JPH05276801A - Position controller for engine-driven farm machines - Google Patents

Abstract

PURPOSE:To improve the response of positioning and enable fine adjustment by providing blind sectors before and after the setting position which has been determined by the positioning means, and temporarily canceling the blind sector immediately after the positioning means is actuated. CONSTITUTION:Blind sectors are provided before and after the target set position indicated by the positioning means. A controller is installed for canceling the blind sectors immediately after the positioning means is actuated, to enable fine adjustment operation by means of a positioning lever 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position control device for a power agricultural machine such as a tractor.

[0002]

2. Description of the Related Art A power operating machine such as a so-called electronically controlled tractor or combine is provided with a position operation lever for raising and lowering a working unit and a position detector for detecting the height of the working unit. Is a position setting device consisting of a potentiometer on the rotation base of the position operation lever,
Further, a position detector of the same type is provided on the rotary base of the lift arm.

The control valve is electrically controlled so that the difference between the set position value and the detected position value, that is, the deviation becomes zero. Every time the deviation occurs, the control unit controls the control valve. When a control output is output to the valve, the working part may violently reciprocate up and down, causing a hunting phenomenon. Therefore, in the conventional device, the deviation is near zero, in other words, it is a target. In the vicinity of the position, a dead zone region is often provided before and after the position.

[0004]

By the way, in such a conventional apparatus, when the position operation lever is moved back and forth for fine adjustment, dead zone regions are set before and after the target height set by the position operation lever. Therefore, the position operation lever has to be largely moved, and there is a problem that the responsiveness is lacking.

[0005]

SUMMARY OF THE INVENTION The present invention is proposed in view of the above-mentioned problems, and an object thereof is to improve responsiveness and enable fine adjustment. Therefore, the following technical measures were taken. That is, it has the position setting means 21 and the position detection means 23,
Lift up to the position specified by the position setting means 21.
In a position control device for a power farming machine configured to move up and down, the dead zone is provided before and after a target set position, and this dead zone is temporarily set immediately after the position setting means 21 is operated. A position controller for a power farming machine is characterized in that a controller 41 for removing is provided.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. First, the structure will be described. 1 is a tractor, and front and rear wheels 2 and 2 and rear wheels 3 and 3 are provided at the front and rear portions of the body,
The rotational power of the engine 1b in the bonnet 1a is appropriately decelerated by a transmission in the transmission case 4 and transmitted to the front wheels 2, 2 and the rear wheels 3, 3.

A hydraulic cylinder case 5 is fixedly provided on the upper rear portion of the transmission case 4. Hydraulic cylinder case
A single-acting hydraulic cylinder 6 is provided in the space 5, and lift arms 7 are provided on both left and right sides of the hydraulic cylinder case 5.
7 is rotatably supported. In addition, here, the hydraulic cylinder 6 and the lift arms 7 and 7 are combined into a hydraulic lifting mechanism 8.
Collectively.

Top link 10, lower link 11, 1
A rotary tiller 14 is movably connected to the rear end of the three-point link mechanism 12 composed of 1, and the lift arm 7 and
7 and the lower link 11, 11 between the lift rod 1
5, 15 are interposed and connected. Reference numeral 20 is a position operation lever, and a position setting device 21 for setting the ground height of the ground work machine connected to the rear part of the tractor-1 is attached to the rotation base of the position operation lever 20.

On the other hand, a position detector 23 for detecting the rotation angle of the lift arm 7 on one side, that is, the height of the ground work machine is attached to the rotation base part, and is set by the position operation lever 20. The lift arms 7 and 7 are rotated to a certain position and stopped at that position, which constitutes a position control system. On the control panel 25 provided near the seat 24, ON-OFF for raising and lowering the working machine together with the position operation lever 20.
An up / down switch 28 of a type, a raising position setting dial 29 for setting the maximum rising position of the working machine, and a working depth setting dial 30 for setting the working depth of the working machine are provided.

A rotary tiller 14, which is an example of a working machine connected to the rear part of the machine body, has a tiller part 34, a main cover 35 covering the upper part of the tiller part 34, and a rotary part at the rear part of the main cover 35. The rear cover 36, etc., which are rotatably and pivotally attached, is constructed so that the lower end portion of the rear cover 36 is brought into sliding contact with the ground to elastically press the plowing soil surface to make it even. At the rear end of the upper portion, a plowing depth detector 37 for detecting the turning angle of the rear cover 36 is provided.

Next, the control system of this apparatus will be explained based on the block diagram shown in FIG. The position setter 21 for setting the height of the rotary tiller 14 and the actual lifter.
The position detector 23 for detecting the position of the frame 7 is connected to a control device 41 composed of a CPU via an A / D converter 40. The raising / lowering switch 28 is directly connected to the control device 41 without passing through the A / D converter 40, and when the raising / lowering switch 28 is turned on, the rotary tilling device 14 reaches the height set by the raising position setting dial 29. Rise, OF
When set to F, the position operation lever 20 descends to a height determined by the lever.

A tilling depth setting dial 30, a raising position setting dial 29 provided in the vicinity of the seat 24, and a tilling depth detector 37 for detecting the tilling depth of the rotary tiller 14 are respectively connected via an A / D converter 40. Connected to the control device 41. Normally, the position operation lever 20 raises and lowers the rotary cultivating device 14, but when the rotary cultivating device 14 is moved up and down in a hurry, such as when turning at the ridge, the raising and lowering switch 2 is used.
Press 8. An ascending proportional control valve 44 and a descending proportional control valve 45 for moving the rotary tiller 14 up and down are connected to the output side of the controller 41. In both position control and plowing depth control (depth control), pulse control proportional to the deviation, so-called duty control, is performed.
Proportional control valves 44, 4 for either raising or lowering
5 is operated to move the rotary tiller 14 up and down.

Next, the operation of this embodiment will be described based on the flowchart of FIG. First, the states of each setter, detector and switch are read (step S1),
Then, it is judged whether or not the position operation lever 20 has been operated to get out of the dead zone (step S2). When the position operation lever 20 is operated largely in the front-back direction beyond the dead zone, duty control based on the deviation is performed.

On the other hand, when the position operation lever 20 is operated in the minute range for the first time within the dead zone, the displacement amount of the set value of the position operation lever 20 is detected (step S3), and the displacement amount is 2 bits. When it is determined that the operation is performed in the direction away from the stop position, the dead zone width is set to zero (steps S4, S5, S6). Then, after that, the duty control is performed based on the deviation as described above.

Then, in step S10, the dead zone which has been zero until then is once reset, and the dead zone is set before and after the target set value. Since one cycle of this main flow is executed at intervals of 10 msec, the dead zone is set to zero at the moment when the position operation lever 20 is slightly operated, but it is 10 msec.
After that, the dead zone is set again, and there is no fear that a hunting phenomenon will occur during control.

FIGS. 4 and 5 are diagrams for explaining the operation in which these relationships are easily understood. FIG. 4 is based on the conventional method, and the stop position of the lift arm 7 with respect to the target value of the position operation lever 20 is represented by the point X. A dead zone region for 3 bits and a hysteresis for 1 bit are set before and after the target position, and in order to raise or lower the lift arm 7, the position operation lever 20 is moved by the amount exceeding the dead zone and the hysteresis amount. You have to move it big. On the other hand, in FIG. 5, the dead zone is removed only at the moment when the position operation lever 20 is operated.
It shows that the dead zone is set again after msec. Therefore, according to the latter method, the operation amount when starting to move the lift arm 7 is small, and the lift arm 7 is small.
Since it moves instantly, fine adjustment becomes easy, and furthermore, a dead zone is provided after the output, so that hunting can be eliminated.

Since the rotary tiller 14 described in this embodiment is constructed so that the dead zone can be changed variously during the depth control, that point will also be briefly described. Needless to say, the rear cover 36 captures the change in the working depth and electrically feeds it back to the control device 41 to raise and lower the entire rotary tiller 14 to maintain the working depth at the set depth. To do.

The applicant has already applied for a method of fuzzy inferring the dead zone from the relationship between the operating speed of the rear cover 36 and the set plowing depth value, but at the beginning of the control, that is, the rear cover 36 is lifted from the lifting position. Since the rear cover 36 itself is not changed during the lowering, the smooth plowing depth control may not be performed. Also, even when the tractor-1 is stopped, the amount of soil is insufficient immediately before the rear cover 36, and the rear cover 36 rotates downward simultaneously with the stop of the airframe, which causes the rotary cultivating. There is a drawback that the device 14 is slightly submerged to deepen the working depth.

The improved device described here is intended to eliminate such a problem, and is a rotary tiller 14
In order to smoothly shift to fuzzy control. At the same time, the rear cover 36 of the rotary cultivator 14 is prevented from reacting too sensitively when the airframe is stopped. The operation will be described below based on the flowchart of FIG.

First, the states of the setting devices, detectors and switches are read (step S1). Then, it is determined whether or not the rear cover 36 is descending. If the rear cover 36 is descending, the dead zone is increased (step S15), and if the rear cover 36 finishes descending and the rear cover 36 lands, it is determined whether the depth control has been performed. Is determined (step S3). Immediately after shifting to the depth control, the dead zone timer is set (step S4), and until the timer counts up, the magnitude relationship between the fuzzy inferred dead zone and the dead zone gradually decreasing depending on the timer value. And a larger dead zone value is always set (step S12). Then, when the dead zone timer times out, the fuzzy inferred dead zone is set according to how the rear cover 36 changes (step S6). In this way, the dead zone width is set separately until the dead zone timer times out and after the dead zone timer expires, and thereafter the plowing depth set value and the plowing depth detection value (depth sensor value) are set. And the output is determined according to the difference (steps S7 to S11). FIG. 7 is a diagram for explaining the operation, which illustrates this easily. In the figure, the portion indicated by the solid line is the dead zone used for control.

Further, as described above, when the tractor-1 is stopped, the amount of soil that has been blown backward by the tilling section 34 is insufficient, resulting in the rear cover.
When 36 moves to the front side, the signal in the same state as when the plowing depth becomes shallow is sent to the control unit. Then, the plowing section 34
The output in the direction of lowering the power is output from the control device 41 to the control valve, and when the airframe stops, the tiller 34
May descend and dig the ground deeper than necessary. Therefore, in such a case, the dead zone is increased in conjunction with the depression operation of the clutch pedal so that the down command is not issued (steps S13 and S).
15). As a result, the plowing part 34 does not largely descend even if the airframe stops, so that a large dent does not occur there.

[0022]

As described above, the present invention has the position setting means 21 and the position detecting means 23, and is configured so that the lift arm 7 moves up and down to the position designated by the position setting means 21. In the position control device for the power agricultural machine, the dead zone is provided before and after the target set position, and the dead zone is temporarily provided immediately after the position setting means 21 is operated. Since it is a position control device for a power farming machine characterized by:
Can move quickly and accurately, and fine adjustment of the position has become easy.

[Brief description of drawings]

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

FIG. 2 is a block diagram showing a control system.

FIG. 3 is a flowchart showing the operation of this control device.

FIG. 4 is an operation explanatory view.

FIG. 5 is an operation explanatory view.

FIG. 6 is a flowchart regarding tilling depth control.

FIG. 7 is an explanatory diagram showing a transition of a dead zone.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 tractor 2 front wheel 3 rear wheel 8 hydraulic lifting mechanism 14 rotary tiller 21 position setting means (position setting device) 23 position detecting means (position detector) 41 control device

Claims (1)

[Claims] 1. A position control device for a power farming machine comprising a position setting means 21 and a position detecting means 23, wherein the lift arm 7 is configured to move up and down to a position designated by the position setting means 21. A dead zone is provided before and after the target setting position, and this dead zone is
A position control device for a power agricultural machine, which is provided with a control device 41 for temporarily removing the position setting means 21 immediately after the operation.