JPH04176778A - Steering control device for mobile working vehicle - Google Patents

Abstract

PURPOSE:To allow the parallel displacement to a target position by correcting a drive signal outputted from a control unit to a front wheel steering driving device and a rear wheel steering driving device on the basis of the detection result from an inclination sensor. CONSTITUTION:A drive signal is outputted from a control unit 17 to a front wheel steering driving device 11 and a rear wheel steering driving device 14 on the basis of the steering operation signal from a remote controlled setter 19, and a moving working vehicle is steered. At the time of running operation by the same phase mode, the drive signal is corrected on the basis of the detection result from an inclination sensor 18 so that the steering angles of a valley side front wheel 1 (2) and a valley side rear wheel 3 (4) are conformed to each other. Thus, the front wheels 1, 2 and the rear wheels 3, 4 can be steered so as to conform the steering angles of the valley side front wheel 1 (2) and the valley side rear wheel 3 (4) to each other. In the case of displacing the moving working vehicle in parallel obliquely on an inclined ground, it can be precisely moved to a target position.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a steering control device for a mobile work vehicle in which both front wheels and rear wheels are steered.

Conventional technology Conventionally, in a mobile work vehicle with a four-wheel body in which both the front and rear wheels are steered, there is an in-phase mode in which the front wheels and rear wheels are steered in the same direction, and an in-phase mode in which the front wheels and rear wheels are steered in the same direction. It is common to have an anti-phase mode for steering in the opposite direction. When turning the mobile work vehicle, the front and rear wheels are steered in opposite directions using the reverse phase mode, and when the mobile work vehicle is moved diagonally in parallel, the front and rear wheels are steered in the opposite direction using the same phase mode. are being steered in the same direction.

Further, the front wheel and rear wheel steering mechanisms are generally configured to satisfy the Ackermann theory when turning the mobile work vehicle by steering operation in an antiphase mode. That is, the front wheels are as shown in Figure 6.
In the case of right steering, the steering angle of the right front wheel is larger than the steering angle of the left front wheel, and in the case of left steering, the steering angle of the left front wheel is larger than the steering angle of the right front wheel. On the other hand, for the rear wheels, as shown in Figure 7, when steering to the right, the steering angle of the left rear wheel is larger than that of the right rear wheel, and when steering to the left, the steering angle of the right rear wheel becomes larger. The angle becomes larger than the steering angle of the left rear wheel.

Problems to be Solved by the Invention Therefore, when a mobile work vehicle is moved diagonally in parallel by steering operation in the same phase mode, the steering angle between the right front wheel and the right rear wheel, and the left front wheel and left rear wheel are It is not possible to match the steering angle with the

Furthermore, on a slope, the center of gravity of the mobile work vehicle moves to the valley side and the driving force of the wheels on the valley side increases.
The traveling direction of the mobile work vehicle is determined by the steering angle of the front wheels on the valley side and the rear wheels on the valley side, but because the steering angles of the front wheels on the valley side and the rear wheels on the valley side are different, It is difficult to move the object in parallel to the desired position.

Means for Solving the Problems A front wheel steering drive device connected to the front wheels, a rear wheel steering drive device connected to the rear wheels, and a front wheel steering drive device connected to the front wheels based on a steering operation signal from a steering operation section. The mobile work vehicle is provided with the rear wheel steering drive device and a control device that outputs a drive signal for driving the rear wheel steering drive device, and the mobile work vehicle is provided with a tilt angle sensor that detects the tilt of the mobile work vehicle in the left-right direction, and the vehicle is steered in the same phase mode. A correction means is provided for correcting the drive signal during operation based on the detection result from the tilt angle sensor.

When a mobile work vehicle is moved diagonally in parallel by steering operation in the same phase mode, the drive signal output from the control device to the front wheel steering drive device and the rear wheel steering drive device is based on the detection result from the tilt angle sensor. The front wheel steering drive device and the rear wheel steering drive device are driven based on the corrected drive signal.

Example An embodiment of the present invention will be described based on the drawings.

On the abdomen of the mobile work vehicle 5, in which the left and right front wheels 1, 2 and the left and right rear wheels 3, 4 are both steered, a wheel is located between the front wheels 1, 2 and the rear wheels 3, 4. A mower 6 is attached so as to be movable up and down. The front wheels 1 and 2 are connected to each other by a ring mechanism 7 configured to satisfy Ackermann theory, and the rear wheels 3 and 4 are connected to each other by a link mechanism 8 configured to satisfy Ackermann theory. .

Next, on the front wheels 1 and 2 side, there is a moving member 10 that extends in the front-rear direction and is rotatable in a horizontal plane around the support shaft 9.
The distal end of the movable member 10 is connected to the link mechanism 7, and the front wheel 1 is connected to the rear end of the movable member 10.
, 2 are connected to a front wheel steering drive device 11 for steering the wheels. Similarly, a movable member 13 is provided on the rear wheels 3 and 4 side and extends in the front-rear direction and is rotatable in a horizontal plane around a support shaft 12.
3 is connected to the link mechanism 8, and the moving member 1
A rear wheel steering drive device I4 for steering and driving the rear wheels 3 and 4 is connected to the tip of the rear wheel 3. A front wheel steering angle detector 15 for detecting the front wheel steering angle is provided on the outer periphery of the support shaft 9, and a rear wheel steering angle detector 16 for detecting the rear wheel steering angle is provided on the outer periphery of the support shaft 12. is provided.

Further, the mobile work vehicle 5 is connected to the front wheel steering angle detector 15 and the rear wheel steering angle detector 16, and the front wheel steering drive device 11
A control device 17 is provided to which the rear wheel steering drive device 14 and the rear wheel steering drive device 14 are connected. Furthermore, the mobile work vehicle 5 is provided with a tilt angle sensor 18 that detects the tilt of the mobile work vehicle 5 in the left-right direction.
8 is connected to the control device 14.

Next, a remote setting device 19 is provided which is a steering operation section for remotely controlling the mobile work vehicle 5, and a steering operation signal from this remote setting device 19 is inputted to the control device 17 by radio. be done. The remote setting device 19 includes a steering setting device 20 for setting a steering target operation angle (operation direction and operation amount), and a steering mode switching device 21 for switching the steering mode between an in-phase mode and an anti-phase mode. A vehicle speed setting device 22 for setting the vehicle speed of the vehicle 5 is provided. Then, from the control device 17, the remote setting device 19
A drive signal is outputted to the front wheel steering drive device 11 and the rear wheel steering drive device 14 based on the steering operation signal from the mobile work vehicle 5, and the mobile work vehicle 5 is steered.

Here, in the control device 17, during driving operation in the same phase mode, based on the detection result from the inclination angle sensor 18, the front wheel l (or 2) on the valley side and the rear wheel 3 ( or 4) is provided with a correction means (not shown) for correcting the drive signal so that the steering angle coincides with the steering angle.

In such a configuration, first, the entire steering control of the mobile work vehicle 5 will be explained based on the flowchart of FIG. 8. A steering target operation angle is input from the steering setting device 20, and a steering mode is input from the steering mode switching device 21. When the steering mode is the anti-phase mode, the steering angle of the right front wheel 2 and the right rear wheel 4 are adjusted according to the direction of steering operation, as shown in FIG. 5(a) in the case of a right turn. In the case of left turning, the steering angles ``θ1'' of the left front wheel 1 and the steering angle ``θ1'' of the left rear wheel 3 become equal, as shown in FIG. 5(b). A steering operation is performed that makes θ and ″ equal. Therefore,
The mobile work vehicle 5 turns smoothly with a small turning radius. On the other hand, when the steering mode is the same phase mode, the drive signal is corrected by the correction means based on the detection result from the tilt angle sensor 18, and a steering operation is performed based on the corrected drive signal.

Next, correction of the drive signal (correction of the steering angle) during the steering operation in the same phase mode will be explained based on FIG. 9. In addition, on a slope, as shown in FIG. 3, the center of gravity of the mobile work vehicle 5 moves to the valley side, and as a result, the driving force between the front wheels on the valley side and the rear wheels on the valley side increases.
The traveling direction of the mobile work vehicle 5 is determined by the front wheel on the valley side and the rear wheel on the valley side. The detected value (tilt angle) "α" detected by the tilt angle sensor 18 is input to the determination means in the control device 17, and this tilt angle "α" and the determination value "-" for determining left tilt are input.
A comparison is made between β'' and a determination value ``+β'' for determining rightward tilt.

In the case of “α ku 1 β”, it is determined that the work area is inclined to the left, and as shown in Fig. 4 (a), the steering angle ゛ θ 1 ′ of the left front wheel 1 and the left rear Steering angle of wheel 3 ``θ,''
The drive signal is corrected so that they are equal, and the steering angle is corrected along with the correction of the drive signal.

In the case of α〉+β″, it is determined that the work area is inclined to the right, and as shown in FIG. 4(C), the steering angle of the right front wheel 2 is The drive signal is corrected so that the steering angles ``θ4'' of the steering angles are equal to each other, and the steering angle is corrected along with the correction of the drive signals.

On the other hand, in the case of '-β〈α+β'', it is determined that the work area is flat, and as shown in Fig. 4(b), the average steering correction of the left and right front wheels is 1.2. is performed, and the steering angle is corrected along with the correction of the drive signal.

Therefore, when traveling on a slope, when moving the mobile work vehicle 5 diagonally in parallel in the same phase mode, the front wheels on the valley side and the rear wheels on the valley side, which determine the traveling direction of the mobile work vehicle 5, Since the steering angles are equal, the mobile work vehicle 5 can be accurately translated in parallel to the target position.

Effects of the Invention The present invention is provided with an inclination angle sensor that detects the inclination of the mobile work vehicle in the left-right direction as described above, and when the front wheels and rear wheels are being steered in the same phase mode, the control device By correcting the drive signals output to the front wheel steering drive device and the rear wheel steering drive device by the correction means based on the detection results from the inclination angle sensor, the steering between the front wheels on the valley side and the rear wheels on the valley side is corrected. The front wheels and rear wheels can be steered so that the angles match, and when moving the mobile work vehicle diagonally in parallel on a slope, it can be moved accurately to the desired position. .

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; FIG. 1 is a block diagram showing a steering control system, FIG. 2 is a side view showing the entire mobile work vehicle, and FIG. 3 is a mobile work vehicle for use on slopes. FIG. 4 is an explanatory diagram showing the steering angle of the front wheels and rear wheels after correction by the correction means, and FIG. 5 is an explanatory diagram showing the change in the center of gravity position. FIG. FIG. 6 is an explanatory diagram illustrating the steering angle between the front wheels and the rear wheels in the case where the correction is not performed by the correction means. Figure 8 is an explanatory diagram showing the relationship between the rear wheel steering angle and the rear wheel steering angle in a state where no correction is performed by the correction means.
The figure is a flowchart explaining the entire steering control, and FIG. 9 is a flowchart explaining the correction by the correction means. 1.2...Front wheel, 3,4...Rear wheel, 5...Mobile work vehicle, 11...Front wheel steering drive device, 14...
・Rear wheel steering drive device, 17...control device, 1
8... Tilt angle sensor, 19... Steering operation unit amount Requester Ishikawajima Shibaura Machinery Co., Ltd. JL4-841
1j SuT Rino'J'Nl! Dμ [1113 Figures (a) (b) (c) ,,y3LL Figure (a) (b) (C)=
03 Eclipse=Go to 22e2″e.” 5 Figures (a) (b) θ2゛θ4 θ1゛O3 Left steering left rear wheel J3 q Figure

Claims (1)

[Claims] a front wheel steering drive device connected to the front wheels; a rear wheel steering drive device connected to the rear wheels; and a front wheel steering drive device and the rear wheel steering drive device based on a steering operation signal from a steering operation section. A mobile work vehicle is provided with a control device that outputs a drive signal to drive the mobile work vehicle, and a tilt angle sensor is provided to detect the tilt of the mobile work vehicle in the left-right direction, and the drive signal is output during steering operation in the same phase mode. A steering control device for a mobile work vehicle, comprising a correction means for correcting based on a detection result from the inclination angle sensor.