JPH0257482A - Control method for hydraulically-driven car - Google Patents

Abstract

PURPOSE:To provide possibility of automatic running along the desired operating path by calculating the running distance of a left and a right wheel from the sensed values of revolving speeds of the wheel of an oil-hydraulically operated car, and controlling the amount of discharged pressure oil in accordance with the result from comparison of this running distance from the running distance calculated for the target straight line. CONSTITUTION:When the vehicle concerned is run from the starting point A to the target point B, the revolving speeds of a left and a right wheel are sensed by rotation sensing devices 13a, 13b, and the running distances La, Lb of the wheels are determined through integration 21a, 21b of rotation signals. Then calculators 22a, 22b calculate La+Lb and La-Lb, respectively, and a setting device 23b sets (La+Lb)/2 while another 23a sets (La-Lb)/2H. Another calculator 24 multiplies the output of these setting devices 23b, 23a, and on the basis of the result from multiplication the control gain G is obtained with the aid of a calculator 27 and an integrator 29, and a left and a right hydraulic pump and the swash plate angle of hydraulic motor are controlled.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method of controlling a hydraulically driven vehicle.

In particular, the present invention relates to a method for controlling the straightness of a construction vehicle that combines a pump and a motor.

[Conventional technology] Conventionally, in hydraulically driven vehicles used for construction vehicles, etc.
Approximately 30% when moving the vehicle forward or backward on a straight path
It is desired to maintain a straight path with a deviation of no more than about 30 cm for each step. For this purpose, each wheel 51 is
．． 52 or the rotational speed of the orbit is 8 with a tachometer of 53.54
11 and compared in the electronic orbit control device 55, il
(The vehicle @ A control method for making the rotational speeds of 51 and 52 the same is known.

[Problems to be Solved by the Invention] However, according to the conventional control method for a hydraulically driven vehicle, the relative difference in the rotational speed of the wheels or the track is determined and the rotational speeds of the wheels are made the same. The disadvantage is that once the vehicle starts traveling and turns once, the driver cannot reach the target because the direction is different even if the rotational speed of the wheels is the same, and the driver must operate the vehicle to reach the desired target. .

The present invention has focused on the above-mentioned conventional problems, and aims to provide a control method for a hydraulically driven vehicle that allows the driver to reach a desired target without any operation.

[Means for Solving the Problems] In order to achieve the above object, a method for controlling a hydraulically driven vehicle according to the present invention detects the rotational speed of the left and right rotating wheels by a detection means, and determines the rotational speed of the rotating wheels from the detected rotational speed. Calculate the distance traveled,
The displacement of the direction and position in which the hydraulically driven vehicle is traveling is determined from the travel distance calculated for one oscillation straight line, and the discharge of at least one of the pump and motor is adjusted so that at least one of them is within the allowable value. It is characterized by increasing or decreasing the amount.

[Function] According to the above configuration, the rotational speed of each wheel or track is measured, each measured rotational speed is calculated into a traveling distance and compared, and the direction and distance of the wheel or track are determined from the traveling distance of the target straight line. The system determines the positional deviation and outputs an electrical signal based on the difference to operate the pump and/or the motor to increase or decrease the discharge amount, thereby maintaining the desired working path without operator operation. Control the rotation speed of each wheel.

[Example] Hereinafter, an example of a method for controlling a hydraulically driven vehicle according to the present invention will be described in detail with reference to the drawings. FIG. 1 is an overall configuration diagram of one embodiment of the present invention, FIG. 2 is a diagram illustrating the bending of a vehicle during running in one embodiment, and FIG. 3 is a block diagram. In Figure 1, a power source 1 such as an engine
A pair of variable displacement pumps 28.2b (hereinafter referred to as pumps) are connected to the pipes 3a and 3b.

Variable displacement motors 5a and 5b (hereinafter referred to as motors) are driven via motors 4a and 4b to rotate left and right wheels 6a and 6b. The pumps 2a, 2b are equipped with control units 7a, 7b consisting of servos, etc., on the pump swash plates 8a, 8b.
The motors 5a and 5b are provided with a control device 9a including a servo, etc.
9b is connected to the motor swash plates 10a, 10b, and based on commands from the controller 11, the positions of the pump swash plates 8a, 8b and the motor swash plates 10a, 10b are controlled by control devices 7a, 7b, 9a, 9b consisting of servos, etc. is determined, the determined pump capacity is discharged, and each motor 5a, 5b is rotated based on a command from the controller 11.

The controller 11 receives a speed signal from an operating lever 12 (hereinafter referred to as the lever) according to the lever position and a straight-line signal 6.
and rotation signals are input. Also, the left and right wheels 6a, 6
Rotation detection devices 13a and 13b such as tachometers are provided at b, and each rotation signal is fed back to the controller 11. The controller 11 includes RAM, ROM, C
It consists of a PU, a clock oscillator, etc. Furthermore, check valves L4 are installed on the pipes 3a, 3b, 4a, and 4b.
An amount of oil corresponding to the amount of leakage is supplied from pumps 15a and 1.5b via a and 14b. The operation of the above configuration will now be described with reference to FIGS. 2 to 4.

In Figures 2 and 3, when going from the starting point Δ to point B, when the vehicle moves from point P to point Q at time T, the traveling distance of the left wheel is La, and the distance of the right wheel is The distance traveled is Lb, the deviation of I'1 neck is y, and the deviation in one direction is θ.

, the width at the center of the wheel is 11. Now, when a command is output from the lever 12 to travel on the 11x forward route, the rotation detection devices ff 13 a, 13 for the left and right wheels 6 a - 6 b
Rotation is detected at point b and a rotation signal is transmitted to integrators 21a and 21b. The integrators 2La and 21b integrate each time according to the signal from the timer clock oscillator, and the left and right wheels 6a
, 6b are calculated, and the computing unit 22a,
22b.

The arithmetic unit 22b adds La + L b, and the arithmetic unit 22a subtracts La-Lb, setting 8:÷23a.
, 23b. In setting X23b (La+Lb)
/2 is set and sent to the calculators 24 and 25, and the setter 23a inputs (
La-Lb)/2H is set and output to the arithmetic unit 24 and integrator 26. In the arithmetic unit 24, ((La+Lb)/2)X
((La = L b ) / 2 (I)) is calculated and transmitted to the arithmetic unit 27 .

In the integrator 26, the direction deviation is 0, =I11. ．． ．． l+((
L a - L b ) / 2 H) is determined, and the signal from the lever 12 receives via the OR circuit 28 whether or not the rotation signal (STR, 5TL) is commanded.
If a command is given, the integration is stopped and canceled; if not, it is transmitted to the arithmetic unit 26. In the computing unit 25, 0. ,
−++ ((La Lb)/2H) is computed and transmitted to the computing unit 278. In the arithmetic unit 27, [0−−+ + ((
L a −L b ) / 2) I)] X ((La
+Lb)/2) is calculated, and the integrator 29 calculates the position shift y.
. =y−−++((La+Lb)/2)Xθ−−++
((La" Lb)/4H) is obtained, and the control gain G is obtained by receiving the signal from the lever 12 to confirm whether or not the rotation signal (STR, 5TL) is commanded via the OR circuit 28. Control devices 7a and 7b each include left and right pumps, motor servos, etc., and use this control gain G to slow down fast-rotating wheels and speed up slow-rotating wheels.

The positions of the pump swash plates 8a, 8b and the motor swash plates 10a, 10b are determined by 9a, 9b, and the determined pump capacity is discharged, and each motor 5a, 5b corrects its rotation based on the command from the controller 11. ing.

In the above example, an open circuit was used for the pump and motor circuit, but an open circuit may also be used, and the pump and motor were combined with a variable displacement pump swash plate and a variable displacement motor.
It goes without saying that a variable displacement pump swash plate and a fixed displacement motor, and a fixed displacement pump swash plate and a variable displacement motor may be used.

[Effects of the Invention] As explained above, according to the present invention, the number of rotations of the left and right rotating wheels is detected to control a hydraulically driven vehicle, and the traveling distance of the rotating wheels is calculated from the detected number of rotations, The displacement of the direction and position of the vehicle is calculated from the travel distance calculated for the target straight line, and the discharge amount of at least one of the pump and motor is increased or decreased so that at least one of them is within the allowable value. The rotational speed of each wheel can be controlled to maintain the desired working path without any operation by the driver. Therefore, excellent effects such as easier operation can be obtained.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of one embodiment of the present invention. FIG. 2 is a diagram illustrating the bending of a vehicle during driving according to an embodiment of the present invention. FIG. 3 is a block diagram of the present invention. FIG. 4 is an overall configuration diagram of a conventional embodiment. 9a, 9b-1/Variable field 11 (shaped motor control device 10
a, 10 b-・Swash plate 11 of variable displacement motor...
- Controller 12 - - Operation lever Applicant: Komatsu Ltd. 1 -... 2 a, 3 a, 5 a. 6a. 7a. 8a. Power source 2b =... Variable displacement pump 3b, 4a, 4b - = Piping 5b...
- Variable displacement motor 6b - Left and right wheels 7 b - Variable displacement pump control device 8b =
...-Swash plate of variable displacement pump

Claims (1)

[Claims] In a hydraulically driven vehicle that transmits power by combining a pump and a motor, the number of revolutions of the left and right rotating wheels is detected by a detection means, the distance traveled by the rotating wheels is calculated from the detected number of revolutions, and the target distance of the hydraulically driven vehicle is determined. The method is characterized in that the displacement in the traveling direction and position is determined from the travel distance calculated for a straight line, and the discharge amount of at least one of the pump and the motor is increased or decreased so that at least one of them is within a tolerance value. How to control a hydraulically driven vehicle.