Cooperative control system and method for inner ring and outer ring of servo valve

Abstract

The invention discloses an inner and outer ring cooperative control system and method for a servo valve, and the system comprises an inner ring control loop which is used for monitoring the working current of an electro-mechanical converter of the servo valve and the actual position of a valve element in real time, and forming a dual closed-loop feedback mechanism of the current and the position; the outer loop control loop is used for monitoring the output pressure of the servo valve and feeding back a real-time pressure signal to a pressure closed loop; a system controller; and a power supply unit. Through the synergistic effect of the inner ring and the outer ring, double optimization of rotation of the electro-mechanical converter and output pressure of the pressure servo valve is achieved. The quick response and stability of the inner ring provide a solid foundation for the accurate tracking of the outer ring, and the high-performance control of the outer ring ensures the accurate execution of a control instruction and the stability and reliability of pressure output of the whole system, so that the comprehensive performance of the pressure servo valve is effectively improved; and the industrial application requirements of high precision, high response and strong robustness are met.

Description

Technical Field

[0001] The present invention relates to the technical field of servo valve automatic control, and in particular to an inner and outer ring coordinated control system and method of a servo valve. Background Art

[0002] In the field of fluid control technology, servo valves, as a key control element, are widely used in aviation, aerospace, industrial automation and other fields to accurately control the flow, pressure and direction of fluids. Traditional servo valve control systems usually adopt a single closed-loop control strategy, such as current closed-loop control or position closed-loop control, to achieve control of certain output variables of the servo valve. For example, the Chinese invention patent with application number 201710431334.8 discloses a servo valve for closed-loop control of flow, which adopts a current closed-loop control scheme to achieve control of the servo valve flow. However, a single closed-loop control can often only optimize a specific output variable, and cannot fully consider the various complex factors in the operation of the servo valve. For example, accurate control of the valve core position cannot be guaranteed by current closed-loop control alone, because the relationship between current and valve core position is affected by a variety of nonlinear factors. Similarly, position closed-loop control alone may also lead to a decrease in control accuracy due to ignoring current fluctuations.

[0003] New control methods and technologies have also emerged in the existing servo valve control system. For example, the Chinese invention patent with application number 202410102081.X discloses a dual-redundancy servo valve closed-loop control drive method. This technical solution limits the servo valve control instruction and performs closed-loop current control, drive and output. According to the fault monitoring results and the system working status, the main and standby working switching and the main working mode are realized. The main channel monitors the circuit and load status through current acquisition, and the standby channel monitors the circuit status through current acquisition. However, the above schemes are still difficult to meet the needs of complex systems for multi-variable, high-precision, and high-stability control. Especially in application scenarios with high dynamic requirements, single closed-loop control usually lacks an effective anti-interference mechanism, which is prone to external interference, resulting in a decrease in control performance or even loss of control.

[0004] In view of the above situation, the present invention aims to provide a new solution to solve this problem. Summary of the invention

[0005] In view of the above situation, in order to overcome the defects of the prior art, the purpose of the present invention is to provide an inner and outer ring coordinated control system of a servo valve.

[0006] The technical solution is: a servo valve inner and outer ring coordinated control system, including:

[0007] Inner control loop: used to monitor the working current of the electric-mechanical converter of the servo valve and the actual position of the valve core in real time, forming a dual closed-loop feedback mechanism of current and position;

[0008] Outer control loop: used to monitor the output pressure of the servo valve and feed back the real-time pressure signal to the pressure closed loop;

[0009] A system controller, configured to receive feedback signals from the inner control loop and the outer control loop, calculate an error amount based on the feedback signals and system given parameters, and adjust control parameters in real time according to the error amount to achieve precise control of the output variable of the servo valve;

[0010] The power supply unit is used to provide power to the system.

[0011] Preferably, the inner control loop includes:

[0012] A current sensor, used to monitor the operating current of the electro-mechanical converter and feed back the current signal to the system controller;

[0013] The position sensor is installed inside the servo valve and is used to detect the position of the servo valve core displacement in real time and feed back the position signal to the system controller.

[0014] Preferably, the outer control loop includes:

[0015] Pressure sensor: installed at the output pressure end of the servo valve, used to detect the output pressure and feed back the pressure signal to the system controller.

[0016] Preferably, the detection input end of the system controller is also provided with an input signal conditioning module, specifically comprising:

[0017] An amplification and noise reduction circuit is used to amplify the sensor signal and suppress the noise component in the signal at the same time;

[0018] The amplitude stabilization adjustment circuit is used to stably adjust the output signal amplitude of the amplification and noise reduction circuit.

[0019] Preferably, the amplification and noise reduction circuit includes an op amp U1, the in-phase input terminal of the op amp U1 is connected to the sensor signal input port through a resistor R1 and is grounded through a capacitor C1, the inverting input terminal of the op amp U1 is connected to one end of a capacitor C2 and is grounded through a parallel resistor R3 and capacitor C3, and the other end of the capacitor C2 is connected to the output terminal of the op amp U1 through a resistor R2.

[0020] Preferably, the amplitude stabilization adjustment circuit includes a MOS tube Q1 and a voltage regulator tube DZ1, the gate of the MOS tube Q1 is connected to the output end of the operational amplifier U1, the drain of the MOS tube Q1 is connected to the power supply VCC, the source of the MOS tube Q1 is connected to the cathode of the voltage regulator tube DZ1, one end of the capacitor C4 and the system controller, the anode of the voltage regulator tube DZ1 is grounded, and the other end of the capacitor C4 is grounded through the resistor R4.

[0021] Preferably, the system controller uses an STM32 single-chip microcomputer.

[0022] Preferably, a signal isolator is provided between the inner control loop and the outer control loop.

[0023] A control method for an inner and outer ring coordinated control system of a servo valve comprises the following steps:

[0024] Current closed loop control:

[0025] By sampling the current flowing through the electro-mechanical converter in real time, a current signal is generated, and the current signal is fed back to the system controller;

[0026] Compare the feedback current signal with the given current reference value and calculate the current error;

[0027] The system controller adjusts the current driving the electro-mechanical converter to reduce the current error until the current error approaches zero, thereby achieving stable current control;

[0028] Position closed loop control:

[0029] By real-time detection of the valve core displacement of the electro-mechanical converter, a position signal is generated, and the position signal is fed back to the system controller;

[0030] Compare the feedback position signal with the given position reference value to form a position error;

[0031] The system controller reduces the position error by adjusting the driving force of the electro-mechanical converter until the valve core reaches the predetermined position;

[0032] Outer loop control:

[0033] By real-time detection of the output pressure of the servo valve, a pressure signal is generated, and the pressure signal is fed back to the system controller;

[0034] Compare the feedback pressure signal with the given pressure target value and calculate the pressure error;

[0035] The system controller adjusts the output pressure of the servo valve to ensure the tracking performance of the servo valve output pressure to the control command of the system controller.

[0036] Through the above technical scheme, the beneficial effects of the present invention are as follows: the present application realizes the dual optimization of the rotation of the electro-mechanical converter and the output pressure of the pressure servo valve through the synergistic effect of the inner and outer rings. The rapid response and stability of the inner ring provide a solid foundation for the precise tracking of the outer ring, while the high-performance control of the outer ring ensures the accurate execution of the control instructions and the stable and reliable pressure output of the system as a whole, thereby effectively improving the comprehensive performance of the pressure servo valve and meeting the industrial application requirements of high precision, high response and strong robustness. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A block diagram of the system module structure provided in one embodiment of the present invention.

[0038] Figure 2 A schematic diagram of system control provided in accordance with an embodiment of the present invention.

[0039] Figure 3 A circuit schematic diagram of a signal conditioning module provided in accordance with an embodiment of the present invention. DETAILED DESCRIPTION

[0040] The above and other technical contents, features and effects of the present invention are described in detail below with reference to the attached Figure 1 To Attachment Figure 3 The detailed description of the embodiments will clearly show that the structural contents mentioned in the following embodiments are all based on the drawings in the specification.

[0041] Exemplary embodiments of the present invention will be described below with reference to the accompanying drawings.

[0042] like Figure 1 and 2 As shown, a servo valve inner and outer ring coordinated control system includes:

[0043] Inner control loop: used to monitor the working current of the servo valve's electro-mechanical converter and the actual position of the valve core in real time, forming a dual closed-loop feedback mechanism of current and position;

[0044] Outer control loop: used to monitor the output pressure of the servo valve and feed back the real-time pressure signal to the pressure closed loop;

[0045] A system controller, for receiving feedback signals from the inner control loop and the outer control loop, calculating an error amount based on the feedback signals and given system parameters, and adjusting control parameters in real time according to the error amount, so as to achieve precise control of the output variable of the servo valve;

[0046] The power supply unit is used to provide power to the system to ensure that all components can operate normally.

[0047] In the above, the inner control loop includes:

[0048] A current sensor is used to monitor the operating current of the electro-mechanical converter and feed back the current signal to the system controller;

[0049] The position sensor is installed inside the servo valve to detect the position of the servo valve core displacement in real time and feed back the position signal to the system controller.

[0050] The outer control loop includes:

[0051] Pressure sensor: installed at the output pressure end of the servo valve, used to detect the output pressure and feed back the pressure signal to the system controller.

[0052] In the specific implementation, the inner control loop monitors the working current of the electro-mechanical converter and the actual position of the valve core in real time through a high-precision sensor, forming a dual closed-loop feedback mechanism of current and position. Based on the quantitative feedback control theory, the loop can quickly and accurately adjust the working state of the electro-mechanical converter to ensure that the valve core can move according to the predetermined trajectory and realize the precise control of the valve core position.

[0053] The outer control loop is mainly responsible for monitoring the output pressure of the servo valve and feeding back the real-time pressure signal to the pressure closed loop through the pressure sensor. Using this pressure feedback information, the outer control loop can dynamically adjust the set point or control parameters of the inner control loop to achieve precise regulation of the output pressure. This process ensures that the servo valve can closely track and respond to external control instructions, and maintain the stability and accuracy of the output pressure even when the system parameters change or external disturbances exist.

[0054] The detection input end of the system controller is also equipped with an input signal conditioning module, whose main function is to improve the quality of the sensor signal and ensure that the system controller can receive accurate and stable signals, thereby improving the accuracy and reliability of the entire control system. The signal conditioning module specifically includes:

[0055] An amplification and noise reduction circuit is used to amplify the sensor signal and suppress the noise component in the signal at the same time;

[0056] The amplitude stabilization adjustment circuit is used to stably adjust the output signal amplitude of the amplification and noise reduction circuit.

[0057] Specifically, Figure 3 As shown, the amplification and noise reduction circuit includes an operational amplifier U1, a non-inverting input terminal of the operational amplifier U1 is connected to a sensor signal input port through a resistor R1, and is grounded through a capacitor C1, an inverting input terminal of the operational amplifier U1 is connected to one end of a capacitor C2, and is grounded through a parallel resistor R3 and the capacitor C3, and the other end of the capacitor C2 is connected to the output terminal of the operational amplifier U1 through a resistor R2.

[0058] The amplitude stabilization regulation circuit includes a MOS tube Q1 and a voltage regulator tube DZ1. The gate of the MOS tube Q1 is connected to the output end of the operational amplifier U1, the drain of the MOS tube Q1 is connected to the power supply VCC, the source of the MOS tube Q1 is connected to the cathode of the voltage regulator tube DZ1, one end of the capacitor C4 and the system controller, the anode of the voltage regulator tube DZ1 is grounded, and the other end of the capacitor C4 is grounded through the resistor R4.

[0059] In the above, the specific working process of the signal conditioning module is as follows: the current sensor, position sensor or pressure sensor converts the detected physical quantity into an electrical signal and inputs it into the sensor signal input port of the signal conditioning module. The amplification and noise reduction circuit uses the op amp U1 to amplify the sensor signal. At the same time, the capacitor C1 and the resistor R1 form a low-pass filter at the feedback end of the op amp U1 to filter out the high-frequency noise in the signal to improve the signal-to-noise ratio of the feedback signal. The capacitor C3 plays a role in eliminating thermal noise at the inverting input end of the op amp U1, effectively improving the amplification accuracy of the op amp U1. The amplified signal enters the amplitude stabilization adjustment circuit for further conditioning, and the output signal of the op amp U1 is received by using the good temperature characteristics of the MOS tube Q1, and the output signal is stabilized by the voltage regulator DZ1. At the same time, the RC filter network composed of the capacitor C4 and the resistor R4 further smoothes the output signal, reduces the ripple, and ensures that the amplitude of the signal received by the system controller is stable.

[0060] The signal processed by the signal conditioning module is sent to the detection input of the system controller for further processing, analysis and control decision-making. Specifically, the system controller uses an STM32 microcontroller, which converts the analog signal from the signal conditioning module into a digital signal through its built-in ADC (analog-to-digital converter) module. The CPU (central processing unit) integrated inside the microcontroller processes the collected digital signals, including filtering, denoising, linearization, etc., to improve the accuracy and reliability of the data. At the same time, the microcontroller also calculates and analyzes the processed data according to the preset control algorithm (such as PID control, fuzzy control, etc.) to generate control instructions.

[0061] In the above, a signal isolator is arranged between the inner control loop and the outer control loop. The signal isolator can disconnect the direct circuit connection between the control loops through isolation technology without affecting the normal transmission of the signal, thereby improving the anti-interference ability of the system, ensuring the stability and reliability of the signal, and protecting the equipment in each control loop from potential damage.

[0062] As another embodiment of the present application, a control method of an inner and outer ring coordinated control system of a servo valve includes the following steps:

[0063] Current closed loop control:

[0064] By sampling the current flowing through the electro-mechanical converter in real time, a current signal is generated and the current signal is fed back to the system controller;

[0065] Compare the feedback current signal with the given current reference value and calculate the current error;

[0066] The system controller adjusts the current driving the electro-mechanical converter to reduce the current error until the current error approaches zero, thereby achieving stable current control;

[0067] Position closed loop control:

[0068] By real-time detection of the valve core displacement of the electro-mechanical converter, a position signal is generated and fed back to the system controller;

[0069] Compare the feedback position signal with the given position reference value to form a position error;

[0070] The system controller reduces the position error by adjusting the driving force of the electro-mechanical converter until the valve core reaches the predetermined position;

[0071] Outer loop control:

[0072] By real-time detection of the output pressure of the servo valve, a pressure signal is generated and the pressure signal is fed back to the system controller;

[0073] Compare the feedback pressure signal with the given pressure target value and calculate the pressure error;

[0074] The system controller adjusts the output pressure of the servo valve to ensure the tracking performance of the servo valve output pressure to the control command of the system controller.

[0075] In summary, the control system achieves dual optimization of the rotation of the electro-mechanical converter and the output pressure of the pressure servo valve through the synergy of the inner and outer loops. The rapid response and stability of the inner loop provide a solid foundation for the precise tracking of the outer loop, while the high-performance control of the outer loop ensures the accurate execution of the control instructions and the stable and reliable pressure output of the system as a whole, thereby effectively improving the comprehensive performance of the pressure servo valve and meeting the industrial application requirements of high precision, high response and strong robustness.

[0076] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, and the indirect coupling or communication connection of devices or units can be electrical, mechanical or other forms.

[0077] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0078] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0079] The above is a further detailed description of the present invention in combination with a specific implementation method, and it cannot be determined that the specific implementation of the present invention is limited to this; for technical personnel in the technical field to which the present invention belongs and related technical fields, based on the technical solution of the present invention, the expansion and replacement of operating methods and data should all fall within the protection scope of the present invention.

Claims

1. A servo valve inner and outer ring coordinated control system, characterized in that: include: Inner control loop: used to monitor the working current of the electric-mechanical converter of the servo valve and the actual position of the valve core in real time, forming a dual closed-loop feedback mechanism of current and position; Outer control loop: used to monitor the output pressure of the servo valve and feed back the real-time pressure signal to the pressure closed loop; A system controller, configured to receive feedback signals from the inner control loop and the outer control loop, calculate an error amount based on the feedback signals and system given parameters, and adjust control parameters in real time according to the error amount to achieve precise control of the output variable of the servo valve; The power supply unit is used to provide power to the system.

2. According to claim 1, the inner and outer ring coordinated control system of a servo valve is characterized in that: The inner control loop comprises: A current sensor, used to monitor the operating current of the electro-mechanical converter and feed back the current signal to the system controller; The position sensor is installed inside the servo valve and is used to detect the position of the servo valve core displacement in real time and feed back the position signal to the system controller.

3. According to claim 2, the inner and outer ring coordinated control system of a servo valve is characterized in that: The outer control loop comprises: Pressure sensor: installed at the output pressure end of the servo valve, used to detect the output pressure and feed back the pressure signal to the system controller.

4. The inner and outer ring coordinated control system of a servo valve according to claim 3, characterized in that: The detection input end of the system controller is also provided with an input signal conditioning module, which specifically includes: An amplification and noise reduction circuit is used to amplify the sensor signal and suppress the noise component in the signal at the same time; The amplitude stabilization adjustment circuit is used to stably adjust the output signal amplitude of the amplification and noise reduction circuit.

5. The inner and outer ring coordinated control system of a servo valve according to claim 4, characterized in that: The amplification and noise reduction circuit includes an operational amplifier U1, a non-inverting input terminal of the operational amplifier U1 is connected to a sensor signal input port through a resistor R1 and is grounded through a capacitor C1, an inverting input terminal of the operational amplifier U1 is connected to one end of a capacitor C2 and is grounded through a parallel resistor R3 and the capacitor C3, and the other end of the capacitor C2 is connected to the output terminal of the operational amplifier U1 through a resistor R2.

6. The inner and outer ring coordinated control system of a servo valve according to claim 5, characterized in that: The amplitude stabilization adjustment circuit includes a MOS tube Q1 and a voltage regulator tube DZ1, the gate of the MOS tube Q1 is connected to the output end of the operational amplifier U1, the drain of the MOS tube Q1 is connected to the power supply VCC, the source of the MOS tube Q1 is connected to the cathode of the voltage regulator tube DZ1, one end of the capacitor C4 and the system controller, the anode of the voltage regulator tube DZ1 is grounded, and the other end of the capacitor C4 is grounded through a resistor R4.

7. The inner and outer ring coordinated control system of a servo valve according to claim 6, characterized in that: The system controller uses an STM32 single-chip microcomputer.

8. The inner and outer ring coordinated control system of a servo valve according to claim 1, characterized in that: A signal isolator is provided between the inner control loop and the outer control loop.

9. A control method for an inner and outer loop coordinated control system of a servo valve according to any one of claims 1 to 8, characterized in that: The steps include: Current closed loop control: By sampling the current flowing through the electro-mechanical converter in real time, a current signal is generated, and the current signal is fed back to the system controller; Compare the feedback current signal with the given current reference value and calculate the current error; The system controller adjusts the current driving the electro-mechanical converter to reduce the current error until the current error approaches zero, thereby achieving stable current control; Position closed loop control: By real-time detection of the valve core displacement of the electro-mechanical converter, a position signal is generated, and the position signal is fed back to the system controller; Compare the feedback position signal with the given position reference value to form a position error; The system controller reduces the position error by adjusting the driving force of the electro-mechanical converter until the valve core reaches the predetermined position; Outer loop control: By real-time detection of the output pressure of the servo valve, a pressure signal is generated, and the pressure signal is fed back to the system controller; Compare the feedback pressure signal with the given pressure target value and calculate the pressure error; The system controller adjusts the output pressure of the servo valve to ensure the tracking performance of the servo valve output pressure to the control command of the system controller.

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