Analog device of electro-hydraulic servo control system

Abstract

The application discloses an analog device of an electro-hydraulic servo control system, which is internally provided with a twin model of an electro-hydraulic servo executing device, wherein the electro-hydraulic servo executing device comprises an instruction device, a hydraulic source, an electro-hydraulic servo valve, a servo oil cylinder, a load and a sensor device; a valve control signal input end of the analog device is connected with a servo valve control current output end of a servo controller of the electro-hydraulic servo executing device; an instruction signal output end of the analog device is connected with an instruction signal input end of the servo controller; a current feedback output end of the analog device is connected with a current feedback input end of the servo controller; and a voltage feedback output end of the analog device is connected with a voltage feedback input end of the servo controller. The application realizes the simulation of the electro-hydraulic servo executing device based on the twin model, and can simulate the running process of the electro-hydraulic servo valve control system in combination with the servo controller, without the application of a large and heavy hydraulic source, executing element, feedback sensor and the like.

Description

[0001] Technology Neighborhood

[0002] This invention relates to the field of industrial electro-hydraulic servo control, and in particular to a simulation device for an electro-hydraulic servo control system. Background Technology

[0003] Figure 1 As shown: An electro-hydraulic servo valve control system refers to a hydraulic control system with a control servo element (electro-hydraulic servo valve SV) as its control core. It typically consists of a command unit (FIC), a servo controller (SC), a hydraulic power source (HS), a servo element (voltage servo valve SV), an actuator (servo cylinder SM), a position feedback sensor (ZE), and a load (L). The servo controller (SC) controls the opening and closing direction and degree of the electro-hydraulic servo valve SV based on the command signals from the FIC, thereby controlling the movement direction and speed of the actuator (servo cylinder SM). The load (L) is usually the stator fan of an axial flow fan. The movement of the actuator (servo cylinder SM) drives the movement of the load (L), ultimately controlling the system. However, in practical applications, the hydraulic power source, actuator, feedback sensor, and other physical equipment are bulky and heavy. Furthermore, if used in new product development, they are prone to overload, oil leakage, and signal open circuit accidents, making them unsuitable for installation and testing in R&D settings such as offices and buildings. The market urgently needs a simulation device to simulate the operation and signal transformation processes of this system to meet the process testing needs in new product development. Summary of the Invention

[0004] The purpose of this invention is to provide a simulation device for an electro-hydraulic servo control system, which combines a servo controller to simulate the operation of an electro-hydraulic servo valve control system without the need for a large, bulky hydraulic power source, actuators, feedback sensors, etc.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] The present invention provides a simulation device for an electro-hydraulic servo control system. The simulation device is equipped with a twin model of an electro-hydraulic servo actuator, which includes a command device, a hydraulic source, an electro-hydraulic servo valve, a servo cylinder, a load, and a sensor device.

[0007] The valve control signal input terminal of the simulation device is connected to the servo valve control current output terminal of the servo controller of the electro-hydraulic servo actuator; the command signal output terminal of the simulation device is connected to the command signal input terminal of the servo controller.

[0008] The current feedback output terminal of the simulation device is connected to the current feedback input terminal of the servo controller; the voltage feedback output terminal of the simulation device is connected to the voltage feedback input terminal of the servo controller.

[0009] Optionally, the twin model can be constructed as follows:

[0010] Acquire the voltage feedback signal and current feedback signal of the electro-hydraulic servo actuator when different servo valve control currents are input;

[0011] The servo valve-controlled current is used as the input, and the voltage feedback signal and current feedback signal are used as the output to construct training samples;

[0012] The neural network model is trained based on the training samples, so that the first output of the neural network model is consistent with the voltage feedback signal, and the second output of the neural network model is consistent with the current feedback signal, thereby obtaining the trained neural network model as the twin model.

[0013] Optionally, the servo controller incorporates a dual-loop control algorithm. The outer loop control algorithm calculates the current command signal based on the difference between the voltage command signal and the voltage feedback signal. The inner loop control algorithm calculates the servo valve control current based on the difference between the current command signal and the current feedback signal. Here, the voltage feedback signal characterizes the position feedback value, and the current feedback signal characterizes the speed feedback value. The corresponding voltage command signal characterizes the position command value, and the current command signal characterizes the speed command value.

[0014] Optionally, the outer loop control algorithm is one of a PI control algorithm and a PID control algorithm.

[0015] Optionally, the simulation device includes an MCU main control board, and a main control signal input / output terminal and a main control feedback output terminal connected to the MCU main control board;

[0016] The main control signal input / output terminal includes a command signal output terminal and a valve control signal input terminal; the main control feedback output terminal includes a current feedback output terminal and a voltage feedback output terminal.

[0017] The twin model is set inside the MCU main control board.

[0018] Optionally, there may be multiple current feedback output terminals and multiple voltage feedback output terminals.

[0019] Optionally, the simulation device further includes: redundant signal input / output terminals and redundant feedback output terminals connected to the MCU main control board;

[0020] The redundant signal input / output terminals include a command signal output terminal and a valve control signal input terminal, and the redundant feedback output terminals include a current feedback output terminal and a voltage feedback output terminal.

[0021] Optionally, the simulation device further includes: a touch screen connected to the MCU main control board, a feedback signal adjustment knob, and a command signal adjustment knob;

[0022] The feedback signal adjustment knob is used to adjust the magnitude of the voltage feedback signal and current feedback signal output to the servo controller, and the command signal adjustment knob is used to adjust the magnitude of the voltage command signal output to the servo controller.

[0023] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0024] This invention discloses a simulation device for an electro-hydraulic servo control system. The simulation device includes a twin model of an electro-hydraulic servo actuator, which comprises a command device, a hydraulic power source, an electro-hydraulic servo valve, a servo cylinder, a load, and a sensor device. The valve control signal input terminal of the simulation device is connected to the servo valve control current output terminal of the servo controller of the electro-hydraulic servo actuator. The command signal output terminal of the simulation device is connected to the command signal input terminal of the servo controller. The current feedback output terminal of the simulation device is connected to the current feedback input terminal of the servo controller. The voltage feedback output terminal of the simulation device is connected to the voltage feedback input terminal of the servo controller. This invention simulates the electro-hydraulic servo actuator based on a twin model, and can simulate the operation process of an electro-hydraulic servo valve control system in conjunction with a servo controller, eliminating the need for large and bulky hydraulic power sources, actuators, feedback sensors, etc. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 A schematic diagram of an electro-hydraulic servo control system provided for the background art of this invention;

[0027] Figure 2 This is a schematic diagram of the simulation device provided in an embodiment of the present invention;

[0028] Figure 3 An electrical topology block diagram of the analog device provided in an embodiment of the present invention;

[0029] Explanation of reference numerals in the attached figures:

[0030] 1. Host computer digital communication interface; 2. Power supply; 3. Housing; 4. Touch screen; 5. MCU main control board; 6. Command signal adjustment knob; 7. Feedback signal adjustment knob; 8. Terminal of main control feedback output; 9. Terminal of redundant feedback output; 10. Terminal of main control signal input / output; 11. Terminal of redundant signal input / output. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] The purpose of this invention is to provide a simulation device for an electro-hydraulic servo control system, which combines a servo controller to simulate the operation of an electro-hydraulic servo valve control system without the need for a large, bulky hydraulic power source, actuators, feedback sensors, etc.

[0033] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] This invention uses an MCU control system in conjunction with peripheral circuits to simulate the actions and signal transformation processes of all devices within an electro-hydraulic servo control system, excluding the servo controller. This is used to build a simulation platform for the electro-hydraulic servo control system, thereby assisting in the development of new servo controller products and the verification of product performance. The invention uses a twin model-based simulation device to simulate the generation of command signals, the power output process of the hydraulic source (SC), the control process of the servo element (voltage servo valve SV), the action process of the actuator (electro-hydraulic servo valve SV), the acquisition of position signals from the feedback sensor (ZE), the analysis of the servo valve control signals output by the servo controller, and the analysis of the servo controller alarm signals, simulating the control processes and system states. A touchscreen display, signal adjustment buttons, and signal terminals are provided to enable parameter debugging and signal input / output of this simulated system. Details are as follows:

[0035] like Figure 2 and Figure 3As shown, a simulation device for an electro-hydraulic servo control system is provided. The simulation device includes a twin model of an electro-hydraulic servo actuator, which comprises a command device, a hydraulic source, an electro-hydraulic servo valve, a servo cylinder, a load, and a sensor device. The valve control signal input terminal of the simulation device is connected to the servo valve control current output terminal of the servo controller of the electro-hydraulic servo actuator. The command signal output terminal of the simulation device is connected to the command signal input terminal of the servo controller. The current feedback output terminal of the simulation device is connected to the current feedback input terminal of the servo controller. The voltage feedback output terminal of the simulation device is connected to the voltage feedback input terminal of the servo controller.

[0036] The twin model is constructed as follows: voltage feedback signals and current feedback signals of the electro-hydraulic servo actuator are obtained when different servo valve control currents are input; the servo valve control current is used as input, and the voltage feedback signals and current feedback signals are used as outputs to construct training samples; a neural network model is trained based on the training samples, so that the first output of the neural network model is consistent with the voltage feedback signal, and the second output of the neural network model is consistent with the current feedback signal, thereby obtaining the trained neural network model as the twin model.

[0037] The calculation process of the twin model of this invention can also be established in other ways, such as constructing mathematical models of each component and then connecting them, or simulating the speed of action, stroke position, etc. of each device through integration and a series of preset parameters. However, this method has a large computational load. The neural network model method of this invention is a preferred method after verification. In addition, when simulating the speed of action, stroke position, etc. of each device through integration and a series of preset parameters, it is specifically achieved by performing logical operations on the difference between the servo valve control signal and the midpoint of the valve control signal through integration on the MCU main control board 5. The magnitude of the feedback signal is adjusted by the magnitude of the integral value, and the integral speed is adjusted by adjusting the magnitude of the integral time coefficient and the integral ratio coefficient. This algorithm is used to simulate the speed of hydraulic power output and the lag of the action response of the actuator, so that the simulator is closer to the actual application situation. To illustrate specifically, the valve control signal is used to adjust the position of the electro-hydraulic servo valve. Taking an electro-hydraulic servo valve with a threshold of ±60mA as an example, the steady-state current of the valve control signal is 0mA. When the servo controller outputs a valve control signal of 1mA, it indicates that the electro-hydraulic servo valve needs to move in the positive direction. Simultaneously, the movement of the electro-hydraulic servo valve drives the sensor to move, and the sensor's feedback signal changes synchronously. When the servo controller detects that the change in the position feedback signal has reached the target value, the output valve control signal becomes 0mA (the steady-state current), and the electro-hydraulic servo valve stops moving. This simulation device simulates the action process of the electro-hydraulic servo valve after receiving the valve control signal and the change in the sensor's feedback signal.

[0038] The servo controller incorporates a dual-loop control algorithm. The outer loop control algorithm calculates the current command signal based on the difference between the voltage command signal and the voltage feedback signal. The inner loop control algorithm calculates the servo valve control current based on the difference between the current command signal and the current feedback signal. The outer loop control algorithm is either a PI control algorithm or a PID control algorithm; however, this is not limited to either.

[0039] like Figure 2 and Figure 3 As shown, the specific structure of the above simulation device is as follows:

[0040] The simulation device includes an MCU main control board 5, and a main control signal input / output terminal and a main control feedback output terminal connected to the MCU main control board 5; the main control signal input / output terminal includes a command signal output terminal and a valve control signal input terminal; the main control feedback output terminal includes a current feedback output terminal and a voltage feedback output terminal; the twin model is set inside the MCU main control board 5. The terminals 10 of the main control signal input / output terminal and 8 of the main control feedback output terminal are as follows... Figure 2 As shown.

[0041] The number of current feedback output terminals is multiple. Figure 3 There are 3 in the middle), and the number of voltage feedback output terminals is multiple ( Figure 3 Only one is shown here, but it can be adjusted as needed.

[0042] The simulation device further includes: redundant signal input / output terminals and redundant feedback output terminals connected to the MCU main control board 5; the redundant signal input / output terminals include command signal output terminals and valve control signal input terminals, and the redundant feedback output terminals include current feedback output terminals and voltage feedback output terminals. The terminals 11 of the redundant signal input / output terminals and 9 of the redundant feedback output terminals are as follows: Figure 2 As shown.

[0043] For example, in this embodiment of the invention, the valve control signal input terminal is an AD acquisition interface, which acquires the servo valve control signal output by the servo controller through an AD conversion circuit, and the servo valve control signal adopts an independent dual-channel dual-redundant interface setting.

[0044] The simulation device also includes: a touch screen 4 connected to the MCU main control board 5, a feedback signal adjustment knob 7, and a command signal adjustment knob 6; the feedback signal adjustment knob 7 is used to adjust the magnitude of the voltage feedback signal and current feedback signal output to the servo controller, and the command signal adjustment knob 6 is used to adjust the magnitude of the voltage command signal output to the servo controller.

[0045] The simulation device in this embodiment of the invention also includes a power supply 2 for supplying power to the touch screen 4 and the MCU main control board 5.

[0046] In this embodiment of the invention, the power supply 2 and the MCU main control board 5 of the simulation device are disposed inside the housing 3, and the ports are disposed on the housing 3.

[0047] like Figure 3 As shown, in the simulation device of this invention, the command signal (i.e., the voltage command signal, which is set with dual redundancy) is, in another embodiment, a current command signal with selectable signal ranges of 4-20mA and 0-24mA. It is adjustable in 6 segments via a current command signal adjustment knob, with the 4mA and 20mA segments positioned close together for easy and rapid full-scale switching. The current feedback signal (3 independently adjustable channels) and voltage feedback signal are output control signals (output to the servo controller). The current feedback signal range is selectable between 4-20mA and 0-24mA, and the voltage feedback signal range is 0-10V / DC. The servo valve control signal (i.e., the servo valve control current) is the input signal. To meet the simulation requirements of a redundant electro-hydraulic servo control system with dual servo controllers, both the signal interfaces and logic operation methods provide two independent channels: one for main control and one for redundancy. The three current feedback signals are used to simulate the three independent signals from the three redundant position sensors. Specifically, manually turning the command signal adjustment knob 6 of the simulation device of this invention to different mA levels causes the device to output a specific command signal. The command signal levels provided by the device are 0mA, 2mA, 4mA, 6mA, 8mA, 10mA, 12mA, 14mA, 16mA, 18mA, 20mA, 4mA, and ANY. Two 4mA levels are provided to accommodate the 20mA and 4mA levels when the level values ​​increase sequentially. This arrangement facilitates testing the response characteristics of the servo controller under full-scale large signal switching. The ANY level is controlled by the host computer software; in this level, the signal output is controlled by the host computer software to output any value. The interface for connecting to the host computer software is... Figure 2 The host computer digital communication interface 1.

[0048] The command signal is sent to the servo controller. After receiving the command signal, the servo controller responds to the command signal and outputs the corresponding servo valve control signal after calculation. The servo valve control signal is then returned to the valve control signal input terminal of the simulation device of the present invention. After receiving the valve control signal output by the servo controller, the simulation device of the present invention begins to simulate the action process of the hydraulic source, electro-hydraulic servo valve, and servo cylinder, and finally expresses it through the voltage feedback signal and current feedback signal of the simulated position sensor signal generated by the simulation device of the present invention.

[0049] The position sensor analog signal generated by the simulation device of this invention is fed back to the servo controller. After receiving the feedback signal (voltage feedback signal and current feedback signal), the servo controller processes the feedback signal and then further adjusts the signal strength of the servo valve control signal based on the processing result. This adjusted servo valve control signal is then acquired by the simulation device of this invention, thus forming a signal closed loop. Finally, it is determined whether the servo controller has the ability to adjust the correct valve control signal according to the real-time changes of the command signal and feedback signal, and to ensure the time efficiency of the valve control signal, thereby concluding whether the servo controller has servo control capability.

[0050] Electro-hydraulic servo control systems are commonly used in metallurgical and power generation applications where the equipment is very expensive. System downtime due to control system failure can result in significant losses. To improve system stability, practical applications often employ a redundant operating mode with one servo controller as backup. In this redundant control system, both the command signal and the position sensor feedback signal are dual independent signals; some feedback signals even have three redundant signals per channel. In this redundant electro-hydraulic servo control system, the two servo controllers maintain heartbeat communication. When the main controller fails and the heartbeat signal stops, the redundant controller immediately and automatically takes over system control. The device of this invention features independent dual command signals and dual position feedback signals, with each position feedback signal also supporting independent output of three redundant feedback signals.

[0051] The device of the present invention is equipped with an independent feedback signal adjustment knob 7, which means that the magnitude of the feedback signal can be directly adjusted without having to perform logical calculations based on the servo valve control signal, thereby enabling the device of the present invention to have the capability of opening and closing tests.

[0052] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0053] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A simulation device for an electro-hydraulic servo control system, characterized in that, The simulation device contains a twin model of an electro-hydraulic servo actuator, which includes a command device, a hydraulic source, an electro-hydraulic servo valve, a servo cylinder, a load, and a sensor device. The valve control signal input terminal of the simulation device is connected to the servo valve control current output terminal of the servo controller of the electro-hydraulic servo actuator; the command signal output terminal of the simulation device is connected to the command signal input terminal of the servo controller. The current feedback output terminal of the simulation device is connected to the current feedback input terminal of the servo controller; the voltage feedback output terminal of the simulation device is connected to the voltage feedback input terminal of the servo controller. The twin model is constructed as follows: Acquire the voltage feedback signal and current feedback signal of the electro-hydraulic servo actuator when different servo valve control currents are input; The servo valve-controlled current is used as the input, and the voltage feedback signal and current feedback signal are used as the output to construct training samples; The neural network model is trained based on the training samples, so that the first output of the neural network model is consistent with the voltage feedback signal, and the second output of the neural network model is consistent with the current feedback signal, thereby obtaining the trained neural network model as the twin model.

2. The simulation device for the electro-hydraulic servo control system according to claim 1, characterized in that, The servo controller is equipped with a dual closed-loop control algorithm. The outer loop control algorithm is used to calculate the current command signal based on the difference between the voltage command signal and the voltage feedback signal. The inner loop control algorithm is used to calculate the servo valve control current based on the difference between the current command signal and the current feedback signal.

3. The simulation device for the electro-hydraulic servo control system according to claim 2, characterized in that, The outer loop control algorithm is one of the PI control algorithm and the PID control algorithm.

4. The simulation device for the electro-hydraulic servo control system according to claim 1, characterized in that, The simulation device includes an MCU main control board, and a main control signal input / output terminal and a main control feedback output terminal connected to the MCU main control board; The main control signal input / output terminal includes a command signal output terminal and a valve control signal input terminal; the main control feedback output terminal includes a current feedback output terminal and a voltage feedback output terminal. The twin model is set inside the MCU main control board.

5. The simulation device for the electro-hydraulic servo control system according to claim 4, characterized in that, The number of current feedback output terminals is multiple, and the number of voltage feedback output terminals is multiple.

6. The simulation device for the electro-hydraulic servo control system according to claim 4, characterized in that, The simulation device also includes: redundant signal input / output terminals and redundant feedback output terminals connected to the MCU main control board; The redundant signal input / output terminals include a command signal output terminal and a valve control signal input terminal, and the redundant feedback output terminals include a current feedback output terminal and a voltage feedback output terminal.

7. The simulation device for the electro-hydraulic servo control system according to claim 4, characterized in that, The simulation device also includes: a touch screen connected to the MCU main control board, a feedback signal adjustment knob, and a command signal adjustment knob; The feedback signal adjustment knob is used to adjust the magnitude of the voltage feedback signal and current feedback signal output to the servo controller, and the command signal adjustment knob is used to adjust the magnitude of the voltage command signal output to the servo controller.

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