Driving control mechanism for work vehicles

Abstract

To provide a running control mechanism for a work vehicle which homogenizes an operation feeling in a manual running and an operation feeling relating to a control change in an automatic running, and which has improvements in production and in cost.SOLUTION: A running control mechanism for a work vehicle includes: a steering device 9 that operates the travelling direction of a running vehicle body 2; a steering sensor 70 that detects an operation amount of the steering device 9; a running control unit 40 to which an output by the steering sensor 70 is input; a running drive device 71 that drives running wheels 4 and 4 on the basis of a command from the running control unit 40; and a positioning device 30 that detects the position of the running vehicle body 2. The running control mechanism has a manual work mode control and an automatic running-straight mode control. In the manual work mode control, the running control unit 40 executes a running control in accordance with the operation amount of the steering device 9. In the automatic running-straight mode control, the running control unit 40 executes a running-straight control on the basis of a preset running-straight route and of a detection signal from the positioning device 30. Under the automatic running-straight control, when the steering device 9 is operated, the running-straight route is corrected in accordance with the operation amount thereof, and the running-straight control is executed on the basis of the corrected running-straight route and of a detection signal from a vehicle body position detecting device.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a travel control mechanism for a work vehicle such as a tractor. [Background technology]

[0002] A conventional technology is known for rice transplanters that automatically travels straight ahead according to a preset target orientation of the vehicle body, and if it deviates from the target, corrects the target orientation by pressing a trim switch provided on a control panel, etc. That is, in a field work vehicle equipped with a control unit that performs autonomous straight-ahead steering control that operates the rudder angle of the steering device in a direction that reduces the deviation of the vehicle orientation from a separately set target orientation for a reciprocating process based on vehicle orientation information indicating the vehicle direction, a manual operation tool that corrects the target orientation is provided, the amount of correction by the manual operation tool is stored, and the target orientation for the subsequent reciprocating process is automatically corrected based on the stored amount of correction (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-110921 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in automatic driving control, the target heading is corrected by pressing a trim switch on the operation panel, etc., whereas in manual driving, driving control is performed by manually operating the steering wheel, and the correction operation is performed by pressing a trim switch, which requires different operations and results in a lack of consistency in the operating feel. Furthermore, in order to correct the target heading by pressing the trim switch, special parts and circuits are required, and improvements are required in terms of both manufacturing and cost.

[0005] An object of the present invention is to provide a driving control mechanism for a work vehicle which unifies the operational feel of control changes for manual driving operation and automatic straight-line operation, and which is improved in terms of both manufacturing and cost. [Means for solving the problem]

[0006] The first aspect of the present invention is A travel control mechanism for a work vehicle, comprising: a steering device that controls a traveling direction of a traveling body; a steering sensor that detects an operation amount of the steering device; a travel control unit that receives an output of the steering sensor; a travel drive device that drives traveling wheels based on an instruction from the travel control unit; and a vehicle body position detection device that detects a position of the traveling body, Equipped with a manual operation mode control and an automatic straight-line mode control, In the manual operation mode control, the travel control unit performs travel control in accordance with an operation amount of the steering device, In the automatic straight-line mode control, the driving control unit performs straight-line driving control based on a preset straight-line driving route and a detection signal from the vehicle body position detection device, This is a driving control mechanism for a work vehicle, characterized in that when the steering device is operated under the automatic straight-line mode control, the straight-line driving path is corrected in accordance with the amount of operation, and straight-line driving control is performed based on the corrected straight-line driving path and the detection signal from the vehicle body position detection device.

[0007] The second aspect of the present invention is The vehicle body position detection device has a positioning device that receives signals from navigation satellites, The driving control unit stores straight driving route data in advance, This is a driving control mechanism for a work vehicle of the first present invention, in which, under the automatic straight-line mode control, the driving control unit corrects the straight-line driving path in accordance with the amount of operation of the steering device, and performs driving control based on the corrected straight-line driving path and a detection signal from the positioning device. Effect of the Invention

[0008] The present invention makes it possible to realize a driving control mechanism for a work vehicle that unifies the operational feel of control changes for manual driving operation and automatic straight-line operation, and is improved in terms of both manufacturing and cost. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a side view of a work vehicle according to an embodiment of the present invention; [Diagram 2] A partial rear view of the steering device of the work vehicle. [Diagram 3] FIG. 1 is a block diagram for explaining driving control of the work vehicle; [Figure 4] An explanatory diagram of the work of the work vehicle in a farm field [Diagram 5] A configuration diagram of the control unit of the work vehicle [Figure 6] FIG. 13 is an explanatory diagram of the correction of a straight path in the automatic straight-line mode control of the work vehicle. [Figure 7] An explanatory diagram (part 1) showing the relationship between steering and straight-line driving path in the automatic straight-line mode control of the same work vehicle. [Figure 8] An explanatory diagram (part 2) showing the relationship between steering and straight-line driving path in the automatic straight-line mode control of the same work vehicle. [Figure 9] An explanatory diagram (part 3) showing the relationship between steering and straight-line driving path in the automatic straight-line mode control of the same work vehicle. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0011] Fig. 1 shows a tractor as an example of a work vehicle according to an embodiment of the present invention. First, the overall configuration of the tractor 1 will be described with reference to Fig. 1.

[0012] The tractor 1, which is a work vehicle, is an agricultural tractor that travels by itself to perform work in fields, etc. In addition to the tractor 1 being driven by an operator (also called an operator) and traveling within a field to perform a predetermined task, the tractor 1 also travels automatically within the field to perform a predetermined task by controlling each part using a control system centered on a travel control unit, which will be described later.

[0013] In the following description, the forward / rearward direction is the direction of travel of the tractor 1 when traveling straight, with the forward side of the traveling direction being defined as "front" and the rear side being defined as "rear." The traveling direction of the tractor 1 is the direction from a driver's seat 8 (described later) toward a steering wheel (steering device) 9 when traveling straight (see FIG. 1).

[0014] The left-right direction is a direction that is horizontally perpendicular to the front-rear direction. Hereinafter, left and right are defined as facing the "front." In other words, when the operator of the tractor 1 (also called the "operator") is seated in the operator's seat 8 and facing forward, the left hand side is the "left" and the right hand side is the "right."

[0015] The up-down direction is the vertical direction. The front-rear direction, the left-right direction, and the up-down direction are perpendicular to each other. Note that each direction is defined for the convenience of explanation, and the present invention is not limited to these directions. In the following, the tractor 1 may be referred to as the "machine body" or the "vehicle body."

[0016] As shown in Fig. 1, the tractor 1 includes a traveling body 2 and a link mechanism for a work implement at the rear of the traveling body 2. The traveling body 2 includes a body frame 3, front wheels 4, rear wheels 5, a bonnet 6, an engine E, a control unit 7, and a transmission case 10. The body frame 3 is the main frame of the traveling body 2.

[0017] The front wheels 4 are a pair, one on the left and one on the right, and are primarily used for steering (steered wheels). The rear wheels 5 are a pair, one on the left and one on the right, and are primarily used for driving (drive wheels). The tractor 1 may be configured to be switchable between two-wheel drive (2WD) in which the rear wheels 5 are driven, and four-wheel drive (4WD) in which both the front wheels 4 and the rear wheels 5 are driven. In this case, both the front wheels 4 and the rear wheels 5 are driven wheels. The traveling body 2 may be equipped with a crawler device instead of the wheels (front wheels 4 and rear wheels 5). In this case, the traveling crawlers are the drive wheels.

[0018] The bonnet 6 is provided at the front of the traveling vehicle body 2 so as to be freely opened and closed. The bonnet 6 can be rotated (opened and closed) in the vertical direction with the rear part as the center of rotation. When closed, the bonnet 6 covers the engine E mounted on the vehicle body frame 3. The engine E is the drive source of the tractor 1, and is a heat engine such as a diesel engine or a gasoline engine. Note that the bonnet 6 may also rotate around the front part.

[0019] The control section 7 is provided on the upper part of the traveling vehicle body 2, and includes a control seat 8 and a steering wheel (steering device) 9. The control seat 8 is a seat for the driver. The steering wheel 9 is operated by the driver when steering the front wheels 4. The control section 7 includes a display section (meter panel) 9a in front of the steering wheel 9 that displays various information.

[0020] The control unit 7 also includes various operation levers, such as a forward / reverse lever, an accelerator lever, a main speed change lever, and an auxiliary speed change lever, as well as various operation pedals, such as an accelerator pedal, a brake pedal, and a clutch pedal.

[0021] In FIG. 2, reference numeral 60 denotes a mode changeover switch, which is a switch for changing over between a work mode control and a traveling mode control, which will be described later.

[0022] Reference numeral 61 denotes an automatic steering on / off switch, which is a switch for selecting whether to turn on or off an automatic steering mode control, which will be described later.

[0023] Reference numeral 62 denotes an A, B point setting means, which will be described later, for setting parallel straight-line travel routes within the travel route within the field 50. Travel route setting means 40d of the travel control unit 40 is means for automatically generating parallel straight-line travel routes based on the A, B point setting information.

[0024] The automatic steering on / off switch 61 and the A, B point setting means 62 are turned on / off by the up / down operation of the automatic steering setting lever 63. When the automatic steering setting lever 63 is first operated to be lowered, point A is stored, when it is operated to be lowered again, point B is stored, and when the automatic steering setting lever 63 is first operated to be raised with points A and B stored in memory, the automatic steering mode control is turned on, and when it is operated to be raised again, the automatic steering mode control is turned off.

[0025] The transmission case 10 houses a transmission (speed change mechanism). The transmission 10 appropriately reduces the speed of power (rotational power) transmitted from the engine E and transmits the power to rear wheels 5, which are driving wheels, and a PTO (Power Take-off) shaft.

[0026] A working machine that performs work in a field is connected to the rear of the traveling body 2, and a PTO shaft that transmits power to drive the working machine protrudes rearward from the transmission case 10. The PTO shaft transmits rotational power that has been appropriately reduced by the transmission to the working machine attached to at least the rear of the traveling body 2. The working machine is a machine that performs work in a field. For example, the working machine is a rotary tiller that performs tilling work in the field. The rotary tiller tills the field (soil) by rotating the tilling tines using the power transmitted from the PTO shaft.

[0027] The tractor 1 also includes a driving control unit 40 as shown in Fig. 5. The driving control unit 40 controls the engine E (40a is an engine ECU) and also controls the traveling speed of the traveling vehicle body 2 (40b is a traveling system ECU). The driving control unit 40 also controls the working equipment. 40c is a recording unit that records various data.

[0028] The tractor 1 also includes a positioning device 30. The positioning device 30 is provided on the upper part of the traveling body 2 and measures the position of the traveling body 2. The positioning device 30 is, for example, a Global Navigation Satellite System (GNSS), and can perform positioning and timing by receiving radio waves from a navigation satellite S orbiting in the sky. Here, the positioning device 30 is an example of the vehicle body position detection device of the present invention. Note that the vehicle body position detection device of the present invention is not limited to the positioning device 30, and may be realized by other means.

[0029] Also, 20 is a sensor that detects the direction (orientation) of the traveling vehicle body 2. 40h is a means for calculating the vehicle speed based on a signal from the positioning device 30. 40i is a timer. 40k is a traveling stop determination means that calculates how far the tractor 1 has traveled while the operator is away from the cockpit 8, based on the vehicle speed, and stops the tractor 1 when a predetermined distance is exceeded. Vs is a sensor attached to the vehicle body frame 3 that detects the speed of the tractor 1. 100 is a remote control device (remote control), and the tractor 1 can be remotely controlled by the operator operating the remote control device 100.

[0030] FIG. 3 is a block diagram showing an overview of the control of the work vehicle of this embodiment. A steering sensor 70 for detecting the steering angle is attached below the steering device 9. The output signal of this steering sensor 70 is output to the driving control unit 40. In other words, it is a steer-by-wire system. On the other hand, an output signal from a positioning device 30 that receives radio waves from a navigation satellite S and performs positioning is also input to the driving control unit 40. Furthermore, a control signal from the driving control unit 40 is output to a driving drive unit 71. The driving drive unit 71 drives a front wheel drive actuator 72 to change the direction of the front wheels 4,4. Reference numeral 73 denotes a front wheel angle sensor, the output of which is input to the driving control unit 40 and feedback controlled.

[0031] Next, an outline of how to cultivate a farm field with the tractor 1 will be described.

[0032] Fig. 4 is a diagram showing a typical travel route of the tractor 1. Here, 50 indicates a farm field, 50a indicates a main range area in the approximate center of the farm field 50 where the tractor travels back and forth, and 50b indicates a headland area outside the main range area 50a. 51 indicates a bank, and 52 indicates an entrance and exit. The headland travel route in the headland area 50b is set up in multiple steps (3 lines), with one revolution being one step. 53 indicates a road.

[0033] As shown by the dashed line, the tractor 1 performs automatic work traveling back and forth in the main range area 50a, and then performs automatic work traveling only once around the headland area 50b immediately surrounding the outer circumferential shape.

[0034] Such a route is set by the driving route setting means 40d of the driving control unit 40 and pre-recorded in the recording unit 40c. The driving system ECU 40b operates the steering device 9 and the transmission 10 while comparing the satellite signals received by the positioning device 30 with the pre-recorded route data to cause the tractor 1 to drive autonomously for work.

[0035] Furthermore, once the tractor 1 leaves the entrance / exit 52 and is on the road 53, the steering device 9 is manually operated to cause the tractor 1 to travel on the road. The control of the cruise control unit 40 according to the various modes will be described below.

[0036] As shown in FIG. 5, the driving control unit 40 can execute a driving mode control 40e, a work mode control 40f, and an automatic steering mode control 40g.

[0037] Here, the traveling mode control 40e is a control mode in which the brakes do not operate even when the steering device 9 is operated, and is a mode that is appropriate and used when traveling on a road 53. The work mode control 40f is a control mode in which the brakes operate according to at least the amount of operation of the steering device 9, and is a mode that is appropriate and used when performing various types of work in the field 50. The automatic steering mode control 40g is a control mode in which the steering device 9 is automatically steered along a preset travel route, and is a mode that is appropriate and used when traveling for work on a straight route in the field 50. That is, in a farm field, there is an automatic steering mode control 40g when the preset travel route is a straight line, and a control in which the vehicle body is traveled by manually operating the steering device 9. The former corresponds to the automatic straight-line mode control of the present invention, and the latter corresponds to the manual operation mode control of the present invention.

[0038] Further, the manual operation mode control and the automatic straight ahead mode control will be described.

[0039] In the manual operation mode control, as shown in Fig. 3, the steering sensor 70 detects the rotation angle of the steering device 9, and outputs a signal detected as the operation amount of the steering device 9 to the driving control unit 40. The driving control unit 40 controls the driving drive device 71, which is composed of a steering solenoid and the like, in response to the operation amount signal. Furthermore, the driving drive device 71 drives a front wheel drive actuator 72 to move the front wheels 4, 4. A front wheel angle sensor 73 detects the change angle of the front wheels 4, 4, and outputs the result to the driving control unit 40.

[0040] The traveling drive device 71 receives the signal and performs feedback control to control the front wheels 4,4.

[0041] On the other hand, in the automatic straight-line mode control, the positioning device 30 receives radio waves from the navigation satellite S and outputs the positioning signal to the driving control unit 40, and the driving control unit 40 compares the straight-line driving route recorded in advance in the recording unit 40c with the contents of the input positioning signal, and if they match, it leaves them as they are, but if they do not match, it outputs a command signal to the driving drive unit 71 to rotate the front wheels 4,4 in the direction that resolves the mismatch. The driving drive unit 71 drives the front wheels 4,4 accordingly.

[0042] However, under the automatic straight-line mode control, the driver may determine that the straight-line state is deviated while watching the traveling of the traveling vehicle body 2. This is because the accuracy of the navigation satellite S may decrease in mountainous areas. In such a case, the driver rotates the steering device 9 to the side that eliminates the deviation, even under the automatic straight-line mode control. If the driver wants to change to the left, the driver rotates to the left, and if the driver wants to change to the right, the driver rotates to the right. As a result, the steering sensor 70 detects the angle and outputs it to the traveling control unit 40. Since the signal is input from the steering sensor 70 even under the automatic straight-line mode control, the traveling control unit 40 determines that the deviation is eliminated, and changes and corrects the straight-line traveling path 74 previously set in the recording unit 40c in the direction that eliminates the deviation according to the angle (FIG. 6(B)). Thereafter, the traveling control unit 40 executes the above-mentioned straight-line control according to the corrected straight-line traveling path 74' (FIG. 6(A)).

[0043] 7 to 9 are explanatory diagrams showing the relationship between the operation of the steering device 9 and a straight-ahead travel path 74 under automatic straight-ahead mode control. As shown in FIG. 7, the straight-ahead travel path 74 moves parallel to the direction in which the steering device 9 is operated, depending on the amount of operation. That is, when the steering device 9 is steered clockwise from the neutral angle A to angle A', the straight-ahead travel path 74 moves parallel to the right with respect to the traveling direction of the vehicle, and is corrected to a straight-ahead travel path 74'. When the steering device 9 is further steered clockwise from angle A' to angle A'', the straight-ahead travel path 74' moves further parallel to the right and is corrected to a straight-ahead travel path 74''.

[0044] 8, the straight travel path 74 moves in parallel depending on the time for which the steering device 9 is operated. That is, when the steering device 9 is steered clockwise from the neutral angle A to angle A' and maintained for T seconds, the straight travel path 74 is corrected from the straight travel path 74' that moves in parallel to the right relative to the traveling direction of the vehicle immediately after the steering to a straight travel path 74'' that moves further in parallel to the right.

[0045] Immediately after that, as shown in Figure 9, when the steering device 9 is steered counterclockwise from angle A' to the neutral angle A, the straight traveling path 74'', which has been moving parallel to the right, is corrected to a straight traveling path 74' which has moved parallel to the left with respect to the traveling direction of the vehicle. In this way, the straight traveling path 74 moves parallel in proportion to the value obtained by integrating the steering amount of the steering device 9 with respect to time.

[0046] By controlling in this manner, the behavior of the tractor 1 in response to the operation of the steering device 9 under the automatic straight-line mode control becomes qualitatively similar to the behavior of the tractor 1 under the manual operation mode control, and automatic steering and manual steering can coexist without any sense of incongruity. Also, the original straight-line travel path 74 can be corrected to an arbitrarily shifted straight-line travel path 74' according to the steering time.

[0047] Furthermore, when the steering device 9 is steered by a predetermined steering amount (for example, 180 degrees) or more, the automatic straight-line mode control may be terminated or interrupted and the control may be switched to the manual operation mode control. This allows the tractor 1 to turn just by operating the steering device 9, without having to terminate the automatic straight-line mode control by a special operation.

[0048] By doing so, it is possible to correct the straight path in the automatic straight mode control in the same way as in the manual operation mode control.

[0049] As described above, the configuration of the present invention may be realized in software or in hardware.

[0050] Furthermore, the program of the invention related to the present invention is a program for causing a computer to execute all or part of the steps (or processes, operations, actions, etc.) of the control method of the invention related to the present invention described above, and is a program that operates in cooperation with a computer.

[0051] In addition, the recording medium of the invention related to the present invention is a recording medium having a program recorded thereon for causing a computer to execute all or part of the operations of all or part of the steps (or processes, operations and actions, etc.) of the control method of the invention related to the present invention described above, and is a computer-readable recording medium in which the read program is used in cooperation with a computer.

[0052] In addition, the above-mentioned "some steps (or processes, operations, actions, etc.)" means one or some steps among the multiple steps.

[0053] Furthermore, the above-mentioned "operation of a step (or process, operation, action, etc.)" means the operation of all or a part of the above-mentioned steps.

[0054] Furthermore, one mode of use of the inventive program related to the present invention may be in the form of being transmitted through a transmission medium such as the Internet, light, radio waves, or sound waves, being read by a computer, and operating in cooperation with the computer.

[0055] Furthermore, the recording medium includes a ROM (Read Only Memory) and the like.

[0056] Furthermore, a computer is not limited to pure hardware such as a CPU (Central Processing Unit), and may also include firmware, an OS (Operating System), and even peripheral devices. [Industrial Applicability]

[0057] The present invention provides a driving control mechanism for a work vehicle that unifies the operational feel of control changes for manual driving operation and automatic straight-line operation, and is improved in terms of both manufacturing and cost, making it ideal for agricultural work machines such as tractors. [Explanation of symbols]

[0058] 1. Tractor 2 Running vehicle 3 Body frame 4,5 front wheels, rear wheels 7. Control Section 8. Cockpit 9 Steering wheel 10 Mission Case 30 Positioning device (vehicle position detection device) 20 Orientation Sensor 40 Driving control unit 40a Engine ECU 40b Driving system ECU 40c Recording section 40d Travel route setting means 40e Driving mode control 40f Working mode control 40g auto steering mode control 40h Vehicle speed calculation means 40i Timer 40k Driving stop judgment method 40m Elapsed Time Calculation Method 40n Mileage calculation method 50 Fields 50a Main Coverage Area 50b Headland area 51 ridge 52 Entrance / Exit 53 On the road 60 Mode Switch 61 Automatic steering on / off switch 62 A, B point setting means 70 Steering Sensor 71 Traveling drive unit 72 Front wheel drive actuator 73 Front wheel angle sensor 74, 74', 74'' straight route E-Engine S GNSS Vs Speed ​​Sensor

Claims

1. A travel control mechanism for a work vehicle, comprising: a steering device for controlling a traveling direction of a traveling body; a steering sensor for detecting an operation amount of the steering device; a travel control unit for inputting an output of the steering sensor; a travel drive device for driving traveling wheels based on an instruction from the travel control unit; and a vehicle body position detection device for detecting a position of the traveling body, Equipped with a manual operation mode control and an automatic straight-line mode control, In the manual operation mode control, the travel control unit performs travel control in accordance with an operation amount of the steering device, In the automatic straight-line mode control, the driving control unit performs straight-line driving control based on a preset straight-line driving route and a detection signal from the vehicle body position detection device, A driving control mechanism for a work vehicle, characterized in that, under the automatic straight-line mode control, when the steering device is operated, the straight-line driving path is corrected in accordance with the amount of operation, and straight-line driving control is performed based on the corrected straight-line driving path and a detection signal from the vehicle body position detection device.

2. The vehicle body position detection device has a positioning device that receives signals from navigation satellites, The driving control unit stores straight driving route data in advance, 2. The work vehicle driving control mechanism according to claim 1, wherein under the automatic straight-line mode control, the driving control unit corrects the straight-line driving path in accordance with an amount of operation of the steering device, and performs driving control based on the corrected straight-line driving path and a detection signal from the positioning device.

Images