Automatic driving control system for work vehicles

Abstract

The present invention aims to provide an automatic driving control device for a work vehicle that can quickly return to a set work route even when the work surface is soft and the vehicle's trajectory is prone to deviating from the work route. [Solution] An automatic steering device is provided for a work vehicle that recognizes the position of the vehicle, which is determined by a positioning device 61, on a map of the work site and automatically steers along a set work route L. The automatic driving control device for the work vehicle is characterized by providing a tilt sensor 37 that detects the tilt of the vehicle in the front, rear, left, and right directions, and performing steering corrections to the work route L at varying speeds based on the tilt angle fluctuation values ​​detected by the tilt sensor 37.

Description

Technical Field

[0001] The present invention relates to an automatic travel control device for a work vehicle that travels and works on a work site where the surface of farmland or the like is partially soft.

Background Art

[0002] The operator of the work vehicle sits in the driver's seat provided on the vehicle body and drives the work implement while operating the vehicle body to perform various operations. In recent years, as described in Japanese Unexamined Patent Application Publication No. 2023-158461, an automatic travel control device for a work vehicle has been developed that can receive radio waves from a satellite, recognize the position of the vehicle body on a map, and travel along a work route set on the map in automatic operation to perform work.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The automatic travel control device travels along a set work route while recognizing the position of the vehicle body in the work site with a vehicle body position recognition device. However, when the work site is hard and the vehicle body is stable, it is easy to travel automatically along the work route. However, when the work site is soft and the traveling wheels sink and the vehicle body tilts forward and backward or left and right, it is difficult to travel along the work route, and it becomes difficult to travel neatly along the work route.

[0005] An object of the present invention is to provide an automatic travel control device for a work vehicle that can quickly return to and travel along a set work route even when the work site is soft and the travel locus is likely to deviate from the work route.

Means for Solving the Problems

[0006] The problems of the present invention described above are solved by the following technical means.

[0007] The invention of claim 1 is an automatic driving control device for a work vehicle equipped with an automatic steering device that recognizes the position of the vehicle, which is positioned by a positioning device 61, on a map of the work site and automatically steers along a set work route L, characterized in that an inclination sensor 37 is provided to detect the tilt of the vehicle in the front, rear, left, and right directions, and steering corrections to the work route L are made slowly or quickly based on the inclination angle fluctuation value detected by the inclination sensor 37.

[0008] The invention of claim 2 is an automatic driving control device for a work vehicle according to claim 1, characterized in that when the tilt angle fluctuation value of the tilt sensor 37 is large, the correction of the path error with respect to the work route L is performed more gradually, and when the tilt angle fluctuation value is small, the correction of the path error with respect to the work route L is performed more rapidly.

[0009] The invention of claim 3 is an automatic driving control device for a work vehicle according to claim 2, characterized in that when the tilt angle fluctuation value of the tilt sensor 37 is small, the driving speed is reduced to correct the path error to the work route L. [Effects of the Invention]

[0010] In the invention of claim 1, the tilt sensor 37 detects the tilt of the machine while it is working using an automatic control system, and adjusts the speed of the track error correction to the work route L based on the tilt angle fluctuation value. This allows for changes in the machine's response to steering due to differences in the hardness of the work ground, and the speed of the track correction can be adjusted based on the tilt angle fluctuation value of the tilt sensor 37, resulting in a smooth track with minimal disturbance and a good work site.

[0011] In the invention of claim 2, if the tilt angle fluctuation value of the tilt sensor 37 is large and it is predicted that the work site is hard, the error correction with respect to the work route L is performed gradually, and if the tilt angle fluctuation value is small and it is predicted that the work site is soft, the error correction with respect to the work route L is performed rapidly. As a result, the track can be adjusted according to the hardness or softness of the work site, making it possible to create a good work site with a track that is less disturbed.

[0012] In the invention of claim 3, if the work surface is soft and the tilt angle fluctuation value of the tilt sensor 37 is small, and the track is likely to deviate from the work route L, the machine's travel speed is reduced, allowing the wheels to smoothly correct the track and return to the work route L without digging into the soft work surface. [Brief explanation of the drawing]

[0013] [Figure 1] This is a right side view of a work vehicle according to an embodiment of the present invention. [Figure 2] This is a front view showing the control mechanism of the work vehicle. [Figure 3] This is a control block diagram for automatic driving control. [Figure 4] This is a plan view of the work vehicle's track during course correction. [Figure 5] (A), (B), (C), (D) represent the change in speed from sluggish to responsive steering. [Figure 6] This is a graph of the vibration waveform of the aircraft detected by the tilt sensor. [Modes for carrying out the invention]

[0014] Hereinafter, embodiments of the present invention will be described with reference to the examples shown in the drawings. In the description of the embodiments, the left and right directions in the forward direction of the aircraft will be referred to as left and right, respectively, the forward direction will be referred to as forward, and the reverse direction will be referred to as backward, but this does not limit the configuration of the present invention.

[0015] As shown in Figure 1, the work vehicle 1 according to this embodiment has a positioning device 61, a communication device 63, and an automatic driving control device 34 that controls automatic driving and work operations. It is capable of performing automatic driving work in a field 9 and also provides control that enables automatic movement between fields. Furthermore, this control system also includes a remote operation terminal 7 that can transmit control information to the automatic driving control device 34 via wireless communication through the cloud 3.

[0016] The work vehicle 1 applied to this automatic driving control system is a tractor 10 as an example thereof. The tractor 10 in the present embodiment is a tractor that is capable of automatic traveling and work (automatic driving mode) in addition to traveling and work (manual driving mode) by manual operation of an operator, and its automatic driving mode and manual driving mode can be switched by operating a driving mode changeover switch 35.

[0017] As shown in FIG. 1, the tractor 10 has a work implement 27 for performing required work in the field 9 mounted on the rear portion of its traveling vehicle body. In the embodiment, a rotary tiller attached to the three-point link mechanism 28 or the like so as to be able to be lifted and lowered is exemplified as the work implement 27. The work implement 27 is not limited thereto, and any work implement that can be mounted on the tractor 10 and is used for work performed in the field 9 may be used, for example, a seeder, a lawn mower, or the like.

[0018] Further, the tractor 10 has a front wheel 11 that functions as a steering wheel disposed at the front portion of the traveling vehicle body, and a rear wheel 12 that functions as a drive wheel disposed at the rear portion of the traveling vehicle body. An engine 14 is mounted in an engine room (space) covered with a bonnet 13 at the front portion of the traveling vehicle body. The rotational power of the engine 14 is mainly appropriately decelerated by a transmission 16 in a transmission case 15 and then transmitted to the front wheel 11 and the rear wheel 12 via a transmission shaft (drive axle), while a part of the rotational power is transmitted to the work implement 27 via a PTO shaft 18 protruding from the rear end portion of the transmission case 15.

[0019] The tractor 10 has a cab 20 provided on the upper part of the traveling body. Inside the cab 20, a driver's seat 21 is arranged, and a steering wheel 22 is arranged in front of the driver's seat 21. Near the driver's seat 21 and the steering wheel 22, various operating levers such as a forward / backward switching lever 23, various switches not shown, a display device for displaying necessary information, etc. are arranged. Also, inside the lower part of the cab 20, various pedals such as a clutch pedal 24a, a brake pedal 24b, and an accelerator pedal not shown are arranged.

[0020] Figure 2 shows the steering mechanism of the left and right front wheels 11, 11. The rotation of the steering wheel 22 is transmitted to the hydraulic steering mechanism 26 by the wheel shaft 23 to drive the steering cylinder 31 to steer the left and right front wheels 11, 11. However, a steering gear 30 driven by a steering motor 24 of the automatic driving control device 34 is meshed with the wheel shaft 23, and the rotation of the wheel shaft 23 during automatic driving is controlled by the automatic driving control device 34. The steering angles of the left and right front wheels 11, 11 are detected by a steering angle sensor 29 and transmitted to the automatic driving control device 34.

[0021] Figure 3 is a control block diagram of automatic driving control. A switching signal of an operation mode switch 35 is input to the automatic driving control device 34, a map of the working area is input from map data 36, the inclination of the front, rear, left, and right of the machine body is input from an inclination sensor 37 provided on the machine body over time, the position of the machine body on the map obtained from a satellite by a positioning device 61 is input, the steering angles of the left and right front wheels 11, 11 are input from the steering angle sensor 29, a control signal for the working machine 27 is output to the working machine control unit 32, a steering angle is output to the steering motor 24, and various control data are output to the display 39.

[0022] In the automatic driving control device 34, a work route L such as reciprocating movement of the working area such as a farm field is created by a work route creation unit 38 according to the work content performed by the work vehicle 1, control is performed by the steering control unit 25 of the machine body to make the traveling direction follow the work route, and the traveling speed of the machine body is controlled by the traveling speed control unit 40.

[0023] Figure 4 shows the work vehicle 1 steering its left and right front wheels 11, 11 toward the work route L on the map created by the work route creation unit 38 to correct its course, steering so that the center of the machine 1G is on the work route L.

[0024] Figure 6 shows the vibration waveform of the tilt sensor 37 installed on the body of the work vehicle 1. When the ground is soft, the waveform is large and slow, and the tilt angle fluctuation value α is small. When the ground is hard, the waveform is small and fine, and the tilt angle fluctuation value β is large.

[0025] Figure 5 shows the process of returning the work vehicle 1 to the work route L when it deviates from the work route L, and shows the steering angle adjustment from insensitive (A) to sensitive (D). The sensitivity changes from sensitive to insensitive as the tilt angle fluctuation value detected by the tilt sensor 37 changes from small α to large β, and the track correction changes from rapid to slow. When the tilt angle fluctuation value is small and the fluctuation range is small, the track correction is slow, and when the tilt angle fluctuation value is large and the fluctuation range is large, the track correction is quick.

[0026] Furthermore, if the inclination angle fluctuation value is smaller than a predetermined value, it is advisable to further reduce the travel speed so that the machine can smoothly correct its course without digging into the soft work ground. [Explanation of symbols]

[0027] L Work Route 37 Tilt Sensor 61 Positioning device

Claims

1. An automatic steering system for a work vehicle that recognizes the position of the machine, which is positioned by a positioning device 61, on a map of the work site and automatically steers along a set work route L, is provided with a tilt sensor 37 that detects the tilt of the machine in the front, rear, left, and right directions, and is characterized by adjusting the speed of steering corrections to the work route L based on the tilt angle fluctuation value detected by the tilt sensor 37.

2. The automatic driving control device for a work vehicle according to claim 1, characterized in that when the tilt angle fluctuation value of the tilt sensor 37 is larger, the correction of the path error with respect to the work route L is performed more gradually, and when the tilt angle fluctuation value is smaller, the correction of the path error with respect to the work route L is performed more rapidly.

3. The automatic driving control device for a work vehicle according to claim 2, characterized in that when the tilt angle fluctuation value of the tilt sensor 37 is smaller than a predetermined value, the driving speed is further reduced to correct the path error to the work route L.

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