JPH06104003B2 - Agricultural work machine automatic control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an agricultural work machine automatic control device for performing automatic lifting control, automatic attitude control, etc. of an agricultural work machine (cultivator work machine) attached to a tractor or the like. It is a thing.

○ Conventional technology As an automatic control device for agricultural work machines of this type, Japanese Patent Publication No. 57-
No. 74005, "Automatic lifting control device for ground work vehicle" is known.

With respect to the positioning operation of the attitude control of the work machine, it is necessary to prevent overrun, and in the above-mentioned known technique, the lowering speed in the range near the set lowering position is maintained at a lower setting speed. However, it is insufficient to prevent unnecessary hunting after positioning, and it is necessary to provide a dead zone in the front and back around the positioning position.

○ Problems to be solved by the invention When setting the above-mentioned dead zone, in order to improve the positioning accuracy, it is better that the dead zone is narrow (the operation of the sensitivity setting machine is “sharp”), but the operating speed is fast. However, if the dead zone is widened (the operation of the sensitivity setting device is made "blunt"), the positioning accuracy is lowered. In particular,
When the operating speed is switched in multiple stages, it is necessary to deal with the condition of high operating speed, and it is necessary to widen the dead zone, so the above-mentioned problem is remarkable.

Therefore, an object of the present invention is to always properly select the width of the dead zone to improve the positioning accuracy.

In order to achieve the above-mentioned object, the present invention has a first dead zone setting device (12) for setting a fixed first dead zone and a width larger than the first dead zone. And a sensitivity setting device (11) for setting a variable second dead zone, and when the deviation from the second dead zone starts, the generation of the control output signal S ³ is started, and by entering the first dead zone, the control output signal S ³ The dead zone selection circuit (10) for controlling the generation of the control output signal from the comparator (3) is provided to stop the generation of the noise, and the setting signal S ¹ from the setting device (1) and the sensor (2) is intended to vary in the event stop of the detection signal S ² and a comparator (3) at start of generation width control output signal S ³ of the dead zone for comparing the control output signal S ^3.

Action of the invention Setting signal S ¹ from the setter and detection signal S ² from the sensor (2)
Are calculated by the comparator (3), and the generation of the control output signal S ³ from the comparator (3) is controlled by the dead zone selection circuit (10),
Generates a control output signal S ³ by deviating from the second dead zone is determined on the sensitivity setting selected by the operator, the control output signal S ³ by entering the narrower first dead zone width than the second dead zone with a fixed value Stop the occurrence of. When the control output signal S ³ is generated, the working machine lifting solenoid valve (5) is operated via the solenoid valve drive circuit (4), and when the control output signal S ³ is stopped, the working machine lifting solenoid valve (5) is operated. To stop.

Example In the working machine attitude control, the setter (1) in FIG. 1 is a working machine-to-machine position setter (tilt setter), and the sensor (2) is a working machine position sensor (tilt detector). In automatic tillage depth control, the setting device (1) is used as the working implement tillage depth setting device,
The sensor (2) is a working depth sensor.

A controller (controller) (8) has an input terminal for the setting device (1), the sensor (2), and the sensitivity setting device (11) and an output terminal for the working machine lifting solenoid valve (5). , A comparator (3) for comparing the set signal S ¹ from the setter (1) with the detection signal S ² from the sensor (2), and a control output signal S ³ from the comparator (3) are supplied. An electromagnetic valve drive circuit (4) for driving and controlling the electromagnetic valve (5) for raising and lowering the working machine.

In the embodiment, the solenoid valve drive circuit (4) is composed of an ascending discriminator (6a) and its current amplifier (7a), and a descending discriminator (6b) and its current amplifier (7b). .

The dead zone selection circuit (10), which is an essential part of the present invention, changes and controls the dead zone width of the comparator (3) of the above-mentioned control device (8), and it is variable by the sensitivity setting unit (11). A second dead zone is set, and a first dead zone setting device (12) for setting a first dead zone for setting a first dead zone having a fixed width narrower than the second dead zone is additionally provided.

The width of the second dead zone of the sensitivity setting device (11) can be changed by the operator's selection operation (for example, selection of "sharp", "medium", and "blunt").

The comparator (3) is configured to start the correction operation when the sensor signal voltage is out of the second dead zone, and stop the correction operation when the sensor signal voltage is in the first dead zone.

The hydraulic lifting device (9) has a lifting cylinder (14) for connecting the machine and the working machine and for rotating a lift arm (13) for lifting and lowering the working machine with respect to the machine. As shown in FIG. 2, including a control mechanism, a hydraulic pump (16), a choke valve (1) in addition to the working machine lifting solenoid valve (5) and slow return stop valve (15).
7), relief valve (18) and safety valve (1
9) is included.

In the second embodiment shown in FIG. 3, the comparator (3) of the control device (8) is caused to function by a microcomputer.
Controlled by a controller that has an analog switch (21), A / D converter (22), one-chip microcomputer (20) that has a comparison calculation function (3) 'between sensor signals and setting signals, and a solenoid valve drive circuit (4) Configure the device (8).

In the embodiment shown in FIG. 3, the dead zone selection circuit (1
In order to make the one-chip microcomputer (20) function as 0), the function shown in the flowchart of FIG. 4 is programmed in the one-chip microcomputer (20).

The width of the first dead zone depends on the time (normally a few msec to a few + msec) from the operating state of the equipped work machine lifting solenoid valve (5) to the non-operating state, flow rate, and cylinder diameter. Back calculation, set the width of the first dead zone depending on which deviation amount before actual positioning in actual operation switches from the operating state to the non-operating state when stopping at the set positioning stop position when stopping, This is 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 the automatic plowing depth control will be described with reference to FIG.

With the set voltage of the plowing depth setting device (1) as the center of positioning, the above-mentioned first and second dead zones are provided above and below the pledging depth setting device (1), and by comparing with the sensor voltage for detecting the actual plowing depth, the plowing depth sensor voltage becomes
When it goes out of the second dead zone, the correction operation starts (a),
If it is within the first dead zone, the correction operation is stopped (B).

Incidentally, FIG. 6 shows a conventional example. Since the end point (b) ′ of the correction operation is improper, it rises or falls beyond the set value, and when the dead band set value is “pure”, the set position is set. The deviation accuracy becomes better than that.

Effect of the Invention According to the present invention, the width of the second dead zone is arbitrarily selected by the setting operation of the sensitivity setting device, the starting point of the correction operation is appropriately selected, and the correction operation can be freely performed, so that the quick correction operation according to the working state can be performed. At the same time, since the first dead zone setting device for setting the first dead zone which enables the position to be set to a predetermined setting position by stopping the correction operation is provided, the variation in the positioning accuracy is eliminated and the correction operation is repeated (hunting). It is possible to prevent the phenomenon) and perform accurate plowing depth automatic control and work implement attitude control.

[Brief description of drawings]

FIG. 1 is a block diagram showing the outline of an agricultural work machine automatic control apparatus according to 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 the agricultural work machine automatic control apparatus according to the second embodiment (using a microcomputer) of the present invention. Fourth
The figure is a flow chart showing the function of the microcomputer as the dead zone selection circuit which is the main part of the present invention. FIG. 5 is an explanatory view showing the operation of the present invention, and FIG. 6 is an explanatory view showing a conventional example. 1 …… Setter 2 …… Sensor 3 …… Comparator 4 …… Solenoid valve drive circuit 5 …… Work machine lift solenoid valve 10 …… Dead zone selection circuit 11 …… Sensitivity setter 12 …… First dead zone setter

Claims (1)

[Claims] 1. A comparator (3) for comparing a setting signal S ¹ from a setting device (1) and a detection signal S ² from a sensor (2),
In the agricultural work machine automatic control device that supplies the control output signal S ³ from the comparator (3) to the solenoid valve drive circuit (4) for the work machine raising / lowering solenoid valve (5) to perform work machine raising / lowering control,
To set a fixed first dead zone, the first dead zone setter (1
2) and a sensitivity setting device (11) for setting a variable second dead zone having a width larger than that of the first dead zone.
For controlling the generation of the control output signal from the comparator (3) so as to start the generation of the control output signal S ^{3 when} it is out of the dead zone and to stop the generation of the control output signal S ^{3 when} it is in the first dead zone. An agricultural work machine automatic control device comprising a dead zone selection circuit (10).