PID (Proportion Integration Differentiation) self-tuning vacuum pressure regulating device

Abstract

The invention provides a PID self-tuning vacuum pressure adjusting device. The PID self-tuning vacuum pressure adjusting device comprises a human-computer interface, an external interface, a control unit, a pressure acquisition module, a PID self-tuning unit, a power execution unit and a valve, the PID self-tuning unit realizes a pressure adjustment function, is different from a conventional PID adjustment algorithm, has the capability of automatically correcting PID parameters, outputs a valve position adjustment value, controls the pressure to quickly approach a target position, and reduces steady-state errors. The power execution unit receives the target valve position, and a driving motor drives a speed reducer to run to the target position; the valve department controls the through-flow area of the pipeline so as to adjust the pressure value of the pipeline. By the adoption of the device, for the vacuum pressure adjusting technology with hysteresis quality, the pressure of the cavity can be adjusted more accurately, steady-state errors are smaller, fluid waste caused by fluctuation is reduced, equipment can be separated from a PLC to operate independently according to a preset target value, flexibility is higher, and the equipment cost can be reduced.

Description

Technical Field

[0001] The invention relates to the field of vacuum pressure regulation, and in particular to a PID self-tuning vacuum pressure regulation method and device. Background Art

[0002] In the daily use of pressure control, most valve electric devices respond passively. The device receives the instructions sent by PLC or DCS and then runs to the specified position. The pressure acquisition is transmitted to the controller of PLC or DCS through the transmitter, and then the calculation is executed and sent to the valve electric device. The control of the whole process is relatively slow and occupies the resources of the controller. The valve electric device itself does not have the ability to self-regulate the pipeline pressure. In order to quickly respond to the pressure adjustment of the pipeline fluid, the function of collecting pipeline pressure is added to the device. The device can form a small closed-loop system according to the preset pressure value to self-regulate the pipeline pressure. Usually, the pressure closed-loop adjustment mostly adopts the conventional PID algorithm (PID algorithm is the abbreviation of proportional, integral, and derivative. It is a common control algorithm used to maintain the stability of the system) to realize the pressure adjustment function. However, the conventional PID adjustment requires experienced engineers to debug multiple times before it can be stable. In addition, for the vacuum pressure, which has a hysteresis in the pressure feedback system, when the ordinary PID algorithm is used, the actual pressure value adjusted has a large steady-state fluctuation. Therefore, the PID self-tuning module is added to reduce the workload of PID adjustment and also reduce the fluctuation value of the steady-state temperature difference. Summary of the invention

[0003] Purpose of the invention: The technical problem to be solved by the present invention is to provide a PID self-tuning vacuum pressure regulating device for the deficiencies of the prior art, including a human-machine interface, an external interface, a control unit, a pressure acquisition module, a PID self-tuning unit, a power execution unit and a valve;

[0004] The human-machine interface is connected to the control unit and is used to display device information and set parameters for the device. The information displayed on the device includes valve position opening value, pressure value, remote mode information, alarm information and valve action information. The parameter setting includes valve stroke setting, protection threshold setting and communication address setting.

[0005] The external interface is used to connect with an external programmable controller PLC or distributed control system DCS, can receive instructions from the system, upload device status to the system, and communicate with the system using a bus;

[0006] The control unit is connected to the human-machine interface, the external interface, the PID self-tuning unit and the pressure acquisition module respectively; it is used to collect the pressure signal transmitted by the pressure module, receive the target pressure sent by the external interface, and then output the result to the PID self-tuning unit, and at the same time transmit the information to the human-machine interface for current information display;

[0007] The pressure acquisition module is used to collect the electrical signal of the external pressure sensor and convert it into a pressure value;

[0008] The PID self-tuning unit is connected to the power execution unit to realize the pressure adjustment function, receive the actual pressure value and the target pressure transmitted by the control unit, calculate the pressure difference, and output the target valve position opening value through PID calculation. The unit can automatically correct the PID parameters, thereby controlling the pressure to quickly approach the target pressure;

[0009] The power execution unit is connected with the PID self-tuning unit and the valve, and is used to receive the target valve position opening value given by the PID self-tuning unit, and then drive the motor to drive the reducer to run to the target valve position opening;

[0010] The valve is connected to the power execution unit and is used to control the flow area of ​​the pipeline to adjust the pressure value of the pipeline.

[0011] The PID self-tuning unit is used to perform the following steps:

[0012] Step 1: Use the prototype to collect the actual operating pressure data on site, and use the mathematical modeling tool to analyze and fit the initial values ​​Kp, Ki, and Kd of the PID control, where Kp represents the proportional coefficient, Ki represents the integral coefficient, and Kd represents the differential coefficient;

[0013] Step 2, after the device is started, read the initial values ​​Kp, Ki, and Kd of the PID for calculation (PID calculation, i.e., calculating the target valve position opening by the feedback pressure and the required pressure), calculate the target valve position opening, and update Kp, Ki, and Kd;

[0014] Step 3, obtain the actual pressure value of the current valve through the pressure sensor, compare it with the target pressure value, and obtain the error e and the error change rate ec;

[0015] Step 4, fuzzy processing is performed on the error e and the error change rate ec to obtain Δkp, Δki, and Δkd, where Δkp is the change in the proportional coefficient, Δki is the change in the integral coefficient, and Δkd is the change in the differential coefficient;

[0016] Step 5, the error e, error change rate ec, Δkp, Δki, Δkd are fuzzified into seven fuzzy subsets, the seven fuzzy subsets are PB, PM, PS, ZO, NS, NM and NB, the elements in the fuzzy subsets PB, PM, PS, ZO, NS, NM and NB represent: negative large, negative medium, negative small, zero, positive small, positive medium and positive large; based on the fuzzy subsets, the hysteresis triangle membership function is used as the membership function of the controller input and output variables;

[0017] Step 6, respectively establish fuzzy control rule tables of Δkp, Δki, and Δkd, and obtain the fuzzy relationship of each control rule by querying the fuzzy control rule table;

[0018] Step 7, select the special maximum membership method to defuzzify Δkp, Δki, and Δkd;

[0019] Step 8: Calculate the final control value K' based on the PID parameter correction values ​​Δkp, Δki, and Δkd p , K i ', K' d :

[0020]

[0021] Where K p , K i , K d is the PID parameter of the previous cycle, Δkp, Δki, Δkd are the parameter increments output by the adaptive fuzzy PID algorithm, K' p , K i ', K' d It is the updated PID parameter, i.e. the final control quantity.

[0022] In step 5, the hysteresis triangle membership function is used as the membership function of the controller input and output variables, specifically including:

[0023] For e, ec, Δkp, Δki, Δkd, we establish basic fuzzy domains [-t i , t i ], where i = 1, 2, 3, 4, 5, t i are the maximum values ​​of e, ec, Δkp, Δki, and Δkd in actual tests, respectively. In the present invention, t1=3, t2=1.2, t3=1.2, t4=0.12, and t5=0.12;

[0024] The membership function u of the hysteresis triangle of e and ec is:

[0025] If e and ec are not in the hysteresis region,

[0026] If e and ec are in the hysteresis region of two fuzzy subsets, then e and ec belong to the fuzzy subset that is closer to the previous periodic fuzzy subset among the two fuzzy subsets;

[0027] Δkp, Δki, and Δkd do not consider the hysteresis region, so the membership of Δkp, Δki, and Δkd is calculated according to the following formula:

[0028]

[0029] Where u is the membership degree, a, b, c are the left, middle and right vertices of the subset membership triangle respectively, Δkp, Δki, Δkd calculate the membership degree of each subset respectively, Δkp, Δki, Δkd belong to the fuzzy subset with the largest membership degree respectively, when e and ec are not in the hysteresis zone, the membership degree of each subset is calculated respectively, and finally e and ec belong to the subset with the largest membership degree. When e and ec are in the hysteresis zone, e and ec belong to the subset closer to the membership subset of the previous period, where the left, middle and right vertices of each membership triangle are set as:

[0030] The left, center, and right vertices of the NB triangle are set to [none, -t, -2t / 3]; the left, center, and right vertices of the NM triangle are set to [-t, -2t / 3, -t / 3]; the left, center, and right vertices of the NS triangle are set to [-2t / 3, -t / 3, 0]; the left, center, and right vertices of the ZO triangle are set to [-t / 3, 0, t / 3]; the left, center, and right vertices of the PS triangle are set to [0, t / 3, 2t / 3]; the left, center, and right vertices of the NM triangle are set to [t / 3, 2t / 3, t]; the NB triangle is [2t / 3, t, none];

[0031] The hysteresis zone is the area where the membership degree between every two consecutive membership triangles is close. Each hysteresis zone is set as follows:

[0032] The hysteresis zone of NB triangle and NM triangle is [-11t / 12,-9t / 12]; the hysteresis zone of NM triangle and NS triangle is [-7t / 12,-5t / 12]; the hysteresis zone of NS triangle and ZO triangle is [-3t / 12,-t / 12]; the hysteresis zone of ZO triangle and PS triangle is [t / 12,3t / 12]; the hysteresis zone of PS triangle and PM triangle is [5t / 12,7t / 12]; the hysteresis zone of PM triangle and PB triangle is [9t / 12,11t / 12].

[0033] In step 6, the fuzzy table of Δkp, Δki, and Δkd is described as follows:

[0034] For Δkp, if e belongs to NB, then when ec belongs to NB, Δkp belongs to PB; when ec belongs to NM, Δkp belongs to PM; when ec belongs to NS, Δkp belongs to PM; when ec belongs to ZO, Δkp belongs to PS; when ec belongs to PS, Δkp belongs to PS; when ec belongs to PM, Δkp belongs to PS; when ec belongs to PB, Δkp belongs to ZO;

[0035] If e belongs to NM, then when ec belongs to NB, Δkp belongs to PM; when ec belongs to NM, Δkp belongs to PM; when ec belongs to NS, Δkp belongs to PM; when ec belongs to ZO, Δkp belongs to PS; when ec belongs to PS, Δkp belongs to PS; when ec belongs to PM, Δkp belongs to ZO; when ec belongs to PB, Δkp belongs to ZO;

[0036] If e belongs to NS, then when ec belongs to NB, Δkp belongs to PS; when ec belongs to NM, Δkp belongs to PM; when ec belongs to NS, Δkp belongs to PM; when ec belongs to ZO, Δkp belongs to PS; when ec belongs to PS, Δkp belongs to ZO; when ec belongs to PM, Δkp belongs to NS; when ec belongs to PB, Δkp belongs to NS;

[0037] If e belongs to ZO, then when ec belongs to NB, Δkp belongs to PS; when ec belongs to NM, Δkp belongs to PM; when ec belongs to NS, Δkp belongs to PS; when ec belongs to ZO, Δkp belongs to ZO; when ec belongs to PS, Δkp belongs to NS; when ec belongs to PM, Δkp belongs to NM; when ec belongs to PB, Δkp belongs to NM;

[0038] If e belongs to PS, then when ec belongs to NB, Δkp belongs to NS; when ec belongs to NM, Δkp belongs to PS; when ec belongs to NS, Δkp belongs to ZO; when ec belongs to ZO, Δkp belongs to NS; when ec belongs to PS, Δkp belongs to NS; when ec belongs to PM, Δkp belongs to NM; when ec belongs to PB, Δkp belongs to NM;

[0039] If e belongs to PM, then when ec belongs to NB, Δkp belongs to NS; when ec belongs to NM, Δkp belongs to ZO; when ec belongs to NS, Δkp belongs to NS; when ec belongs to ZO, Δkp belongs to NS; when ec belongs to PS, Δkp belongs to NM; when ec belongs to PM, Δkp belongs to PM; when ec belongs to PB, Δkp belongs to PB;

[0040] If e belongs to PB, then when ec belongs to NB, Δkp belongs to NS; when ec belongs to NM, Δkp belongs to ZO; when ec belongs to NS, Δkp belongs to ZO; when ec belongs to ZO, Δkp belongs to NM; when ec belongs to PS, Δkp belongs to NM; when ec belongs to PM, Δkp belongs to NB; when ec belongs to PB, Δkp belongs to NB;

[0041] For Δki, if e belongs to NB, then when ec belongs to NB, Δkp belongs to NB; when ec belongs to NM, Δkp belongs to NM; when ec belongs to NS, Δkp belongs to NM; when ec belongs to ZO, Δkp belongs to NS; when ec belongs to PS, Δkp belongs to NS; when ec belongs to PM, Δkp belongs to ZO; when ec belongs to PB, Δkp belongs to ZO;

[0042] If e belongs to NM, then when ec belongs to NB, Δkp belongs to NB; when ec belongs to NM, Δkp belongs to NM; when ec belongs to NS, Δkp belongs to NM; when ec belongs to ZO, Δkp belongs to NS; when ec belongs to NS, Δkp belongs to PS; when ec belongs to PM, Δkp belongs to ZO; when ec belongs to PB, Δkp belongs to ZO;

[0043] If e belongs to NS, then when ec belongs to NB, Δkp belongs to NM; when ec belongs to NM, Δkp belongs to NM; when ec belongs to NS, Δkp belongs to NS; when ec belongs to ZO, Δkp belongs to ZO; when ec belongs to PS, Δkp belongs to ZO; when ec belongs to PM, Δkp belongs to PS; when ec belongs to PB, Δkp belongs to PS;

[0044] If e belongs to ZO, then when ec belongs to NB, Δkp belongs to NM; when ec belongs to NM, Δkp belongs to NS; when ec belongs to NS, Δkp belongs to ZO; when ec belongs to ZO, Δkp belongs to ZO; when ec belongs to PS, Δkp belongs to PS; when ec belongs to PM, Δkp belongs to PM; when ec belongs to PB, Δkp belongs to PM;

[0045] If e belongs to PS, then when ec belongs to NB, Δkp belongs to NM; when ec belongs to NM, Δkp belongs to NS; when ec belongs to NS, Δkp belongs to ZO; when ec belongs to ZO, Δkp belongs to PS; when ec belongs to PS, Δkp belongs to PM; when ec belongs to PM, Δkp belongs to PM; when ec belongs to PB, Δkp belongs to PB;

[0046] If e belongs to PM, then when ec belongs to NB, Δkp belongs to ZO; when ec belongs to NM, Δkp belongs to ZO; when ec belongs to NS, Δkp belongs to PS; when ec belongs to ZO, Δkp belongs to PS; when ec belongs to PS, Δkp belongs to PM; when ec belongs to PM, Δkp belongs to PB; when ec belongs to PB, Δkp belongs to PB;

[0047] If e belongs to PB, then when ec belongs to NB, Δkp belongs to ZO; when ec belongs to NM, Δkp belongs to ZO; when ec belongs to NS, Δkp belongs to PS; when ec belongs to ZO, Δkp belongs to PM; when ec belongs to PS, Δkp belongs to PM; when ec belongs to PM, Δkp belongs to PB; when ec belongs to PB, Δkp belongs to PB;

[0048] For Δkd, if e belongs to NB, then when ec belongs to NB, Δkp belongs to PS; when ec belongs to NM, Δkp belongs to PS; when ec belongs to NS, Δkp belongs to NB; when ec belongs to ZO, Δkp belongs to NB; when ec belongs to PS, Δkp belongs to NM; when ec belongs to PM, Δkp belongs to NM; when ec belongs to PB, Δkp belongs to PS;

[0049] If e belongs to NM, then when ec belongs to NB, Δkp belongs to PS; when ec belongs to NM, Δkp belongs to NS; when ec belongs to NS, Δkp belongs to NB; when ec belongs to ZO, Δkp belongs to NM; when ec belongs to NM, Δkp belongs to PS; when ec belongs to PM, Δkp belongs to NS; when ec belongs to PB, Δkp belongs to ZO;

[0050] If e belongs to NS, then when ec belongs to NB, Δkp belongs to ZO; when ec belongs to NM, Δkp belongs to NS; when ec belongs to NS, Δkp belongs to NM; when ec belongs to ZO, Δkp belongs to NM; when ec belongs to PS, Δkp belongs to NS; when ec belongs to PM, Δkp belongs to NS; when ec belongs to PB, Δkp belongs to ZO;

[0051] If e belongs to ZO, then when ec belongs to NB, Δkp belongs to ZO; when ec belongs to NM, Δkp belongs to NS; when ec belongs to NS, Δkp belongs to NS; when ec belongs to ZO, Δkp belongs to NS; when ec belongs to PS, Δkp belongs to NS; when ec belongs to PM, Δkp belongs to NS; when ec belongs to PB, Δkp belongs to ZO;

[0052] If e belongs to PS, then when ec belongs to NB, Δkp belongs to ZO; when ec belongs to NM, Δkp belongs to NS; when ec belongs to NS, Δkp belongs to ZO; when ec belongs to ZO, Δkp belongs to ZO; when ec belongs to PS, Δkp belongs to ZO; when ec belongs to PM, Δkp belongs to PS; when ec belongs to PB, Δkp belongs to ZO;

[0053] If e belongs to PM, then when ec belongs to NB, Δkp belongs to PB; when ec belongs to NM, Δkp belongs to NS; when ec belongs to NS, Δkp belongs to PS; when ec belongs to ZO, Δkp belongs to PS; when ec belongs to PS, Δkp belongs to PS; when ec belongs to PM, Δkp belongs to PS; when ec belongs to PB, Δkp belongs to PB;

[0054] If e belongs to PB, then when ec belongs to NB, Δkp belongs to PB; when ec belongs to NM, Δkp belongs to PM; when ec belongs to NS, Δkp belongs to PM; when ec belongs to ZO, Δkp belongs to PM; when ec belongs to PS, Δkp belongs to PS; when ec belongs to PM, Δkp belongs to PS; when ec belongs to PB, Δkp belongs to PB.

[0055] In step 7, the exact values ​​of Δkp, Δki, and Δkd are determined according to the fuzzy subsets of Δkp, Δki, and Δkd and the fuzzy subsets of Δkp', Δki', and Δkd', respectively, where Δkp', Δki', and Δkd' are the values ​​of the upper period of Δkp, Δki, and Δkd, respectively. The special maximum membership method specifically includes:

[0056] Confirm m by the following method i , where i = 3, 4, 5, m i They are the numbers with the largest membership in the fuzzy subsets to which Δkp, Δki, and Δkd belong respectively:

[0057] If Δkp belongs to NB, m3 is -t3; if Δkp belongs to NM, m3 is -2t3 / 3; if Δkp belongs to NS, m3 is -t3 / 3; if Δkp belongs to ZO, m3 is 0; if Δkp belongs to PS, m3 is t3 / 3; if Δkp belongs to PM, m3 is 2t3 / 3; if Δkp belongs to PB, m3 is t3;

[0058] If Δki belongs to NB, m4 is -t4, if Δkp belongs to NM, m4 is -2t4 / 3, if Δkp belongs to NS, m4 is -t4 / 3, if Δkp belongs to ZO, m4 is 0, if Δkp belongs to PS, m4 is t4 / 3, if Δkp belongs to PM, m4 is 2t4 / 3, if Δkp belongs to PB, m4 is t4;

[0059] If Δkd belongs to NB, m5 is -t5, if Δkp belongs to NM, m5 is -2t5 / 3, if Δkp belongs to NS, m5 is -t5 / 3, if Δkp belongs to ZO, m5 is 0, if Δkp belongs to PS, m5 is t5 / 3, if Δkp belongs to PM, m5 is 2t5 / 3, if Δkp belongs to PB, m5 is t5;

[0060] Confirm i Then calculate Δkp, Δki, Δkd according to the fuzzy subsets to which Δkp', Δki', Δkd' belong:

[0061] Let PB, PM, PS, ZO, NS, NM and NB be respectively the decreasing integers 7, 6, 5, 4, 3, 2, 1. If the fuzzy subset to which Δkp' belongs is larger than the fuzzy subset to which Δkp belongs, then:

[0062]

[0063] If the fuzzy subset to which Δkp' belongs is smaller than the fuzzy subset to which Δkp belongs, then:

[0064]

[0065] If the fuzzy subset to which Δkp' belongs is equal to the fuzzy subset to which Δkp belongs, then:

[0066] Δkp=m3

[0067] If the fuzzy subset to which Δki' belongs is larger than the fuzzy subset to which Δki belongs, then:

[0068]

[0069] If the fuzzy subset to which Δki' belongs is smaller than the fuzzy subset to which Δki belongs, then:

[0070]

[0071] If the fuzzy subset to which Δki' belongs is equal to the fuzzy subset to which Δki belongs, then:

[0072] Δki=m4

[0073] If the fuzzy subset to which Δkd' belongs is larger than the fuzzy subset to which Δkd belongs, then:

[0074]

[0075] If the fuzzy subset to which Δkd' belongs is smaller than the fuzzy subset to which Δkd belongs, then:

[0076]

[0077] If the fuzzy subset to which Δkd' belongs is equal to the fuzzy subset to which Δkd belongs, then:

[0078] Δkd=m5.

[0079] The human-machine interface includes a button switch, a screen display, an LED indication and an infrared remote control input. The button switch is used to switch between remote and local modes. In the local mode, the valve can be opened and closed by pressing a button; the screen display shows the valve opening value and the current pressure value through a dot matrix screen; the LED indication is used to indicate the current status, displaying fully closed, fully open, local and alarm information; the infrared remote control input is used to realize the interface switching and data modification functions of the screen.

[0080] The external interface includes switch input and switch output, analog input and analog output, and 485 communication interface;

[0081] The switch input supports valve opening command, valve closing command, stop command, and emergency action command input;

[0082] Switch output supports open position, closed position and alarm indication;

[0083] The analog input is the valve adjustment command, using 4-20mA corresponding to 0-100% valve opening;

[0084] The analog output is the feedback valve opening value, using 4~20mA corresponding to 0~100% valve opening;

[0085] The 485 communication interface adopts digital communication technology, can receive commands and feedback status, and complete data transmission with the programmable controller PLC.

[0086] The control unit includes an MCU unit (Microcontroller Unit; MCU), which collects command information from an external interface and pressure information from a pressure module, transmits data to a human-machine interface and a PID self-tuning unit, and feeds back data to an external interface for status feedback.

[0087] The power execution unit includes a motor drive, a motor and a reducer. The motor drive receives instructions from the PID self-tuning unit, drives the motor to drive the reducer to rotate, and drives the valve to run to the target position.

[0088] The valve is a vacuum valve for vacuum regulation.

[0089] The present invention has the following beneficial effects: by using the device of the present invention, the equipment can realize the pressure control of the pipeline by self-calculation according to the preset pressure value, which can reduce the computing resources of the main controller. Similarly, for some small equipment, it can be separated from the PLC or DCS and run independently, which is more flexible. It can also reduce the procurement cost of the PLC or DCS. By using the self-tuning PID calculation, for the vacuum pressure regulation process with hysteresis, the pressure of the chamber can be adjusted more accurately, the steady-state error is smaller, and the fluid waste caused by fluctuations is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0090] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments, and the above and / or other advantages of the present invention will become more clear.

[0091] Figure 1 The structure block diagram of the PID self-tuning electric device for vacuum pressure regulation of the present invention.

[0092] Figure 2 The present invention is a flow chart of the PID self-tuning process of the PID self-tuning electric device for vacuum pressure regulation.

[0093] Figure 3 The figure is a schematic diagram of the use of the vacuum pressure regulating device for PID self-tuning of the present invention.

[0094] Figure 4 It is a schematic diagram of hysteresis zone setting. DETAILED DESCRIPTION

[0095] like Figure 1 , Figure 2 As shown, this embodiment provides a PID self-tuning vacuum pressure regulating device, including a human-machine interface, an external interface, a control unit, a pressure acquisition module, a PID self-tuning unit, a power execution unit and a valve; the human-machine interface displays the device information of the device and receives the key switch to set the parameters; the external interface unit realizes the connection with the external PLC or DCS, collects the device status, sends instructions or bus communication; the control unit is responsible for the calculation core of the entire device; the pressure acquisition module collects the electrical signal of the pressure sensor and converts it into a pressure value. The PID self-tuning unit realizes the pressure regulation function, which is different from the conventional PID regulation algorithm. It has the ability to automatically correct the PID parameters, output the valve position adjustment value, control the pressure to quickly approach the target position, and reduce the steady-state error. The power execution unit receives the target valve position, drives the motor to drive the reducer, and runs to the target position; the valve department realizes the control of the pipeline flow area to adjust the pressure value of the pipeline.

[0096] The calculation of the PID self-tuning unit is divided into the following steps:

[0097] Step 1, using the prototype to collect the actual operating pressure data on site, and using the MATLAB tool to analyze and fit the initial values ​​Kp, Ki, and Kd of the PID control, where Kp represents the proportional coefficient, Ki represents the integral coefficient, and Kd represents the differential coefficient;

[0098] The transfer function of its PID control system is:

[0099]

[0100] According to the PID system transfer function, the opening data and valve pressure data of the actual field test were fitted and analyzed in MATLAB, and the initial Kp, Ki, and Kd values ​​were obtained as follows:

[0101]

[0102] Step 2: After the device is started, the initial values ​​Kp, Ki, and Kd of the PID are read and operated to calculate the target valve position opening;

[0103] Step 3, obtain the actual pressure value on the current valve through the pressure sensor, compare it with the target pressure value, and obtain the error e and the error change rate ec;

[0104] Step 4, fuzzy processing is performed on the error e and the error change rate ec to obtain Δkp, Δki, and Δkd, where Δkp is the change in the proportional coefficient, Δki is the change in the integral coefficient, and Δkd is the change in the differential coefficient;

[0105] Step 5, the error e, error change rate ec, Δkp, Δki, Δkd are fuzzified into seven fuzzy subsets, which are PB, PM, PS, ZO, NS, NM and NB. The elements in the fuzzy subsets PB, PM, PS, ZO, NS, NM and NB represent: negative large, negative medium, negative small, zero, positive small, positive medium and positive large respectively; based on the fuzzy subsets, the hysteresis triangle membership function is used as the membership function of the controller input and output variables. The hysteresis triangle membership function algorithm is as follows

[0106] For e, ec, Δkp, Δki, Δkd, we establish basic fuzzy domains [-t i , t i ] where t i (i=1,2,3,4,5) are the maximum values ​​of e, ec, Δkp, Δki, and Δkd in the actual test. In this case, t1=3, t2=1.2, t3=1.2, t4=0.12, and t5=0.12. The membership functions of the hysteresis triangle of e and ec are as follows:

[0107] If e and ec are not in the hysteresis region,

[0108] If e and ec are in the hysteresis region of two fuzzy subsets, then e and ec belong to the fuzzy subset that is closer to the previous periodic fuzzy subset among the two fuzzy subsets;

[0109] Δkp, Δki, and Δkd do not consider the hysteresis region, so the membership of Δkp, Δki, and Δkd is calculated according to the following formula:

[0110]

[0111] Where u is the membership degree, a, b, c are the left, middle and right vertices of the subset membership triangle respectively, Δkp, Δki, Δkd calculate the membership degree of each subset respectively, Δkp, Δki, Δkd belong to the fuzzy subset with the largest membership degree respectively, when e and ec are not in the hysteresis zone, the membership degree of each subset is calculated respectively, and finally e and ec belong to the subset with the largest membership degree. When e and ec are in the hysteresis zone, e and ec belong to the subset closer to the membership subset of the previous period, where the left, middle and right vertices of each membership triangle are set as follows:

[0112] NB triangle [none, -t, -2t / 3]; NM triangle [-t, -2t / 3, -t / 3]; NS triangle [-2t / 3, -t / 3, 0]; ZO triangle [-t / 3, 0, t / 3]; PS triangle [0, t / 3, 2t / 3]; NM triangle [t / 3, 2t / 3, t]; NB triangle [2t / 3, t, none];

[0113] like Figure 4 As shown in the figure, the hysteresis zone is the area where the membership degree between every two consecutive membership triangles is close. Each hysteresis zone is set as follows:

[0114] NB triangle and NM triangle [-11t / 12,-9t / 12]; NM triangle and NS triangle [-7t / 12,-5t / 12]; NS triangle and ZO triangle [-3t / 12,-t / 12]; ZO triangle and PS triangle [t / 12,3t / 12]; PS triangle and PM triangle [5t / 12,7t / 12]; PM triangle and PB triangle [9t / 12,11t / 12].

[0115] In this case, the error e' of the previous cycle is 1.21, which belongs to the fuzzy subset PS. The valve pressure collected in the current cycle is 100.50Pa, and the expected pressure value is 100.00Pa. The error e is 0.50. According to the hysteresis triangle membership function, e = 0.50 belongs to the hysteresis area of ​​the ZO and PS fuzzy subsets. Since e' belongs to the fuzzy subset PS, e finally belongs to the fuzzy subset PS. Similarly, ec = 0.71 belongs to the PM fuzzy subset.

[0116] Step 6, respectively establish fuzzy control rule tables for Δkp, Δki, and Δkd, and obtain the fuzzy relationship of each control rule by querying the fuzzy control rule table. The fuzzy tables of Δkp, Δki, and Δkd are as follows: Table 1 is the Δkp fuzzy control rule, Table 2 is the Δki fuzzy control rule, and Table 3 is the Δkd fuzzy control rule.

[0117] Table 1

[0118]

[0119] Table 2

[0120]

[0121]

[0122] Table 3

[0123]

[0124] According to the fuzzy subsets to which e and ec obtained in step 6 belong, it can be concluded by looking up the table that Δkp, Δki, and Δkd belong to fuzzy subsets NM, PM, and PS respectively.

[0125] Step 7: Use the special maximum membership method to defuzzify Δkp, Δki, and Δkd. The exact values ​​of Δkp, Δki, and Δkd are determined according to their fuzzy subsets and the fuzzy subsets of Δkp', Δki', and Δkd', respectively. Δkp', Δki', and Δkd' are the values ​​of the upper period of Δkp, Δki, and Δkd, respectively. Taking this case as an example, the specific algorithm is as follows:

[0126] Confirm m according to Table 4 below i , where i = (3, 4, 5) are the numbers with the largest membership in the fuzzy subsets to which Δkp, Δki, and Δkd belong respectively.

[0127] Table 4

[0128]

[0129]

[0130] If Δkp belongs to NB, m3 is -t3; if Δkp belongs to NM, m3 is -2t3 / 3; if Δkp belongs to NS, m3 is -t3 / 3; if Δkp belongs to ZO, m3 is 0; if Δkp belongs to PS, m3 is t3 / 3; if Δkp belongs to PM, m3 is 2t3 / 3; if Δkp belongs to PB, m3 is t3;

[0131] If Δki belongs to NB, m4 is -t4, if Δkp belongs to NM, m4 is -2t4 / 3, if Δkp belongs to NS, m4 is -t4 / 3, if Δkp belongs to ZO, m4 is 0, if Δkp belongs to PS, m4 is t4 / 3, if Δkp belongs to PM, m4 is 2t4 / 3, if Δkp belongs to PB, m4 is t4;

[0132] If Δkd belongs to NB, m5 is -t5, if Δkp belongs to NM, m5 is -2t5 / 3, if Δkp belongs to NS, m5 is -t5 / 3, if Δkp belongs to ZO, m5 is 0, if Δkp belongs to PS, m5 is t5 / 3, if Δkp belongs to PM, m5 is 2t5 / 3, if Δkp belongs to PB, m5 is t5;

[0133] Since Δkp, Δki, and Δkd belong to fuzzy subsets NM, PM, and PS respectively in this case,

[0134]

[0135] Confirm i Then calculate Δkp, Δki, Δkd according to the fuzzy subsets to which Δkp', Δki', Δkd' belong, where Δkp', Δki', Δkd' are Δkp, Δki, Δkd of the previous period:

[0136] Let PB, PM, PS, ZO, NS, NM and NB be respectively the decreasing integers 7, 6, 5, 4, 3, 2, 1. If the fuzzy subset to which Δkp' belongs is larger than the fuzzy subset to which Δkp belongs, then:

[0137]

[0138] If the fuzzy subset to which Δkp' belongs is smaller than the fuzzy subset to which Δkp belongs, then:

[0139]

[0140] If the fuzzy subset to which Δkp' belongs is equal to the fuzzy subset to which Δkp belongs, then:

[0141] Δkp=m3

[0142] Similarly, if the fuzzy subset to which Δki' belongs is larger than the fuzzy subset to which Δki belongs, then:

[0143]

[0144] If the fuzzy subset to which Δki' belongs is smaller than the fuzzy subset to which Δki belongs, then:

[0145]

[0146] If the fuzzy subset to which Δki' belongs is equal to the fuzzy subset to which Δki belongs, then:

[0147] Δki=m4

[0148] If the fuzzy subset to which Δkd' belongs is larger than the fuzzy subset to which Δkd belongs, then:

[0149]

[0150] If the fuzzy subset to which Δkd' belongs is smaller than the fuzzy subset to which Δkd belongs, then:

[0151]

[0152] If the fuzzy subset to which Δkd' belongs is equal to the fuzzy subset to which Δkd belongs, then:

[0153] Δkd=m5

[0154] In this case, Δkp', Δki', and Δkd' belong to the fuzzy subsets NB(1), PM(6), and PM(6), respectively, while Δkp, Δki, and Δkd belong to the fuzzy subsets NM(2), PM(6), and PS(5), respectively. NB is less than NM, PM is equal to PM, and PM is greater than PS. Therefore, the exact values ​​of Δkp, Δki, and Δkd are:

[0155]

[0156] Δki=m4=0.08

[0157]

[0158] Step 8: Calculate the final control value K' based on the PID parameter correction values ​​Δkp, Δki, and Δkd p , K i ', K' d :

[0159]

[0160] Where K p , K i , K d is the PID parameter of the previous cycle, Δkp, Δki, Δkd are the parameter increments output by the adaptive fuzzy PID algorithm, K' p , K i ', K' d It is the updated PID parameter, i.e. the final control quantity.

[0161] The human-machine interface includes a button switch, screen display, LED indication and infrared remote control input. The button switch is used to switch between remote and local modes. In the local mode, the valve can be opened and closed by pressing the button; the screen display shows the valve opening value, current pressure value and other information through a dot matrix screen; the LED indicator light indicates the current status, and displays information such as fully closed, fully open, local, alarm, etc.; the infrared remote control input function can realize the screen interface switching and data modification functions.

[0162] External interfaces include switch input and output, analog input and output, and 485 communication interface. Switch input supports valve opening command, valve closing command, stop command, and emergency action command input; switch output supports open position, close position, alarm and other indications; analog input is valve adjustment command, using 4-20mA corresponding to 0-100% valve opening, analog output is feedback valve opening value, using 4-20mA corresponding to 0-100% valve opening. 485 communication interface uses digital communication technology, can receive commands and feedback status, and complete data transmission with PLC end.

[0163] The control unit includes an MCU unit (Microcontroller Unit; MCU), which collects command information from an external interface and pressure information from a pressure module, transmits data to a human-machine interface and a PID self-tuning unit, and feeds back data to an external interface for status feedback.

[0164] The power execution unit includes a motor drive, a motor and a reducer. The motor drive receives instructions from the PID self-tuning unit, drives the motor to drive the reducer to rotate, and drives the valve to run to the target position.

[0165] The valve is a vacuum valve for vacuum regulation.

[0166] Figure 3 A schematic diagram showing an actual field application of the device. The chamber is a gas reaction chamber that needs to maintain a certain negative pressure. A trace amount of gas is input into the reaction chamber, and the vacuum pump is used to evacuate the gas. The pressure sensor is installed on the output pipe of the reaction chamber. When the valve opening is at its maximum, that is, 100%, the vacuum pump works at full capacity. At this time, the pressure in the chamber is the smallest, close to vacuum. When the valve opening is at its minimum, that is, 0%, that is, when the valve is fully closed, the vacuum pump has the smallest amount of air pumping, and a trace amount of gas slowly enters, and the pressure in the chamber will increase. The pressure regulation function is completed by the opening of the valve. The response speed of the pressure sensor of the entire system, plus the fluctuation of the intake volume and the fluctuation of the vacuum pump, require PID pressure regulation. As a result of conventional PID regulation, the pressure value fluctuates above and below the target pressure value, and the amplitude is large. The PID self-tuning method is used. As a result, the maximum error of the pressure value fluctuation is reduced by 30% of the original error.

[0167] The present invention provides a PID self-tuning vacuum pressure regulating device. There are many methods and ways to implement the technical solution. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, some improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention. All components not specified in this embodiment can be implemented by existing technologies.

Claims

1. A PID self-tuning vacuum pressure regulating device, characterized in that: Including human-machine interface, external interface, control unit, pressure acquisition module, PID self-tuning unit, power execution unit and valve; The human-machine interface is connected to the control unit and is used to display device information and set parameters for the device. The information displayed on the device includes valve position opening value, pressure value, remote mode information, alarm information and valve action information. The parameter setting includes valve stroke setting, protection threshold setting and communication address setting. The external interface is used to connect with an external programmable controller PLC or distributed control system, can receive instructions from the system, upload device status to the system, and communicate with the system using a bus; The control unit is respectively connected to the human-machine interface, the external interface, the PID self-tuning unit and the pressure acquisition module; It is used to collect the pressure signal transmitted by the pressure module, receive the target pressure sent by the external interface, and then output the result to the PID self-tuning unit, and at the same time transmit the information to the human-machine interface for current information display; The pressure acquisition module is used to collect the electrical signal of the external pressure sensor and convert it into a pressure value; The PID self-tuning unit is connected to the power execution unit to realize the pressure adjustment function, receive the actual pressure value and the target pressure transmitted by the control unit, calculate the pressure difference, and output the target valve position opening value through PID calculation. The unit can automatically correct the PID parameters, thereby controlling the pressure to quickly approach the target pressure; The power execution unit is connected with the PID self-tuning unit and the valve, and is used to receive the target valve position opening value given by the PID self-tuning unit, and then drive the motor to drive the reducer to run to the target valve position opening; The valve is connected to the power execution unit and is used to control the flow area of ​​the pipeline to adjust the pressure value of the pipeline.

2. The device according to claim 1, characterized in that The PID self-tuning unit is used to perform the following steps: Step 1: Use the prototype to collect the actual operating pressure data on site, and use the mathematical modeling tool to analyze and fit the initial values ​​Kp, Ki, and Kd of the PID control, where Kp represents the proportional coefficient, Ki represents the integral coefficient, and Kd represents the differential coefficient; Step 2: After the device is started, the initial values ​​Kp, Ki, and Kd of the PID are read for operation, the target valve position opening is calculated, and Kp, Ki, and Kd are updated; Step 3, obtain the actual pressure value of the current valve through the pressure sensor, compare it with the target pressure value, and obtain the error e and the error change rate ec; Step 4, fuzzy processing is performed on the error e and the error change rate ec to obtain Δkp, Δki, and Δkd, where Δkp is the change in the proportional coefficient, Δki is the change in the integral coefficient, and Δkd is the change in the differential coefficient; Step 5, the error e, error change rate ec, Δkp, Δki, Δkd are fuzzified into seven fuzzy subsets, the seven fuzzy subsets are PB, PM, PS, ZO, NS, NM and NB, the elements in the fuzzy subsets PB, PM, PS, ZO, NS, NM and NB represent: negative large, negative medium, negative small, zero, positive small, positive medium and positive large; based on the fuzzy subsets, the hysteresis triangle membership function is used as the membership function of the controller input and output variables; Step 6, respectively establish fuzzy control rule tables of Δkp, Δki, and Δkd, and obtain the fuzzy relationship of each control rule by querying the fuzzy control rule table; Step 7, select the special maximum membership method to defuzzify Δkp, Δki, and Δkd; Step 8: Calculate the final control value K' based on the PID parameter correction values ​​Δkp, Δki, and Δkd p , K i ', K' d : Where K p , K i , K d is the PID parameter of the previous cycle, Δkp, Δki, Δkd are the parameter increments output by the adaptive fuzzy PID algorithm, K' p , K i ', K' d It is the updated PID parameter, i.e. the final control quantity.

3. The device according to claim 2, characterized in that In step 5, the hysteresis triangle membership function is used as the membership function of the controller input and output variables, specifically including: For e, ec, Δkp, Δki, Δkd, we establish basic fuzzy domains [-t i , t i ], where i = 1, 2, 3, 4, 5, t i are the maximum values ​​of e, ec, Δkp, Δki, and Δkd in actual tests, respectively. In the present invention, t1=3, t2=1.2, t3=1.2, t4=0.12, and t5=0.12; The membership function u of the hysteresis triangle of e and ec is: If e and ec are not in the hysteresis region, If e and ec are in the hysteresis region of two fuzzy subsets, then e and ec belong to the fuzzy subset that is closer to the previous periodic fuzzy subset among the two fuzzy subsets; Δkp, Δki, and Δkd do not consider the hysteresis region, so the membership of Δkp, Δki, and Δkd is calculated according to the following formula: Where u is the membership degree, a, b, c are the left, middle and right vertices of the subset membership triangle respectively, Δkp, Δki, Δkd calculate the membership degree of each subset respectively, Δkp, Δki, Δkd belong to the fuzzy subset with the largest membership degree respectively, when e and ec are not in the hysteresis zone, the membership degree of each subset is calculated respectively, and finally e and ec belong to the subset with the largest membership degree. When e and ec are in the hysteresis zone, e and ec belong to the subset closer to the membership subset of the previous period, where the left, middle and right vertices of each membership triangle are set as: The left, center, and right vertices of the NB triangle are set to [none, -t, -2t / 3]; the left, center, and right vertices of the NM triangle are set to [-t, -2t / 3, -t / 3]; the left, center, and right vertices of the NS triangle are set to [-2t / 3, -t / 3, 0]; the left, center, and right vertices of the ZO triangle are set to [-t / 3, 0, t / 3]; the left, center, and right vertices of the PS triangle are set to [0, t / 3, 2t / 3]; the left, center, and right vertices of the NM triangle are set to [t / 3, 2t / 3, t]; the NB triangle is [2t / 3, t, none]; The hysteresis zone is the area where the membership degree between every two consecutive membership triangles is close. Each hysteresis zone is set as follows: The hysteresis zone of NB triangle and NM triangle is [-11t / 12,-9t / 12]; the hysteresis zone of NM triangle and NS triangle is [-7t / 12,-5t / 12]; the hysteresis zone of NS triangle and ZO triangle is [-3t / 12,-t / 12]; the hysteresis zone of ZO triangle and PS triangle is [t / 12,3t / 12]; the hysteresis zone of PS triangle and PM triangle is [5t / 12,7t / 12]; the hysteresis zone of PM triangle and PB triangle is [9t / 12,11t / 12].

4. The device according to claim 3, characterized in that In step 6, the fuzzy table of Δkp, Δki, and Δkd is described as follows: For Δkp, if e belongs to NB, then when ec belongs to NB, Δkp belongs to PB; when ec belongs to NM, Δkp belongs to PM; When ec belongs to NS, Δkp belongs to PM; when ec belongs to ZO, Δkp belongs to PS; When ec belongs to PS, Δkp belongs to PS; When ec belongs to PM, Δkp belongs to PS; When ec belongs to PB, Δkp belongs to ZO; If e belongs to NM, then when ec belongs to NB, Δkp belongs to PM; when ec belongs to NM, Δkp belongs to PM; when ec belongs to NS, Δkp belongs to PM; when ec belongs to ZO, Δkp belongs to PS; When ec belongs to PS, Δkp belongs to PS; When ec belongs to PM, Δkp belongs to ZO; when ec belongs to PB, Δkp belongs to ZO; If e belongs to NS, then Δkp belongs to PS when ec belongs to NB; When ec belongs to NM, Δkp belongs to PM; When ec belongs to NS, Δkp belongs to PM; when ec belongs to ZO, Δkp belongs to PS; When ec belongs to PS, Δkp belongs to ZO; When ec belongs to PM, Δkp belongs to NS; when ec belongs to PB, Δkp belongs to NS; If e belongs to ZO, then Δkp belongs to PS when ec belongs to NB; When ec belongs to NM, Δkp belongs to PM; When ec belongs to NS, Δkp belongs to PS; When ec belongs to ZO, Δkp belongs to ZO; When ec belongs to PS, Δkp belongs to NS; when ec belongs to PM, Δkp belongs to NM; when ec belongs to PB, Δkp belongs to NM; If e belongs to PS, then when ec belongs to NB, Δkp belongs to NS; when ec belongs to NM, Δkp belongs to PS; When ec belongs to NS, Δkp belongs to ZO; when ec belongs to ZO, Δkp belongs to NS; when ec belongs to PS, Δkp belongs to NS; when ec belongs to PM, Δkp belongs to NM; when ec belongs to PB, Δkp belongs to NM; If e belongs to PM, then when ec belongs to NB, Δkp belongs to NS; when ec belongs to NM, Δkp belongs to ZO; when ec belongs to NS, Δkp belongs to NS; when ec belongs to ZO, Δkp belongs to NS; when ec belongs to PS, Δkp belongs to NM; when ec belongs to PM, Δkp belongs to PM; When ec belongs to PB, Δkp belongs to PB; If e belongs to PB, then when ec belongs to NB, Δkp belongs to NS; when ec belongs to NM, Δkp belongs to ZO; When ec belongs to NS, Δkp belongs to ZO; when ec belongs to ZO, Δkp belongs to NM; when ec belongs to PS, Δkp belongs to NM; when ec belongs to PM, Δkp belongs to NB; when ec belongs to PB, Δkp belongs to NB; For Δki, if e belongs to NB, then when ec belongs to NB, Δkp belongs to NB; When ec belongs to NM, Δkp belongs to NM; when ec belongs to NS, Δkp belongs to NM; when ec belongs to ZO, Δkp belongs to NS; when ec belongs to PS, Δkp belongs to NS; when ec belongs to PM, Δkp belongs to ZO; when ec belongs to PB, Δkp belongs to ZO; If e belongs to NM, then Δkp belongs to NB when ec belongs to NB; When ec belongs to NM, Δkp belongs to NM; when ec belongs to NS, Δkp belongs to NM; when ec belongs to ZO, Δkp belongs to NS; when ec belongs to NS, Δkp belongs to PS; When ec belongs to PM, Δkp belongs to ZO; when ec belongs to PB, Δkp belongs to ZO; If e belongs to NS, then when ec belongs to NB, Δkp belongs to NM; when ec belongs to NM, Δkp belongs to NM; when ec belongs to NS, Δkp belongs to NS; when ec belongs to ZO, Δkp belongs to ZO; When ec belongs to PS, Δkp belongs to ZO; When ec belongs to PM, Δkp belongs to PS; When ec belongs to PB, Δkp belongs to PS; If e belongs to ZO, then when ec belongs to NB, Δkp belongs to NM; when ec belongs to NM, Δkp belongs to NS; when ec belongs to NS, Δkp belongs to ZO; when ec belongs to ZO, Δkp belongs to ZO; When ec belongs to PS, Δkp belongs to PS; When ec belongs to PM, Δkp belongs to PM; when ec belongs to PB, Δkp belongs to PM; If e belongs to PS, then when ec belongs to NB, Δkp belongs to NM; when ec belongs to NM, Δkp belongs to NS; when ec belongs to NS, Δkp belongs to ZO; when ec belongs to ZO, Δkp belongs to PS; When ec belongs to PS, Δkp belongs to PM; when ec belongs to PM, Δkp belongs to PM; when ec belongs to PB, Δkp belongs to PB; If e belongs to PM, then when ec belongs to NB, Δkp belongs to ZO; when ec belongs to NM, Δkp belongs to ZO; when ec belongs to NS, Δkp belongs to PS; When ec belongs to ZO, Δkp belongs to PS; When ec belongs to PS, Δkp belongs to PM; when ec belongs to PM, Δkp belongs to PB; when ec belongs to PB, Δkp belongs to PB; If e belongs to PB, then Δkp belongs to ZO when ec belongs to NB; When ec belongs to NM, Δkp belongs to ZO; When ec belongs to NS, Δkp belongs to PS; When ec belongs to ZO, Δkp belongs to PM; when ec belongs to PS, Δkp belongs to PM; when ec belongs to PM, Δkp belongs to PB; when ec belongs to PB, Δkp belongs to PB; For Δkd, if e belongs to NB, then when ec belongs to NB, Δkp belongs to PS; When ec belongs to NM, Δkp belongs to PS; When ec belongs to NS, Δkp belongs to NB; When ec belongs to ZO, Δkp belongs to NB; When ec belongs to PS, Δkp belongs to NM; when ec belongs to PM, Δkp belongs to NM; when ec belongs to PB, Δkp belongs to PS; If e belongs to NM, then Δkp belongs to PS when ec belongs to NB; When ec belongs to NM, Δkp belongs to NS; when ec belongs to NS, Δkp belongs to NB; When ec belongs to ZO, Δkp belongs to NM; when ec belongs to NM, Δkp belongs to PS; When ec belongs to PM, Δkp belongs to NS; when ec belongs to PB, Δkp belongs to ZO; If e belongs to NS, then when ec belongs to NB, Δkp belongs to ZO; when ec belongs to NM, Δkp belongs to NS; when ec belongs to NS, Δkp belongs to NM; when ec belongs to ZO, Δkp belongs to NM; when ec belongs to PS, Δkp belongs to NS; when ec belongs to PM, Δkp belongs to NS; when ec belongs to PB, Δkp belongs to ZO; If e belongs to ZO, then Δkp belongs to ZO when ec belongs to NB; When ec belongs to NM, Δkp belongs to NS; when ec belongs to NS, Δkp belongs to NS; when ec belongs to ZO, Δkp belongs to NS; when ec belongs to PS, Δkp belongs to NS; when ec belongs to PM, Δkp belongs to NS; when ec belongs to PB, Δkp belongs to ZO; If e belongs to PS, then when ec belongs to NB, Δkp belongs to ZO; when ec belongs to NM, Δkp belongs to NS; when ec belongs to NS, Δkp belongs to ZO; when ec belongs to ZO, Δkp belongs to ZO; When ec belongs to PS, Δkp belongs to ZO; When ec belongs to PM, Δkp belongs to PS; When ec belongs to PB, Δkp belongs to ZO; If e belongs to PM, then when ec belongs to NB, Δkp belongs to PB; when ec belongs to NM, Δkp belongs to NS; when ec belongs to NS, Δkp belongs to PS; When ec belongs to ZO, Δkp belongs to PS; When ec belongs to PS, Δkp belongs to PS; When ec belongs to PM, Δkp belongs to PS; When ec belongs to PB, Δkp belongs to PB; If e belongs to PB, then when ec belongs to NB, Δkp belongs to PB; when ec belongs to NM, Δkp belongs to PM; When ec belongs to NS, Δkp belongs to PM; when ec belongs to ZO, Δkp belongs to PM; when ec belongs to PS, Δkp belongs to PS; When ec belongs to PM, Δkp belongs to PS; When ec belongs to PB, Δkp belongs to PB.

5. The device according to claim 4, characterized in that In step 7, the exact values ​​of Δkp, Δki, and Δkd are determined according to the fuzzy subsets of Δkp, Δki, and Δkd and the fuzzy subsets of Δkp', Δki', and Δkd', respectively, where Δkp', Δki', and Δkd' are the values ​​of the upper period of Δkp, Δki, and Δkd, respectively. The special maximum membership method specifically includes: Confirm m by the following method i , where i = 3, 4, 5, m i They are the numbers with the largest membership in the fuzzy subsets to which Δkp, Δki, and Δkd belong respectively: If Δkp belongs to NB, m3 is -t3; if Δkp belongs to NM, m3 is -2t3 / 3; if Δkp belongs to NS, m3 is -t3 / 3; if Δkp belongs to ZO, m3 is 0; if Δkp belongs to PS, m3 is t3 / 3; if Δkp belongs to PM, m3 is 2t3 / 3; if Δkp belongs to PB, m3 is t3; If Δki belongs to NB, m4 is -t4, if Δkp belongs to NM, m4 is -2t4 / 3, if Δkp belongs to NS, m4 is -t4 / 3, if Δkp belongs to ZO, m4 is 0, if Δkp belongs to PS, m4 is t4 / 3, if Δkp belongs to PM, m4 is 2t4 / 3, if Δkp belongs to PB, m4 is t4; If Δkd belongs to NB, m5 is -t5, if Δkp belongs to NM, m5 is -2t5 / 3, if Δkp belongs to NS, m5 is -t5 / 3, if Δkp belongs to ZO, m5 is 0, if Δkp belongs to PS, m5 is t5 / 3, if Δkp belongs to PM, m5 is 2t5 / 3, if Δkp belongs to PB, m5 is t5; Confirm i Then calculate Δkp, Δki, Δkd according to the fuzzy subsets to which Δkp', Δki', Δkd' belong: Let PB, PM, PS, ZO, NS, NM and NB be respectively the decreasing integers 7, 6, 5, 4, 3, 2, 1. If the fuzzy subset to which Δkp' belongs is larger than the fuzzy subset to which Δkp belongs, then: If the fuzzy subset to which Δkp' belongs is smaller than the fuzzy subset to which Δkp belongs, then: If the fuzzy subset to which Δkp' belongs is equal to the fuzzy subset to which Δkp belongs, then: Δkp=m3 If the fuzzy subset to which Δki' belongs is larger than the fuzzy subset to which Δki belongs, then: If the fuzzy subset to which Δki' belongs is smaller than the fuzzy subset to which Δki belongs, then: If the fuzzy subset to which Δki' belongs is equal to the fuzzy subset to which Δki belongs, then: Δki=m4 If the fuzzy subset to which Δkd' belongs is larger than the fuzzy subset to which Δkd belongs, then: If the fuzzy subset to which Δkd' belongs is smaller than the fuzzy subset to which Δkd belongs, then: If the fuzzy subset to which Δkd' belongs is equal to the fuzzy subset to which Δkd belongs, then: Δkd=m5.

6. The device according to claim 5, characterized in that The human-machine interface includes a button switch, a screen display, an LED indication and an infrared remote control input. The button switch is used to switch between remote and local modes. In the local mode, the valve can be opened and closed by pressing a button; the screen display shows the valve opening value and the current pressure value through a dot matrix screen; the LED indication is used to indicate the current status, displaying fully closed, fully open, local and alarm information; the infrared remote control input is used to realize the interface switching and data modification functions of the screen.

7. The device according to claim 6, characterized in that The external interface includes switch input and switch output, analog input and analog output, and 485 communication interface; Switch input supports valve opening command, valve closing command, stop command, and emergency action command input; Switch output supports open position, closed position and alarm indication; The analog input is the valve adjustment command; The analog output is the opening value of the feedback valve; The 485 communication interface adopts digital communication technology, can receive commands and feedback status, and complete data transmission with the programmable controller PLC.

8. The device according to claim 7, characterized in that The control unit includes an MCU unit, which collects command information from an external interface and pressure information from a pressure module, transmits data to a human-machine interface and a PID self-tuning unit, and feeds back data to an external interface for status feedback.

9. The device according to claim 8, characterized in that The power execution unit includes a motor drive, a motor and a reducer. The motor drive receives instructions from the PID self-tuning unit, drives the motor to drive the reducer to rotate, and drives the valve to run to the target position.

10. The device according to claim 1, characterized in that The valve is a vacuum valve for vacuum regulation.

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