JPH0693803B2 - Posture control device for ground work equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention automatically maintains the working depth, left-right posture, and front-back posture of a ground work machine at the working depth and left-right posture specified by an operator. The present invention relates to a control device for plowing depth and the like, which is mainly applicable to tractors and the like.

[Conventional technology]

For example, the conventional tilling depth control device is detected by the tilling depth setting value specified by the tilling depth setting device operated by the investigator and the tilling depth sensor provided in the ground work machine. The control unit constantly calculates an eccentricity value, which is the difference between the detected working depth and
The ground work machine is automatically moved up and down to eliminate this eccentricity value.Since the unevenness of the ground surface always affects the plowing depth detection value, the control unit can control it based on the momentary fluctuation of the plowing depth detection value. The lift command is constantly output, and the hydraulic lifter groove of the tractor moves up and down from beginning to end.

[Problems to be solved by the invention]

However, even if a certain time is required for the operation of the hydraulic lifting mechanism and the controller constantly gives commands,
It is not possible to follow this, and for example, even though the lowering command has already been output, it can be said that the hydraulic lifting mechanism has just begun to rise, so due to the operation delay, the lifting operation is constantly repeated and becomes the hunting state, There is a problem that the working depth cannot be stable.

Then, in order to prevent such hunting, a dead band is provided by giving a certain width to the set value, but if the dead band is widened, the control delay becomes large.

[Means for solving problems]

According to the present invention, for example, stable control is performed for local unevenness, but a plowing depth control device devised so as to respond quickly when the detected value is changing in a direction outside the set value range. The configuration is specified by a setter (I ₁ ) that specifies the control state of the working depth (2) of the ground working machine (2) connected to the tractor (1) and the lateral posture. The plowing depth and left / right posture of the ground work machine (2) are controlled so that the detection value (D) detected by the sensor (S ₁ ) for detecting the plowing depth / horizontal direction is within the set value range. A tractor having a control unit (13) for operating the detected value (D) only when the detected value (D) changes in a direction away from the set value range (R). The control unit (13) is configured to control the ground work machine (2) to return it to the inside of R). An attitude control system of the ground working machine, characterized.

[Action]

Even when the detected value is out of the set value range, if the detected value is changing toward the set value range,
Since the control for changing the plowing depth and the horizontal posture of the ground work implement (2) is not performed, the detected value will soon fall within the set value range due to the change in the approaching direction. When the overshoot from the range disappears and the detected value is changing away from the set value range, the control operation will be performed to return the detected value to the set value range.
Despite the change in the approaching direction, the problem of jumping out of the set value range due to the forced control operation toward the set value range can be solved.

〔Example〕

Next, one embodiment of the present invention will be exemplarily described in the case of tilling depth control.

As shown in the side view in FIG. 2, the ground work implement (2) is attached to the tractor (1) and the lower links (3) at the lower left and right,
A lift piston (8) of a lift cylinder (7) of a hydraulic lifting mechanism (6), which is connected by a working machine connection link mechanism (5) consisting of (3) and a top link (4) at the center upper part.
The left and right lift arms (9), (9) that move up and down as the robot moves in and out are moved to the left and right lift rods (10), (10).
It is connected to the lower links (3) and (3) via the, and is set by the operator using the setting tool (I ₁ ) for the working depth, which is composed of something like a volume, for automatic control of the working depth. Until the detection value of the working depth detected by the sensor (S ₁ ) for detecting the working depth of the ground working machine (2) matches the set value range (R) of the working depth, the rising solenoid valve (11 ) Or a command to turn on / off the lowering solenoid valve (12) from a control section (13) configured by a microcomputer or the like, an ascending drive section (14) or a lowering drive section (15). It is amplified and output via the solenoid valve for raising (11).
The lowering solenoid valve (12) is a proportional solenoid valve that controls opening and closing of the flow oil opening area in proportion to the amount of current applied to the solenoid. A control current having a magnitude proportional to the difference is output from the control section (13), and a pulse current having a pulse width proportional to the control current value is added to the solenoid section. The pressure oil flow rate is supplied to or discharged from the lift cylinder (7) to cause the lift arm (9).
The ascending / descending speed of is also proportional to this difference.

As the sensor (S ₁ ) for plowing depth in the illustrated example, a sensor which detects the movement of the rear cover (16) which is in sliding contact with the surface of the cultivated soil by, for example, a linear movement type potentiometer (17) is used. .

Then, when the detected value (D) is outside the set value range (R) and the detected value is changing from the set value range (R) toward the approaching direction, the control operation of the ground work implement (2), that is, the raising and lowering operation. When the detected value (D) changes in a direction away from the set value range (R) so that no operation is performed, the detected value (D) is returned within the set value range (R), A control unit (13) is configured so that an ON / OFF operation command of the solenoid valve (11) or the descending solenoid valve (12) is output, and a detection value (D) is shown in the upper part of FIG. The vertical axis represents the mileage or the horizontal axis represents the travel distance or time, and the detected value (D) deviated upward from the set value range (R).
Changes away from the set value range (R) (away from the upper limit value (Ru) of the set value range (R)) U ₁ , U ₂ , U ₃
In between, as shown in the lower part of Fig. 3, the lowering solenoid valve (11)
Is turned on, and the detected value (D) is changing so as to approach the set value range (R), between N ₁ , N ₂ and N ₃ ,
The descending solenoid valve (11) remains off, and the detection value (D) that has fallen downward from the set value range (R) moves away from the set value range (R) (the lower limit value of the set value range (R) ( between V _1, V ₂ are changed as far away) from Rd) will become the increase solenoid valve as shown in FIG. 3 the lower (12) is turned on, the detected value (D) is set During K ₁ and K ₂ which are changing so as to approach the value range (R), the rising solenoid valve (12) is controlled to remain off.

In the illustrated example, a normal control value range (Rm) is provided outside the set value range (R), and the detected value (D) exceeds the normal control value range (Rm), for example, during Um, The control unit (13) is configured to control the ON operation of the lowering solenoid valve (11) so that the detected value (D) falls within the normal control value range (Rm).

The control procedure described above is shown as a flow chart in FIG.

In FIG. 1, reference numeral (16) is an up / down switch, and while the up / down switch (16) is operated, the up command is connected and output, and is operated to the down position (18). It is configured so that the descending command is connected during the period.

In addition, the rotation angle of the lift arm (9) is controlled so that the ground work implement (2) is controlled to the lift set value as the height designated by the lift setter (I ₂ ) composed of something like a volume. The control unit (13) controls the ascending drive unit (14) and the descending drive unit (15) so that the lift detection values of the lift sensor (S ₂ ) configured by a potentiometer are the same. It is driven.

When controlling the left-right direction posture of the ground work implement (2),
Instead of the plowing depth sensor (S ₁ ), for example, a bubble type or pendulum type right inclination sensor is provided in the ground working machine (2) or the tractor (1), and the front and rear direction of the ground working machine (2) When controlling the posture, a front-back inclination sensor such as a bubble type may be provided, and the present invention provides a ground work machine (2).
It is applicable to various controls of

〔The invention's effect〕

The tillage depth control device according to the present invention is configured as described above, and the detection value (D) is set even when the detection value (D) is out of the set value range (R). When the value is changing toward the value range (R), the control for changing the plowing depth and the horizontal posture of the ground working machine (2) is not performed, and therefore the detected value ( D) will soon fall within the set value range (R), and there will be no overshoot from the set value range, and the set value range (R)
When the detected value (D) is moving away from,
Since the control operation is performed to return the detected value (D) to within the set value range (R), it is forced toward the set value range (R) despite the change in the approach direction. The problem of popping out of the set value range (R) due to the control operation is solved, and by setting the set value range (R) to an appropriate size that is not excessive, for example, When the detected value (D) exceeds the set value range (R) due to small unevenness of the ground surface, the return control is always performed only in the direction away from the set value range (R), and the set value range (R)
From now on, stable control without jumping out can be realized.

[Brief description of drawings]

FIG. 1 shows one example of the present invention. FIG. 1 shows a control circuit and a second circuit.
The figure is a side view of the tractor, FIG. 3 is a control characteristic diagram, and FIG. 4 is a flow chart. Explanation of code (1) …… Tractor, (2) …… Ground work machine (13) …… Control unit (D) …… Detected value, (R) …… Set value range (I ₁ ) …… Setter, ( S ₁ ) …… Sensor

Claims (1)

[Claims] 1. A sensor for detecting a plowing depth and a horizontal posture within a set value range designated by a setter for designating a control state of a plowing depth and a horizontal posture of a ground work machine connected to a tractor. It is a tractor having a control unit for controlling the working depth and the left-right direction posture of the ground work machine so that the detected value detected by the tractor changes, and the detected value changes in the direction away from the set value range. An attitude control device for a ground work machine, wherein a control unit is configured to control the ground work machine so as to return the detected value to within a set value range only at times.