Automated driving method, automated driving system, and automated driving program

Abstract

To provide an automatic traveling method, an automatic traveling system and an automatic traveling program capable of improving accuracy of the azimuth angle of a work vehicle.SOLUTION: An acquisition processing part 112 acquires a measurement azimuth angle D0 measured by an inertial measurement device 165 for measuring the azimuth angle of a work vehicle 10. An adjustment processing part 115 adjusts weight corresponding to the measurement azimuth angle D0 on the basis of vehicle speed Vf of the work vehicle 10. An estimation processing part 116 estimates an azimuth angle D1 corresponding to a present attitude of the work vehicle 10, on the basis of the measurement azimuth angle D0 with the weight adjusted by the adjustment processing part 115, positional information of the work vehicle 10, and angle speed information of the vehicle 10. A traveling processing part 111 allows automatic traveling of the work vehicle 10 on the basis of the azimuth angle D1 estimated by the estimation processing part 116.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to an automatic driving method, an automatic driving system, and an automatic driving program that can automatically drive a work vehicle.

Background Art

[0002] There is known a work vehicle that performs automatic driving by traveling on a preset target path based on the position information of the work vehicle. For example, there is known a technique of setting a forward target point on the target path and performing steering control so that the work vehicle heads toward the forward target point based on the azimuth angle of the work vehicle, thereby automatically driving the work vehicle along the target path (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, as a device for calculating the azimuth angle of a work vehicle, there are an azimuth sensor, an inertial measurement device, and the like. Since the inertial measurement device measures the orientation of the vehicle body using a three-axis gyro sensor and a three-axis acceleration sensor, when the work vehicle travels at a low speed, the output values obtained from each sensor become small. For this reason, there arises a problem that the accuracy of the azimuth angle of the work vehicle decreases and the traveling accuracy decreases.

[0005] An object of the present invention is to provide an automatic driving method, an automatic driving system, and an automatic driving program capable of improving the accuracy of the azimuth angle of a work vehicle.

Means for Solving the Problems

[0006] The automatic driving method according to the present invention is an automatic driving method that performs the following: acquiring a measured azimuth angle measured by a measuring unit that measures the azimuth angle of a work vehicle; adjusting a weight corresponding to the measured azimuth angle based on the vehicle speed of the work vehicle; estimating an azimuth angle corresponding to the current attitude of the work vehicle based on the measured azimuth angle whose weight has been adjusted according to the vehicle speed, the position information of the work vehicle, and the angular velocity information of the work vehicle; and automatically driving the work vehicle based on the estimated azimuth angle.

[0007] Furthermore, the automatic driving method according to the present invention is an automatic driving method that performs the following: acquiring a measured azimuth angle measured by a measuring unit that measures the azimuth angle of a work vehicle; estimating an azimuth angle corresponding to the current posture of the work vehicle based on the measured azimuth angle, the position information of the work vehicle, and the angular velocity information of the work vehicle; selecting either the measured azimuth angle or the estimated azimuth angle as the output azimuth angle based on the vehicle speed of the work vehicle; and automatically driving the work vehicle based on the output azimuth angle.

[0008] The automated driving system according to the present invention comprises an acquisition processing unit, an estimation processing unit, and a driving processing unit. The acquisition processing unit acquires a measured azimuth angle measured by a measuring unit that measures the azimuth angle of a work vehicle. The estimation processing unit adjusts a weight corresponding to the measured azimuth angle acquired by the acquisition processing unit based on the vehicle speed of the work vehicle, and estimates an azimuth angle corresponding to the current attitude of the work vehicle based on the weighted measured azimuth angle, the position information of the work vehicle, and the angular velocity information of the work vehicle. The driving processing unit drives the work vehicle automatically based on the azimuth angle estimated by the estimation processing unit.

[0009] The automatic driving program according to the present invention is an automatic driving program that causes one or more processors to perform the following actions: acquire a measured azimuth angle measured by a measuring unit that measures the azimuth angle of a work vehicle; adjust a weight corresponding to the measured azimuth angle based on the vehicle speed of the work vehicle; estimate an azimuth angle corresponding to the current attitude of the work vehicle based on the measured azimuth angle whose weight has been adjusted according to the vehicle speed, the position information of the work vehicle, and the angular velocity information of the work vehicle; and automatically drive the work vehicle based on the estimated azimuth angle. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide an automated driving method, an automated driving system, and an automated driving program that can improve the accuracy of the azimuth angle of a work vehicle. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a block diagram showing the configuration of an automated driving system according to Embodiment 1 of the present invention. [Figure 2] Figure 2 is an external view showing an example of a work vehicle according to an embodiment of the present invention. [Figure 3] Figure 3 shows an example of a target route for a work vehicle according to an embodiment of the present invention. [Figure 4] Figure 4 shows an example of the driving state of a work vehicle according to an embodiment of the present invention. [Figure 5] Figure 5 is a block diagram showing the specific configuration of a vehicle control device according to Embodiment 1 of the present invention. [Figure 6] Figure 6 shows an example of a method for determining the estimated target section in a vehicle control device according to an embodiment of the present invention. [Figure 7] Figure 7 is a graph showing an example of a method for adjusting parameters in a vehicle control device according to Embodiment 1 of the present invention. [Figure 8] Figure 8 is a block diagram showing another configuration of the vehicle control device according to Embodiment 1 of the present invention. [Figure 9]FIG. 9 is a flowchart showing an example of the procedure of the automatic driving process executed by the automatic driving system according to Embodiment 1 of the present invention. [Figure 10] FIG. 10 is a block diagram showing the configuration of the automatic driving system according to Embodiment 2 of the present invention. [Figure 11] FIG. 11 is a block diagram showing the specific configuration of the vehicle control device according to Embodiment 2 of the present invention. [Figure 12] FIG. 12 is a graph showing an example of a method for determining the azimuth angle in the vehicle control device according to Embodiment 2 of the present invention. [Figure 13A] FIG. 13A is a diagram showing another example of a method for determining an estimation target section in the vehicle control device according to an embodiment of the present invention. [Figure 13B] FIG. 13B is a diagram showing another example of a method for determining an estimation target section in the vehicle control device according to an embodiment of the present invention. [Figure 14A] FIG. 14A is a diagram showing another example of a method for resetting an estimated value in the vehicle control device according to an embodiment of the present invention. [Figure 14B] FIG. 14B is a diagram showing another example of a method for resetting an estimated value in the vehicle control device according to an embodiment of the present invention. [Figure 14C] FIG. 14C is a diagram showing another example of a method for resetting an estimated value in the vehicle control device according to an embodiment of the present invention. Embodiments for Carrying Out the Invention

[0012] The following embodiments are an example of embodying the present invention and do not limit the technical scope of the present invention.

[0013] [Embodiment 1] As shown in FIG. 1, the automatic driving system 1 according to Embodiment 1 of the present invention includes a work vehicle 10 and an operation terminal 20. The work vehicle 10 and the operation terminal 20 can communicate via a communication network N1. For example, the work vehicle 10 and the operation terminal 20 can communicate via a mobile phone line network, a packet line network, or a wireless LAN. The automatic driving system 1 is a system that automatically drives the work vehicle 10 in the farm field F.

[0014] In this embodiment, the case where the work vehicle 10 is a tractor will be described as an example. As another embodiment, the work vehicle 10 may be a rice transplanter, a combine, a construction machine, a snow removal vehicle, or the like. The work vehicle 10 is configured to be able to automatically drive (autonomously drive) in the farm field F (see FIG. 3) according to a preset target route R. Note that the work vehicle 10 can perform a predetermined operation while automatically driving in the farm field F.

[0015] The work vehicle 10 automatically drives according to the target route R generated in advance for the farm field F based on the position information of the current position of the work vehicle 10 calculated by the positioning unit 16. The target route R includes a work route (straight travel route R1) (the solid line part in FIG. 3) where the work implement 14 performs work and a non-work route (turning route R2) (the dotted line part in FIG. 3) where the work implement 14 does not perform work, and includes a plurality of straight travel routes R1 and a plurality of turning routes R2 from the work start position S to the work end position G. The target route R shown in FIG. 3 indicates the route for the work vehicle 10 to automatically drive on each of the straight travel route R1 and the turning route R2.

[0016] For example, in the farm field F shown in FIG. 3, the work vehicle 10 reciprocates parallel to a plurality of straight travel routes R1 from the work start position S to the work end position G, and the work implement 14 performs work on each straight travel route R1. The target route R is not limited to the route shown in FIG. 3 and is appropriately set according to the work content.

[0017] The work vehicle 10 may be a vehicle that automatically travels along the target route R with an operator on board, or it may only automatically travel along a straight route. For example, the operator may be on board the work vehicle 10 and operate it while switching between automatic travel (automatic steering) along the straight route R1 and manual travel (manual steering) along the turning route R2. Alternatively, the operator may be on board the work vehicle 10 and operate it to change the vehicle speed (travel speed) (accelerator operation, brake operation, etc.) while automatically traveling along the target route R or a part of the target route R (for example, the straight route R1). Furthermore, the work vehicle 10 may automatically travel along the target route R while controlling its speed according to vehicle speed information set for each work route. In addition, the work vehicle 10 may automatically travel along the target route R without an operator on board.

[0018] The operation terminal 20 displays various information related to the work performed by the work vehicle 10 on its display unit, and receives operator input and executes processing corresponding to that input. For example, the operator can operate the operation terminal 20 to set information necessary for automatic driving or to output a work start instruction (or automatic driving start instruction) to the work vehicle 10. The operation terminal 20 also displays information such as the work status and driving status of the work vehicle 10 while it is automatically driving. The operator can understand the work status and driving status using the operation terminal 20. The operation terminal 20 is, for example, a portable terminal (such as a tablet) that the operator can carry and is a device that can be attached to and detached from the work vehicle 10. Alternatively, the operation terminal 20 may be a device fixed to the work vehicle 10.

[0019] [Work Vehicle 10] As shown in Figures 1 and 2, the work vehicle 10 includes a vehicle control device 11, a storage unit 12, a running device 13, a work machine 14, a communication unit 15, a positioning unit 16, and the like. The vehicle control device 11 is electrically connected to the storage unit 12, the running device 13, the work machine 14, the positioning unit 16, and the like. The vehicle control device 11 and the positioning unit 16 may also be capable of wireless communication.

[0020] The communication unit 15 is a communication interface for connecting the work vehicle 10 to the communication network N1 by wire or wireless connection and for performing data communication with external devices such as the operation terminal 20 via the communication network N1 in accordance with a predetermined communication protocol.

[0021] The storage unit 12 is a non-volatile storage unit such as an HDD (Hard Disk Drive) or SSD (Solid State Drive) that stores various types of information. The storage unit 12 stores control programs such as an automatic driving program that causes the vehicle control device 11 to execute the automatic driving process described later (see Figure 9). For example, the automatic driving program is non-temporarily recorded on a computer-readable recording medium such as a flash ROM, EEPROM, CD, or DVD, and is read by a predetermined reading device (not shown) and stored in the storage unit 12. The automatic driving program may also be downloaded from a server (not shown) to the work vehicle 10 via a communication network N1 and stored in the storage unit 12. The storage unit 12 may also store route data of the target route R generated at the operation terminal 20.

[0022] The running gear 13 is the drive unit that moves the work vehicle 10. As shown in Figure 2, the running gear 13 includes an engine 131, front wheels 132, rear wheels 133, transmission 134, front axle 135, rear axle 136, steering wheel 137, etc. The front wheels 132 and rear wheels 133 are provided on the left and right sides of the work vehicle 10, respectively. Furthermore, the running gear 13 is not limited to a wheel type with front wheels 132 and rear wheels 133, but may also be a crawler type with crawlers provided on the left and right sides of the work vehicle 10.

[0023] The engine 131 is a power source such as a diesel engine or gasoline engine that is driven using fuel supplied to a fuel tank (not shown). The running gear 13 may be equipped with an electric motor as a power source together with the engine 131, or in place of the engine 131. A generator (not shown) is connected to the engine 131, and power is supplied from the generator to electrical components such as the vehicle control device 11 and the battery installed on the work vehicle 10. The battery is charged by the power supplied from the generator. The vehicle control device 11 and electrical components such as the positioning unit 16 installed on the work vehicle 10 can be driven by the power supplied from the battery even after the engine 131 is stopped.

[0024] The driving force of the engine 131 is transmitted to the front wheels 132 via the transmission 134 and front axle 135, and to the rear wheels 133 via the transmission 134 and rear axle 136. The driving force of the engine 131 is also transmitted to the work equipment 14 via the PTO shaft (not shown). When the work vehicle 10 is driving automatically, the travel device 13 performs driving operations according to the commands of the vehicle control device 11.

[0025] The implement 14 may be, for example, a tiller, a ditch digger, a grass cutter, a plow, a fertilizer spreader, a seed planter, or a spreader, and may be detachable from the work vehicle 10. This allows the work vehicle 10 to perform various tasks using each of the implements 14. Figure 2 shows a tiller as an example of an implement 14.

[0026] The steering wheel 137 is an operating unit operated by an operator or a vehicle control device 11. For example, in the travel device 13, the angle of the front wheels 132 is changed by a hydraulic power steering mechanism (not shown) or the like in response to the operation of the steering wheel 137 by the vehicle control device 11, thereby changing the direction of travel of the work vehicle 10.

[0027] In addition to the steering wheel 137, the running gear 13 is equipped with a shift lever (not shown), accelerator, brakes, etc., which are operated by the vehicle control device 11. In the running gear 13, the gears of the transmission 134 are switched to forward gear or reverse gear, etc., in response to the operation of the shift lever by the vehicle control device 11, and the driving mode of the work vehicle 10 is switched to forward or reverse, etc. The vehicle control device 11 also controls the rotational speed of the engine 131 by operating the accelerator. The vehicle control device 11 also controls the rotation of the front wheels 132 and rear wheels 133 using electromagnetic brakes by operating the brakes.

[0028] The positioning unit 16 is a communication device that includes a positioning control unit 161, a memory unit 162, a communication unit 163, a positioning antenna 164, and an inertial measurement unit 165 (IMU). For example, as shown in Figure 2, the positioning unit 16 is installed on top of the cabin 138 where the operator sits. However, the installation location of the positioning unit 16 is not limited to the cabin 138. Furthermore, the positioning control unit 161, memory unit 162, communication unit 163, positioning antenna 164, and inertial measurement unit 165 of the positioning unit 16 may be distributed and arranged at different locations on the work vehicle 10. As mentioned above, the positioning unit 16 is connected to the battery, and the positioning unit 16 can operate even when the engine 131 is stopped. In addition, the positioning unit 16 may be replaced with, for example, a mobile phone terminal, a smartphone, or a tablet terminal.

[0029] The positioning control unit 161 is a computer system comprising one or more processors and storage memory such as non-volatile memory and RAM. The storage unit 162 is a non-volatile memory that stores a program for causing the positioning control unit 161 to perform positioning processing, and data such as positioning information and movement information. For example, the program is non-temporarily recorded on a computer-readable recording medium such as flash ROM, EEPROM, CD, or DVD, and is read by a predetermined reading device (not shown) and stored in the storage unit 162. Alternatively, the program may be downloaded from a server (not shown) to the positioning unit 16 via a communication network N1 and stored in the storage unit 162.

[0030] The communication unit 163 is a communication interface that connects the positioning unit 16 to the communication network N1 by wire or wireless connection and performs data communication with external devices such as base stations (not shown) via the communication network N1 in accordance with a predetermined communication protocol. The positioning antenna 164 is an antenna that receives radio waves (GNSS signals) transmitted from satellites.

[0031] The positioning control unit 161 calculates the current position of the work vehicle 10 based on the GNSS signals received by the positioning antenna 164 from satellites. For example, when the work vehicle 10 is automatically driving in field F, the positioning antenna 164 receives radio waves (transmission time, orbital information, etc.) transmitted from each of several satellites. The positioning control unit 161 then calculates the distance between the positioning antenna 164 and each satellite, and calculates the current position (latitude and longitude) of the work vehicle 10 based on the calculated distance. Alternatively, the positioning control unit 161 may perform positioning using a real-time kinematic method (RTK-GPS positioning method (RTK method)) which calculates the current position of the work vehicle 10 using correction information corresponding to a base station (reference station) close to the work vehicle 10. In this way, the work vehicle 10 automatically drives using positioning information obtained using the RTK method. The current position of the work vehicle 10 may be the same as the positioning position (for example, the position of the positioning antenna 164), or it may be a position shifted from the positioning position.

[0032] The inertial measurement device 165 is equipped with a 3-axis gyro sensor, a 3-axis accelerometer, and the like, and measures the attitude of the work vehicle 10 while it is in motion. For example, the inertial measurement device 165 measures the azimuth angle of the work vehicle 10. The inertial measurement device 165 also measures the azimuth angle of the work vehicle 10 while it is automatically moving and transmits the measurement result (measured azimuth angle D0) to the vehicle control device 11 (see Figure 5). The inertial measurement device 165 is an example of a measurement unit of the present invention.

[0033] The vehicle control device 11 includes control devices such as a CPU, ROM, and RAM. The CPU is a processor that performs various arithmetic operations. The ROM is a non-volatile memory unit that stores control programs such as a BIOS and OS in advance to allow the CPU to perform various arithmetic operations. The RAM is a volatile or non-volatile memory unit that stores various information and is used as a temporary memory (work area) for the various processes performed by the CPU. The vehicle control device 11 controls the work vehicle 10 by executing various control programs stored in advance in the ROM or memory unit 12 using the CPU.

[0034] Specifically, as shown in Figure 1, the vehicle control device 11 includes various processing units such as a driving processing unit 111, an acquisition processing unit 112, a section determination processing unit 113, a reset determination processing unit 114, an adjustment processing unit 115, an estimation processing unit 116, and an output processing unit 117. The vehicle control device 11 functions as these various processing units by executing various processes according to the automatic driving program using the CPU. Some or all of these processing units may be composed of electronic circuits. The automatic driving program may be a program that causes multiple processors to function as processing units.

[0035] The driving processing unit 111 controls the movement of the work vehicle 10. Specifically, the driving processing unit 111 makes the work vehicle 10 automatically move along the target route R based on position information indicating the current position of the work vehicle 10, which is determined by the positioning control unit 161. For example, when the positioning state becomes RTK positioning capable and the operator presses the start button on the operation screen (not shown) of the operation terminal 20, the operation terminal 20 outputs a work start instruction to the work vehicle 10. When the driving processing unit 111 receives the work start instruction from the operation terminal 20, it starts the automatic movement of the work vehicle 10 based on position information indicating the current position of the work vehicle 10, which is determined by the positioning control unit 161.

[0036] Furthermore, the driving processing unit 111 controls the direction of travel of the work vehicle 10 by controlling the steering angle (steering angle) of the work vehicle 10. Figure 4 shows an example of the driving state of the work vehicle 10. In the state shown in Figure 4, the current position P0 of the work vehicle 10 is a distance L1 from the target path R. The symbol α1 indicates the current azimuth angle with respect to the target path R, and the symbol θ1 indicates the current steering angle. Here, if a target point P1 (forward target point) is set in front of the work vehicle 10 and on the target path R, and the target azimuth angle of the work vehicle 10 is α2, then the target steering angle θ of the work vehicle 10 is expressed as "α1 + θ1 + α2". The driving processing unit 111 calculates the target steering angle θ based on the current position P0 (position information) measured by the positioning control unit 161, the target azimuth angle α2 obtained from the current position P0 and target point P1, the current azimuth angle α1, and the current steering angle θ1. The driving processing unit 111 then controls the steering angle of the work vehicle 10 based on the target steering angle θ to control the direction of travel of the work vehicle 10.

[0037] As described above, the driving processing unit 111 automatically drives the work vehicle 10 along the target route R based on the position information and the target steering angle θ. As a result, the work vehicle 10 performs work with the work implement 14 while automatically driving along the target route R. The target route R is generated, for example, by the operation terminal 20. The work vehicle 10 obtains route data for the target route R from the operation terminal 20 and automatically drives within the field F along the target route R (see Figure 3).

[0038] Furthermore, when the driving processing unit 111 receives a work stop instruction from the operation terminal 20, it stops the automatic driving of the work vehicle 10. For example, when an operator presses the stop button on the operation screen (not shown) of the operation terminal 20, the operation terminal 20 outputs a work stop instruction to the work vehicle 10. When the driving processing unit 111 receives the work stop instruction from the operation terminal 20, it stops the automatic driving of the work vehicle 10. As a result, the work vehicle 10 stops automatic driving and stops the work performed by the work machine 14. The driving processing unit 111 is an example of the driving processing unit of the present invention.

[0039] As described above, in order to automatically drive the work vehicle 10 according to the target path R, it is necessary to measure the current azimuth angle of the work vehicle 10 with high precision and control the steering angle. However, with conventional technology, when the work vehicle 10 is traveling at low speed, the accuracy of the azimuth angle of the work vehicle 10 decreases (the azimuth angle drifts), which reduces the driving accuracy of the work vehicle 10. In contrast, the automatic driving system according to this embodiment can improve the accuracy of the azimuth angle of the work vehicle, as shown below. A specific example of the vehicle control device 11 will be described below with reference to Figure 5.

[0040] The acquisition processing unit 112 acquires the azimuth angle (hereinafter referred to as the measured azimuth angle D0) measured by the inertial measuring device 165, which measures the azimuth angle of the work vehicle 10. When the automatic driving of the work vehicle 10 starts, the inertial measuring device 165 measures the measured azimuth angle D0 at a predetermined period and transmits it to the vehicle control device 11. The acquisition processing unit 112 acquires the measured azimuth angle D0 from the inertial measuring device 165 at a predetermined period. As shown in Figure 5, the acquisition processing unit 112 outputs the information of the measured azimuth angle D0 acquired from the inertial measuring device 165 to the estimation processing unit 116 and the output processing unit 117. The acquisition processing unit 112 is an example of the acquisition processing unit of the present invention.

[0041] The section determination processing unit 113 determines whether the travel path (travel section) of the work vehicle 10 is an estimation target section for estimating the azimuth angle. Specifically, the section determination processing unit 113 determines whether the travel path is an estimation target section based on the route information d0.

[0042] Here, for example, the vehicle speed Vf of the work vehicle 10 is set to a low speed (e.g., 1 km / h) on the straight-ahead path R1 where high work accuracy is required, and to a high speed (e.g., 2 km / h) on the turning path R2 where no work is performed. In this case, as shown in Figure 6, the section determination processing unit 113 determines that the travel path is the target section for estimation when it is the straight-ahead path R1, and determines that it is not the target section for estimation when it is the turning path R2. As shown in Figure 5, the section determination processing unit 113 outputs a determination result d1 indicating that the travel path of the work vehicle 10 is the target section for azimuth angle estimation, or that the travel path of the work vehicle 10 is not the target section for azimuth angle estimation, to the reset determination processing unit 114 and the output processing unit 117.

[0043] The reset determination processing unit 114 determines whether or not to reset the estimated value in the estimation processing unit 116, which estimates the azimuth angle (current azimuth angle) of the work vehicle 10. Specifically, the reset determination processing unit 114 determines whether or not to reset the cumulative error of the estimated value (attitude state) of the Kalman filter KF, which estimates the azimuth angle D1 of the work vehicle 10. For example, as shown in Figure 5, the reset determination processing unit 114 determines whether or not to reset the estimated value based on the determination result d1 of the section determination processing unit 113, the reset determination information d2, and the vehicle speed Vf of the work vehicle 10. The reset determination information d2 is information that defines the timing for resetting the estimated value, and for example, as shown in Figure 6, it is information that indicates the starting point Rp of the straight-line route R1 (the estimated target section). Note that the reset determination information d2 may be information determined according to the method of setting the starting point Rp (location information, information indicating the automatic driving state, route information, etc.).

[0044] For example, the reset determination processing unit 114 determines to reset the estimated value when the work vehicle 10 is located at the starting point Rp of the straight path R1 and the vehicle speed Vf is less than or equal to a predetermined vehicle speed (e.g., 2 km / h). As shown in Figure 5, the reset determination processing unit 114 outputs a determination result Rf to the estimation processing unit 116 indicating whether to reset the estimated value in the estimation processing unit 116 or not.

[0045] The adjustment processing unit 115 sets information (parameter Pf) for adjusting the weight corresponding to the measured azimuth angle D0 based on the vehicle speed Vf of the work vehicle 10 and outputs it to the estimation processing unit 116. Specifically, the adjustment processing unit 115 adjusts the parameter Pf used in the azimuth angle estimation process in the estimation processing unit 116 according to the vehicle speed Vf of the work vehicle 10. The adjustment processing unit 115 outputs the adjusted parameter Pf to the estimation processing unit 116. Parameter Pf is, for example, the variance in the observation of the azimuth angle in the Kalman filter KF of the estimation processing unit 116, and corresponds to the Kalman gain parameter. Specific examples of parameter Pf will be described later.

[0046] The estimation processing unit 116 estimates the azimuth angle D1 (current azimuth angle α1 in Figure 4) corresponding to the current attitude of the work vehicle 10. Specifically, the estimation processing unit 116 is composed of a Kalman filter KF, which estimates the azimuth angle D1 of the work vehicle 10 based on the determination result Rf of the reset determination processing unit 114, the parameter Pf set in the adjustment processing unit 115, position information f1, angular velocity information f2, and the measured azimuth angle D0 obtained from the acquisition processing unit 112. Position information f1 is information indicating the position of the work vehicle 10 as measured by the positioning control unit 161 (positioning information). Angular velocity information f2 is information on the angular velocity of the work vehicle 10 as measured by the inertial measuring device 165. Note that the angular velocity information f2 may also include acceleration information of the work vehicle 10. The Kalman filter KF calculates state estimates (azimuth angles) that indicate the attitude state of the work vehicle 10, including roll angle, pitch angle, and yaw angle, based on position information f1 and angular velocity information f2.

[0047] Also, the Kalman filter KF calculates a state estimate value (azimuth angle) based on the state estimated by the estimation model and the state estimated by the observed value (measured azimuth angle D0). Further, the Kalman filter KF adjusts the weight of the state estimated by the estimation model and the weight of the state estimated by the observed value (measured azimuth angle D0) with a parameter Pf corresponding to the vehicle speed Vf to estimate the azimuth angle. For example, when the estimated value estimated by the estimation model is set as x1(k) and the estimated value estimated by the observed value (measured azimuth angle D0) is set as x2(k), the Kalman filter KF can obtain the estimated value x(k) by the formula "x(k)=K·x1(k)+(1-K)·x2(k)". The coefficient K (where 0<K<1) in the above formula corresponds to the parameter Pf. As shown in the above formula, the smaller the parameter Pf (coefficient K), the larger the weight of the state (x2(k)) estimated by the observed value (measured azimuth angle D0), and the more dominant the measured azimuth angle D0 becomes. Also, the larger the parameter Pf, the larger the weight of the state (x1(k)) estimated by the estimation model, and the less dominant the measured azimuth angle D0 becomes.

[0048] Also, the Kalman filter KF calculates the azimuth angle D1 based on a parameter (weight) set according to the vehicle speed Vf of the work vehicle 10. For example, as shown in FIG. 7, when the vehicle speed Vf is 2 km / h (the first vehicle speed of the present invention) or more, the adjustment processing unit 115 sets the parameter Pf to "Pf1" (the first parameter of the present invention). That is, when the vehicle speed Vf is 2 km / h or more, the adjustment processing unit 115 sets the parameter Pf1 (the parameter Pf1 in which the measured azimuth angle D0 becomes dominant in the estimation result of the azimuth angle) in which the weight of the state (x2(k)) estimated by the measured azimuth angle D0 increases and the weight of the state (x1(k)) estimated by the estimation model decreases.

[0049] Further, when the vehicle speed Vf is 1 km / h (the second vehicle speed of the present invention) or less, the adjustment processing unit 115 sets the parameter Pf to "Pf2" (the second parameter of the present invention) (where Pf1 < Pf2). That is, when the vehicle speed Vf is 1 km / h or less, the adjustment processing unit 115 sets the parameter Pf2 (the parameter Pf2 in which the measured azimuth angle D0 becomes non-dominant in the azimuth angle estimation result) such that the weight of the state (x1(k)) estimated by the estimation model increases and the weight of the state (x2(k)) estimated by the measured azimuth angle D0 decreases.

[0050] Further, when the vehicle speed Vf is between 1 km / h and 2 km / h, the adjustment processing unit 115 sets a parameter Pf that linearly changes (gradually decreases) according to the vehicle speed Vf.

[0051] When the Kalman filter KF acquires the parameter Pf1 when the vehicle speed Vf is 2 km / h or more, it calculates an azimuth angle D1 in which the weight of the state estimated by the measured azimuth angle D0 increases, that is, the measured azimuth angle D0 becomes dominant.

[0052] Further, when the Kalman filter KF acquires the parameter Pf2 when the vehicle speed Vf is 1 km / h or less, it calculates an azimuth angle D1 in which the weight of the state estimated by the estimation model increases, that is, the measured azimuth angle D0 becomes non-dominant.

[0053] Further, when the Kalman filter KF acquires a parameter Pf interpolated according to the vehicle speed Vf when the vehicle speed Vf is between 1 km / h and 2 km / h, it calculates an azimuth angle D1 in which the weight of the state estimated by the estimation model and the weight of the state estimated by the measured azimuth angle D0 corresponding to the parameter Pf are adjusted according to the parameter Pf.

[0054] In this way, the estimation processing unit 116 adjusts the weight corresponding to the measured azimuth angle D0 based on the vehicle speed Vf of the work vehicle 10, and estimates the azimuth angle D1 corresponding to the current attitude of the work vehicle 10 based on the weighted measured azimuth angle D0, the position information of the work vehicle 10, and the angular velocity information of the work vehicle 10. For example, the estimation processing unit 116 estimates the azimuth angle D1 using a Kalman filter KF to which the measured azimuth angle D0, a parameter Pf that adjusts the weight of the state estimated from the measured azimuth angle D0, and the position information f1 and angular velocity information f2 of the work vehicle 10 are input. Furthermore, the Kalman filter KF estimates the azimuth angle D1 such that the slower the vehicle speed Vf of the work vehicle 10, the smaller the weight of the state estimated from the measured azimuth angle D0 becomes, and the faster the vehicle speed Vf of the work vehicle 10, the larger the weight of the state estimated from the measured azimuth angle D0 becomes.

[0055] Furthermore, if an operator is riding in the work vehicle 10, the operator may be able to change the vehicle speed Vf of the automatically driving work vehicle 10. For example, the operator may be able to change the vehicle speed Vf of the automatically driving work vehicle 10 by operating the gear shift lever (not shown) of the work vehicle 10. In this case, the estimation processing unit 116 estimates the azimuth angle D1 based on the parameter Pf corresponding to the vehicle speed change operation by the operator.

[0056] The estimation processing unit 116 outputs the information of the estimated azimuth angle D1 to the output processing unit 117.

[0057] The Kalman filter KF resets the cumulative error of the estimated value before performing the estimation process. For example, when the work vehicle 10 reaches the starting point Rp of the straight path R1 and the vehicle speed Vf of the work vehicle 10 is less than or equal to a predetermined vehicle speed (2 km / h in the above example), the estimation processing unit 116 obtains a determination result Rf (see Figure 5) from the reset determination processing unit 114 indicating that the estimated value should be reset. In this case, the Kalman filter KF resets the estimated value and then performs the estimation process. This allows the Kalman filter KF to reset the cumulative error of the estimated value, thereby enabling it to obtain an appropriate estimated value. The estimation processing unit 116 is an example of the estimation processing unit of the present invention.

[0058] The output processing unit 117 outputs an output azimuth angle D2 (current azimuth angle α1 shown in Figure 4) which is used for the driving processing (e.g., steering control) of the driving processing unit 111. Specifically, the output processing unit 117 selects either the measured azimuth angle D0 or the estimated azimuth angle D1 as the output azimuth angle D2 based on route information relating to the path traveled by the work vehicle 10. That is, the output processing unit 117 switches the output azimuth angle D2 between the measured azimuth angle D0 and the azimuth angle D1 based on the route information.

[0059] For example, as shown in Figure 5, the output processing unit 117 obtains the determination result d1 from the section determination processing unit 113, the azimuth angle D1 from the estimation processing unit 116, and the measured azimuth angle D0 from the acquisition processing unit 112. Based on the determination result d1, it outputs the measured azimuth angle D0 or azimuth angle D1 as the output azimuth angle D2 to the driving processing unit 111.

[0060] For example, when the travel path of the work vehicle 10 is a straight path R1 (see Figure 6) corresponding to low-speed travel, the output processing unit 117 outputs the azimuth angle D1 obtained from the estimation processing unit 116 as the output azimuth angle D2 to the travel processing unit 111. On the other hand, when the travel path of the work vehicle 10 is a turning path R2 (see Figure 6) corresponding to high-speed travel, the output processing unit 117 outputs the measured azimuth angle D0 measured by the inertial measuring device 165 as the output azimuth angle D2 to the travel processing unit 111.

[0061] In another embodiment, as shown in Figure 8, the output processing unit 117 may select either the measured azimuth angle D0 or the estimated azimuth angle D1 as the output azimuth angle D2 based on the route information and the vehicle speed Vf of the work vehicle 10. For example, if the travel route of the work vehicle 10 is a straight route R1 and the vehicle speed Vf of the work vehicle 10 is less than a predetermined vehicle speed (e.g., 2 km / h), the output processing unit 117 outputs the azimuth angle D1 obtained from the estimation processing unit 116 as the output azimuth angle D2 to the travel processing unit 111. If the travel route of the work vehicle 10 is a straight route R1 and the vehicle speed Vf of the work vehicle 10 is equal to or greater than a predetermined vehicle speed (e.g., 2 km / h or a speed faster than 2 km / h), the output processing unit 117 outputs the measured azimuth angle D0 measured by the inertial measuring device 165 as the output azimuth angle D2 to the travel processing unit 111.

[0062] The driving processing unit 111 uses the output azimuth angle D2 output by the output processing unit 117 as the current azimuth angle α1 (see Figure 4) (α1=D2), calculates the target steering angle θ of the work vehicle 10 (θ=α1+θ1+α2), and controls the steering angle of the work vehicle 10 based on the target steering angle θ. In this way, the driving processing unit 111 automatically drives the work vehicle 10 based on the azimuth angle D1 estimated by the estimation processing unit 116. As a result, the work vehicle 10 can automatically drive along the target path R with high accuracy even when driving at low speeds.

[0063] [Operating terminal 20] As shown in Figure 1, the operating terminal 20 is an information processing device comprising an operation control unit 21, a storage unit 22, an operation display unit 23, and a communication unit 24, etc. The operating terminal 20 may be composed of a mobile device such as a tablet or a smartphone.

[0064] The communication unit 24 is a communication interface for connecting the operating terminal 20 to the communication network N1 by wire or wireless connection and for performing data communication with one or more external devices such as work vehicles 10 via the communication network N1 in accordance with a predetermined communication protocol.

[0065] The operation display unit 23 is a user interface comprising a display unit such as a liquid crystal display or an organic EL display that displays various information, and an operation unit such as a touch panel, mouse, or keyboard that accepts operations. The operator can register various information (such as work vehicle information, field information, and work information described later) by operating the operation unit on the operation screen displayed on the display unit. The operator can also issue a work start command to the work vehicle 10 by operating the operation unit. Furthermore, when the work vehicle 10 is operating unmanned, the operator may, from a location away from the work vehicle 10, understand the driving status of the work vehicle 10 as it automatically travels within the field F according to the target route R by looking at the driving trajectory displayed on the operation terminal 20.

[0066] The storage unit 22 is a non-volatile storage unit such as an HDD or SSD that stores various types of information. The storage unit 22 stores a control program that causes the operation control unit 21 to execute predetermined control processing. For example, the control program is non-temporarily recorded on a computer-readable recording medium such as a flash ROM, EEPROM, CD, or DVD, and is read by a predetermined reading device (not shown) provided on the operation terminal 20 and stored in the storage unit 22. Alternatively, the control program may be downloaded from a server (not shown) to the operation terminal 20 via a communication network N1 and stored in the storage unit 22. The storage unit 22 may also store work information transmitted from the work vehicle 10.

[0067] Furthermore, a dedicated application for automatically driving the work vehicle 10 is installed in the memory unit 22. The operation control unit 21 starts the dedicated application and performs various processing tasks such as setting information related to the work vehicle 10, generating the target route R for the work vehicle 10, and issuing work start instructions to the work vehicle 10.

[0068] The operation control unit 21 includes control devices such as a CPU, ROM, and RAM. The CPU is a processor that performs various arithmetic operations. The ROM is a non-volatile memory unit that stores control programs such as a BIOS and OS in advance to allow the CPU to perform various arithmetic operations. The RAM is a volatile or non-volatile memory unit that stores various information and is used as a temporary memory (work area) for the various processes performed by the CPU. The operation control unit 21 controls the operation terminal 20 by executing various control programs stored in advance in the ROM or memory unit 22 using the CPU.

[0069] Specifically, the operation control unit 21 sets information related to the work vehicle 10 (hereinafter referred to as "work vehicle information"). The operation control unit 21 sets information such as the model of the work vehicle 10, the location on which the positioning antenna 164 is attached to the work vehicle 10, the type of work equipment 14, the size and shape of the work equipment 14, and the position of the work equipment 14 relative to the work vehicle 10, by having the operator perform an operation to register this information on the operation terminal 20.

[0070] Furthermore, the operation control unit 21 sets information related to field F (hereinafter referred to as field information). The operation control unit 21 sets information such as the location and shape of field F, the work start position S where work begins, the work end position G where work ends, and the work direction by performing an operation to register this information on the operation terminal 20. The work direction refers to the direction in which the work vehicle 10 is driven while working with the implement 14 in the area of ​​field F excluding headlands, non-working areas, etc.

[0071] Information on the location and shape of field F can be automatically acquired, for example, by having an operator ride in the work vehicle 10 and drive it in a circle around the perimeter of field F, while recording the changes in the position information of the positioning antenna 164 during that time. Alternatively, the location and shape of field F can also be acquired based on a polygon obtained by having an operator operate the operation terminal 20 to specify multiple points on the map displayed on the terminal 20. The area identified by the acquired location and shape of field F is the area in which the work vehicle 10 can travel (driving area).

[0072] Furthermore, the operation control unit 21 sets information regarding how the work will be performed in detail (hereinafter referred to as work information). The operation control unit 21 is configured to be able to set work information such as whether or not there will be coordinated work between the work vehicle 10 (unmanned tractor) and the manned work vehicle 10, the number of skips which is the number of work paths to be skipped when the work vehicle 10 turns in the headland, the width of the headland, and the width of the non-cultivated land.

[0073] Furthermore, the operation control unit 21 generates a target route R, which is the route along which the work vehicle 10 will automatically travel, based on the setting information. In this embodiment, the target route R includes a work route (straight route R1) in which the work machine 14 performs work and a non-work route (turning route R2) in which the work machine 14 does not perform work (see Figure 3). The operation control unit 21 can generate and store the target route R of the work vehicle 10 based on each of the setting information.

[0074] Specifically, the operation control unit 21 generates a target route R (see Figure 3) based on the work start position S and work end position G registered in the field setting. The target route R is not limited to the route shown in Figure 3.

[0075] Furthermore, the operation control unit 21 sets information on the vehicle speed Vf of the work vehicle 10 in relation to the target route R. For example, the operator can set the vehicle speed Vf during work (travel speed on the straight route R1), the vehicle speed during turns (travel speed on the turning route R2), etc. The operation control unit 21 registers the set vehicle speed information in relation to the target route R. The operation control unit 21 outputs the route data of the generated target route R to the work vehicle 10. In addition, the operation control unit 21 outputs work start instructions and work end instructions to the work vehicle 10 based on the operator's operations.

[0076] Furthermore, the operation control unit 21 receives instructions from the operator to start work (work start instruction operation) and instructions to stop work of the automatically moving work vehicle 10 (work stop instruction operation). When the operation control unit 21 receives the work start instruction operation, it outputs the work start instruction to the work vehicle 10. As a result, the vehicle control device 11 of the work vehicle 10 receives the work start instruction from the operation terminal 20. When the vehicle control device 11 receives the work start instruction, it starts the work and driving of the work vehicle 10. Also, when the operation control unit 21 receives the work stop instruction operation, it outputs the work stop instruction to the work vehicle 10. As a result, the vehicle control device 11 of the work vehicle 10 receives the work stop instruction from the operation terminal 20. When the vehicle control device 11 receives the work stop instruction, it stops the work and driving of the work vehicle 10.

[0077] When the work vehicle 10 receives route data for the target route R transmitted from the operation terminal 20, it stores it in the storage unit 12. The work vehicle 10 is configured to automatically travel when its current location is within the field F, and is configured not to automatically travel when its current location is outside the field F. Furthermore, the work vehicle 10 is configured to automatically travel, for example, when its current location coincides with the work start position S.

[0078] When the work vehicle 10's current position coincides with the work start position S, and the operator presses the start button on the operation screen to give a work start instruction, the vehicle control device 11 initiates work using the work implement 14. In other words, the operation control unit 21 permits the work vehicle 10 to move automatically on the condition that its current position coincides with the work start position S. However, the conditions for permitting the work vehicle 10 to move automatically are not limited to the above conditions.

[0079] The vehicle control device 11 automatically drives the work vehicle 10 from the work start position S to the work end position G based on information about the target path R, and raises and lowers the work implement 14 to perform the work. The vehicle control device 11 also automatically drives the work vehicle 10 while changing the vehicle speed Vf of the work vehicle 10 based on the vehicle speed Vf associated with the target path R. For example, the vehicle control device 11 sets the vehicle speed Vf to "1 km / h" when the work vehicle 10 is traveling on a straight path R1, and sets the vehicle speed Vf to "2 km / h" when the work vehicle 10 is traveling on a turning path R2, and drives the work vehicle 10 automatically.

[0080] Furthermore, once the work vehicle 10 has completed its work, the vehicle control device 11 may automatically drive it from the work completion position G to the entrance of the field F. When the work vehicle 10 is driving automatically, the operation control unit 21 can receive the status of the work vehicle 10 (position, speed, etc.) from the work vehicle 10 and display it on the operation display unit 23.

[0081] The operating terminal 20 may also be able to access a website (agricultural support site) for agricultural support services provided by a server (not shown) via the communication network N1. In this case, the operating terminal 20 can function as an operating terminal for the server by having a browser program executed by the operation control unit 21. The server then comprises the processing units described above and executes each of the processes.

[0082] [Automatic driving process] The following describes an example of the automated driving process performed by the automated driving system 1, with reference to Figure 9.

[0083] Furthermore, the present invention can be understood as an invention of an automated driving method that performs one or more steps included in the automated driving process. The one or more steps included in the automated driving process described herein may be omitted as appropriate. The execution order of each step in the automated driving process may differ to the extent that similar effects are produced. Moreover, although the vehicle control device 11 is used as an example in this description, an automated driving method in which one or more processors distribute and execute each step in the automated driving process can also be considered as another embodiment.

[0084] Here, it is assumed that the control unit 21 has set a target path R (see Figure 3) for the field F, which includes a straight path R1 and a turning path R2.

[0085] In step S1, the vehicle control device 11 of the work vehicle 10 starts automatic driving. Specifically, when the operation control unit 21 receives a work start instruction from the operator, the vehicle control device 11 starts automatic driving according to the target route R. For example, the vehicle control device 11 starts automatic driving when the current position of the work vehicle 10 coincides with the work start position S (the starting position of the straight route R1).

[0086] Next, in step S2, the vehicle control device 11 acquires the measured azimuth angle D0 from the inertial measuring device 165. The vehicle control device 11 acquires the measured azimuth angle D0 at a predetermined period.

[0087] Next, in step S3, the vehicle control device 11 determines whether the travel path (travel section) of the work vehicle 10 is a section for azimuth angle estimation. For example, the section determination processing unit 113 determines whether the travel path is a straight path R1 based on the path information d0. The vehicle control device 11 determines that the travel path is a section for estimation if it is a straight path R1, and determines that it is not a section for estimation if it is a turning path R2. If the vehicle control device 11 determines that the travel path is a section for estimation (S3:Yes), it moves the process to step S4. On the other hand, if the vehicle control device 11 determines that the travel path is not a section for estimation (S3:No), it moves the process to step S31.

[0088] In step S4, the operation control unit 21 resets the cumulative error of the estimate in the Kalman filter KF (see Figure 5).

[0089] Next, in step S5, the operation control unit 21 adjusts the parameter Pf used to calculate the estimated value in the Kalman filter KF based on the vehicle speed Vf of the work vehicle 10. Specifically, the operation control unit 21 sets the parameter Pf to be smaller as the vehicle speed Vf of the work vehicle 10 increases, and larger as the vehicle speed Vf of the work vehicle 10 decreases. For example, as shown in Figure 7, the vehicle control device 11 sets the parameter Pf1 when the vehicle speed Vf is 2 km / h or more, sets the parameter Pf2 when the vehicle speed Vf is 1 km / h or less, and sets the parameter Pf to change linearly (decrease) according to the vehicle speed Vf between 1 km / h and 2 km / h.

[0090] Furthermore, the operation control unit 21 sets a parameter Pf1 (a parameter Pf1 in which the measured azimuth angle D0 becomes dominant in the estimated values ​​in the Kalman filter KF) such that when the vehicle speed Vf is 2 km / h or more, the weight of the state estimated by the measured azimuth angle D0 (the estimated value "x2(k)" mentioned above) becomes larger, and the weight of the state estimated by the estimation model (the estimated value "x1(k)" mentioned above) becomes smaller. Furthermore, the operation control unit 21 sets a parameter Pf2 (a parameter Pf2 in which the measured azimuth angle D0 becomes non-dominant in the estimated values ​​in the Kalman filter KF) such that when the vehicle speed Vf is 1 km / h or less, the weight of the state estimated by the estimation model becomes larger, and the weight of the state estimated by the measured azimuth angle D0 becomes smaller.

[0091] Next, in step S6, the operation control unit 21 estimates the azimuth angle D1 (current azimuth angle α1 in Figure 4) corresponding to the current attitude of the work vehicle 10. For example, the operation control unit 21 estimates the azimuth angle D1 based on the parameter Pf set in the Kalman filter KF according to the vehicle speed Vf of the work vehicle 10. For example, the Kalman filter KF estimates the azimuth angle D1 using parameter Pf1 when the vehicle speed Vf is 2 km / h or more. Also, the Kalman filter KF estimates the azimuth angle D1 using parameter Pf2 when the vehicle speed Vf is 1 km / h or less. Furthermore, when the vehicle speed Vf is between 1 km / h and 2 km / h, the Kalman filter KF estimates the azimuth angle D1 using parameter Pf interpolated from the linear characteristics (see Figure 7).

[0092] In this way, the operation control unit 21 estimates the azimuth angle D1 such that the weight of the state estimated from the measured azimuth angle D0 becomes larger (the estimation element becomes weaker) as the vehicle speed Vf of the work vehicle 10 increases, and estimates the azimuth angle D1 such that the weight of the state estimated from the measured azimuth angle D0 becomes smaller (the estimation element becomes stronger) as the vehicle speed Vf of the work vehicle 10 decreases.

[0093] Next, in step S7, the operation control unit 21 outputs the estimated azimuth angle D1 as the output azimuth angle D2 (see Figure 5). On the other hand, in step S31, the operation control unit 21 outputs the measured azimuth angle D0 measured by the inertial measuring device 165 as the output azimuth angle D2 (see Figure 5).

[0094] Thus, when the travel path of the work vehicle 10 is a straight path R1 (see Figure 6) corresponding to low-speed travel (S3:Yes), the operation control unit 21 outputs the estimated azimuth angle D1 as the output azimuth angle D2 (S7). On the other hand, when the travel path of the work vehicle 10 is a turning path R2 (see Figure 6) corresponding to high-speed travel (S3:No), the operation control unit 21 outputs the measured azimuth angle D0 measured by the inertial measuring device 165 as the output azimuth angle D2 (S31).

[0095] Next, in step S8, the operation control unit 21 calculates the target steering angle θ of the work vehicle 10 based on the output azimuth angle D2. For example, the operation control unit 21 calculates the target steering angle θ (θ = α1 + θ1 + α2) of the work vehicle 10 based on the current azimuth angle α1 (output azimuth angle D2), the current steering angle θ1, and the target azimuth angle α2 (see Figure 4).

[0096] Next, in step S9, the operation control unit 21 controls the steering angle of the work vehicle 10 based on the target steering angle θ and controls the automatic driving of the work vehicle 10.

[0097] Next, in step S10, the vehicle control device 11 determines whether the work vehicle 10 has completed its work. For example, if the work vehicle 10 has reached the work completion position G (S10: Yes), the vehicle control device 11 terminates the process. On the other hand, if the work vehicle 10 has not reached the work completion position G (S10: No), the process moves to step S2 and the above process is repeated. In this manner, the automatic driving system 1 executes the automatic driving process.

[0098] As described above, the automatic driving system 1 according to Embodiment 1 acquires the measured azimuth angle D0 measured by a measuring unit (inertial measuring device 165) that measures the azimuth angle of the work vehicle 10, adjusts the weight corresponding to the measured azimuth angle D0 based on the vehicle speed Vf of the work vehicle 10, estimates the azimuth angle D1 corresponding to the current attitude of the work vehicle 10 based on the measured azimuth angle D0 whose weight has been adjusted according to the vehicle speed Vf, the position information of the work vehicle 10, and the angular velocity information of the work vehicle 10, and automatically drives the work vehicle 10 based on the estimated azimuth angle D1.

[0099] According to the above configuration, the weight corresponding to the measured azimuth angle D0 can be adjusted according to the vehicle speed Vf of the work vehicle 10 to estimate the azimuth angle D1 (current azimuth angle) of the work vehicle 10. For example, when the vehicle speed Vf of the work vehicle 10 is slow (when traveling at low speed), the weight of the state estimated by the measured azimuth angle D0 in the Kalman filter KF can be reduced (making the measured azimuth angle D0 non-dominant) to estimate the azimuth angle D1. In this way, when the work vehicle 10 is traveling at low speed, the measured azimuth angle D0 is not used as is, but the influence (weight) of the measured azimuth angle D0 on the estimated value of the Kalman filter KF is reduced to estimate the azimuth angle D1. As a result, the work vehicle 10 can estimate the azimuth angle D1 with high accuracy even when traveling at low speed, when the accuracy of azimuth angle measurement decreases. Therefore, the accuracy of the azimuth angle of the work vehicle 10 can be improved, enabling high-precision automated driving. Furthermore, in sections where azimuth estimation is unnecessary (for example, high-speed driving sections), the accuracy of automated driving can be maintained by using the conventionally measured azimuth angle D0 for steering control.

[0100] [Embodiment 2] Figure 10 is a block diagram showing the configuration of the automated driving system 1 according to Embodiment 2 of the present invention. The differences from the automated driving system 1 according to Embodiment 1 will be explained below. In Figure 10, components having the same function as those in the automated driving system 1 according to Embodiment 1 (see Figure 1) are denoted by the same reference numerals.

[0101] As shown in Figure 10, in the work vehicle 10 according to Embodiment 2, the adjustment processing unit 115 (see Figure 1) is omitted in the vehicle control device 11.

[0102] Figure 11 shows a specific example of the vehicle control device 11 according to Embodiment 2. In the vehicle control device 11 according to Embodiment 2, the Kalman filter KF of the estimation processing unit 116 receives the determination result Rf from the reset determination processing unit 114, position information f1, angular velocity information f2, and measured azimuth angle D0 as input. The Kalman filter KF estimates the azimuth angle D1 of the work vehicle 10 based on the determination result Rf, position information f1, angular velocity information f2, and measured azimuth angle D0. For example, when the travel path of the work vehicle 10 is a straight path R1 (see Figure 6) corresponding to low-speed travel, the Kalman filter KF estimates the azimuth angle D1 of the work vehicle 10 based on the position information f1, angular velocity information f2, and measured azimuth angle D0.

[0103] The output processing unit 117 receives the determination result d1 from the section determination processing unit 113, the estimation result (azimuth angle D1) from the estimation processing unit 116, the measurement result (measured azimuth angle D0) from the inertial measuring device 165, and the vehicle speed Vf of the work vehicle 10 as input. For example, when the vehicle speed Vf falls below 2 km / h, the output processing unit 117 outputs azimuth angle D1 as output azimuth angle D2 to the driving processing unit 111. Also, when the vehicle speed Vf is 2 km / h or higher, the output processing unit 117 outputs measured azimuth angle D0 as output azimuth angle D2 to the driving processing unit 111.

[0104] As described above, the vehicle control device 11 according to Embodiment 2 acquires the measured azimuth angle D0 measured by the inertial measuring device 165 that measures the azimuth angle of the work vehicle 10, estimates the azimuth angle D1 corresponding to the current attitude of the work vehicle 10 based on the measured azimuth angle D0, the position information of the work vehicle 10, and the angular velocity information of the work vehicle 10, selects either the measured azimuth angle D0 or the estimated azimuth angle D1 as the output azimuth angle D2 based on the vehicle speed Vf of the work vehicle 10, and has a configuration to automatically drive the work vehicle 10 based on the output azimuth angle D2.

[0105] In another embodiment, as shown in Figure 12, the output processing unit 117 may set a predetermined vehicle speed range (e.g., 1 km / h to 2 km / h) as a dead zone to suppress rapid fluctuations in the output azimuth angle D2. In this case, the output processing unit 117 outputs the measured azimuth angle D0 as the output azimuth angle D2 until the vehicle speed Vf decreases to 1 km / h, and outputs the azimuth angle D1 (estimated azimuth angle) as the output azimuth angle D2 when the vehicle speed Vf becomes 1 km / h or less. Furthermore, the output processing unit 117 outputs the azimuth angle D1 (estimated azimuth angle) as the output azimuth angle D2 until the vehicle speed Vf increases to 2 km / h, and outputs the measured azimuth angle D0 as the output azimuth angle D2 when the vehicle speed Vf becomes 2 km / h or more.

[0106] In other words, the output processing unit 117 selects the estimated azimuth angle D1 as the output azimuth angle D2 when the vehicle speed Vf of the work vehicle 10 is less than or equal to a first vehicle speed (e.g., 1 km / h), and selects the measured azimuth angle D0 as the output azimuth angle D2 when the vehicle speed Vf of the work vehicle 10 is greater than or equal to a second vehicle speed (e.g., 1 km / h or 2 km / h) that is greater than or equal to the first vehicle speed.

[0107] In the automatic driving process according to Embodiment 2, step S5 of the automatic driving process according to Embodiment 1 (see Figure 9) is omitted. Also, in the automatic driving process according to Embodiment 2, in step S3 of the automatic driving process according to Embodiment 1, the vehicle control device 11 determines whether the driving path (driving section) of the work vehicle 10 is within the section for azimuth angle estimation, and whether the vehicle speed Vf of the work vehicle 10 is less than a predetermined vehicle speed. If the vehicle control device 11 determines that the driving path is within the section for estimation and the vehicle speed Vf is less than the predetermined vehicle speed (S3: Yes), it moves the process to step S4. On the other hand, if the vehicle control device 11 determines that the driving path is not within the section for estimation, or determines that the vehicle speed Vf is greater than or equal to the predetermined vehicle speed (S3: No), it moves the process to step S31. The other processes are the same as the automatic driving process according to Embodiment 1.

[0108] As described above, the automatic driving system 1 according to Embodiment 2 acquires the measured azimuth angle D0 measured by the measuring unit (inertial measuring device 165) that measures the azimuth angle of the work vehicle 10, estimates the azimuth angle D1 corresponding to the current attitude of the work vehicle 10 based on the position information and angular velocity information of the work vehicle 10, selects either the measured azimuth angle D0 or the estimated azimuth angle D1 as the output azimuth angle D2 based on the vehicle speed Vf of the work vehicle 10, and automatically drives the work vehicle 10 based on the output azimuth angle D2.

[0109] According to the above configuration, for example, when the vehicle speed Vf of the work vehicle 10 is slow, the work vehicle 10 can be driven automatically based on the azimuth angle D1 corresponding to the estimated value of the Kalman filter KF. As a result, the work vehicle 10 can estimate the azimuth angle D1 with high accuracy even when driving at low speeds. Therefore, the accuracy of the azimuth angle of the work vehicle 10 can be improved, enabling highly accurate automatic driving.

[0110] [Other embodiments] Other configuration examples applicable to each of the above-described embodiments 1 and 2 are described below.

[0111] [Method for determining the target interval for estimation] In the example shown in Figure 6, the section determination processing unit 113 determines, based on the route information d0, whether the travel route (travel section) of the work vehicle 10 is an estimation target section for estimating the azimuth angle ([Method 1 for determining the estimation target section]). For example, the section determination processing unit 113 determines that the travel route is an estimation target section when it is a straight route R1, and determines that it is not an estimation target section when it is a turning route R2.

[0112] As another example of the method for determining the estimated target section ([Method 2 for determining the estimated target section]), the section determination processing unit 113 may determine, based on work information, whether the travel path of the work vehicle 10 is the estimated target section. Figure 13A shows an example of the work information. In Figure 13A, the work vehicle 10 performs a predetermined operation (e.g., trenching) on ​​the first sub-path R1a of the straight-ahead path R1, and does not perform any work on the second sub-path R1b of the straight-ahead path R1. That is, the first sub-path R1a is a work path (work section), and the second sub-path R1b and the turning path R2 are non-work paths (non-work sections).

[0113] Here, for example, the vehicle speed Vf of the work vehicle 10 is set to a low speed in work routes where high work accuracy is required, and to a high speed in turning routes R2 where no work is performed. In this case, as shown in Figure 13A, the section determination processing unit 113 determines that the travel route in which the work vehicle 10 performs work is the estimated target section, and determines that the travel route in which the work vehicle 10 does not perform work is not the estimated target section. That is, the section determination processing unit 113 determines that the work section is the estimated target section, and that the non-work section is not the estimated target section.

[0114] For example, the section determination processing unit 113 determines that the travel path is the estimated target section when the work implement 14 is descending, and determines that the travel path is not the estimated target section when the work implement 14 is ascending. Also, for example, the section determination processing unit 113 determines that the travel path is the estimated target section when the rotation speed of the PTO shaft is equal to or greater than a predetermined rotation speed, and determines that the travel path is not the estimated target section when the rotation speed of the PTO shaft is less than a predetermined rotation speed. The raising and lowering state of the work implement 14 and the rotation speed of the PTO shaft are examples of the work information.

[0115] As another example of the method for determining the estimated target section ([Method 3 for determining the estimated target section]), the section determination processing unit 113 may determine whether the travel path of the work vehicle 10 is the estimated target section based on the travel mode of the work vehicle 10. The travel mode includes, for example, a first travel mode in which the vehicle automatically travels only along the straight path R1, and a second travel mode in which the vehicle automatically travels along both the straight path R1 and the turning path R2. In this case, the section determination processing unit 113 determines that the travel path is the estimated target section when the travel mode is the first travel mode, and determines that the travel path is not the estimated target section when the travel mode is the second travel mode. The first travel mode may be selected for work where precision is required, and the second travel mode may be selected for work where precision is not required. In such cases, by adopting determination method 3, the work precision when traveling at low speed along the straight path R1 can be improved.

[0116] As another example of the method for determining the estimated target section ([Method 4 for determining the estimated target section]), the section determination processing unit 113 may combine the above-described determination methods 1 to 3. For example, the section determination processing unit 113 determines that the travel path is the estimated target section when the travel mode is the first travel mode, the travel path is the straight path R1, and the work machine 14 is descending. Alternatively, the section determination processing unit 113 determines that the travel path is the estimated target section when the travel mode is the second travel mode, the travel path is the straight path R1, and the work machine 14 is descending.

[0117] Here, immediately after the completion of low-speed work, the measured azimuth angle D0 has drifted significantly, so stopping the estimation process immediately may worsen the accuracy of the azimuth angle. For this reason, if automatic driving continues after the completion of low-speed work, it is desirable to continue the azimuth angle estimation process until the accuracy of the measured azimuth angle D0 returns to normal. Accordingly, for example, as shown in Figure 13B, the section determination processing unit 113 determines that the first partial path R1a and the second partial path R1b immediately after the completion of work in the first partial path R1a are the sections to be estimated, when the driving mode is the second driving mode. Also, for example, the section determination processing unit 113 determines that the straight path R1 and the turning path R2 immediately after the completion of work in the straight path R1 are the sections to be estimated, when the driving mode is the second driving mode.

[0118] The determination result d1 from the interval determination processing unit 113 is input to the reset determination processing unit 114, and the reset determination processing unit 114 determines whether or not to reset the cumulative error of the estimated value based on the determination result d1 (see Figure 5, etc.). The estimation processing unit 116 also performs estimation processing based on the determination result Rf from the reset determination processing unit 114 (see Figure 5, etc.). That is, the estimation processing unit 116 determines whether or not to perform azimuth angle estimation processing based on at least one of the following: path information related to the path traveled by the work vehicle 10 (straight path R1, turning path R2), work information related to the work performed by the work vehicle 10 (work implement 14, information related to the PTO axis), and travel mode information related to the travel mode of the work vehicle 10.

[0119] Furthermore, the determination result d1 of the section determination processing unit 113 is input to the output processing unit 117, and the output processing unit 117 outputs either the measured azimuth angle D0 or the estimated azimuth angle D1 as the output azimuth angle D2 to the driving processing unit 111 based on the determination result d1 (see Figure 5, etc.). The output processing unit 117 outputs the output azimuth angle D2 to the driving processing unit 111 based on the determination result d1 according to the determination methods 1 to 4 described above (see Figure 5, etc.). In other words, the output processing unit 117 selects either the measured azimuth angle D0 or the azimuth angle D1 as the output azimuth angle D2 based on at least one of the following: route information related to the path traveled by the work vehicle 10 (straight path R1, turning path R2), work information related to the work of the work vehicle 10 (work implement 14, information related to the PTO axis), and driving mode information related to the driving mode of the work vehicle 10, and outputs it to the driving processing unit 111.

[0120] [How to reset the estimated value] In the example shown in Figure 6, the reset determination processing unit 114 determines whether the work vehicle 10 has reached the estimated target section. If it determines that the work vehicle 10 has reached the estimated target section, the Kalman filter KF resets the cumulative error of the estimated value ([Method 1 for resetting the estimated value]). For example, the Kalman filter KF resets the cumulative error of the estimated value when the work vehicle 10 reaches the starting point Rp of the straight path R1.

[0121] Another example of the method for resetting the estimated value ([Method 2 for resetting the estimated value]) is that, for example, as shown in Figure 14A, the Kalman filter KF may reset the estimated value when the work vehicle 10 reaches the starting point Rs of the first low-speed section in each estimation target section. In the example shown in Figure 14A, the straight path R1c includes two low-speed sections. In this case, the Kalman filter KF resets the estimated value when it reaches the starting point Rs of the first low-speed section, but does not reset the estimated value when it reaches the starting point of the next low-speed section.

[0122] Another example of the method for resetting the estimated value ([Method 3 for resetting the estimated value]) is that, for example, as shown in Figure 14B, the Kalman filter KF may reset the estimated value when the work vehicle 10 reaches the starting point Rt of each low-speed travel section in each estimation target section. In the example shown in Figure 14B, the straight path R1c includes two low-speed travel sections. In this case, the Kalman filter KF resets the estimated value when it reaches the starting point Rt of the first low-speed travel section, and again when it reaches the starting point Rt of the next low-speed travel section.

[0123] As another example of the method for resetting the estimated value ([Method 4 for resetting the estimated value]), as shown in Figure 14C, for example, the Kalman filter KF may reset the estimated value when the work vehicle 10 reaches point Rx after traveling through a waiting section (after a predetermined time has elapsed or after traveling a predetermined distance) after starting work in each low-speed travel section in each estimation target section. In the example shown in Figure 14B, the straight-ahead path R1c includes two low-speed travel sections. In this case, the Kalman filter KF resets the estimated value when the vehicle reaches point Rx, which is separated from the starting point of the first low-speed travel section by the amount of the waiting section, and again when the vehicle reaches point Rx, which is separated from the starting point of the next low-speed travel section by the amount of the waiting section. Thus, if the effect of azimuth drift is small immediately after the start of low-speed work, the vehicle control device 11 may control steering based on the measured azimuth angle D0 for a predetermined section (waiting section) immediately after the start of the low-speed travel section. Furthermore, it is desirable that the vehicle control device 11 adjusts the predetermined time or distance corresponding to the waiting section so that the estimated value of the Kalman filter KF can be reset at an appropriate timing.

[0124] The automated driving system of the present invention may consist of a work vehicle 10 alone, or a vehicle control device 11 alone. Alternatively, the present invention may be implemented as an estimation device, estimation method, and estimation program for estimating the azimuth angle of the work vehicle 10. In this case, the estimation device may include the processing units of the vehicle control device 11. Furthermore, the automated driving system may be mounted on the work vehicle 10, or on the operation terminal 20.

[0125] [Notes on the invention] The following is an overview of the invention extracted from the above-described embodiments. Note that each configuration and processing function described below can be selected and combined as desired.

[0126] <Note 1> The measurement unit that measures the azimuth angle of the work vehicle will acquire the measured azimuth angle, Based on the vehicle speed of the aforementioned work vehicle, the weight corresponding to the measured azimuth angle is adjusted, Based on the measured azimuth angle, whose weight is adjusted according to the vehicle speed, the position information of the work vehicle, and the angular velocity information of the work vehicle, the azimuth angle corresponding to the current attitude of the work vehicle is estimated. Based on the estimated azimuth angle, the work vehicle is to be driven automatically, An automated driving method that performs this task.

[0127] <Note 2> The azimuth angle is estimated such that the slower the vehicle speed of the work vehicle, the smaller the weight of the state estimated from the measured azimuth angle. The automatic driving method described in Appendix 1.

[0128] <Note 3> When the vehicle speed of the work vehicle is equal to or greater than the first vehicle speed, the azimuth angle is estimated by setting a first parameter such that the state estimated from the measured azimuth angle becomes dominant in the estimation result of the azimuth angle, When the vehicle speed of the work vehicle is slower than or equal to a second vehicle speed (slower than the first vehicle speed), a second parameter is set in which the state estimated from the measured azimuth angle becomes non-dominant in the estimation result of the azimuth angle, and the azimuth angle is estimated. The automatic driving method described in Appendix 1 or 2.

[0129] <Note 4> The azimuth angle is estimated by setting a parameter that changes linearly according to the vehicle speed between the first vehicle speed and the second vehicle speed. The automatic driving method described in Appendix 3.

[0130] <Note 5> The process further involves selecting either the measured azimuth angle or the estimated azimuth angle as the output azimuth angle based on at least one of the following: route information relating to the path the work vehicle travels, work information relating to the work vehicle's work, and driving mode information relating to the work vehicle's driving mode. Based on the output azimuth angle, the work vehicle is made to move automatically. The automatic driving method described in any of the appendices 1 to 4.

[0131] <Note 6> When the vehicle speed of the work vehicle is less than a predetermined speed, the estimated azimuth angle is selected as the output azimuth angle; when the vehicle speed of the work vehicle is equal to or greater than the predetermined speed, the measured azimuth angle is selected as the output azimuth angle. The automatic driving method described in Appendix 5.

[0132] <Note 7> The azimuth angle is estimated using a Kalman filter to which the measured azimuth angle, a parameter corresponding to the vehicle speed of the work vehicle, the position information of the work vehicle, and the angular velocity information of the work vehicle are input. The automatic driving method described in any of the appendices 1 to 6.

[0133] <Note 8> The measurement unit that measures the azimuth angle of the work vehicle will acquire the measured azimuth angle, Based on the measured azimuth angle, the position information of the work vehicle, and the angular velocity information of the work vehicle, the azimuth angle corresponding to the current attitude of the work vehicle is estimated. Based on the vehicle speed of the aforementioned work vehicle, either the measured azimuth angle or the estimated azimuth angle is selected as the output azimuth angle. Based on the output azimuth angle, the work vehicle is to be driven automatically, An automated driving method that performs this task.

[0134] <Note 9> When the vehicle speed of the work vehicle is equal to or greater than the first vehicle speed, the measured azimuth angle is selected as the output azimuth angle. When the vehicle speed of the work vehicle is less than or equal to the second vehicle speed which is less than or equal to the first vehicle speed, the estimated azimuth angle is selected as the output azimuth angle. The automatic driving method described in Appendix 8.

[0135] <Note 10> A determination is made as to whether or not to perform the azimuth angle estimation process based on at least one of the following: route information relating to the route the work vehicle travels, work information relating to the work performed by the work vehicle, and driving mode information relating to the driving mode of the work vehicle. The automatic driving method described in any of the appendices 1 to 9. [Explanation of Symbols]

[0136] 1: Automated driving system 10: Work vehicles 11: Vehicle control system 16: Positioning Unit 20: Operating terminal 111: Driving section 112: Acquisition Processing Unit 113: Interval determination processing unit 114: Reset determination processing unit 115: Adjustment Processing Unit 116: Estimation Processing Unit 117: Output Processing Unit 161: Positioning Control Unit 165: Inertial measurement device (measurement unit) D0: Measured azimuth angle D1 :Azimuth D2: Output azimuth F: Field KF: Kalman filter Pf: Parameter Pf1: Parameter (1st parameter) Pf2: Parameter (2nd parameter) R: Target path R1: Straight route R2: Turning path Rf: Judgment result Vf:Vehicle speed d0: Route information d1: Judgment result d2: Reset judgment information f1: Location information f2: Angular velocity information

Claims

1. The measurement unit that measures the azimuth angle of the work vehicle will acquire the measured azimuth angle, Based on the vehicle speed of the aforementioned work vehicle, the weight corresponding to the measured azimuth angle is adjusted, Based on the measured azimuth angle, whose weight is adjusted according to the vehicle speed, the position information of the work vehicle, and the angular velocity information of the work vehicle, the azimuth angle corresponding to the current attitude of the work vehicle is estimated. Based on the estimated azimuth angle, the work vehicle is to be driven automatically, An automated driving method that performs this task.

2. The azimuth angle is estimated such that the slower the vehicle speed of the work vehicle, the smaller the weight of the state estimated from the measured azimuth angle. The automatic driving method according to claim 1.

3. When the vehicle speed of the work vehicle is equal to or greater than the first vehicle speed, the azimuth angle is estimated by setting a first parameter such that the state estimated from the measured azimuth angle becomes dominant in the estimation result of the azimuth angle, When the vehicle speed of the work vehicle is slower than or equal to a second vehicle speed (slower than the first vehicle speed), a second parameter is set in which the state estimated from the measured azimuth angle becomes non-dominant in the estimation result of the azimuth angle, and the azimuth angle is estimated. The automatic driving method according to claim 1.

4. Between the first vehicle speed and the second vehicle speed, a third parameter is set that changes linearly according to the vehicle speed to estimate the azimuth angle. The automatic driving method according to claim 3.

5. The process further involves selecting either the measured azimuth angle or the estimated azimuth angle as the output azimuth angle based on at least one of the following: route information relating to the path the work vehicle travels, work information relating to the work vehicle's work, and driving mode information relating to the work vehicle's driving mode. Based on the output azimuth angle, the work vehicle is made to move automatically. An automated driving method according to any one of claims 1 to 4.

6. Further, the process is to select either the measured azimuth angle or the estimated azimuth angle as the output azimuth angle based on at least one of the route information relating to the route the work vehicle travels, the work information relating to the work vehicle's work, and the driving mode information relating to the driving mode of the work vehicle. Based on the output azimuth angle, the work vehicle is made to move automatically. When the vehicle speed of the work vehicle is less than a predetermined speed, the estimated azimuth angle is selected as the output azimuth angle; when the vehicle speed of the work vehicle is equal to or greater than the predetermined speed, the measured azimuth angle is selected as the output azimuth angle. The automatic driving method according to claim 1.

7. The azimuth angle is estimated using a Kalman filter to which the measured azimuth angle, a parameter corresponding to the vehicle speed of the work vehicle, the position information of the work vehicle, and the angular velocity information of the work vehicle are input. An automated driving method according to any one of claims 1 to 4.

8. The measurement unit that measures the azimuth angle of the work vehicle will acquire the measured azimuth angle, Based on the measured azimuth angle, the position information of the work vehicle, and the angular velocity information of the work vehicle, the azimuth angle corresponding to the current attitude of the work vehicle is estimated. Based on the vehicle speed of the aforementioned work vehicle, either the measured azimuth angle or the estimated azimuth angle is selected as the output azimuth angle. Based on the output azimuth angle, the work vehicle is to be driven automatically, An automated driving method that performs this task.

9. When the vehicle speed of the work vehicle is equal to or greater than the first vehicle speed, the measured azimuth angle is selected as the output azimuth angle. When the vehicle speed of the work vehicle is less than or equal to the second vehicle speed which is less than or equal to the first vehicle speed, the estimated azimuth angle is selected as the output azimuth angle. The automatic driving method according to claim 8.

10. A determination is made as to whether or not to perform the azimuth angle estimation process based on at least one of the following: route information relating to the route the work vehicle travels, work information relating to the work performed by the work vehicle, and driving mode information relating to the driving mode of the work vehicle. The automatic driving method according to claim 1 or 8.

11. An acquisition processing unit that acquires the measured azimuth angle measured by a measurement unit that measures the azimuth angle of a work vehicle, Based on the vehicle speed of the work vehicle, the weight corresponding to the measured azimuth angle acquired by the acquisition processing unit is adjusted, and the weighted measured azimuth angle and the position information of the work vehicle are used. An estimation processing unit that estimates the azimuth angle corresponding to the current attitude of the work vehicle based on the angular velocity information of the work vehicle, A driving processing unit that automatically drives the work vehicle based on the azimuth angle estimated by the estimation processing unit, An automated driving system equipped with [the following features].

12. The measurement unit that measures the azimuth angle of the work vehicle will acquire the measured azimuth angle, Based on the vehicle speed of the aforementioned work vehicle, the weight corresponding to the measured azimuth angle is adjusted, Based on the measured azimuth angle, whose weight is adjusted according to the vehicle speed, the position information of the work vehicle, and the angular velocity information of the work vehicle, the azimuth angle corresponding to the current attitude of the work vehicle is estimated. Based on the estimated azimuth angle, the work vehicle is to be driven automatically, An automated driving program that causes one or more processors to execute.

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