High-speed electromagnetic valve control system and method adapting to working conditions and controlling parameter changes

Abstract

The invention relates to a high-speed electromagnetic valve control system and method adapting to working conditions and controlling parameter changes. The system comprises an upper computer, a switching signal generator, a controller, a voltage source, a current sensor, a current differential processing module, a pressure detection system and a high-speed electromagnetic valve, and the voltage source comprises a variable positive voltage source and a negative voltage source; in the valve element opening stage, whether a valve element is fully opened or not is judged through current and derivative feedback information of the current; in the full-open stage of the valve element, high-frequency PWM voltage which is adaptive to the pressure working conditions and controlling parameter changes is applied; and in the valve element closing stage, the closing excitation time, the zero current maintaining time and the pre-excitation time are optimally distributed, and the amplitude of the pre-excitation voltage is regulated and controlled in a self-adaptive mode. According to the system and method, high-dynamic control over the high-speed electromagnetic valve can be achieved only by setting the control parameters of the switching signals, the response time is shortened, energy consumption is reduced, the duty ratio range for achieving full opening and full closing of the valve element under high frequency is widened, and control accuracy, adaptability and robustness are improved.

Description

Technical field [0001] The present invention belongs to the field of solenoid valve control, and specifically, a high speed solenoid valve control system and method for adapting a working condition and control parameter change. Background technique [0002] High-speed solenoid valve as a new type of hydraulic control element for digital control, replacing the valve opening opening degree throttling control, can greatly reduce the throttling loss of the valve control system, improve the anti-pollution capability of the electro-hydraulic control system, easy to achieve hydraulic digitization And high reliability control. [0003] In recent years, researchers have tried to be coupled to proportional control by high frequency discrete fluid, and the control effect of this technology depends on the dynamic characteristics of high-speed solenoid valves in the hydraulic system. Therefore, the dynamic characteristics of the high speed solenoid valve are a major obstacle to the developmen...

AI Technical Summary

Problems solved by technology

For example, the patent CN105443840B discloses a solenoid valve intelligent control system and its method. The disadvantage is: by performing function fitting on the pressure value and the opening current feedback value of the previous experimental test, the fitting result is used to judge whether the valve core is fully Open, the data processing is more cumbersome; and, in order to ensure that the spool is fully open, it is necessary to select a large open current feedback value in the actual measurement, resulting in a time lag in voltage switching, that is, due to the existence of coil inductance, when the high voltage is switched to the maintenance voltage At this time, the current needs to drop for a period of time to maintain the full-on current, and the current change is not timely enough, causing the coil to generate excess current, resulting in increased energy consumption

[0006] (2) When the high-speed solenoid valve is in the continuous on-off cycle working state, the PWM maintenance voltage applied during the fully open stage of the valve core is difficult to adapt to the changing pressure conditions and switching Signal

For example, patent CN105676690B discloses a solenoid valve intelligent control system and its method based on voltage pulse width modulation. It is difficult to adapt to the adjustment of the PWM maintenance voltage to meet the changing pressure conditions; and, if the PWM maintenance voltage with a fixed frequency is applied, due to the change of the switch signal control parameters (duty ratio g, period T), when the switch signal falling edge arrives, the instant , it is difficult to ensure that the real-time current value under different pressure conditions and different switch signal control parameters can be exactly in the middle value of the high-frequency flutter current ripple, that is, to maintain the full-on current value, so that the initial point of decline is not accurate enough, which is not conducive to high-frequency control of the falling current

[0007](3) The single high-voltage excitation makes the opening response speed of the spool not fast enough; at the same time, for different pressure conditions, the electromagnetic delay time of the spool opening is also within There are large differences under different pressure conditions, which further cause large differences in opening response time

For example, the patent CN105805392B discloses a PWM control method for improving the response speed of a high-speed switching solenoid valve. The disadvantage is that: a single high-voltage excitation makes the coil current rise from zero during the valve core opening stage, and the response is not fast enough; and when the pressure As the working conditions increase, the required critical opening current value is also greater, and the coil current rise time is also longer, which prolongs the delay time of opening the electromagnetic valve, and thus makes the opening response time of the high-speed solenoid valve very sensitive to pressure changes and not stable enough.

[0008] (4) When the duty cycle of the switch signal is high, after applying a negative voltage to reduce the coil current to zero, even if a pre-excitation voltage with the amplitude of the rated voltage is applied It also fails to raise the current to the desired pre-excitation current value

For example, patent CN111828715A discloses a control system and method for realizing rapid movement of solenoid valves. The disadvantage is that when the duty ratio of the switch signal is high, the applied negative voltage reduces the coil current to zero, and due to the zero current maintenance phase Existence, the pre-excitation voltage will also be unable to increase the coil current to the required pre-excitation current value due to the short pre-excitation time, and even cannot keep the coil current stable near the pre-excitation current value before the excitation high voltage arrives. As a result, the turn-on response time of the next cycle increases, making the original pre-excitation method invalid when the switching signal has a high duty cycle

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