JPH0335522B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an output control device for hydraulic equipment, and more particularly, an electromagnetic proportional control valve is interposed in a flow path of an actuator connected to a pressure fluid source, and the control valve is controlled by an electromagnetic proportional control valve. The present invention relates to an output control device for hydraulic equipment that controls an output value to an actuator to a preset target value by sequentially changing a control signal.

Prior Art and Problems to be Solved by the Invention Conventionally, output control devices for this type of hydraulic equipment have been constructed with an open-loop control circuit as a whole to eliminate the troublesomeness of closed-loop control and to eliminate machine differences. There was a desire for something that would improve static accuracy, approximate the output of the flow path to the target value with high precision, and connect the input and output with linearity, but it has not been possible to obtain anything that can meet this requirement in practice. I couldn't do it.

Means for Solving the Problems In order to meet the above needs, the present invention provides control to the control valve by interposing an electromagnetic proportional control valve in the flow path of an actuator connected to an output source that supplies pressure fluid to hydraulic equipment. In an output control device for hydraulic equipment that uses a control circuit to control the output value to an actuator to a preset target value by sequentially changing signals, the above control circuit has a learning operation circuit and an actual operation circuit that can be switched by a switch. Therefore, when performing a learning operation in advance, the learning operation circuit has a means for extracting the output value of the actuator as an electric signal at a constant timing, corresponding to each target value of learning, sequentially from the previous time, this time, and the next time. , a subtracter that sequentially compares each of the target values and the output value of the extraction means and calculates the difference between the two, and an adder that adds the current subtraction value and the output value output last time. A comparator that sequentially repeats transmitting the output as a control signal to the control valve, and further includes a comparator that compares the difference between each target value of the subtracter and the input value with a constant value, and an output of the comparator. and a register for sequentially storing the adder as a correction value, and on the other hand,
The actual operation circuit is provided with a means for extracting the corrected value of the register corresponding to the operation target value when performing the actual operation, and controls the control valve using the corrected value of the extracting means as a control signal. This is a newly created output control device for hydraulic equipment featuring the following features:

Effects According to the device of the present invention having the configuration as described above, when performing a learning operation in advance, the output value to the actuator is sequentially changed at a constant timing from the previous time, this time, and the next time, corresponding to each learning target value. Pick up as an electrical signal, sequentially compare each of the target values and the output value, and control the control valve by using the calculated value, which is the sum of the current comparison value and the output value output last time, as the next control signal, The above calculated values when the difference between each target value and the output value falls within a certain range are sequentially stored as correction values, and then when actual operation is performed, the above correction values corresponding to the operation target values are retrieved. The above control valve is controlled using the corrected value as a control signal, which improves the linearity of open circuit proportional valve control. At the same time, it automatically corrects the machine differences of each element equipment in a straight line relationship, and as a result, it achieves excellent effects such as being able to obtain multiple uniform systems (main machines) with no machine differences. It is something that can be done.

Embodiments Hereinafter, embodiments of the present invention shown in the drawings will be described in detail.

In FIG. 1, the pressure in the flow path 3 of an electromagnetic proportional pressure control valve 4 such as a relief valve provided in the flow path 3 that supplies fluid from a pressure fluid source 2 such as a pump to a load 1 such as hydraulic equipment is controlled. The control signal to the electromagnetic proportional pressure control valve 4 is sequentially varied by the control circuit 5,
By controlling the pressure in the flow path 3, the pressure in the load 1 is regulated.

The control circuit 5 includes a learning operation circuit 5a, an actual operation circuit 5b, and a changeover switch SW that turns ON only one of the two circuits.
The learning operation circuit 5a, which is turned on by SW, learns the output adjustment of the electromagnetic proportional pressure control valve 4 in advance, finds the relationship data between the adjusted pressure in the flow path 3 and the control signal of the electromagnetic proportional pressure control valve 4, and then switches Switch SW
When actually adjusting the output of the electromagnetic proportional pressure control valve 4 in the actual operation circuit 5b by switching the , the electromagnetic proportional pressure control valve 4 is controlled based on the related data obtained in the learning operation circuit 5a. Make it.

The learning operation circuit 5a, which performs learning in advance and imports related data before actual operation, is operated by turning the switch SW ON.
The fluid pressure in the flow path 3 is sequentially picked up as an electric signal Yj by the pick-up b in accordance with the fixed timing by the timing control circuit a, such as the previous time, this time, the next time, and so on. At the same timing, one of the fluid pressure learning target values T ₁ i set in advance and stored in memory is taken out as the first learning target value, and the above
While Yj is AD converted d, T ₁ i is amplified by a constant coefficient K (Xi = K・T ₁ i), and these Xi and Yj are simultaneously sent to the subtractor f, and the difference ε( ε=
Xi − Yj). On the other hand, after attenuating the value Xi obtained by amplifying the learning target value by a constant coefficient α, this value (α·Xi) and the output ε of the subtractor f
is sent to the comparator h, and when ε is equal to or smaller than the value of (α·Xi), it outputs YES and turns on the AND gate k. Also, after timely amplifying the output of the subtractor f (β・εi) that passes through the comparator h, an adder or integrator m compares the current amplification value (β・εi) with the previous amplification value. The sum ( _{Zi =}
Calculate Zi _-1 +β・ε). The previous output value (Zi _-1 ) is obtained by storing the output value (β・εi _-1 ) obtained at the previous measurement timing in the integrator m, outputting it at the current measurement timing, and calculating the current amplification value ( β・
εi). The output Zi of the integrator m is a switch
After passing through the SW, D/A conversion is performed and the width is amplified at the appropriate time.
(γZi), and this value is used as a control signal to the electromagnetic proportional pressure control valve 4. b like this,
This time, a series of arithmetic processing of the learning operation circuit 5a consisting of c, d, e, g, f, h, m, SW, n, p will be explained.
Next time, one after another, repeating the measurement timing one after another, ε is (α・Xi) as the output of comparator h.
When AND gate k is turned on when the value is equal to or smaller than the value of , the value of integrator m at that time is passed through AND gate k to register r (Z (Ti) = Zi)
is stored as a modified value corresponding to the first learning target value, and then at the next counter s (Ti)
is counted up and becomes (T=T ₁ i+ ₁ ),
With this output, the memory c is switched to the second learning target value. Once the second learning target value is set, the series of calculations as described above is performed again this time.
Next time, one after another, etc., the value of the integrator m when the comparator h turns on the AND gate k is stored as the corrected value corresponding to the second learning target value. By repeating these operations, the corrected values corresponding to the learning target values of the first, second, etc. will be stored in register r in sequence, and all these memorized values will be stored in the next stage's memory. Transferred to q. Next, switch the switch SW to the actual operation circuit 5b.
When turned ON, the first operation target value v is set at a certain timing by the timing control circuit a.
The correction value (Zi) corresponding to (T ₂ i) is taken out from the memory q, passed through the switch SW, and then sent to the D/A.
This value is converted n and increased in width p (Zi+ ₁ = γZi) as appropriate, and this value is used as a control signal to the electromagnetic proportional pressure control valve 4 in the first cycle. Also, at the next timing, the correction value (Zi+ ₁ ) corresponding to the second operation target value is taken out from the memory q, passed through the switch SW, and then D/A converted n to increase the width p at the appropriate time.
(Zi+ ₂ =αZγ+ ₁ ), and this value is used as a control signal to the electromagnetic proportional pressure control valve 4 in the second time. In this way, the next third, fourth, etc. are performed in sequence, and if necessary, an appropriate number of times is selected to control the electromagnetic proportional pressure control valve 4 during operation. In the above embodiment, an electromagnetic proportional pressure valve is used as the electromagnetic proportional control valve, and this electromagnetic proportional pressure valve provides linearity between two points including the lowest pressure (lower limit pressure) and the highest pressure (upper limit pressure) in the flow path. However, an electromagnetic proportional flow valve may be used instead of the electromagnetic proportional pressure valve, and it goes without saying that in this case linearity can be obtained between two points including the minimum flow rate and the maximum flow rate. do not have. In addition, the above electromagnetic proportional pressure valve is
This includes electromagnetic proportional relief valves, electromagnetic proportional pressure reducing valves, etc.

Therefore, the above embodiment uses a control circuit consisting of an electromagnetic proportional pressure valve, its drive amplifier, a hydraulic pressure amount detector, and a digital control device, and uses a control circuit based on the difference (ε) between the target value and the output value. The value obtained by (β・
Add the output value before the amplifier input, that is, the Z value, which was output last time to ε), and substitute this as the current Z value. Finally, ε approaches 0 to improve the accuracy (ε≦α・
X), and when it reaches a certain accuracy (ε≦α・
X), store Z as Z(t), execute this over the entire control range, then switch the circuit and set T
→Z(T)→D/A→Amplifier→Solenoid proportional pressure valve→
The output hydraulic pressure amount is controlled so that linearity can be obtained between input and output (T-Y).

Therefore, the output control device for hydraulic equipment of the above embodiment has an actuator 1 connected to an output source 2.
By interposing an electromagnetic proportional control valve 4 in the flow path 3 and sequentially changing the control signal to the control valve 4, the control circuit controls the output value to the actuator 1 to a preset target value. In the output control device of hydraulic equipment, the above control circuit is a switch SW.
The learning operation circuit 5a and the actual operation circuit 5 can be switched by
In other words, when performing a learning operation in advance, the learning operation circuit 5a sets the output value of the actuator to the previous, current, and previous time in accordance with each learning target value c.
means b for extracting as an electrical signal at a constant timing one after another; a subtracter f for sequentially comparing each target value with the output value of the extracting means and calculating the difference between the two;
An adder m is provided for adding the current subtraction value and the output value output last time, and the output of the adder m is transmitted as a control signal to the control valve 4, and this is sequentially repeated. It is equipped with a comparator h that compares the difference between each target value c input value of the subtractor f with a constant value, and a register r that sequentially stores the adder m as a correction value using the output of the comparator h, and furthermore, The circuit 5b is provided with a means q for extracting the corrected value of the register r corresponding to the operation target value when performing actual operation, and the corrected value of the extracting means q included in the control circuit is used as a control signal. The signal is sent to an output control device to control the control valve 4.

Effects of the Invention As detailed in the above embodiments, the present invention provides the following advantages: by interposing an electromagnetic proportional control valve in the flow path of an actuator connected to a pressure fluid source and sequentially changing the control signal to the control valve, As an output control device for hydraulic equipment that controls the output value to the actuator to a preset target value, a learning operation is performed in advance, that is, corresponding to each learning target value, the output value to the actuator is changed from the previous value. , this time, the next time and so on, are picked up as electrical signals at a certain timing, and the above target values and output values are sequentially compared, and the calculated value, which is the sum of the current comparison value and the previous output value, is used as a control signal to control the control valve. This is sequentially repeated, and the calculated values when the difference between each target value and the output value falls within a certain range are sequentially stored as correction values, and then actual operation is performed. Sometimes, take out the above correction value corresponding to the operation target value,
The above-mentioned control valve is controlled using the corrected value as a control signal, and the above-mentioned simple configuration achieves the intended purpose, that is, improves the linearity of open circuit proportional valve control, and improves the linearity of the open circuit proportional valve control. Connect a linear relationship between the set numerical value and the output pressure (or flow rate), and at the same time automatically correct the machine differences of each element equipment, resulting in multiple uniform systems (main machines) with no machine differences. It is possible to achieve the intended purpose.

[Brief explanation of the drawing]

FIG. 1 is a flowchart of an output control device for hydraulic equipment according to the present invention. 1... Actuator, 2... Pressure fluid source, 3
...Flow path, 4...Solenoid proportional control valve, 5...Control circuit, 5a...Learning operation circuit, 5b...Actual operation circuit, b...Takeout means, f...Subtractor, m...Adder , h... comparator, q... extraction means.

Claims (1)

[Claims] 1 By interposing an electromagnetic proportional control valve 4 in the flow path 3 of the actuator 1 connected to the output source 2 and sequentially changing the control signal to the control valve 4, the output value to the actuator 1 can be adjusted to a preset target. In the output control device for hydraulic equipment, which is controlled by a control circuit so as to achieve the desired value, the control circuit is composed of a learning operation circuit 5a and an actual operation circuit 5b, which are switched by a switch SW. when performing the learning, means b for extracting the output value of the actuator as an electric signal at a constant timing sequentially from the previous time, this time, and the next time corresponding to each target value c of learning, and each target value and the output value of the extracting means. and an adder m that adds the current subtraction value and the output value output last time, and uses the output of the adder m as a control signal to control the control valve. In addition, a comparator h compares the difference between each target value c of the subtracter f and the input value with a constant value, and the output of the comparator h is used to transmit the data to the adder. The actual operation circuit 5b is provided with a register r for sequentially storing m as a correction value, and on the other hand, the actual operation circuit 5b is provided with a means q for taking out the correction value of the register r corresponding to the operation target value when performing the actual operation. An output control device for hydraulic equipment, characterized in that the control valve 4 is controlled using the corrected value of the extraction means q as a control signal.