JPS62155001A - Automatic controller of agricultural working machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an automatic control device for agricultural working machines for performing automatic lifting control, automatic posture control, etc. of agricultural working machines (cultivating working machines) attached to tractors, etc. It is something.

○ Conventional technology This type of automatic control device for agricultural working machines is
No. 74005 ``Automatic elevation control device for ground work vehicle'' is known.

Regarding the positioning operation for posture control of the working machine, it is necessary to prevent overrun, and in the above-mentioned known technology, the lowering speed in the range near the set lowering position is maintained at a lower set speed.

However, this is insufficient to prevent unnecessary hunting after positioning, and it is necessary to provide a dead zone before and after the positioning position.

○Problems to be solved by the invention When setting the above-mentioned dead zone, in order to improve positioning accuracy, it is better to have a narrower dead zone (to make the operation of the sensitivity setting device sharper), but the operating speed is faster. If the dead zone is widened (the sensitivity setting device is operated "sluggishly"), the positioning accuracy will deteriorate. In particular, when the operating speed is switched in multiple stages, it is necessary to accommodate the condition of high operating speed and the dead zone needs to be widened, so the above-mentioned pressure is significant.

Therefore, it is an object of the present invention to always properly select the width of the dead zone to increase the degree of positioning ljf.

Means for Solving Problems O In order to achieve the above-mentioned object, the present invention provides a first dead zone setting device (12) for setting an unchanging first dead zone, and a first dead zone having a width larger than the first dead zone. a sensitivity setter (11) for setting a variable second dead zone; ) dead zone selection circuit (10) for controlling the generation of a control output signal from
The setting signal S1 from the setting device (1) and the sensor (2
) The width of the dead zone for the comparator (3) that compares the detection signal S2 from the sensor (3) is changed between when the correction operation starts and when the correction operation is stopped.

The comparator (3) calculates the setting signal S1 from the action setting device of the invention and the detection signal S2 from the sensor (2), and the generation of the control output signal S3 from the comparator (3) is controlled by the dead zone selection circuit ( 10) to generate a control output signal S3 by deviating from the second dead zone determined by the sensitivity setting selected by the operator, and entering a first dead zone having a width narrower than the second dead zone at a fixed value. This causes the generation of the control output signal S3 to be stopped. When the control output signal S3 is generated, the solenoid valve (5) for lifting and lowering the work machine is actuated via the solenoid valve drive circuit (4), and the control output signal S3 is activated.
When this stops, the operation of the solenoid valve (5) for lifting and lowering the work equipment is stopped.

O Embodiment In the work machine attitude control, the setting device (1) in FIG. In automatic plowing depth control, the setting device (1) is used as a work machine plowing depth setting device,
Let sensor (2) be a plowing depth sensor.

The control device (controller) (8) has the above-mentioned setting device (1
), has an input terminal to the sensor (2) and the sensitivity setting device (11), and an output terminal to the solenoid valve (5) for lifting and lowering the work equipment, and has a setting signal S1 from the setting device (1) and the sensor (2). a comparator (3) that compares the detection signal S2 from the comparator (3), and a solenoid valve drive circuit (to which the control output signal S3 from the comparator (3) is supplied and controls the solenoid valve (5) for lifting and lowering the working machine. 4
).

In the embodiment, the electromagnetic valve drive circuit (4) was composed of a rising discriminator (6a) and its current amplifier (7a), and a descending discriminator (6b) and its current amplifier (7b). .

The dead band selection circuit (10), which is a main part of the present invention, changes and controls the dead band width of the comparator (3) of the above-mentioned control device (8). 2
A first dead zone setting device (12) is provided for setting a dead zone and for setting a first dead zone having a fixed width narrower than the second dead zone.

The width of the second dead zone of the sensitivity setting device (11) is variable by the operator's selection operation (for example, selection of "acute", "medium", and "dull").

The comparator (3) is configured to start a correction operation when the sensor signal voltage deviates from the second dead zone, and to stop the correction operation when it falls within the first dead zone.

The hydraulic lifting device (9) is a lifting cylinder (14) that connects the machine and the work equipment and rotates a lift arm (13) for raising and lowering the work equipment with respect to the machine.
As shown in Fig. 2, in addition to the solenoid valve (5) for lifting and lowering the work equipment and the slow return stop valve (15), it also includes a hydraulic pump (16), a choke valve (17), and a relief valve. It includes a valve (18) and a safety valve (19).

In the second embodiment shown in FIG. 3, the comparator (3) of the control device (8) is operated by a microcomputer,
Analog switch (21), A/D converter (22)
, a one-chip microcomputer (20) with a comparison calculation function (3) between sensor signals and setting signals, and a solenoid valve drive circuit (4).
) constitutes a control device (8).

In the embodiment of FIG. 3, the dead zone selection circuit (1
0), the one-chip microcomputer (20) is programmed with the functions shown in the flowchart of FIG.

The width of the first dead zone is the solenoid valve (5
) from the operating state to the non-operating state (usually several m5ec to several tens of m5ec) and the diameter of the flow roof and cylinder, and calculate the amount of deviation before positioning in actual operation. When switching from the operating state to the non-operating state, the width of the first dead zone is set depending on whether or not the motor stops at the set positioning stop position at the time of stopping, and this width is set as a fixed value.

The second dead zone is set outside the first dead zone, and its value is variable by operating the sensitivity selector (11).

Next, the operation in the case of automatic plowing depth control will be explained with reference to FIG.

With the setting voltage of the plowing depth setter (1) as the center of positioning, the above-mentioned 1. A second dead zone is provided, and when the tilling depth sensor voltage deviates from the second dead zone by comparison with the sensor voltage that detects the actual plowing depth, a correction operation is started.
, if it falls within the first dead zone, the correction operation is stopped (b).

In addition, Fig. 6 shows a conventional example, and shows the end point (b) of the correction operation.
° is inappropriate and rises or falls beyond the set value,
If the set value of the dead band width is "blunt", the deviation will be 717 degrees better than the set position.

Effects of the Invention The present invention allows the width of the second dead zone to be arbitrarily selected by the setting operation of the sensitivity setting device, and the starting point of the correction operation to be changed by selecting consecutive rooms, and to perform quick correction operations according to the working conditions. At the same time, a first dead zone setting device is provided to set a first dead zone that enables positioning at a predetermined setting position by stopping the correction operation, which eliminates variations in positioning accuracy and eliminates repeated correction operations. This has the effect of preventing the hunting phenomenon (hunting phenomenon) as well as enabling accurate automatic control of plowing depth and control of work machine posture.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the outline of an automatic control device for agricultural working machines implementing a first embodiment of the present invention. FIG. 2 is a hydraulic circuit diagram of the hydraulic lifting device. FIG. 3 is a block diagram showing the outline of an automatic control device for agricultural working machines according to a second embodiment (using a microcomputer) of the present invention. Fourth
The figure is a flowchart showing the function of a microcomputer as a dead zone selection circuit, which is a main part of the present invention. FIG. 5 is an explanatory diagram showing the operation of the present invention. FIG. 6 is an explanatory diagram showing a conventional example. 1...Setting device 2...Sensor 3...Comparator 4...Solenoid valve drive circuit 5...Solenoid valve for lifting and lowering work equipment 10...Dead zone selection circuit 11...Sensitivity setting device 12...First dead band setting device Applicant Seirei Kogyo Co., Ltd. Agent Patent attorney Colophon Fumio Fig. 6 7C1 Ido

Claims (1)

[Claims] A comparator (3) that compares the setting signal S^1 from the setting device (1) and the detection signal S^2 from the sensor (2), and a control output signal S^3 from the comparator (3). In an agricultural work machine automatic control device that supplies a solenoid valve drive circuit (4) for a solenoid valve (5) for lifting and lowering a work machine to control the lifting and lowering of the work machine,
In order to set an unchanging first dead zone, a first dead zone setting device (1
2) and a sensitivity setting device (11) for setting a variable second dead zone having a width larger than the first dead zone, and a correction operation is started when the second dead zone is moved out of the second dead zone. The comparator (
3) An automatic control device for an agricultural working machine, characterized in that it is provided with a dead zone selection circuit (10) for controlling the generation of control output signals.