed by deep learning of artificial intelligence. To construct the position estimation model, past performance data from when autonomous driving was performed is used. As shown in FIG. 6, the position estimation model can be constructed by inputting performance data such as the work vehicle position P10, steering angle, steering direction, driving line L1, and coupling information (length of coupling member 8a, mounting position of coupling member 8a) from when autonomous driving was performed into various computers that perform deep learning of artificial intelligence.

[0034] When constructing the position estimation model, a positioning device capable of measuring the connection position P12 is used in advance. In this regard, the actual position of the coupling position P12 measured by the positioning device may be stored as teaching data for the coupling position P12, and the teaching data may be added to the actual data to construct a position estimation model by performing deep learning on a computer, or the coupling position P12 may be estimated by deep learning without inputting teaching data (actual position), and the method for constructing the trained model is not limited.

[0035] The coupling device 8 also includes a communication device 71 that wirelessly connects to external devices such as personal computers, mobile terminals, and servers, and an input interface 72 that wiredly connects to personal computers, mobile terminals, electronic storage media, and the like. The coupling device 8 acquires the position estimation model and the connection information by wirelessly connecting the communication device 71 to the external device. Alternatively, the coupling device 8 acquires the position estimation model and the connection information by connecting the external device to the input interface 72. When the coupling device 8 acquires the position estimation model, the acquired position estimation model and the connection information are stored in the second control device 70. The position estimation model and the connection information may also be acquired from the tractor 1 via the in-vehicle network N1.

[0036] In other words, the second control device 70 has the position estimation model and coupling information described above, and estimates the coupling position P12 by applying the work vehicle position P10, steering angle, steering direction, traveling line L1, and coupling information to the position estimation model.The second control device 70 then extends and retracts the hydraulic cylinder 8b so that the position deviation ΔK1 between the estimated coupling position P12 and the traveling line L1 during autonomous driving becomes zero, i.e., in the direction that eliminates the position deviation ΔK1.

[0037] In the above-described embodiment, control is performed to align the connecting position P12 with the traveling line L1 without taking into account the positional deviation between the work vehicle position P10 and the traveling line L1, but if the positional deviation between the work vehicle position P10 and the traveling line L1 is equal to or greater than a predetermined threshold, the hydraulic cylinder 8b may be extended or retracted in a direction that eliminates the positional deviation ΔK1. In addition, when the tractor 1 is operated automatically, the second control device 70 may acquire the current work vehicle position P10, steering angle, steering direction, and driving line L1, and perform reinforcement learning of the learned model (position estimation model) based on the acquired work vehicle position P10, steering angle, steering direction, and driving line L1.

[0038] When constructing the position estimation model, the work vehicle position P10, steering angle, steering direction, driving line L1, and connection information are used as input data, but the input data is not limited to this; for example, at least the work vehicle position P10, driving line L1, and connection information are used as input data, and the other parameters may be parameters other than the steering angle and steering direction, and are not limited to this. As described above, the second control device 70 can control the coupling position P12 (the position of the work implement 2) independently of the tractor 1 when the tractor 1 is operated automatically.

[0039] In the above-described embodiment, the coupling position P12 was changed in accordance with the automatic operation of the tractor 1, but the second control device 70 may also change the coupling position P12 based on the past driving performance of the tractor 1 and the work implement 2. The second control device 70 controls the coupling position P12 based on the driving history including the tractor work vehicle position P10 and the device position P20 of the work device 2. As shown in FIG. 7, the device position P20 of the work device 2 is the position of both ends of the work device 2 in the width direction. The device position P20 of the work device 2 can be calculated using the following first method and second method. The device position P20 of the work device 2 is calculated by the second control device 70.

[0040] As shown in Figures 1 and 7, in the first method, a positioning device 75 having the same configuration as the positioning device 40 is provided in advance on the working device 2, and a position that is a predetermined distance L11 away in the width direction from the positioning position P13 measured by the positioning device 75 can be set as the device position P20 of the working device 2. In the second method, an angle detection device capable of detecting the angle θ1 of the connecting member 8a relative to the tractor 1 is used. The connecting position P12 is determined based on the angle θ1 detected by the angle detection device and the length L12 of the connecting member 8a, and the device position P20 can be calculated by adding or subtracting the distances from the connecting position P12 to both widthwise ends of the working device 2 (distance X1 in the width direction, distance Y1 in the traveling direction). Note that the device position P20 of the working device 2 differs slightly between the first method and the second method described above, but either method may be adopted. The above-described method of calculating the device position P20 of the working device 2 is one example and is not limited thereto.

[0041] Figure 8A shows an example of data stored in the second control device 70 when the second control device 70 calculates the device position P20 using the first method while the tractor 1 is traveling, and the calculated device position P20 and work vehicle position P10 are used as travel history data. Figure 8B shows an example of data stored in the second control device 70 when the second control device 70 calculates the device position P20 using the second method while the tractor 1 is traveling, and the calculated device position P20 and work vehicle position P10 are used as travel history data.

[0042] When the tractor 1 is coupled to the work implement 2 to perform work, the second control device 70 refers to past driving records in the same field and calculates trajectories J1 and J2 between the work vehicle position P10 and the implement position P20, as shown in Figure 7. The trajectory J1 is the trajectory of the work vehicle position P10, and the trajectory J2 is the trajectory of the implement position P20. When the tractor 1 starts traveling, the second control device 70 refers to the device position P20 as shown in FIG. P The current running state of the working device 2 and the past running state of the working device 2 are monitored by calculating a past trajectory J2 from the current device position P20 and comparing the current device position P20 with the past trajectory J2.

[0043] 7, if the distance between the trajectory J2, which is the past travel record, and an obstacle 79 in the field is greater than a predetermined distance while the tractor 1 is traveling, the second control device 70 determines that the trajectory J2 is appropriate and changes the coupling position P12 so that the current device position P20 coincides with the trajectory J2. On the other hand, if the distance between the trajectory J2 and the obstacle 79 in the field is not greater than a predetermined distance, the second control device 70 determines that the trajectory J2 of the working device 2 is inappropriate for the field and changes the coupling position P12 when the tractor 1 is traveling so that it differs from the trajectory J2.

[0044] For example, in section A5 in FIG. 7 , trajectory J2 is too close to obstacle 79. Therefore, when the working implement 2 is located in section A5, the second control device 70 extends or retracts hydraulic cylinder 8b to change the position of the implement position P20 so that the implement position P20 is away from obstacle 79, as shown in trajectory J3 in section A5. Note that obstacle 79 refers to water treatment equipment (drainage pipes, water supply pipes, water supply and drainage gutters) located in the field, trees planted in the field, banks, etc., but the obstacle 79 is not limited thereto. Furthermore, obstacle 79 may be registered together with the traveling line L1 by specifying its location in the field unit 65 when creating the traveling line L1 for automatic driving, or it may be detected by an obstacle detection sensor that detects obstacles during automatic driving and the position detected by the obstacle detection sensor may be registered; the method of registering obstacles is not limited thereto.

[0045] In the above-described embodiment, the second control device 70 of the coupling device 8 changes the position of the coupling position P12 so as not to approach the obstacle 79, but the present invention is not limited to this. In the above-described embodiment, the second control device 70 acquired the work vehicle position P10 measured by the positioning device 40 via the in-vehicle network N1, etc., but the second control device 70 may also estimate the work vehicle position P10 of the tractor 1 based on the connection position P11 of the first connection part 8a1.

[0046] 1 and 9A, the coupling device 8 is equipped with a positioning device 77 that can measure the coupling position P11 of the first coupling portion 8a1. Similar to the positioning device 40, the positioning device 77 can measure the position (coupling position) P11 of the first coupling portion 8a1 using the global positioning system. When the stroke of the hydraulic cylinder 8b is fixed (when the angle θ1 of the connecting member 8a relative to the tractor 1 is fixed) and the connecting position P11 measured by the positioning device 77 changes while the tractor 1 is traveling, the second control device 70 determines that the position of the tractor 1 has changed. In other words, when the angle θ1 of the connecting member 8a is fixed while the tractor 1 is traveling, a change in the connecting position P11 can be inferred to mean that the work vehicle position of the tractor 1 has changed.

[0047] The second control device 70 estimates the position of the positioning device 40 (work vehicle position P10) by adding or subtracting the distance from the positioning device 77 to the positioning device 40 of the tractor 1 (distance X2 in the width direction and distance Y2 in the traveling direction) to the coupling position P11 determined by the positioning device 77. Even if the angle θ1 of the coupling member 8a relative to the tractor 1 changes, the second control device 70 can calculate (estimate) the position corresponding to the positioning device 40, i.e., work vehicle position P10, by correcting the distance X2 in the width direction and the distance Y2 in the traveling direction in accordance with the angle θ1.

[0048] As described above, if the coupling device 8 can estimate the work vehicle position P10 of the tractor 1, the second control device 70 can change the coupling position P12 without obtaining the work vehicle position P10 from the tractor 1. In the above-described embodiment, the position determined by the positioning device 75 was used to determine the device position P20. However, instead, as shown in Figures 1 and 9B, the device position P20 may be determined by a positioning device 78 capable of determining the connection position P12 of the second connection part 8a2.

[0049] Like the positioning device 40, the positioning device 78 is capable of measuring the position (connection position) P12 of the second connecting portion 8a2 using the global positioning system. When the stroke of the hydraulic cylinder 8b is fixed and the coupling position P12 measured by the positioning device 78 changes while the tractor 1 is traveling, the second control device 70 determines that the device position P20 of the working implement 2 has changed. In other words, when the stroke of the hydraulic cylinder 8b is fixed and the tractor 1 is traveling, a change in the coupling position P12 can be inferred to mean that the device position P20 of the working implement 2 has changed.

[0050] The second control device 70 can calculate the device position P20 by adding or subtracting the distances (distance X1 in the width direction and distance Y1 in the direction of travel) from the coupling position P12 measured by the positioning device 78 to both widthwise ends of the work device 2. If the stroke of the hydraulic cylinder 8b changes, the position corresponding to the positioning device 40, i.e., the work vehicle position P10, can be calculated (estimated) by correcting the distance X1 in the width direction and the distance Y1 in the direction of travel.

[0051] In the above-described embodiment, the connecting device 8 is a swing drawbar that does not raise or lower the working device 2, but instead, it may be a lifting device that raises or lowers the working device 2. As shown in FIG. 10, the coupling device 8 has a lift arm 108a, a lower link 108b, a top link 108c, a lift rod 108d, and a lift cylinder 108e. The front end of the lift arm 108a is supported on the upper rear part of a case (transmission case) that houses the transmission 5 so that it can swing upward or downward. The lift arm 108a swings (lifts up and down) when driven by the lift cylinder 108e. The lift cylinder 108e is made up of a hydraulic cylinder. The lift cylinder 108e is connected to a hydraulic pump via a control valve 34. The control valve 34 is an electromagnetic valve or the like, and extends and retracts the lift cylinder 108e.

[0052] The front end of the lower link 108b is supported on the rear lower part of the transmission 5 so as to be swingable upward or downward. The front end of the top link 108c is supported on the rear part of the transmission 5 above the lower link 108b so as to be swingable upward or downward. The lift arm 108a and the lower link 108b are connected to a rear portion of the lower link 108b and a rear portion of the top link 108c.

[0053] 10, at least one of the left lift rod 108d and the right lift rod 108d is configured as an extendable hydraulic cylinder. By extending or retracting the left lift rod 108d or the right lift rod 108d, which is configured as a hydraulic cylinder, while the lift cylinder 108e is not extended or retracted, the relative position between the tip of the left lower link 108b and the tip of the right lower link 108b can be adjusted. In this embodiment, the right lower link 108b is configured as a hydraulic cylinder. Naturally, the left lower link 108b may also be configured as a hydraulic cylinder.

[0054] In the above-described modified example, lower link 108b corresponds to connecting member 8a, the tip (rear end) of lower link 108b corresponds to second connecting portion 8a2, and the base end (front end) of lower link 108b corresponds to first connecting portion 8a1. For ease of explanation, the connecting position corresponding to second connecting portion 8a2 at the tip of left lower link 108b may be referred to as the "left connecting position P12a," and the connecting position corresponding to second connecting portion 8a2 at the tip of right lower link 108b may be referred to as the "right connecting position P12b."

[0055] The lift cylinder 108e and the right lift rod 108d, which is made up of a hydraulic cylinder, correspond to the hydraulic cylinder 8b. FIG. 11 shows a control block diagram of the tractor 1, the coupling device 8, and the work device 2 in the modified example. 11, the coupling device 8 includes a control valve 155A that controls the lift cylinder 108e (hydraulic cylinder 8b) and a control valve 155B that controls the right lift rod 108d (hydraulic cylinder 8b). Similar to the control valve 55 described above, the control valves 155A and 155B are, for example, three-position solenoid valves.

[0056] The second control device 70 outputs a control signal to the solenoid of the control valve 155A to extend or retract the lift cylinder 108e (hydraulic cylinder 8b). For example, when the lift cylinder 108e (hydraulic cylinder 8b) is contracted, the left and right lift rods 108d, 108d rise, and as they rise, the connecting positions P12a, P12b of the second connecting portion 8a2 also move upward. When the lift cylinder 108e (hydraulic cylinder 8b) is extended, the left and right lift rods 108d, 108d descend, and as they descend, the connecting positions P12a, P12b of the second connecting portion 8a2 also move downward.

[0057] That is, by extending or retracting the lift cylinder 108e (hydraulic cylinder 8b), the connecting positions P12a and P12b are moved in the vertical direction, and the working device 2 can be raised or lowered. The second control device 70 outputs a control signal to the solenoid of the control valve 155B to extend or retract the right lift rod 108d (hydraulic cylinder 8b). For example, when the right lift rod 108d (hydraulic cylinder 8b) is contracted, the right lift rod 108d rises, and the right coupling position P12b also moves upward as the right lift rod 108d rises. When the right lift rod 108d (hydraulic cylinder 8b) is extended, the right lift rod 108d descends, and the right coupling position P12b also moves downward as the right lift rod 108d descends.

[0058] In other words, by extending or retracting the right lift rod 108d (hydraulic cylinder 8b), the connection position P12b moves vertically, and the tilt (tilt in the width direction) of the working device 2, i.e., the posture of the working device 2 in the width direction, can be changed. Now, when the tractor 1 is traveling, the second control device 70 monitors the inclination of the working implement 2. The inclination of the working implement 2 can be grasped from a change in the left connecting position P12a. For example, For example, the second control device 70 determines that the working device 2 is kept horizontal when the left connecting position P12a in the vertical direction is the same as the right connecting position P12b in the vertical direction.

[0059] Furthermore, when the left connecting position P12a is located higher than the right connecting position P12b, the second control device 70 determines that the working device 2 is tilted to the right in the width direction (tilts downward to the right). Furthermore, when the left connecting position P12a is located lower than the right connecting position P12b, the second control device 70 determines that the working device 2 is tilted to the left in the width direction (tilts downward to the left).

[0060] Here, if the posture of the working device 2 changes by more than a threshold value, i.e., if the relative position between the left connecting position P12a and the right connecting position P12b in the vertical direction changes by more than a threshold value, the left connecting position P12a is controlled so that the posture of the working device 2 becomes less than the threshold value. In other words, when the angle at which the working implement 2 is tilted to the left or right is equal to or greater than a predetermined value (above a threshold), the second control device 70 moves the left coupling position P12a upward or downward so that it approaches the right coupling position P12b and the relative vertical position between the left coupling position P12a and the right coupling position P12b becomes less than the threshold. That is, the second control device 70 extends or contracts the right lift rod 108d (hydraulic cylinder 8b) so that the left coupling position P12a moves vertically in a direction that approaches the right coupling position P12b. Note that the left coupling position P12a of the left lift rod 108d can be detected, for example, by attaching a position detection sensor 110 (inclination sensor, acceleration sensor, etc.) to the tip of the left lift rod 108d and having the second control device 70 convert the detection value of the position detection sensor 110 into the left coupling position P12a, thereby obtaining the left coupling position P12a.

[0061] 11, the right coupling position P12b of the right lift rod 108d can be detected by, for example, attaching a stroke sensor 111 that detects the stroke of the right lift rod 108d and having the second control device 70 convert the detection value of the stroke sensor 111 into the right coupling position P12b, thereby determining the right coupling position P12b. Note that the method of calculating the left coupling position P12a and the right coupling position P12b is merely an example and is not limited thereto.

[0062] 11, the coupling device 8 may be equipped with an environmental measuring device 80 that measures the environment around the tractor 1 or the work implement 2. The environmental measuring device 80 is a device that measures wind speed, wind direction, temperature, etc. The second control device 70 changes the left coupling position P12a and the right coupling position P12b of the coupling device 8 based on at least the environmental information (wind speed, wind direction, temperature) measured by the environmental measuring device 80.

[0063] The second control device 70 has a task optimization model for determining the optimal task in response to changes in the environment. The task optimization model is a trained model constructed using deep learning artificial intelligence. Task data from previous tasks is used to construct the task optimization model. The task optimization model can be constructed by inputting task data, such as environmental information (wind speed, wind direction, temperature) from when the task was performed, the attitude of the work device 2 (left coupled position P12a, right coupled position 12b), the height of the work device 2 (stroke of the lift cylinder 108e), and the type of work device 2, into various computers that perform deep learning artificial intelligence.

[0064] 11, the height of the work implement 2 can be obtained by attaching a stroke sensor 112 that detects the stroke of the lift cylinder 108e and having the second control device 70 convert the detected value of the stroke sensor 112 into the height of the work implement 2. The type of work implement 2 can be obtained from either an external device, the tractor 1, or the work implement 2. When the tractor 1 is performing work, the second control device 70 receives environmental information measured by the environmental measurement device 80, the posture of the work implement 2 (left coupling position P12a, right coupling position P12b), the working position, and the like. The height of the work device 2 (stroke of the lift cylinder 108e) and the type of work device 2 are applied to the work optimization model.

[0065] When the second control device 70 obtains the results determined by the task optimization model, i.e., the posture and height of the task device 2 for performing the optimal task, it changes the posture and height of the task device 2 so that they match the results determined by the task optimization model. For example, if the task device 2 is a fertilizer spreader, pesticide spreader, or seed spreader, it can perform optimal spraying work in response to wind speed and wind direction. Also, if the task device 2 is a harvester, spreader, grass collector, or shaping device, and the task device 2 is tilted due to the slope of the field, it can correct the tilt of the task device 2 to the optimal tilt regardless of the slope of the field and perform the task.

[0066] In the above-described embodiment, the coupling device 8 has been described as changing the coupling position P12, P12a, 12b of the second coupling portion 8a2, but instead, as shown in Fig. 4B, if the coupling position P11 of the first coupling portion 8a1 is changeable, the coupling device 8 may change the position of the coupling position P11 of the first coupling portion 8a1. That is, by replacing the coupling position P12 in the above-described embodiment with the coupling position P11, the second control device 70 can change the position of the coupling position P11 in accordance with automatic driving and driving history.

[0067] The coupling device 8 comprises a first coupling part 8a1 that couples to the travellable work vehicle 1, a second coupling part 8a2 that couples to the working implement 2, an actuator 8b that can change the coupling position of either the first coupling part 8a1 or the second coupling part 8a2, and a control device (second control device) 70 that controls the actuator 8b. By controlling the actuator 8b with the control device (second control device) 70 to change the coupling position P11, P12 of either the first coupling part 8a1 or the second coupling part 8a2, the position of the working implement 2 relative to the work vehicle 1 can be changed independently of the work vehicle 1.

[0068] The coupling device 8 controls coupling positions P11, P12 based on the travel line L1 of the work vehicle 1. This makes it possible to position the work implement 2 along the travel line L1, for example, when performing automatic driving or automatic steering along the travel line L1. In other words, regardless of whether the work vehicle 1 is aligned with the travel line L1, the work implement 2 can be aligned along the travel line L1, and work can be performed along the travel line L1.

[0069] The coupling device 8 changes the coupling positions P11, P12 so that the coupling positions P11, P12 coincide with the traveling line L1. This allows the working device 2 to be aligned with the traveling line L1, and allows work to be performed along the traveling line L1. The coupling device 8 controls the coupling positions P11, P12 based on the work vehicle position P10 of the work vehicle 1 and the travel line L1 of the work vehicle 1. Furthermore, if the deviation between the work vehicle position P10 and the travel line L1 is equal to or greater than a threshold value, the coupling device 8 changes the coupling positions P11, P12 in a direction that eliminates the deviation. This makes it possible to move at least the work device 2 closer to the travel line L1 when the work vehicle position P10 of the work vehicle 1 deviates from the travel line L1 (the deviation is equal to or greater than the threshold value).

[0070] If the attitude of the working implement 2 changes by more than a threshold value while the work vehicle 1 is traveling, the coupling positions P11 and P12 are controlled so that the attitude becomes less than the threshold value. This allows the attitude of the working implement 2 to be kept constant, allowing work to be performed in a stable attitude. The coupling device 8 controls the coupling positions P11, P12 based on the travel history including the work vehicle position P10 of the work vehicle 1 and the device position P20 of the work device 2. In this way, the past travel history including the work vehicle position P10 of the work vehicle 1 and the device position P20 of the work device 2 and the current The positions of the work vehicle 1 and the work implement 2 (connection positions P11, P12) can be changed while comparing the work vehicle position P10 and the implement position P20 of the work implement 2, thereby improving the accuracy of work in the same field.

[0071] The coupling device 8 calculates the trajectory J2 of the device position P20 based on the driving record, and if the trajectory J2 is appropriate for the field, changes the coupling positions P11, P12 when the work vehicle 1 is driving so that they match the trajectory J2, and if the trajectory J2 is inappropriate for the field, changes the coupling positions P11, P12 when the work vehicle 1 is driving so that they differ from the trajectory J2. Thus, when the work vehicle 1 drives while towing the work device 2, if the past driving record shows good driving (proper driving), the vehicle can drive in the same way as the past driving record, and if the past driving record shows poor driving (inappropriate driving), the vehicle can drive while correcting the driving to be better than the past driving record.

[0072] The coupling device 8 controls coupling positions P11, P12 based on the environment around the work vehicle 1 or the work implement 2. This allows for spraying work to be performed in a manner suited to the environment, for example, if the work implement 2 is a spraying type work implement 2. The coupling device 8 estimates the work vehicle position P10 of the work vehicle 1 based on the coupling positions P11, P12 of the first coupling part 8a1. In this way, the work vehicle position P10 can be obtained even if the coupling device 8 does not acquire the work vehicle position P10 from the work vehicle 1, and the coupling positions P11, P12 can be adjusted, for example, taking into account the estimated work vehicle position P10.

[0073] The connecting device 8 estimates the device position P20 of the working device 2 based on the connecting positions P11, P12 of the second connecting part 8a2. This allows the connecting device 8 to obtain the device position P20 without acquiring it from the working device 2, and for example, the connecting positions P11, P12 can be adjusted taking into account the ascertained device position P20. The coupling device 8 has a global positioning system, which allows the position of the coupling device 8 to be ascertained independently of the work vehicle 1 and the work device 2.

[0074] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0075] 1: Work vehicle (tractor) 2: Work equipment 8:Coupling device 8a1: 1st connection part 8a2: 2nd connection part 8b: Actuator 20:Device position J1: Orbit J2: Orbit J3: Orbit L1: Driving line P10: Work vehicle position P11: Connection position P12: Connection position P12a: Connection position P12b: Connection position P20:Device position

Claims

1. A control method for a coupling device that couples a work vehicle and a work implement, comprising: The coupling device is A connecting member; a first connecting portion provided at one end of the connecting member, the first connecting portion being swingably supported by a bracket of the work vehicle at a connecting position where the first connecting portion is connected to the work vehicle; a second connecting portion provided at the other end of the connecting member, the second connecting portion being pivotally supported by a bracket of the working device at a connecting position where the second connecting portion is connected to the working device; an actuator capable of changing the connection position of the second connection portion in a swing direction by swinging the connection member around the first connection portion as an axis, a control device that calculates past travel records of the working device including the device position of the working device, and controls the actuator to change the connection position of the second connection part so that the device position of the working device matches the route of the past travel records of the working device.

2. 2. The control method for a coupling device according to claim 1, wherein the control device determines whether the route in the travel history is appropriate, and determines that the route in the travel history is appropriate if a distance between the route in the travel history and an obstacle in the field is equal to or greater than a predetermined value, and if the route in the travel history is appropriate, changes the coupling position of the second coupling part so that the device position of the work device matches the route in the travel history.

3. 3. The control method for a coupling device according to claim 2, wherein the control device determines that the route of the travel history is inappropriate when a distance between the route of the travel history and an obstacle in the field is less than a predetermined value, and changes the coupling position of the second coupling part so that it is different from the route of the travel history.

4. At least one of the work vehicle, the work device, and the coupling device has a positioning device, The control device calculates the device position based on the position measured by the positioning device, and changes the connection position of the second connection part so that the calculated device position matches the route of the driving history.

5. The control device determines the device position based on the angle of the coupling device relative to the work vehicle. and changing the coupling position of the second coupling part so that the calculated device position coincides with the route of the travel history.

6. The control method for a coupling device according to any one of claims 1 to 3, wherein the control device acquires a position estimation model and coupling information via communication, and estimates the coupling position of the second coupling part.

7. 7. The coupling device control method according to claim 1, wherein the control device is capable of acquiring operation information of the working device from the working device via an in-vehicle network.

8. The coupling device includes a pair of lower links, a pair of lift rods, and a pair of lift cylinders, the pair of lower links each correspond to the connecting member, a pair of lower links each having a front end supported so as to be swingable up and down relative to the work vehicle, a rear end connected to the work device, and each lifted and lowered by driving the pair of lift cylinders; 8. The method for controlling a coupling device according to claim 1, wherein the control device extends or retracts at least one of the pair of lift rods, thereby raising or lowering a corresponding lower link of the pair of lower links, thereby changing the attitude of the working device.

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