CN112324735B - High-frequency-response servo proportional valve position control method - Google Patents
High-frequency-response servo proportional valve position control method Download PDFInfo
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- CN112324735B CN112324735B CN202011235608.4A CN202011235608A CN112324735B CN 112324735 B CN112324735 B CN 112324735B CN 202011235608 A CN202011235608 A CN 202011235608A CN 112324735 B CN112324735 B CN 112324735B
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B13/00—Details of servomotor systems ; Valves for servomotor systems
- F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
- F15B13/04—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor
- F15B13/044—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor operated by electrically-controlled means, e.g. solenoids, torque-motors
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B13/00—Details of servomotor systems ; Valves for servomotor systems
- F15B13/16—Special measures for feedback, e.g. by a follow-up device
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B13/00—Details of servomotor systems ; Valves for servomotor systems
- F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
- F15B13/04—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor
- F15B13/0401—Valve members; Fluid interconnections therefor
- F15B2013/0409—Position sensing or feedback of the valve member
Abstract
The invention discloses a high-frequency response servo proportional valve position control method, which is based on a proportional valve position control system, wherein when a low-frequency signal is given, a displacement given signal is compared with a valve core displacement feedback signal to obtain a position deviation, the position deviation is divided into three sections according to a position deviation range, and position PID controller parameters are respectively set for each section of the position deviation; the input current of the proportional electromagnet is determined by the output value of the displacement following part; when a high frequency signal is given, the displacement follower section does not function, and the input current of the proportional electromagnet is determined by the output values of the speed follower section, the feedforward section, and the differential advance section. The invention has the advantages of rapidity and stability, can synchronously follow the displacement of the valve core when the given signal is low-frequency and high-frequency, and solves the problem that a set of PID parameters cannot be simultaneously adapted to the high-frequency and low-frequency given signals.
Description
Technical Field
The invention belongs to the technical field of electro-hydraulic control, and particularly relates to a high-frequency-response servo proportional valve position control method.
Background
The electro-hydraulic proportional valve is the core and the main power amplifying element of the electro-hydraulic proportional control technology and represents the development direction of the fluid control technology. With the continuous development of engineering technology, higher requirements are put on the position control precision and frequency response of the proportional valve. Therefore, it is not easy to develop a high-precision and high-frequency proportional valve position control method. At present, a series of researches are carried out at home and abroad aiming at the position control of a high-frequency response servo proportional valve.
In the existing control method, a positioning error of a system is obtained, and whether the positioning error reaches a preset positioning precision or whether the system generates oscillation is judged to determine a dead zone compensation value; and then, performing compensation correction on the control signal based on the dead zone compensation value, and outputting a correction signal to the electro-hydraulic proportional valve. Compared with the traditional valve, the method has the advantages that the control precision is improved, but the control precision of the high-frequency-response position of the hydraulic valve is difficult to guarantee. And the other method adopts a hybrid control method based on PID and sliding mode variable structure algorithms, namely, the position instruction control precision of the proportional valve servo system is improved by using a PID controller when the system is in a steady state, the instruction response and disturbance inhibition capability of the system are improved by using a sliding mode variable structure nonlinear controller when the system instruction changes violently and the disturbance is large, and meanwhile, the online identification is carried out on the system by adopting a recursive least square algorithm, the system parameters are updated, and the PID and sliding mode variable structure controller are designed in real time. The method separates steady-state and dynamic working conditions, and provides two sets of control methods, but the control method at high frequency has overlarge calculation amount, and the data updating delay can be caused.
Disclosure of Invention
The invention provides a high-performance proportional valve position control system and a high-performance proportional valve position control method aiming at the defects in the prior art, and the high-performance proportional valve position control system and the high-performance proportional valve position control method are used for controlling the position of a high-performance proportional valve. The control method has the advantages of rapidity and stability, can synchronously follow the displacement of the valve core when the given signal is low-frequency and high-frequency, and solves the problem that a set of PID parameters cannot be simultaneously adapted to the high-frequency and low-frequency given signals.
In order to achieve the purpose, the invention adopts the following technical scheme: a high-frequency response servo proportional valve position control method is based on a proportional valve position control system, the proportional valve position control system comprises six parts, namely a displacement following part, a speed following part, a feedforward part, a differential leading part, a current setting part and a current loop part, and high-frequency and low-frequency signals are controlled by different parts respectively.
When a low-frequency signal is given, the displacement given signal is compared with a valve core displacement feedback signal to obtain position deviation, the position deviation is divided into three sections according to the position deviation range, and position PID controller parameter setting is carried out on each section of position deviation; the input current of the proportional electromagnet is determined by the output value of the displacement following part;
when a high-frequency signal is given, the displacement following part does not work, and the input current of the proportional electromagnet is determined by the output values of the speed following part, the feedforward part and the differential preceding part;
wherein the output value of the feedforward part is: a displacement given signal sent by an upper computer is subjected to low-pass filtering and differentiation to form a speed feedforward link, and an acceleration feedforward link is obtained through a differentiation link; the output value of the differential look-ahead section is: firstly, processing the valve element displacement acquired by the valve element LVDT through a low-pass filtering link, then differentiating the processed valve element displacement to form a speed feedback link, and obtaining an acceleration feedback link through a differentiation link; output value of the speed following portion: the displacement given signal sent by the upper computer is subjected to a low-pass filtering link and a differentiation link to obtain a speed given signal, the speed given signal is deviated from a speed feedback signal, and the deviation is subjected to PID controller setting of a speed following part to obtain the output of the speed following part.
In order to optimize the technical scheme, the specific measures adopted further comprise:
furthermore, the displacement following part comprises a displacement given signal link, a valve element LVDT link, a displacement feedback link and a segmented PID controller link;
the speed following part comprises a speed setting link, a speed feedback link and a PID controller link;
the feedforward part comprises a speed feedforward link, a differential link and an acceleration feedforward link;
the differential first part comprises a differential link, a speed feedback link and an acceleration feedback link;
the current setting part comprises a current amplitude limiting link, a proportional electromagnet coefficient link and a flutter signal link;
the current loop part comprises a feedback current link, a PID controller link and a power amplifier circuit link.
Further, the output of the displacement following part, the output of the speed following part, the output of the feedforward part and the output of the differential preceding part are simultaneously used as the input of the current setting part, and the output of the current setting part is set by the current loop part and then is used as the input of the proportional electromagnet.
Furthermore, the proportional valve is a direct-acting type electro-hydraulic proportional valve with valve core displacement feedback and driven by a single electromagnet.
Furthermore, the high-frequency response servo proportional valve consists of a valve body, a position controller and an upper computer; the valve body comprises a single-proportion electromagnet, a valve core and a valve sleeve.
Furthermore, a position instruction given by an upper computer and the valve core displacement acquired by a displacement sensor are input into a position controller, a current value corresponding to the target valve core displacement is obtained through a high-precision control algorithm, then the current value is applied to a proportional electromagnet coil to generate electromagnetic thrust, and the electromagnetic thrust and spring force, hydrodynamic force and friction force jointly act on the valve core to realize the control of the position of the valve core; when the control performance of the valve core position does not meet the requirement, the controller parameters are adjusted through the upper computer, and the adjusted controller parameters are input into the position controller again.
The invention has the beneficial effects that:
1. the control method of the invention automatically decomposes the given signal into a low-frequency part and a high-frequency part which are respectively the dominant low-frequency component of the displacement following part and the dominant high-frequency component of the speed following part, the feedforward part and the differential advance part, thereby solving the problem that a set of PID parameters can not adapt to high-low frequency position signals.
2. The control method adopts speed and acceleration feedforward, speed following and differential advance, when a given signal is high frequency, the speed and acceleration feedforward and speed following can ensure the rapidity of the displacement of the valve core, and the differential advance ensures the stability of the displacement of the valve core.
3. The control method of the invention respectively controls each nonlinear link in the proportional valve position control system, and has the characteristics of flexible control and adaptability to complex working conditions.
Drawings
Fig. 1 is a structural and control schematic diagram of a direct-acting high-frequency-response proportional valve in an embodiment of the invention.
FIG. 2 is a flow chart of the control system of the present invention.
FIG. 3 is a schematic diagram of the control system and method of the present invention.
The attached drawings are annotated: 1-displacement given signal link; 2-a first segment PID controller link; 3-a second segment PID controller link; 4-a third segmented PID controller link; 5-current amplitude limiting; 6-proportional electromagnet coefficient link; 7-flutter signal link; 8-PID controller link; 9-power amplifier circuit link; 10-feedback current link; 11-proportional electromagnet; 12-proportional valve body; 13-valve core LVDT link; 14-displacement feedback link; 15-a first low-pass filtering element; 16-a first differential element; 17-speed feedback link; 18-a second differential element; 19-an acceleration feedback link; 20-speed feed-forward link; 21-acceleration feedforward link; 22-a third differential element; 23-a fourth differential element; 24-a second low-pass filtering element; 25-speed feedback link; 26-PID controller link; speed given segment 27.
Detailed Description
The present invention will now be described in further detail with reference to the accompanying drawings.
Referring to fig. 1-3, in an embodiment of the present invention, a high-frequency response servo proportional valve position control method is provided, which is implemented on the basis of a single electromagnet driven direct-acting electro-hydraulic proportional valve with valve core displacement feedback. The direct-acting high-frequency-response proportional valve consists of a valve body, a position controller and an upper computer. The valve body comprises a single proportion electromagnet, a valve core and a valve sleeve. The proportional electromagnet receives the current output by the position controller to generate thrust to the valve core, and the electromagnetic thrust, the spring force, the hydraulic force and the friction force jointly act with the valve core to further control the position of the valve core. The position of the valve core is detected by a displacement sensor, and a position controller acquires a displacement sensing signal. The parameters of the position controller are set and adjusted by an upper computer, and the position controller outputs current to act on the proportional electromagnet through a high-precision position closed-loop control algorithm to control the output of the proportional electromagnet.
A position instruction given by an upper computer and valve core displacement acquired by a displacement sensor are input into a position controller, a current value corresponding to target valve core displacement is obtained through a high-precision control algorithm, and then the current is applied to a proportional electromagnet coil to generate electromagnetic thrust which acts on a valve core together with spring force, hydrodynamic force and friction force, so that the position of the valve core is controlled. When the control performance of the valve core position does not meet the requirement, adjusting the parameters of the controller through an upper computer, and then performing the steps; the adjusted controller parameters are input into a position controller, and the steps are repeated, namely, a current value corresponding to the displacement of a target valve core is obtained through a high-precision control algorithm, and then the current is applied to a proportional electromagnet coil to generate electromagnetic thrust which is applied to the valve core together with spring force, hydrodynamic force and friction force to realize the control of the position of the valve core.
The invention is based on a high-performance proportional valve position control system, which mainly comprises six parts, namely a displacement following part, a speed following part, a feedforward part, a differential advance (damping) part, a current given part and a current loop part.
The displacement following part comprises a displacement given signal link 1, a valve core LVDT link 12, a displacement feedback link 13, a first segment PID controller link 2, a second segment PID controller link 3 and a third segment PID controller link 4.
The speed following part comprises a speed setting link 27, a speed feedback link 25 and a PID controller link 26.
The feedforward part comprises a speed feedforward link 20, a differentiation link 22 and an acceleration feedforward link 21.
The differential first-action (damping) part comprises a differential link 16, a speed feedback link 17 and an acceleration feedback link 19.
The current setting part comprises a current amplitude limiting link 5, a proportional electromagnet coefficient link 6 and a flutter signal link 7.
The current loop part comprises a feedback current link 10, a PID controller link 8 and a power amplifier circuit link 9.
Wherein: the output of the displacement following part, the output of the speed following part, the output of the feedforward part and the output of the damping part (differential advance part) are simultaneously used as the input of the current setting part, and the output of the current setting part is set by the current loop part and then is used as the input of the proportional electromagnet.
The invention discloses a high-performance proportional valve position control system and a method, which comprise the following contents:
when a low-frequency signal is given, the displacement given signal is compared with the valve core displacement feedback to obtain position deviation, three-section division is carried out on the PID according to the deviation range, and parameter setting of a position PID controller is respectively carried out, so that high-precision position control of the proportional valve can be realized on one hand, and the parameter adjustment is easy on the other hand; meanwhile, the PID is divided into three sections to meet the control precision, and then the PID is divided into more sections, so that the control precision is basically unchanged, but more parameters need to be adjusted, and if the PID is divided into two sections, the control precision is lower. The first segmented PID controller is used for setting when the deviation is between e1 and e2, the second segmented PID controller is used for setting when the deviation is between e3 and e4, and the third segmented PID controller is used for setting when the deviation is between e5 and e 6. At this time, because the given signal is low frequency, the output values of the speed following part, the feedforward part and the differential advance (damping) part have little influence on the output value of the displacement following part, and the proportional electromagnet input current is mainly determined by the output value of the displacement following part.
The displacement follower portion is inactive given a high frequency signal, and the proportional electromagnet input current is determined primarily by the output values of the velocity follower portion, the feedforward portion, and the differential look-ahead (damping) portion. Wherein the output value of the feedforward section: the displacement given signal sent by the upper computer passes through the second low-pass filtering link 24 and the fourth differentiating link 23 to obtain a speed feedforward signal, the speed feedforward signal is divided into two paths, and one path of signal passes through the third differentiating link 22 to reach the acceleration feedforward link 21. Output value of differential preceding section: in order to filter white noise which may be generated in high frequency, firstly, the displacement of the valve core collected by the valve core LVDT link 13 is processed through the first low-pass filtering link 15, and then the displacement is processed through the first differentiation link 16 to the speed feedback link 17, and the speed feedback link 17 is processed through the second differentiation link 18 to obtain the acceleration feedback link 19. Output value of the speed following section: the displacement given signal sent by the upper computer is subjected to a speed given signal 27 obtained by a second low-pass filtering link 24 and a fourth differentiating link 23, the speed given signal 27 is deviated from a speed feedback signal 25, and the deviation is adjusted by a PID controller 26 of a speed following part to obtain speed following output.
The control method of the invention automatically decomposes the given signal into a low-frequency part and a high-frequency part which are respectively the dominant low-frequency component of the displacement following part and the dominant high-frequency component of the speed following part, the feedforward part and the differential advance part, thereby solving the problem that a set of PID parameters can not adapt to high-low frequency position signals.
The control method adopts speed and acceleration feedforward, speed following and differential advance, when a given signal is high frequency, the speed and acceleration feedforward and speed following can ensure the rapidity of the displacement of the valve core, and the differential advance ensures the stability of the displacement of the valve core.
The control method of the invention respectively controls each nonlinear link in the proportional valve position control system, and has the characteristics of flexible control and adaptability to complex working conditions.
The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above-mentioned embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may be made by those skilled in the art without departing from the principle of the invention.
Claims (5)
1. A high-frequency response servo proportional valve position control method is based on a proportional valve position control system, the proportional valve position control system comprises six parts, namely a displacement following part, a speed following part, a feedforward part, a differential leading part, a current given part and a current loop part, and is characterized in that high-frequency signals and low-frequency signals are respectively controlled by different parts:
when a low-frequency signal is given, the displacement given signal is compared with a valve core displacement feedback signal to obtain position deviation, the position deviation is divided into three sections according to the position deviation range, and position PID controller parameter setting is carried out on each section of position deviation; the input current of the proportional electromagnet is determined by the output value of the displacement following part;
when a high-frequency signal is given, the displacement following part does not work, and the input current of the proportional electromagnet is determined by the output values of the speed following part, the feedforward part and the differential preceding part;
wherein the output value of the feedforward part is: a displacement given signal sent by an upper computer is subjected to low-pass filtering and differentiation to form a speed feedforward link, and then is subjected to a differentiation link to obtain an acceleration feedforward link; the output value of the differential look-ahead section is: firstly, processing the valve element displacement acquired by the valve element LVDT through a low-pass filtering link, then differentiating the processed valve element displacement to form a speed feedback link, and obtaining an acceleration feedback link through a differentiation link; output value of the speed following section: the displacement given signal sent by the upper computer is subjected to a low-pass filtering link and a differentiation link to obtain a speed given signal, the speed given signal is deviated from a speed feedback signal, and the deviation is subjected to PID controller setting of a speed following part to obtain the output of the speed following part;
the displacement following part comprises a displacement given signal link, a valve core LVDT link, a displacement feedback link and a segmented PID controller link;
the speed following part comprises a speed setting link, a speed feedback link and a PID controller link;
the feedforward part comprises a speed feedforward link, a differential link and an acceleration feedforward link;
the differential first part comprises a differential link, a speed feedback link and an acceleration feedback link;
the current setting part comprises a current amplitude limiting link, a proportional electromagnet coefficient link and a flutter signal link;
the current loop part comprises a feedback current link, a PID controller link and a power amplifier circuit link.
2. The proportional valve position control method of claim 1, wherein an output of the displacement follower portion, an output of the velocity follower portion, an output of the feedforward portion, and an output of the derivative advance portion are simultaneously inputs to the current set portion, and wherein the output of the current set portion is set by the current loop portion as an input to the proportional solenoid.
3. The proportional valve position control method of claim 1, wherein the proportional valve is a single electromagnet driven direct acting electro-hydraulic proportional valve with spool displacement feedback.
4. The proportional valve position control method of claim 1, wherein the high frequency response servo proportional valve comprises a valve body, a position controller, and an upper computer; the valve body comprises a single-proportion electromagnet, a valve core and a valve sleeve.
5. The proportional valve position control method of claim 4, wherein a position command given by an upper computer and a spool displacement acquired by a displacement sensor are input into a position controller, a current value corresponding to a target spool displacement is obtained through a high-precision control algorithm, and then the current value is applied to a proportional electromagnet coil to generate an electromagnetic thrust which is applied to the spool together with a spring force, a hydrodynamic force and a friction force to realize the control of the spool position; when the control performance of the valve core position does not meet the requirement, the controller parameters are adjusted through the upper computer, and the adjusted controller parameters are input into the position controller again.
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| CN101482133B (en) * | 2009-01-23 | 2011-02-09 | 哈尔滨工业大学 | Controller of three-stage electro-hydraulic servo valve |
| CN104407639A (en) * | 2014-11-26 | 2015-03-11 | 中国工程物理研究院总体工程研究所 | Servo control method and servo control device for high-frequency hydraulic shock excitation system |
| US9739262B2 (en) * | 2014-12-10 | 2017-08-22 | State Grid Corporation Of China | Static testing and calibrating method for PID link of control system of wind turbine |
| CN106246986B (en) * | 2016-06-27 | 2019-02-01 | 南昌大学 | The adaptive proportional valve amplifier of integrated form vibrating signal |
| CN109599246A (en) * | 2018-11-28 | 2019-04-09 | 南京晨光集团有限责任公司 | A kind of Single electromagnet proportional valve controller based on current automatic adaptation |
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