JPH0619405U - Steering control device for agricultural machinery - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a steering control device that enables a traveling vehicle to go straight even if there is no target on the ground. [Structure] An angular velocity sensor 33 is mounted on the traveling machine body so as to detect angular velocity fluctuations in the turning direction, and the detection signal is input to a central processing unit (CPU) 30 such as a microcomputer mounted on the traveling machine body to drive the vehicle. The power steering device 20 in the traveling machine body is controlled so as to move in the traveling direction in which the machine body is set.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a steering control device for an agricultural work machine such as a tractor.

[0002]

[Prior art]

 As a conventional technique for moving a traveling machine body along a traveling direction set in advance, for example, Japanese Patent Laid-Open No. 60-234507 discloses a case where a speed sprayer is run between tree rows. The optical sensors and ultrasonic sensors detect trees standing on the left and right sides of the straight road, and control the steering so that they do not collide with these trees. In Japanese Patent Laid-Open No. 62-61507, a lawn is used to image the boundary between the already cut and uncut areas with a video camera, the direction of the boundary is calculated, and the vehicle runs along the boundary. It is disclosed that the aircraft is advanced.

[0003]

[Problems to be solved by the device]

 However, if there is no such mark, for example, when towing a tiller with a towing vehicle such as a tractor, it may be desirable to keep the steering handle of the towing vehicle set at the beginning. In such a case, the above control means could not be adopted.

Therefore, it is conceivable that the power steering apparatus is provided with a detector such as a potentiometer for detecting the direction of the wheels, and the control for correcting and holding the state where the direction of the steering wheel is first set is executed during traveling. It was However, there was a problem that the detected value of the wheel orientation (angle detected value) would be greatly deviated to the left or right when traveling a long distance even with a small error.

The present invention aims to solve this problem.

[0006]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the steering control device for an agricultural work machine of the present invention is an agricultural work machine in which a traveling machine body such as a tractor is equipped with a power steering device, and the traveling machine body is provided with an angular velocity sensor. The control means is provided so as to detect the angular velocity fluctuation in the turning direction of the vehicle while controlling the power steering device so that the traveling direction is set in accordance with the output signal from the angle sensor. Is.

[0007]

【Example】

 Next, an embodiment embodying the present invention will be described. 1 is a plan view of the tractor and the rotary tiller, and FIG. 2 is a side view thereof. The tractor 1 as a towing vehicle is provided with front and rear wheels 3, 3, 4, 4 on both left and right sides of the traveling machine body 2, and the power of an engine 5 mounted on the front part of the traveling machine body 2 is transmitted via a main clutch 6 to a mission. It is transmitted to the transmission mechanism in the case 7 and transmitted to the rear wheels 4 and 4.

A pair of left and right connecting links 10, 10 are pivotally supported at the rear end of the traveling machine body 2 so as to be vertically rotatable, and the tip ends of the pair of connecting links 10, 10 are turned to the rotary tiller 9. Connect movably. At the rear end of the traveling machine body 2, a pair of left and right raising and lowering arms 11 and 11 arranged above the connecting links 10 and 10 is configured to be driven up and down via a lifting and lowering hydraulic mechanism 17, and one lifting and lowering arm is provided. The arm 11 and the connecting link 10 below it are connected by a connecting rod, while the other elevating arm 11 and the connecting link 10 below it are connected by a hydraulic cylinder 12 that is extendable and retractable. As a result, the rotary tiller can be moved up and down, and it is possible to roll it left and right. Further, it is transmitted to the rotary tiller 9 through the PTO shaft 8 projecting to the rear end of the mission case 7 and the universal joint, and rotationally drives the rotary tiller 13. Reference numeral 14 is a leveling plate made of a rubber plate or the like, and reference numeral 15 is an auxiliary wheel provided behind the leveling plate 14.

The hydraulic pressure to the lifting hydraulic mechanism 17 and the hydraulic cylinder 12 is supplied by a hydraulic pump 16 which is operated by rotational driving of the engine 5. FIG. 3 shows a power steering device 20 such as hydraulic pressure and its control means 21, which responds to the rotation of the steering wheel 22 for turning the front wheels 3, 3 of the traveling machine body 2 left and right. When the lever 24 protruding from the steering gear box 23 is rotated, the hydraulic cylinder 26 is operated via the control valve 25, and the steering arm 27 of the front wheels 3, 3 is rotated, the steering arm 27 is rotated. The direction of the left and right front wheels 3, 3 is changed via the tie rods 28, 28 attached to. A potentiometer 29 for detecting the turning angle (steering angle) is attached to the pivot of the steering arm 27.

Reference numeral 30 is a central processing unit (CPU) in the control means 21 such as a microcomputer mounted on the traveling machine body 2, and includes a read-only memory (ROM) 31 in which a control program and the like are stored and various controls A random access memory (RAM) 32 for temporarily storing data and the like and an interface (not shown) are provided.

On the other hand, an angular velocity sensor 33 in which a rotation axis of a gyro (not shown) is oriented in a vertical (vertical) direction is mounted at a position of a center (turning center) of the traveling machine body 2. A detection signal of the potentiometer 29 is input to a central processing unit (CPU) 30 via an interface, an operation described later is appropriately executed in the central processing unit 30, and then the hydraulic cylinder 26 is operated via the interface. A control signal is output to an actuator (drive circuit) such as the electromagnetic solenoids 35 and 36 of the steering control valve 34.

When the traveling vehicle body 2 is controlled to move straight, the steering wheel 22 is appropriately rotated so that the front wheels 3 and 3 are in a straight traveling state. The detection signal of the angular velocity sensor 33 is stored in the readable / writable memory (RAM) 32 as needed based on this state. At this time, the detection signal of the potentiometer 29 is used to check the direction in which the wheel is in the straight traveling state.

Next, when the traveling machine body 2 changes its direction to the left or right while the traveling machine body 2 moves forward, the detection signal from the angular velocity sensor 33 is generated by turning the traveling machine body 2 to the left or right. Fluctuates. The central processing unit 30 calculates the difference between this detector signal and the reference signal, outputs a control signal to the electromagnetic solenoids 35 and / or 36, operates the automatic steering control valve 34, and causes the hydraulic cylinder 26 to operate. The driving force is used to control so that the so-called rudder is returned to the straight traveling state. Note that, in the angular velocity sensor 33, the detection signal as it is is the degree of fluctuation speed in the left and right directions of the traveling vehicle body 2. However, if this is integrated over a time period that fluctuates, the lateral fluctuation angle of the traveling vehicle body 2 with respect to the straight traveling direction is quickly calculated. Therefore, the potentiometer 29 does not have to be used, but the detection signal of the potentiometer 29 can verify the direction of the front wheels 3, 3 as a result of steering control.

Further, according to the detection signal of the angular velocity sensor 33, the reference value when the traveling vehicle body 2 is oriented in the reference direction and the instantaneous (temporary) fluctuation of the leftward or rightward rotation of the traveling vehicle body 2 are detected. You can be sensitive. Furthermore, if a gyro-type angular velocity sensor is used as in this embodiment, external magnetic disturbances such as when traveling under a high-voltage line are not received, so steering control can be performed more accurately. Can be executed.

[0015]

[Operation and effect of the device]

 As described above, according to the present invention, in an agricultural work machine in which a traveling machine body such as a tractor is provided with a power steering device, an angular velocity sensor is provided on the traveling machine body to detect angular velocity fluctuations in the turning direction of the traveling machine body. On the other hand, since it is provided with a control means for controlling the power steering device so that the traveling body is set in the traveling direction by the output signal from the angle sensor, even if there is no mark on the ground. This has the effect that the direction of travel can be set in a self-contained manner, and steering control for swift straight ahead can be executed.

[Brief description of drawings]

FIG. 1 is a plan view of a tractor and a rotary tiller.

FIG. 2 is a side view of a tractor and a rotary tiller.

FIG. 3 is a block diagram of a power steering device and control means.

[Explanation of symbols]

 2 traveling machine body 3 front wheel 4 rear wheel 9 rotary tiller 20 power steering device 21 control means 22 control handle 25 control valve 25 hydraulic cylinder 33 angular velocity sensor 34 automatic steering control valve

Claims (1)

[Scope of utility model registration request] 1. In an agricultural work machine comprising a power steering device on a traveling machine body such as a tractor, the traveling machine body is provided with an angular velocity sensor so as to detect angular velocity fluctuations in the turning direction of the traveling machine body, and A steering control device for an agricultural work machine, comprising control means for controlling the power steering device so as to move in a traveling direction in which the traveling machine body is set by an output signal from a sensor.