JPS62204A - Drive control mechanism for working device of 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] [Industrial Application Field] The present invention connects a working device such as a tilling rotary to a traveling machine such as a tractor so that it can perform rolling and lifting operations, and uses hydraulic pressure whose operation is controlled by an electromagnetic valve. The present invention relates to a work device drive control mechanism for a work machine configured to move the work device toward a target posture or position using a cylinder.

[Conventional technology]

In the work equipment drive control mechanism of this type of work equipment, conventionally, when controlling the electromagnetic valve, an operating signal is continuously given to the electromagnetic valve while the work equipment is being raised or lowered, whereas an operation signal is continuously given to the solenoid valve while the work equipment is being raised or lowered. By applying a fixed pulse with a constant pulse width to this electromagnetic valve, the drive of the working device could be stopped with less shock.

[Problem that the invention seeks to solve]

However, since the given pulse width is constant,
If the pulse width is small, it tends to take too much time to reach the target position.On the other hand, if the pulse width is made large, overshoot phenomenon or shock may occur when the pulse width exceeds the stopping position. This cannot be avoided, and it has been difficult to select an appropriate pulse width.

Therefore, based on this situation, in response to the deviation between the current position and the target position of the work equipment, if this deviation is large, the pulse width is increased, and if the deviation is small, the pulse width is decreased. Some models use a pulse width modulation method, but even in this case, there are a number of reasons why the pulse width may not actually be applied, such as changes in the weight of the work equipment, changes in the hydraulic oil temperature, and changes in piping resistance. This left problems such as the working equipment not moving or operating suddenly.

The purpose of the present invention is to rationally select the operating speed and position deviation as control elements related to pulse width modulation and change the feedback gain to move the working device to the target posture.
The object of the present invention is to provide a device that can be quickly moved to a target position with little impact and can be stopped at the target position smoothly.

[Means for solving problems]

The characteristic structure according to the present invention is based on the duty in the pulse operation signal for the electromagnetic valve, based on the speed deviation between the target operation speed and the actual operation speed of the working device multiplied by the feedback gain, so that the actual operation speed is the target operation speed. The feedback gain should be set so that it becomes larger as the value decreases, and the feedback gain should be increased only when the positional deviation of the current position from the target position is small and the actual operating speed is greater than the target operating speed, and deceleration operation is required. Its functions and effects are as follows.

[For production]

The duty is reduced as the actual operating speed increases with respect to the target operating speed of the working equipment, and the actual operating speed is suppressed by reducing the ON time of the valve due to the reduction in duty, and the actual operating speed becomes smaller. By increasing the duty cycle and increasing the actual operating speed, it is possible to operate the working device at a speed in line with a target operating speed that is set assuming a desired operating mode.

In other words, since the actual operating speed of the working device is selected as the control element for pulse width modulation, by applying a pulse, it is possible to reliably determine whether the working device is moving as a result. Pulse width modulation adjustment is used to adjust the actual operating state of the working equipment (for example, when the working equipment is in a stopped state but the distance from the target position is short, so the duty given is small and the working equipment does not operate). Since this can be done while actually detecting the actual state (rather than something that is far from the actual state), it can be done more accurately.

〔Effect of the invention〕

As a result, the working device can be moved to the target posture and position quickly and with less impact, despite changes such as changes in the temperature of the hydraulic oil.

Furthermore, when approaching the target position, if the actual operating speed at that point is decelerating, the feedback gain is set large, and even if the speed deviation is the same, the feedback gain and speed deviation are multiplied. The reduction in duty is increased to increase the effect of reducing the duty, and this reduction in duty increases the effect of decelerating the actual operating speed, thereby suppressing overshoot phenomena in the vicinity of the target position.

Therefore, even if the speed deviation is small, the deceleration effect can be increased, and the stopping accuracy can be improved.

〔Example〕

As shown in Fig. 4, the working device (4) is connected to the rear end of the tractor, which is the end of the traveling body (1), through the 39-point links of the lower links (2), (2) and the top link (3).
The tilling rotary, which is one of the two types, is connected to the rotary so that it can be raised and lowered, and the lift arms (6), (6) and lower links (,2), (6), which are swing-driven by hydraulic cylinders (5), are connected to each other so that they can be raised and lowered.
2) are connected by lift rods (7) and (7), so that the working device (4) can be driven up and down against the aircraft. Further, one of the lift rods (7) is also used as a telescopic cylinder, and the working device (4) is configured to be capable of rolling operation;
The tractor (1) is configured to be able to follow the ground regardless of its body inclination.

Next, position control for holding the working device (4) at a desired level relative to the aircraft will be described in detail. As shown in FIG. 3, an electromagnetic valve (9) is interposed in the hydraulic circuit between the hydraulic cylinder (5) and the hydraulic pump (8).
) is a descending side solenoid valve (10), a descending side main valve (11) which is operated ON-OFF by this solenoid valve (10), and an ascending side solenoid valve (
12) and this solenoid valve (12) 0N-
It consists of an ascending main valve (13) that is turned off and a check valve (14) that prevents oil from flowing to the descending side.

To explain in detail the operating mode of the electromagnetic valve (9), the ascending solenoid valve (12) is closed by the ascending signal from the control mechanism (15), and the closing action of the ascending solenoid valve (12) causes the ascending Side main valve (1
3) is closed, and pressure oil from the hydraulic pump (8) is sent to the hydraulic cylinder (5) via the check valve (14).
1) is closed). Subsequently, a descending solenoid valve (10) is activated by a descending signal from the control mechanism (15).
) to open this lower solenoid valve (10).
The main pulp on the descending side (11) is opened by the opening operation of the main pulp (11), and the hydraulic oil from the hydraulic cylinder (5) is transferred to the tank (16).
).

In addition to providing a control mechanism (15) with a built-in microcomputer that issues an operating side m signal to the above-mentioned electromagnetic valve (9),
This control mechanism (15) receives a level signal for the tilling rotary (4) from the lift arm sensor (17) provided on the rotation shaft of the lift arm (6), and settings from the position setting device (18). It is designed to input signals.

The operating signal from the control mechanism (15) to the electromagnetic pulp (9) is a pulse signal, as shown in FIG. seconds) and the main valve (11)
, (13) are output to the electromagnetic pulp (9) for use in a transient state transitioning from an ON state to an OFF state.

As shown in Fig. 1, the ratio of the ON state to one cycle (T) is defined as duty (D), and by changing this duty, the tilling rotary (4) can be quickly and with less impact raised to the target height. Explain the conditions that lead to this. The duty (D) is expressed by the following formula: D = no + K-EV EV=V, -V Do: Basic duty vo: Target operating speed = Actual operating speed: Feedback gain basic duty (D0) By adding the value corresponding to the deviation (HV) between the target operating speed (V0) and the actual operating speed (V) of the tilling rotary (4) to, as shown in Fig. 2 (a) to (c), Be changed. In other words, as shown in FIG. 2 (0), when the target operating speed (V0) is higher than the basic duty (D0), the target operating speed (V0) is set smaller than the basic duty (D0).
If it is smaller than 0), it is set to be larger than the basic duty (D0). Note that the actual operating speed (V) is determined by the tilling rotary (4) at the lift arm sensor (17).
) level signal to the aircraft at an appropriate period (T) (for example, 0.0
4 seconds), and the position information at the time of sampling (
Xl) and the position information (X+t-+) from one cycle before the cycle (
T).

Next, acceleration (
To explain what incorporates A), the actual operating speed at the time of sampling is further based on the actual operating speed (V) calculated based on the position information (X, l) sampled at an appropriate period (T). (Vfi) and the operating speed (v
Acceleration (A) is calculated by dividing the deviation from n-+) by the period (T), and only when this acceleration (A) is A>Q, the duty (D) is decreased as shown below. There is.

D = Do + KEV KaAv7: Actual operating speed V at the time of sampling, -1: Actual operating speed 1 cycle before KA: Feedback gain for acceleration Therefore, depending on the state of acceleration (A), D = D (1 + KEV - KAA ( A＞
0) D = D, + WHV (As2) is set to be used properly.

Furthermore, positional deviation (EX
), the deviation (EX) of the current position (Xn) from the target position (XA) is calculated, and if this position deviation (EX) shows a state close to the dead zone (ΔX), the actual operation is confirmed. Only when the speed (V) requires a deceleration state larger than the target operating speed (V0), the feedback gain (K
) is made larger. In other words, K= Ko + K'(V-VO) (V>VO)
Ko: To the lowest gain ゛: As an auxiliary gain, if the speed deviation gv = v, -v, the gain (K) is increased to further reduce the duty (D), and the actual operating speed (V ) can have a significant deceleration effect.

For those that perform duty (D) control as described above, as shown in FIG. It is set to start from the signal to suppress the overshoot phenomenon of the tilling rotary (4).

The above configuration will be explained using the flow sheet shown in FIG. 7. A timer is set to sample the position information (X,), and each time the timer counts the sampling period (T,) , ) and get the target position (XA
) Calculate the positional deviation (EX) from step ■), judge the magnitude relationship between this deviation (II! state or dead zone (ΔX)? Determine whether it is within range ii (step ■). And tillage rotary (
4) is outside the dead zone (status flag 5F
-2or O) has a solenoid valve (9) to judge the current position.
The process is continued until a time corresponding to one cycle (T2) consisting of ON time and OFF time has elapsed. In other words, M of the sampling period (T1) of the position information (x7)
The sampling is performed until the number of samplings corresponds to the valve driving cycle which is twice the cycle (T2). Also, if it is located within the fuwaza zone (ΔX) (state flag SF = 1)
To stop the operation of the electromagnetic valve (9), input the cycle (T2) into the OFF time memory so that the OFF time of the valve (9) spans one cycle (T2) (
Step ■).

Next, when one cycle (T2) of driving the valve (9) has elapsed, the duty (D) is reset, and the previously calculated OFF time is input into the contents of the OFF time memory (step ■). Calculate the current operating speed (V) based on the position information Cx,,x,,), find the deviation (EV) from the target speed (V0), and calculate the speed (v7) and one cycle (T2).
Previous speed (VR-+) G (7) Speed deviation with period (T2
) to calculate the acceleration (A) (step ■). Then, when the positional deviation (lEXl) is close to the dead zone (ΔX) (nΔ>IEXI>ΔX) and the speed deviation (EV) is negative (that is, the current operating speed is smaller than the target speed) In some cases, the gain (K) for the speed deviation is calculated using the following formula (% formula %) to increase it (step ■).
.

Here, the tilling rotary (4) is again in the ascending state (SF=
2) Determine whether the current is in a falling state (SF=O) or in a dead zone (ΔX) and set the basic duty (D0) to no. U
or 0, and calculate the duty (D) based on the velocity deviation (EV) and acceleration (8) (step
). Based on the value of duty (D) multiplied by 100, if duty (D) is smaller than O, then (D) is regarded as O, and if it is larger than 100, it is regarded as 100, and 0≦D≦1.
In the case of 00, the off time of the pulp (9) is calculated using the calculated value (step ■).

In contrast to the main routine (8) as described above, there is a routine (B) that determines the operating state of the pulp (9) by an interrupt command. The interrupt is executed every time (for example, 1 ms), and is controlled by a timer (2) different from the timer (2) of the main routine (A). Based on the off time (OFFT) calculated in the main routine (A), the elapsed time (+2
) is shorter than 0FFT, the pulp (9) is kept in the OFF state, and if the elapsed time (+2) is longer than 0FFT, the electromagnetic pulp (9) is in the rising state (SF=2).
Turn on the UP valve, turn on the Down pulp in the case of a downward state (SF=O), and then turn on the dead zone (ΔX).
If it is within the range, the pulp is switched to OFF, and the pulp is always operated from the OFF state, and the operating state is determined every 1 ms.

[Another example]

■ The duty control mode of the working device (4) as described above may be used not only for position control (elevating/lowering control) but also for rolling control. If such a system is adopted, it is possible to adopt a duty control mode in which the operating speed is used as a control medium.

◎ In addition, a duty control mode may be adopted for automatic tilling depth control to maintain the working device (4) at a set depth. In this case, the detected value of the cover sensor (19) is used as the tilling depth setting device )
The hydraulic cylinder (9) is controlled by duty to operate the working device (4) in an upward motion until the set value is reached.

[Brief explanation of the drawing]

The drawings show an embodiment of the drive control mechanism for a working device of a working machine according to the present invention, and (4) and (+1) in FIG. , (1m) indicates duty, Figure 2 C),
(El) and (C) are graphs showing the difference in duty due to the deviation of the actual speed from the target speed, Figure 3 shows the configuration of the drive system of the working equipment, and Figure 4 shows the traveling machine and the working equipment. Side view, Figure 5 is a graph showing drive pulses,
FIG. 6 is a graph showing the pulse rise characteristics when shifting from continuous drive control to duty control, and FIG. 7 is a flowchart. (1)......Traveling body, (4)...Working device, (5)...Hydraulic cylinder, (9)...
...Electromagnetic pulp, (D) ...Duty, (v
0)...Target operating speed, (V)...Actual operating speed, (EV)...Speed deviation, (K)...
...Feedback gain, (XA)...
Target position, (x7)...Current position, (EX)
...Position deviation.

Claims (1)

[Claims] A working device (4) connected to the traveling body (1) so as to be freely changeable in attitude or position is configured to be moved toward a target attitude or position by a hydraulic cylinder (5) whose operation is controlled by an electromagnetic valve (9). This is a drive control mechanism for a working device of a working device, in which the duty (D) in the pulse operation signal for the electromagnetic valve (9) is determined by the target operating speed (V_0) and the actual operating speed (V_0) of the working device (4). Speed deviation from (
Based on the product of EV) and feedback gain (K), the actual operating speed (V) is determined by the target operating speed (V_
0) Set it so that the smaller it is, the larger it becomes, and
Feedback gain ( A drive control mechanism for a working device of a working machine configured to increase K).