JP3003334B2 - Tractor lift control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work implement elevation control device for controlling the elevation of a work implement in a tractor on which a work implement such as a rotary cultivator is mounted so as to be movable up and down.

[0002]

2. Description of the Related Art For example, as shown in FIG. 1, a working machine connecting device 2 is provided at a rear portion of a tractor 1, and a working machine 3 such as a rotary cultivator is mounted on the working machine connecting device.
The working machine connecting device 2 in the illustrated example is a 3P hitch, 5 in the figure is a pair of left and right lower links, 6 is a top link in the center of the left and right, and a working machine is provided at the rear end of these links 5, 5, and 6. 3 is attached. Reference numeral 7 denotes a lift arm driven by a hydraulic device provided in the tractor 1, and lower links 5 and 5 are provided at the rear end of the lift arm via lift rods 8 and 8.
The work machine 3 is lifted and lowered by rotating the lift arms 7 and 7 up and down.

The hydraulic device has a hydraulic silling 10 as an actuator. The hydraulic cylinder 10 operates in a direction that protrudes the ram, that is, moves the working machine 3 upward,
The retracting of the ram, that is, the operation in the direction of lowering the work machine 3 is controlled by separate valves. These ascending and descending valves 11 and 12 are proportional solenoid valves, and adjust the oil flow rate by changing the 0N time of a pulse signal for exciting the solenoid.

When the working machine unit 3 is moved up and down with respect to the tractor, the target value of the lift arm angle set by the position lever 14 is compared with the actual lift arm angle detected by the lift arm angle sensor 16, and they match. Thus, the 0N time of the pulse signal has been determined.

[0005]

For this reason, there is a problem in that, when an attempt is made to reduce the shock at the time of stopping the lifting and lowering of the working machine, the operating speed becomes slower when the amount of lifting and lowering is small, and the workability deteriorates. On the other hand, this type of ground work equipment is
In the case of lifting and lowering with a actuator,
The goal is set based on the ground or the vehicle
Even if there is no overshoot
In order to enable descending control, control based on fuzzy inference
(Japanese Unexamined Patent Publication No. 3-91404)
Reference). However, it is described in the publication
Control the vertical movement based on the operating speed of the lift arm.
Of the link, the rattling of the link and fluctuations in the oil temperature
May be different from the operation feeling of the operator.
there were. Therefore, the present invention provides an actual operation feeling of the operator.
Lift control device that can achieve smooth movement according to
It is an object to provide a device.

[0006]

In order to solve the above problems, the present invention has the following arrangement. That is, a work implement lifting control device according to the present invention is a tractor that lifts and lowers a work implement by rotating a lift arm up and down, and a control valve that controls a hydraulic actuator for rotating the lift arm, and an angle of the lift arm. deviation determining the operating tool to be set, a sensor for detecting the angle of the actual lift arm, an operation speed calculating means for determining the operation speed of the operation member, the deviation between the detected value of the set value of the operating member sensor a calculation means determines the output rate of the control valve on the basis of the fuzzy inference deviation of the lift arm angle obtained from the operating speed and the deviation detecting means operating tool obtained from the operating speed calculating means as a membership function output And a flow rate determining means.

[0007]

[Action] A target lift arm angle is set by the operating tool. The actual lift arm angle is detected by the detection means. The set value and the detected value are compared by a deviation calculating means to calculate the deviation between the two and the operation speed of the operating tool. The deviation and the operation speed obtained in this way are processed by the output flow rate determining means based on fuzzy inference,
Determine the output flow of the control valve.

[0008] Since processing the deviation and operation rate based on fuzzy inference, in accordance with the situation at that time can determine the output flow rate of the appropriate actuator control valve, with allows the lifting of the fast working machine, the operator Operation feeling
The lifting and lowering operation can be smoothly performed without impact according to the condition .

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A working machine lifting / lowering control device for a tractor 1 shown in FIG. 1 will be described below. When a rotary cultivator is mounted as a working machine as in the illustrated example, the tractor 1
Two types of elevation control, ie, position control for raising and lowering the rotary cultivator 3 with respect to the machine body and plowing depth control for raising and lowering the rotary cultivator 3 with respect to the ground are performed. Here, position control will be mainly described.

The position control device 20 is configured as shown in the block diagram of FIG. That is, the setting value of the position lever 14, which is an operating tool for setting the lift arm angle, the setting value of the raising position setting dial 15 for setting the upper limit position of the work implement, and the detecting means for detecting the actual lift arm angle. A value detected by a certain lift arm angle sensor 16 is input to the CPU 19 via the input interface 18. The CPU 19 performs processing described later based on these data, and outputs a valve opening / closing signal to the ascending and descending valves 11 and 12 via the output interface 20. This valve opening / closing signal is a pulse signal, and the valve opening / closing operation amount is determined in proportion to the 0N time of the pulse.

The data processing in the CPU 19 is performed in the order shown in the flowchart of FIG. First, each setting device 1
4, 15 and the values of the sensor 16 are read, the actual lift arm angle detected by the lift arm angle sensor 16 is compared with the theoretical lift arm angle, the deviation D is calculated, and the operation of the position lever 14 is performed. The speed S is calculated. The theoretical lift arm angle is a numerical value calculated and empirically obtained from the set value of the position lever 14. The upper limit is the level given by the raising position setting dial 15, and the lift arm angle is displayed in 256 bits. Fuzzy inference is performed using the thus obtained deviation D and operation speed S as input variables, and the output flow rates of the valves 11 and 12 are determined.

When performing fuzzy inference, FIG.Figure
tableThe fuzzy control rule shown in FIG. The horizontal rowdeviation
D, operating speed in vertical columnsS andAnd the output flow rate F in the table.
You. Where NB is negative and large, NM is negative and medium, N
S is negative and small, Z0 is zero, PS is positive and small, PM
Is positive and medium, and PB is positive and large. For example, 1
For row 6 column,deviationD is negative and large (N
B) If the operation speed S is positive and large (PB),
Reduce the output flow rate F of the descending valve 12 slightly (N
S). "That's what it means.

The deviation D, the operating speed S, and the output flow rate F are classified according to their magnitudes, and are given as membership functions as shown in FIGS.

Assuming that the deviation D is d and the operation speed S is s, the output flow rate F in this case is determined (see FIG. 8). At this time, the membership value of the deviation D is P
M is a (= 0.7) given by M, and the membership value of the operation speed S is b ₁ (= 0.0) given by PB.
7) and b ₂ (= 0.2) given by PM. From these, the membership area U of the output flow rate F is obtained, and the output flow rate F in the horizontal axis direction at the center of gravity of the area is determined. When the processing is performed in this manner, the lifting and lowering of the working machine 3 that matches the operational feeling of the position lever 14 can be obtained.

As another position control method,
The output flow rate F may be determined by performing fuzzy inference using the operation state of the position lever as an input function instead of the operation speed of the position lever. Here, the operating state of the position lever means whether the position lever 14 is being operated upward, downward, or stopped.

The fuzzy control rules in this case are as shown in the chart of FIG. The horizontal row indicates the operation state M of the position lever, UM indicates a raising operation, ST indicates an operation stop, and DT indicates a lowering operation. The vertical column is the deviation D, UB is large at the top, UM is medium at the top, US is small at the top,
ZE means zero, DS means small below, DM means medium below, and DB means large below. In the table, the output flow rate F, NB is large at the lowered output, NM is medium at the reduced output, NS is small at the reduced output, Z0 is zero, PS
Is small at the raised output, PM is medium at the raised output, and PB is large at the raised output.

The operation state of the position lever 14;
The membership functions of the deviation D and the output flow rate F are given in FIGS. 10 to 12, respectively.

As described above, assuming that the operating state M is m and the deviation D is d, the output flow rate F in this case is determined (see FIG. 13). At this time, the membership value of the operation state M is 0.9, and the membership value of the deviation D is U
0.6 from M and 0.3 from US. The output flow rate F is determined by finding the membership area U of the output flow rate F that satisfies these, and further finding the center of gravity in the horizontal axis direction.

Even if the deviation between the target value and the actual value of the lift arm angle is the same, an appropriate output flow rate F is obtained when the position lever 14 is being operated and when the operation is completed. Should be different. If the fuzzy rule and membership function are set as described above and the processing is performed, the output flow rate can be made larger during the lever operation than when the lever operation is stopped, and the actual position control is realized. .

[0020]

As described above, according to the present invention, the working machine lifting control device according to the present invention, based on the operation speed of the error and the operation member between the target value and the actual value of the re Futoamu angle fuzzy inference
Control in actual work conditions.
The appropriate output flow rate of the control valve is determined according to the operability of the generator, so that the work machine can be smoothly moved up and down and stopped, and the sensitive lifting control can be prevented.

[Brief description of the drawings]

FIG. 1 is a side view of an agricultural working machine according to one embodiment of the present invention.

FIG. 2 is a block diagram of a work implement elevating control device.

FIG. 3 is a flowchart of the work implement elevation control device shown in FIG. 2;

FIG. 4 is a chart showing a fuzzy control rule in the first example .

FIG. 5 is a diagram showing a membership function of a deviation from a theoretical value in the first example.

FIG. 6 is a diagram illustrating a membership function of a variation amount of a deviation in the first example.

FIG. 7 is a diagram illustrating a membership function of a correction amount in the first example.

FIG. 8 is a diagram illustrating a procedure of fuzzy inference in the first example.

FIG. 9 is a chart showing a fuzzy control rule in the second example.

FIG. 10 is a diagram showing a membership function of a deviation from a theoretical value in the second example.

FIG. 11 is a diagram illustrating a membership function of a variation amount of a deviation in the second example.

FIG. 12 is a diagram illustrating a membership function of a correction amount in the second example.

FIG. 13 is a diagram illustrating a procedure of fuzzy inference in the second example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Tractor 2 Work implement coupling device 3 Rotary cultivator (work implement) 7 Lift arm 10 Hydraulic cylinder (actuator) 11 Lifting valve 12 Lowering valve 14 Position lever (setting means) 16 Lift arm angle sensor (detecting means) 19 CPU ( Deviation calculation means, operation speed calculation means, output flow rate determination means)

Claims (1)

(57) [Claims] 1. A tractor for raising and lowering a working machine by rotating a lift arm up and down, a control valve for controlling a hydraulic actuator for rotating the lift arm, an operating tool for setting an angle of the lift arm, a sensor for detecting an angle of the lift arm, and the operation speed calculating means for determining the operation speed of the operation member, a deviation calculating means for calculating a deviation between the detected value of the set value of the operation member sensor, the operating speed calculated Operating speed of the operating tool obtained by the means and
Deviation Men lift arm angle obtained from the deviation detection means
A work implement lifting / lowering control device, comprising: output flow rate determining means for determining an output flow rate of the control valve based on fuzzy inference as a burship function .