CN112650062B - Control method of switch type intelligent valve positioner based on environment self-learning - Google Patents

Control method of switch type intelligent valve positioner based on environment self-learning Download PDF

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CN112650062B
CN112650062B CN202011563520.5A CN202011563520A CN112650062B CN 112650062 B CN112650062 B CN 112650062B CN 202011563520 A CN202011563520 A CN 202011563520A CN 112650062 B CN112650062 B CN 112650062B
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valve
pwm
valve position
substep
value
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CN112650062A (en
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程前
江爱朋
姜家骥
张博
赵伟杰
徐平
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Hangzhou Dianzi University
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    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B13/00—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion
    • G05B13/02—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion electric
    • G05B13/04—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion electric involving the use of models or simulators
    • G05B13/042—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion electric involving the use of models or simulators in which a parameter or coefficient is automatically adjusted to optimise the performance
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
    • F16K37/00—Special means in or on valves or other cut-off apparatus for indicating or recording operation thereof, or for enabling an alarm to be given
    • F16K37/0075—For recording or indicating the functioning of a valve in combination with test equipment
    • F16K37/0083—For recording or indicating the functioning of a valve in combination with test equipment by measuring valve parameters
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
    • F16K37/00—Special means in or on valves or other cut-off apparatus for indicating or recording operation thereof, or for enabling an alarm to be given
    • F16K37/0075—For recording or indicating the functioning of a valve in combination with test equipment
    • F16K37/0091—For recording or indicating the functioning of a valve in combination with test equipment by measuring fluid parameters

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  • Electrically Driven Valve-Operating Means (AREA)
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Abstract

The invention discloses a control method of a switch type intelligent valve positioner based on environment self-learning, wherein the invention detects air leakage through an internal parameter self-tuning method, and when the air leakage exceeds a certain threshold value, a system alarms; when the air leakage amount is within a certain threshold value from zero, parameters such as a stroke type, an end point position, a maximum overshoot, an optimal PWM duty ratio and compensation PWM are automatically identified, a basis is provided for selection of control parameters of an improved control algorithm, a closed-loop control algorithm calculates required PWM waves by means of the control parameters, a target valve position, a real-time valve position and the like obtained through self-setting, and then outputs corresponding PWM waves to control air inflow and air exhaust amount of the switch type piezoelectric valve, so that the pneumatic valve is quickly and accurately positioned. The closed-loop control algorithm is also added with an environment self-learning function, the compensation PWM is changed in real time according to the change of the environment and is updated into the closed-loop control algorithm, and the self-learning performance of the control method is further improved.

Description

Control method of switch type intelligent valve positioner based on environment self-learning
Technical Field
The invention relates to an automatic instrument, in particular to a control method of a switch type intelligent valve positioner based on environment self-learning.
Background
The intelligent valve positioner is a core component of a pneumatic regulating valve, reduces lag time in regulating signal transmission, accelerates the action of a valve rod, is an important accessory for realizing accurate positioning of a valve, and an internal control algorithm is a key for realizing accurate positioning of the opening of the valve. In recent years, advances in valve positioners have determined regulatory valve market growth, where control algorithm advancement is undoubtedly a key factor representing positioner advancement.
The common control algorithms in the prior pneumatic valve positioner are PID control algorithm and fuzzy control algorithm. The traditional control algorithm needs to know a mathematical model of a controlled system, however, the system has the characteristics of serious nonlinearity, large inertia or large hysteresis and the like due to the fact that the regulating valves are more in types and are influenced by variable forces such as unstable air source pressure, load change, irregular regulating valve installation, valve rod moving friction force, fluid force borne by a valve core and the like in the control process. Therefore, a five-step switch control algorithm which is simple in principle, easy to implement, high in positioning speed and free of the need of knowing an accurate mathematical model of a controlled system is provided. However, when the five-step switch control algorithm meets some working conditions, especially when the system has an air leakage phenomenon, the self-adaption is poor, a serious oscillation phenomenon occurs, and the control effect is very poor.
Disclosure of Invention
The invention provides a valve positioner control method based on environmental self-learning, aiming at the problem that a switch type intelligent valve positioner has poor control effect under some working conditions, the control method detects air leakage through an internal parameter self-setting method, when the air leakage exceeds a certain threshold value, a system alarms, when the air leakage is in a certain range, parameters such as stroke type, end point position, maximum overshoot, optimal PWM duty ratio and compensation PWM are automatically identified, a basis is provided for selecting control parameters of an improved control algorithm, a closed-loop control algorithm calculates required PWM waves by means of the control parameters, target valve positions, real-time valve positions and the like obtained through self-setting, and then the air inflow and the air discharge of a switch type piezoelectric valve are controlled by corresponding PWM waves, so that the pneumatic valve is rapidly and accurately positioned. The closed-loop control algorithm also has an environment self-learning function, changes the compensation PWM in real time according to the change of the environment and updates the compensation PWM into the closed-loop control algorithm.
The control method of the switch type intelligent valve positioner provided by the invention realizes the self-learning control of the environment through the following steps:
step A1: the pneumatic control valve is connected to an external system (a high-pressure air source, a control signal and the like), the intelligent microprocessor calls the pressure checking module, if the indication number of the pressure checking module is within an allowable range, the control valve can normally work, the step A2 is carried out, and otherwise, an alarm is given.
Step A2: firstly, detecting whether air leakage exists in the system or not by a parameter self-tuning method, calling an alarm module to give an alarm when the air leakage exceeds a set value, stopping a control process and not performing any operation; when the air leakage is within a range from zero to a set value, setting parameters (the stroke type, the end point position, the maximum overshoot corresponding to the AD value in the inflation and exhaust stages, the minimum driving PWM, the optimal operation PWM and the compensation PWM) required by closed-loop control, and entering the step A3;
step A3: the LCD module displays the highest control precision epsilon allowed by the intelligent valve positioning device (the highest control precision epsilon can be set by a user), the user manually inputs a target valve position value, and the intelligent microprocessor receives the target valve position value and compares the target valve position value with a real-time valve position value acquired from the valve position acquisition module. If the difference value between the target valve position and the current valve position is larger than the precision requirement set by the user, the step A4 is carried out; otherwise, no operation is performed.
Step A4: and the intelligent microprocessor calls the self-set parameters, performs closed-loop control, calculates the real-time PWM duty ratio and the working state of the piezoelectric switch valve, outputs the PWM and a control instruction to the piezoelectric switch valve so as to control the air intake and exhaust amount of the piezoelectric switch valve, realizes the control of the valve position, and enters the step A3 for cyclic execution.
The pressure detection module is used for judging whether the regulating valve can normally work or not, and the specific implementation steps are as follows:
step B1: and a pressure sensor is arranged at the interface of the air source communication regulating valve and is defined as a pressure sensor A.
Step B2: the intelligent microprocessor records the pressure set by the pressure reducing valve and records the pressure as V.
Step B3: the intelligent microprocessor detects the reading of the pressure sensor A in real time and is marked as V1.
Step B4: v1 and V compare, and both deviations are in 10KPa, then intelligent valve system outside no obvious operating mode exists, and the governing valve can normally work. Otherwise, the outside of the regulating valve system has obvious working condition problems, the normal work of the regulating valve is influenced, and the alarm module of the intelligent valve positioner is called to give an alarm.
The parameter self-tuning method mainly carries out the following parameters required by the closed-loop control method (the air-open valve is selected as an analysis object in the process, and the parameter self-tuning method is also suitable for the air-close valve):
step C1: the type of stroke, the end point position, the range of stroke FSR are obtained. Outputting 100% PWM wave to the switch type piezoelectric valve and sending out an inflation instruction, adjusting the piezoelectric valve to be in an inflation state, detecting a valve position feedback signal and a valve rod speed signal in real time, and detecting that the maximum speed of the valve rod is V up And AD value S corresponding to maximum speed valve position up1 (AD value represents the value of converting analog signal into digital signal), when the speed is detected to be equal to 0, the valve position AD value at the moment is immediately recorded, namely the AD value S corresponding to the top end position far . Outputting 100% PWM wave to the switch type piezoelectric valve and sending out an exhaust instruction, adjusting the piezoelectric valve to be in an exhaust state, detecting a valve position feedback signal and a valve rod speed signal in real time, and detecting that the maximum speed of a valve rod is V down And AD value S corresponding to maximum speed valve position down1 When the detected speed is equal to 0, the valve position AD value at the moment is immediately recorded as the low end position corresponding AD value S near Range of travel FSR ═ S far -S near |。
Step C2: the method specifically comprises the following substeps of setting the compensation PWM in the inflation stage:
substep C2.1: outputting a given PWM wave to the switch type piezoelectric valve, sending an inflation instruction, adjusting the switch type piezoelectric valve to be in an inflation state, acquiring a feedback valve position in real time, immediately outputting minimum driving PWM to the switch type piezoelectric valve once the valve position changes, and once the valve position reaches S 1 Position, immediately sending a valve position holding instruction (neither inflating nor exhausting) to the switch type piezoelectric valve, delaying for 10 seconds, and recording the corresponding AD value S of the valve position at the moment 2 If S is 1 ＝S 2 Write PWM 1 0 and go to step C2.4, otherwise, PWM is written 1 Step C5.2 is entered for 1.
Substep C2.2: judging PWM 1 Whether the limit is exceeded (one)Typically 15), PWM 1 If the air leakage is considered to be serious and the closed-loop control cannot be normally finished due to exceeding the limit, the system is crashed, the alarm module is immediately called to give an alarm, and otherwise, the substep C2.3 is executed.
Substep C2.3: adjusting the valve position to return to the initial position, outputting a given PWM wave to the switch type piezoelectric valve, adjusting the switch type piezoelectric valve to be in an inflation state, acquiring the feedback valve position in real time, outputting the minimum driving PWM to the switch type piezoelectric valve once the valve position changes, and outputting the minimum driving PWM once the valve position reaches S 1 Position, outputting PWM immediately to switched piezoelectric valve 1 And recording the corresponding AD value S of the valve position at the time after 10 seconds of delay 2 If S is 1 ＝S 2 Go to step C2.4, otherwise PWM 1 ＝PWM 1 +1 and step C2.2.
Substep C2.4: performing substeps C2.1-C2.3 in a loop, respectively setting S 1 ＝40％*FSR、S 2 ＝60％*FSR、S 1 Compensated PWM duty cycle at 80% FSR.
Substep C2.5: and obtaining the compensation PWM duty ratios corresponding to different valve positions in the inflation stage through least square linear fitting.
Step C3: the method for setting the compensation PWM in the exhaust stage comprises the following substeps:
substep C3.1: the intelligent microprocessor continuously sends out 100% PWM waves and sends out an inflation instruction, the speed detection module detects the speed in real time, once the speed is 0, the intelligent valve positioner immediately sends out an exhaust instruction, the piezoelectric valve is adjusted to be in an exhaust state, the given PWM waves are output to the switch type piezoelectric valve, the feedback valve position is acquired in real time, once the valve position changes, PWM is immediately output to the switch type piezoelectric valve to start, and once the valve position reaches S 3 Position, immediately sending a valve position holding instruction (neither inflating nor exhausting) to the switch type piezoelectric valve, delaying for 10 seconds, and recording the corresponding AD value S of the valve position at the moment 4 If S is 3 ＝S 4 Write PWM 2 If 0, and go to step C3.4, otherwise, note PWM 1 1 and proceeds to step C3.2.
Substep C3.2: judging PWM 2 If the limit (typically 15) is exceeded, PWM 2 If the air leakage is considered to be serious and the closed-loop control cannot be normally finished due to exceeding the limit, the system is crashed, the alarm module is immediately called to give an alarm, and otherwise, the substep C3.3 is executed.
Substep C3.3: adjusting the valve position to return to the initial position, outputting given PWM wave to the switch type piezoelectric valve, adjusting the switch type piezoelectric valve to be in an exhaust state, acquiring the feedback valve position in real time, and outputting minimum drive PWM to the switch type piezoelectric valve immediately once the valve position changes 1 Once the valve position reaches S 3 Position, outputting PWM immediately to switched piezoelectric valve 2 And recording the corresponding AD value S of the valve position at the time after 10 seconds of delay 4 If S is 3 ＝S 4 Go to step C4.3, otherwise PWM 2 ＝PWM 2 +1, repeat to step C3.2.
Substep C3.4: performing substeps C3.1-C3.3 in a cyclic manner, respectively setting S 3 ＝40％*FSR、S 3 ＝60％*FSR、S 3 Compensated PWM duty cycle at 80% FSR.
Substep C3.5: and obtaining compensation PWM duty ratios corresponding to different valve positions in the exhaust stage through least square linear fitting.
Step C4: minimum drive PWM is obtained. And sending a charging command and 100% PWM to the switch type piezoelectric valve, acquiring a valve position feedback signal in real time, and adjusting the valve position to a 0.5 FSR valve position (wherein, the product is represented, and the FSR represents a stroke range). At the moment, 0% PWM is output to the switch type piezoelectric valve, the PWM is increased by taking 1% as amplitude continuously until the valve rod can slowly and uniformly run, and the PWM value P at the moment is recorded and defined up PWM for minimum drive of inflation phase, and then controlling valve position to x 1 At 0.5 × FSR valve position, outputting 0% PWM and exhaust command to the switch type piezoelectric valve, increasing PWM by 1% until the valve rod can slowly and uniformly run, recording and defining PWM value P at the moment down For minimum drive PWM during the exhaust phase, define minimum drive PWM as P str ＝|P up +P down |/2。
Step C5: determining the maximum overshoot of the inflation stage, sending 100% PWM wave by the intelligent valve positioner, sending an inflation instruction, and adjusting the piezoelectric valve to be in an inflation stateThe data acquisition module acquires the valve position in real time, and once the valve position reaches P up1 In position, the intelligent microprocessor immediately sends a valve position holding instruction to the piezoelectric valve, and the valve position corresponding AD value P is recorded after 10 seconds of delay up2 Defining the AD value corresponding to the maximum overshoot of the inflation stage as P over1 ＝|P up1 -P up2 |。
Step C6: determining the maximum overshoot of the exhaust stage, continuously sending 100% PWM waves by the intelligent microprocessor, sending an inflation instruction, detecting the speed in real time by the speed detection module, immediately sending an exhaust instruction by the intelligent valve positioner once the speed is 0, adjusting the piezoelectric valve to be in an exhaust state, acquiring the valve position in real time by the data acquisition module, and once the valve position reaches P down1 When the position is detected, the intelligent microprocessor immediately sends a valve position holding instruction to the piezoelectric valve, and the valve position corresponding AD value P is recorded by delaying for 10 seconds down2 Defining the maximum overshoot corresponding to AD value in the charging stage as P over2 ＝|P down1 -P down2 |。
Step C7: setting the optimal operation PWM in the inflation stage, and specifically realizing the optimal operation PWM comprises the following substeps:
substep C7.1: defining an optimum acceleration distance L ═ λ FSR (λ ranges from 0.1 to 0.3, and represents the product), H ═ 2 α ═ β × (FSR), p 1 ＝p 2 -β*α*FSR，p 3 ＝p 2 +β*α*FSR，p 2 20% FSR (where p 1 、p 2 、p 3 Representing the valve position and the corresponding AD value for the specific value).
Substep C7.2: and initializing the PWM duty ratio, and outputting the initial PWM wave to the piezoelectric valve by the PWM wave output module.
Substep C7.3: control regulating valve to run to p 0 At the position, the intelligent microprocessor sends an inflation instruction to the piezoelectric valve, the data acquisition module acquires a real-time valve position signal, and once the valve position reaches p 1 And at the position, the intelligent microprocessor immediately sends a holding instruction to the piezoelectric valve, adjusts the piezoelectric valve to be in a holding state, delays for 5 seconds and records the position of the adjusted valve.
Substep C7.4: if the position of the regulating valve is more than p 3 Position, indicating overshoot, the PWM duty is reduced by 10% of the amplitudeThen, the substep C7.3 is continuously executed; if the position of the regulating valve is less than p 3 Position, indicating no overshoot, the PWM duty cycle is increased by 10% and sub-step C7.3 is continued.
Substep C7.5: if the valve position is overshot when the PWM duty ratio is P1 and the valve position is not overshot when the PWM duty ratio is P2, then the binary search is started, i.e. the PWM duty ratio P is set to P2+ (P1-P2)/2, the substep C7.3 is continuously executed, and P can be obtained by executing the loop for multiple times 2 Optimal PWM duty cycle for the valve position.
Substep C7.6: performing substeps C7.3-C7.5 in a loop, respectively setting p 2 ＝40％*FSR、p 2 ＝60％*FSR、p 2 The optimal PWM duty cycle at FSR 80%.
Substep C7.7: and obtaining the optimal operation PWM duty ratio corresponding to different valve positions in the inflation stage through least square linear fitting.
Step C8: setting the optimal operation PWM in the exhaust stage, and concretely realizing the method comprises the following substeps:
substep C8.1: defining an optimum acceleration distance L ═ λ × FSR (λ ranges from 0.1 to 0.3, and represents the product), H ═ 2 α × β × FSR, p 1 ＝p 2 +β*α*FSR，p 3 ＝p 2 -β*α*FSR，p 2 20% FSR (wherein p 1 、p 2 、p 3 Representing the valve position and the corresponding AD value for the specific value).
Substep C8.2: and initializing the PWM duty ratio, and outputting the initial PWM wave to the piezoelectric valve by the PWM wave output module.
Substep C8.3: control regulating valve to run to p 0 At the position, the intelligent microprocessor sends an exhaust instruction to the piezoelectric valve, the data acquisition module acquires a real-time valve position signal, and once the valve position reaches p 1 And at the position, the intelligent microprocessor immediately sends a holding state to the piezoelectric valve, adjusts the piezoelectric valve to be in the holding state, delays for 5 seconds and records the position of the adjusted valve.
Substep C8.4: if the position of the regulating valve is less than p 3 Position, indicating overshoot, the PWM duty cycle is reduced by 10% and substep C8.3 is continued; if the position of the regulating valve is more than p 3 Position, indicating no overshoot, thenThe PWM duty cycle is increased by 10% and step C8.3 is continued.
Substep C8.5: if the valve position is overshot when the PWM duty ratio is P1 and the valve position is not overshot when the PWM duty ratio is P2, then binary search is started, i.e., the PWM duty ratio P is set to P2+ (P1-P2)/2, the step C8.3 is continuously executed, and P can be obtained after multiple times of circular execution 2 Optimal PWM duty cycle of the valve position.
Substep C8.6: performing substeps C8.3-C8.5 in a loop, respectively setting p 2 ＝40％*FSR、p 2 ＝60％*FSR、p 2 Optimal PWM duty cycle at 80% FSR.
Substep C8.7: and obtaining the optimal operation PWM duty ratio corresponding to different valve positions in the exhaust stage by least square linear fitting.
The intelligent microprocessor calls the closed-loop control module to realize the specific implementation steps of quickly positioning the valve position as follows (in the process, the air-open type valve is selected as an analysis object, the algorithm is also suitable for the air-close type valve, the analysis is only carried out in the valve position increasing process, and the algorithm is also suitable for the valve position decreasing process):
step D1: definitions ε ═ β FSR, e 1 ＝S over1 ，e 2 ＝S over2 Receiving a target valve position value r (t) input by a user, acquiring a real-time valve position feedback value c (t), a valve position error e (t), r (t) -c (t), and dividing a control process into a coarse adjustment area, a fine adjustment area and a dead area according to the size of the valve position error; wherein t represents time, beta represents control precision, the system is defaulted to adopt 0.5% precision when leaving factory, beta represents product, epsilon and e 1 、e 2 Representing the valve position, and the specific numerical value is represented by the corresponding AD value.
Step D2: and the intelligent microprocessor acquires a real-time valve position through the data acquisition module, calculates a valve position error, and executes the step D6 if the error is in the coarse adjustment area 1.
Step D3: and (3) acquiring the valve position in real time by the data acquisition module, detecting the real-time speed by the data acquisition module if the error is in the fine adjustment area 1, executing the step D7 once the speed is greater than zero, and executing the step D6 if the error is not in the fine adjustment area 1.
Step D4: the intelligent microprocessor acquires a real-time valve position through the data acquisition module, calculates a valve position error, and if the error is in the fine adjustment area 1,
step D5: the intelligent microprocessor collects a real-time valve position through the data acquisition module, calculates a valve position error, immediately outputs a compensation PWM wave if the error is in a dead zone, and controls the valve position to stay in the dead zone.
Step D6: a given 100% PWM wave is output to the on-off piezoelectric valve and an inflation command is issued to the piezoelectric valve, step D1 is performed.
Step D7: the intelligent microprocessor immediately calculates the corresponding real-time optimal operation PWM at this time according to the real-time valve position, outputs the PWM (at this time, the output PWM is the real-time optimal operation PWM + the compensation PWM) to the piezoelectric valve, controls the valve position to move, and executes step D1.
Step D8: the intelligent microprocessor immediately calculates the corresponding real-time minimum driving PWM according to the real-time valve position, outputs the PWM (at this time, the output PWM is the minimum driving PWM + the compensation PWM) to the piezoelectric valve, and executes step D1.
Finally, detecting a valve position which is finally stopped through a valve position feedback value acquired in real time, recording the times of overshoot if the valve position is overshot, and when the times of overshoot are equal to 5, reducing the PWM by the compensation PWM by 0.5% and updating the compensation PWM to a closed-loop control algorithm; if the dead zone is not reached, recording the times, and when the times is equal to 5, increasing the compensation PWM by 0.5 percent of amplitude; if the PWM duty ratio is overshot when P1 is exceeded and the PWM duty ratio is P2 without reaching the dead zone, then a binary search is started, i.e. the compensation PWM duty ratio P is P2+ (P1-P2)/2, and finally the compensation PWM duty ratio is updated to the closed-loop control algorithm.
Drawings
FIG. 1 is a schematic diagram of a pressure sensor external to a smart valve system according to the present invention
FIG. 2 is a schematic diagram of the compensation PWM setting of the present invention
FIG. 3 is a schematic diagram of the optimal PWM setting of the present invention
FIG. 4 is a schematic of the closed loop control of the present invention
Detailed Description
The control method of the switch type intelligent valve positioner based on the environment self-learning provided by the invention realizes the control of the target valve position through the following steps:
step A1: the pneumatic control valve is connected to an external system (a high-pressure air source, a control signal and the like), the intelligent microprocessor calls the pressure check module, if the reading of the pressure check module is within an allowable range, the control valve can normally work, the step A2 is carried out, and otherwise, an alarm is given.
The pressure detection module is used for judging whether the regulating valve can normally work or not, and the specific implementation steps are as follows:
step B1: and a pressure sensor is arranged at the interface of the air source communication regulating valve, and is defined as a pressure sensor A (shown in a schematic view in figure 1).
Step B2: the intelligent microprocessor records the pressure set by the pressure reducing valve and records the pressure as V.
Step B3: the intelligent microprocessor detects the reading of the pressure sensor A in real time and is marked as V1.
Step B4: v1 and V compare, and both deviations are in 10KPa, then intelligent valve system outside no obvious operating mode exists, and the governing valve can normally work. Otherwise, the outside of the regulating valve system has obvious working condition problems, the normal work of the regulating valve is influenced, and the alarm module of the intelligent valve positioner is called to give an alarm.
Step A2: firstly, detecting whether air leakage exists in the system or not by a parameter self-tuning method, calling an alarm module to give an alarm when the air leakage exceeds a set value, stopping a control process and not performing any operation; when the air leakage is within a range from zero to a set value, setting parameters (the stroke type, the end point position, the maximum overshoot corresponding to the AD value in the inflation and exhaust stages, the minimum driving PWM, the optimal operation PWM and the compensation PWM) required by closed-loop control, and entering the step A3;
the parameter self-tuning method mainly carries out the following parameters required by the closed-loop control method (the air-open valve is selected as an analysis object in the process, and the parameter self-tuning method is also suitable for the air-close valve):
step C1: the type of stroke, the end point position, the stroke range FSR are obtained. Outputting 100% PWM wave to switch type piezoelectric valve and sending out charging instruction to regulate pressureThe electric valve is in an inflation state, a valve position feedback signal and a valve rod speed signal are detected in real time, and the maximum speed of the valve rod is detected to be V up And AD value S corresponding to maximum speed valve position up1 (AD value represents the value of converting analog signal into digital signal), when the speed is detected to be equal to 0, the AD value of the valve position at the moment is recorded immediately, namely the AD value S corresponding to the top position far . Outputting 100% PWM wave to the switch type piezoelectric valve and sending out an exhaust instruction, adjusting the piezoelectric valve to be in an exhaust state, detecting a valve position feedback signal and a valve rod speed signal in real time, and detecting that the maximum speed of a valve rod is V down And AD value S corresponding to maximum speed valve position down1 When the detected speed is equal to 0, the valve position AD value at the moment is immediately recorded as the low end position corresponding AD value S near Range of travel FSR ═ S far -S near |。
Step C2: the setting of the compensation PWM in the charging stage (see the schematic diagram in FIG. 2a) specifically comprises the following sub-steps:
substep C2.1: outputting given PWM waves to the switch type piezoelectric valve, sending an inflation instruction, adjusting the switch type piezoelectric valve to be in an inflation state, acquiring a feedback valve position in real time, immediately outputting minimum drive PWM to the switch type piezoelectric valve once the valve position changes, and once the valve position reaches S 1 Position, immediately sending a valve position holding instruction (neither inflating nor exhausting) to the switch type piezoelectric valve, delaying for 10 seconds, and recording the corresponding AD value S of the valve position at the moment 2 If S is 1 ＝S 2 Write PWM 1 0 and go to step C2.4, otherwise, PWM is written 1 Step C5.2 is entered for 1.
Substep C2.2: judging PWM 1 If the limit (typically 15) is exceeded, PWM 1 If the air leakage is considered to be serious and the closed-loop control cannot be normally finished due to exceeding the limit, the system is crashed, the alarm module is immediately called to give an alarm, and otherwise, the substep C2.3 is executed.
Substep C2.3: adjusting the valve position to return to the initial position, outputting a given PWM wave to the switch type piezoelectric valve, adjusting the switch type piezoelectric valve to be in an inflation state, acquiring the feedback valve position in real time, outputting the minimum driving PWM to the switch type piezoelectric valve once the valve position changes, and outputting the minimum driving PWM once the valve position changesValve position reaches S 1 Position, outputting PWM immediately to switched piezoelectric valve 1 And recording the corresponding AD value S of the valve position at the time after 10 seconds of delay 2 If S is 1 ＝S 2 Go to step C2.4, otherwise PWM 1 ＝PWM 1 +1 and step C2.2.
Substep C2.4: performing substeps C2.1-C2.3 in a loop, respectively setting S 1 ＝40％*FSR、S 2 ＝60％*FSR、S 1 Compensated PWM duty cycle at 80% FSR.
Substep C2.5: and obtaining the compensation PWM duty ratios corresponding to different valve positions in the inflation stage through least square linear fitting.
Step C3: setting the exhaust phase compensation PWM (a schematic diagram is shown in figure 2b), and the specific implementation comprises the following sub-steps:
substep C3.1: the intelligent microprocessor continuously sends out 100% PWM waves and sends out an inflation instruction, the speed detection module detects the speed in real time, once the speed is 0, the intelligent valve positioner immediately sends out an exhaust instruction, the piezoelectric valve is adjusted to be in an exhaust state, the given PWM waves are output to the switch type piezoelectric valve, the feedback valve position is acquired in real time, once the valve position changes, PWM is immediately output to the switch type piezoelectric valve to start, and once the valve position reaches S 3 Position, immediately sending a valve position holding instruction (neither inflating nor exhausting) to the switch type piezoelectric valve, and recording the corresponding AD value S of the valve position at the time after delaying for 10 seconds 4 If S is 3 ＝S 4 Write PWM 2 If 0, and go to step C3.4, otherwise, note PWM 1 1 and proceeds to step C3.2.
Substep C3.2: judging PWM 2 If the limit (typically 15) is exceeded, PWM 2 If the air leakage is considered to be serious and the closed-loop control cannot be normally finished due to exceeding the limit, the system is crashed, the alarm module is immediately called to give an alarm, and otherwise, the substep C3.3 is executed.
Substep C3.3: adjusting the valve position to return to the initial position, outputting a given PWM wave to the switch type piezoelectric valve, adjusting the switch type piezoelectric valve to be in an exhaust state, acquiring a feedback valve position in real time, and outputting a minimum drive PWM to the switch type piezoelectric valve once the valve position changes 1 Once, onceValve position reaches S 3 Position, outputting PWM immediately to switched piezoelectric valve 2 And recording the corresponding AD value S of the valve position at the time after 10 seconds of delay 4 If S is 3 ＝S 4 Go to step C4.3, otherwise PWM 2 ＝PWM 2 +1, repeat to step C3.2.
Substep C3.4: performing substeps C3.1-C3.3 in a loop, respectively setting S 3 ＝40％*FSR、S 3 ＝60％*FSR、S 3 80% offset PWM duty cycle at FSR.
Substep C3.5: and obtaining compensation PWM duty ratios corresponding to different valve positions in the exhaust stage through least square linear fitting.
Step C4: the minimum driving PWM is obtained. And sending a charging command and 100% PWM to the switch type piezoelectric valve, acquiring a valve position feedback signal in real time, and adjusting the valve position to a 0.5 FSR valve position (wherein, the product is represented, and the FSR represents a stroke range). At the moment, 0% PWM is output to the switch type piezoelectric valve, the PWM is increased by taking 1% as amplitude continuously until the valve rod can slowly and uniformly run, and the PWM value P at the moment is recorded and defined up PWM for minimum drive of inflation phase, and then controlling valve position to x 1 At 0.5 × FSR valve position, outputting 0% PWM and exhaust command to the switch type piezoelectric valve, increasing PWM by 1% until the valve rod can slowly and uniformly run, recording and defining PWM value P at the moment down For minimum drive PWM during the exhaust phase, define minimum drive PWM as P str ＝|P up +P down |/2。
Step C5: determining the maximum overshoot of the inflation stage, sending 100% PWM wave by the intelligent valve positioner, sending an inflation instruction, adjusting the piezoelectric valve to be in an inflation state, acquiring the valve position in real time by the data acquisition module, and once the valve position reaches P up1 In position, the intelligent microprocessor immediately sends a valve position holding instruction to the piezoelectric valve, and the valve position corresponding AD value P is recorded after 10 seconds of delay up2 Defining the AD value corresponding to the maximum overshoot of the inflation stage as P over1 ＝|P up1 -P up2 |。
Step C6: determining the maximum overshoot of the exhaust phase, the intelligent microprocessor continuing to emit 100% PWM waves and emittingThe inflation instruction, the speed detection module detects the speed in real time, once the speed is 0, the intelligent valve positioner immediately sends an exhaust instruction, the piezoelectric valve is adjusted to be in an exhaust state, the data acquisition module acquires the valve position in real time, and once the valve position reaches P down1 In position, the intelligent microprocessor immediately sends a valve position holding instruction to the piezoelectric valve, and the valve position corresponding AD value P is recorded after 10 seconds of delay down2 Defining the maximum overshoot corresponding to AD value in the charging stage as P over2 ＝|P down1 -P down2 |。
Step C7: setting the optimal operation PWM (see the schematic diagram in FIG. 3a) in the charging phase includes the following sub-steps:
substep C7.1: defining an optimum acceleration distance L ═ λ FSR (λ ranges from 0.1 to 0.3, and represents the product), H ═ 2 α ═ β × (FSR), p 1 ＝p 2 -β*α*FSR，p 3 ＝p 2 +β*α*FSR，p 2 20% FSR (wherein p 1 、p 2 、p 3 Representing the valve position, and the specific value is the corresponding AD value).
Substep C7.2: and initializing the PWM duty ratio, and outputting the initial PWM wave to the piezoelectric valve by the PWM wave output module.
Substep C7.3: control regulating valve to operate to p 0 At the position, the intelligent microprocessor sends an inflation instruction to the piezoelectric valve, the data acquisition module acquires a real-time valve position signal, and once the valve position reaches p 1 And at the position, the intelligent microprocessor immediately sends a holding instruction to the piezoelectric valve, adjusts the piezoelectric valve to be in a holding state, delays for 5 seconds and records the position of the adjusted valve.
Substep C7.4: if the position of the regulating valve is more than p 3 Position, indicating overshoot, the PWM duty cycle is reduced by 10% and substep C7.3 is continued; if the position of the regulating valve is less than p 3 Position, indicating no overshoot, the PWM duty cycle is increased by 10% and substep C7.3 is continued.
Substep C7.5: if the valve position is overshot when the PWM duty ratio is P1 and the valve position is not overshot when the PWM duty ratio is P2, then the binary search is started, i.e. the PWM duty ratio P is set to P2+ (P1-P2)/2, the substep C7.3 is continuously executed, and P can be obtained after multiple times of circular execution 2 Optimal PWM duty cycle for the valve position.
Substep C7.6: substeps C7.3-C7.5 are executed in a loop to set p respectively 2 ＝40％*FSR、p 2 ＝60％*FSR、p 2 Optimal PWM duty cycle at 80% FSR.
Substep C7.7: and obtaining the optimal operation PWM duty ratio corresponding to different valve positions in the inflation stage through least square linear fitting.
Step C8: setting the optimal operation PWM (schematic diagram shown in figure 3b) in the exhaust stage comprises the following sub-steps:
substep C8.1: defining an optimum acceleration distance L ═ λ FSR (λ takes a value of 0.1 to 0.3, which represents the product), H ═ 2 α ═ β × (FSR), p 1 ＝p 2 +β*α*FSR，p 3 ＝p 2 -β*α*FSR，p 2 20% FSR (wherein p 1 、p 2 、p 3 Representing the valve position, and the specific value is the corresponding AD value).
Substep C8.2: and initializing the PWM duty ratio, and outputting the initial PWM wave to the piezoelectric valve by the PWM wave output module.
Substep C8.3: control regulating valve to run to p 0 At the position, the intelligent microprocessor sends an exhaust instruction to the piezoelectric valve, the data acquisition module acquires a real-time valve position signal, and once the valve position reaches p 1 And at the position, the intelligent microprocessor immediately sends a holding state to the piezoelectric valve, adjusts the piezoelectric valve to be in the holding state, delays for 5 seconds and records the position of the adjusted valve.
Substep C8.4: if the position of the regulating valve is less than p 3 Position, indicating overshoot, the PWM duty cycle is reduced by 10% and substep C8.3 is continued; if the position of the regulating valve is more than p 3 Position, indicating no overshoot, the PWM duty cycle is increased by 10% and step C8.3 is continued.
Substep C8.5: if the valve position is overshot when the PWM duty ratio is P1 and the valve position is not overshot when the PWM duty ratio is P2, a binary search is started, that is, the PWM duty ratio P is set to P2+ (P1-P2)/2, the step C8.3 is continuously executed, and P can be obtained by executing the steps for multiple times in a circulating manner 2 Optimal PWM duty cycle for the valve position.
Substep C8.6: circulation ofSubsteps C8.3-C8.5 are performed to set p respectively 2 ＝40％*FSR、p 2 ＝60％*FSR、p 2 Optimal PWM duty cycle at 80% FSR.
Substep C8.7: and obtaining the optimal operation PWM duty ratio corresponding to different valve positions in the exhaust stage by least square linear fitting.
Step A3: the LCD module displays the highest control precision epsilon allowed by the intelligent valve positioning device (the highest control precision epsilon can be set by a user), the user manually inputs a target valve position value, and the intelligent microprocessor receives the target valve position value and compares the target valve position value with a real-time valve position value acquired from the valve position acquisition module. If the difference value between the target valve position and the current valve position is larger than the precision requirement set by the user, the step A4 is carried out; otherwise, no operation is performed.
Step A4: and the intelligent microprocessor calls the self-set parameters, performs closed-loop control, calculates the real-time PWM duty ratio and the working state of the piezoelectric switch valve, outputs the PWM and a control instruction to the piezoelectric switch valve so as to control the air intake and exhaust amount of the piezoelectric switch valve, realizes the control of the valve position, and enters the step A3 for cyclic execution.
The intelligent microprocessor calls a closed-loop control module, a closed-loop control schematic diagram is shown in FIG. 4, and the specific implementation steps for realizing the rapid positioning of the valve position are as follows (the air-open type valve is selected as an analysis object in the process, the algorithm is also suitable for the air-close type valve, the analysis is only carried out in the process of increasing the valve position, and the algorithm is also suitable for the process of reducing the valve position):
step D1: definitions ε ═ β FSR, e 1 ＝S over1 ，e 2 ＝S over2 Receiving a target valve position value r (t) input by a user, acquiring a real-time valve position feedback value c (t), a valve position error e (t), r (t) -c (t), and dividing a control process into a coarse adjustment area, a fine adjustment area and a dead area according to the valve position error; wherein t represents time, beta represents control precision, the system is defaulted to adopt 0.5% precision when leaving factory, beta represents product, epsilon and e 1 、e 2 Representing the valve position, and the specific numerical value is represented by the corresponding AD value.
Step D2: and the intelligent microprocessor acquires the real-time valve position through the data acquisition module, calculates the valve position error, and executes the step D6 if the error is in the coarse adjustment area 1.
Step D3: and (3) acquiring the valve position in real time by the data acquisition module, detecting the real-time speed by the data acquisition module if the error is in the fine adjustment area 1, executing the step D7 once the speed is greater than zero, and executing the step D6 if the error is not in the fine adjustment area 1.
Step D4: the intelligent microprocessor collects real-time valve positions through the data acquisition module, calculates valve position errors, and if the errors are in the fine adjustment area 1,
step D5: the intelligent microprocessor collects a real-time valve position through the data acquisition module, calculates a valve position error, immediately outputs a compensation PWM wave if the error is in a dead zone, and controls the valve position to stay in the dead zone.
Step D6: a given 100% PWM wave is output to the on-off piezoelectric valve and an inflation command is issued to the piezoelectric valve, step D1 is performed.
Step D7: the intelligent microprocessor immediately calculates the corresponding real-time optimal operation PWM at this time according to the real-time valve position, outputs the PWM (at this time, the output PWM is the real-time optimal operation PWM + the compensation PWM) to the piezoelectric valve, controls the valve position to move, and executes step D1.
Step D8: the intelligent microprocessor immediately calculates the corresponding real-time minimum driving PWM according to the real-time valve position, outputs the PWM (at this time, the output PWM is the minimum driving PWM + the compensation PWM) to the piezoelectric valve, and executes step D1.
Finally, detecting a valve position which is finally stopped through a valve position feedback value acquired in real time, recording the times of overshoot if the valve position is overshot, and when the times of overshoot are equal to 5, reducing the PWM by the compensation PWM by 0.5% and updating the compensation PWM to a closed-loop control algorithm; if the dead zone is not reached, recording the times, and when the times is equal to 5, increasing the compensation PWM by 0.5 percent of amplitude; if the PWM duty ratio is overshot when P1 is exceeded and the PWM duty ratio is P2 without reaching the dead zone, then a binary search is started, i.e. the compensation PWM duty ratio P is P2+ (P1-P2)/2, and finally the compensation PWM duty ratio is updated to the closed-loop control algorithm.
Those skilled in the art to which the invention relates will readily appreciate that certain modifications and substitutions can be made without departing from the spirit and scope of the invention.

Claims (1)

1. A control method of a switch type intelligent valve positioner based on environment self-learning is characterized by comprising the following steps: the environment self-learning control is realized through the following steps:
step A1: the pneumatic regulating valve is connected to an external system, the intelligent microprocessor calls the pressure checking module, if the reading of the pressure checking module is within the allowable range, the regulating valve works normally, the step A2 is carried out, and otherwise, an alarm is given;
the method specifically comprises the following steps:
step B1: a pressure sensor is arranged at the interface of the air source communication regulating valve, and is defined as a pressure sensor A;
step B2: the intelligent microprocessor records the pressure set by the pressure reducing valve and records the pressure as V;
step B3: the intelligent microprocessor detects the reading of the pressure sensor A in real time and records the reading as V1;
step B4: v1 is compared with V, and the deviation of the two is within 10KPa, so that no obvious working condition exists outside the intelligent valve system, and the regulating valve can work normally; otherwise, the outside of the regulating valve system has obvious working condition problems, the normal work of the regulating valve is influenced, and at the moment, an alarm module of the intelligent valve positioner is called to give an alarm;
step A2: firstly, detecting whether air leakage exists in the system or not through a parameter self-setting method, and setting parameters required by closed-loop control when the air leakage is zero to a set value: the stroke type, the end point position, the maximum overshoot corresponding to the AD value in the inflation and exhaust stages, the minimum driving PWM, the optimal operation PWM and the compensation PWM; when the air leakage exceeds the set value, calling an alarm module to give an alarm, stopping the control process, and not performing any operation, otherwise, entering the step A3;
the method comprises the following specific steps:
step C1: obtaining a stroke type, an end point position and a stroke range FSR; outputting 100% PWM wave to switch type piezoelectric valve and sending out inflation instruction, adjusting the piezoelectric valve in inflation state, detecting valve position feedback signal and valve rod speed in real timeDegree signal, detecting the maximum speed of the valve rod as V up And AD value S corresponding to maximum speed valve position up1 When the speed is detected to be equal to 0, the valve position AD value at the moment is immediately recorded as the AD value S corresponding to the top end position far (ii) a Outputting 100% PWM wave to the switch type piezoelectric valve and sending out an exhaust instruction, adjusting the piezoelectric valve to be in an exhaust state, detecting a valve position feedback signal and a valve rod speed signal in real time, and detecting that the maximum speed of a valve rod is V down And AD value S corresponding to maximum speed valve position down1 When the detected speed is equal to 0, the valve position AD value at the moment is immediately recorded as the low end position corresponding AD value S near Range of travel FSR ═ S far -S near |；
Step C2: the method specifically comprises the following substeps of setting the compensation PWM in the inflation stage:
substep C2.1: outputting given PWM waves to the switch type piezoelectric valve, sending an inflation instruction, adjusting the switch type piezoelectric valve to be in an inflation state, acquiring a feedback valve position in real time, immediately outputting minimum drive PWM to the switch type piezoelectric valve once the valve position changes, and once the valve position reaches S 1 Position, immediately sending a valve position holding instruction to the switch type piezoelectric valve, and recording the corresponding AD value S of the valve position at the moment in 10 seconds of delay 2 If S is 1 ＝S 2 Write PWM 1 0 and go to step C2.4, otherwise, PWM is written 1 Entering step C5.2 for 1;
substep C2.2: judging PWM 1 Whether the limit is exceeded, PWM 1 If the air leakage is serious beyond the limit, the closed-loop control cannot be normally finished, the system is crashed, an alarm module is immediately called to give an alarm, and otherwise, the substep C2.3 is executed;
substep C2.3: adjusting the valve position to return to the initial position, outputting a given PWM wave to the switch type piezoelectric valve, adjusting the switch type piezoelectric valve to be in an inflation state, acquiring the feedback valve position in real time, outputting the minimum driving PWM to the switch type piezoelectric valve once the valve position changes, and outputting the minimum driving PWM once the valve position reaches S 1 Position, outputting PWM immediately to switched piezoelectric valve 1 And recording the corresponding AD value S of the valve position at the time after 10 seconds of delay 2 If S is 1 ＝S 2 Entering the stepC2.4, otherwise PWM 1 ＝PWM 1 +1 and go to step C2.2;
substep C2.4: performing substeps C2.1-C2.3 in a loop, respectively setting S 1 ＝40％*FSR、S 2 ＝60％*FSR、S 1 Compensated PWM duty cycle at 80% FSR;
substep C2.5: compensating PWM duty ratios corresponding to different valve positions in the inflation stage can be obtained through least square linear fitting;
step C3: the method for setting the compensation PWM in the exhaust stage specifically comprises the following substeps:
substep C3.1: the intelligent microprocessor continuously sends out 100% PWM waves and sends out an inflation instruction, the speed detection module detects the speed in real time, once the speed is 0, the intelligent valve positioner immediately sends out an exhaust instruction, the piezoelectric valve is adjusted to be in an exhaust state, the given PWM waves are output to the switch type piezoelectric valve, the feedback valve position is acquired in real time, once the valve position changes, PWM is immediately output to the switch type piezoelectric valve to start, and once the valve position reaches S 3 Position, immediately sending a valve position holding instruction to the switch type piezoelectric valve, and recording the corresponding AD value S of the valve position at the moment in 10 seconds of delay 4 If S is 3 ＝S 4 Write PWM 2 If equal to 0, and go to step C3.4, otherwise, note PWM 1 1 and go to step C3.2;
substep C3.2: judging PWM 2 Whether the limit is exceeded, PWM 2 If the air leakage is considered to be serious and the closed-loop control cannot be normally finished due to exceeding the limit, the system is crashed, an alarm module is immediately called to give an alarm, and otherwise, the substep C3.3 is executed;
substep C3.3: adjusting the valve position to return to the initial position, outputting a given PWM wave to the switch type piezoelectric valve, adjusting the switch type piezoelectric valve to be in an exhaust state, acquiring a feedback valve position in real time, and outputting a minimum drive PWM to the switch type piezoelectric valve once the valve position changes 1 Once the valve position reaches S 3 Position, outputting PWM immediately to switched piezoelectric valve 2 And recording the corresponding AD value S of the valve position at the time after 10 seconds of delay 4 If S is 3 ＝S 4 Go to step C4.3, otherwise PWM 2 ＝PWM 2 +1, repeat the entering stepC3.2；
Substep C3.4: performing substeps C3.1-C3.3 in a loop, respectively setting S 3 ＝40％*FSR、S 3 ＝60％*FSR、S 3 (vii) 80% compensated PWM duty cycle at FSR;
substep C3.5: compensating PWM duty ratios corresponding to different valve positions in the exhaust stage can be obtained through least square linear fitting;
step C4: obtaining minimum driving PWM; sending an inflation instruction and 100% PWM to the switch type piezoelectric valve, collecting a valve position feedback signal in real time, and adjusting the valve position to 0.5 × FSR valve position; at the moment, 0% PWM is output to the switch type piezoelectric valve, the PWM continuously increases by taking 1% as amplitude until the valve rod can slowly and uniformly run, and the PWM value P at the moment is recorded and defined up PWM for minimum drive of inflation phase, and then controlling valve position to x 1 At 0.5 × FSR valve position, outputting 0% PWM and exhaust command to the switch type piezoelectric valve, increasing PWM by 1% until the valve rod can slowly and uniformly run, recording and defining PWM value P at the moment down For minimum drive PWM in the exhaust phase, defining minimum drive PWM as P str ＝|P up +P down |/2；
Step C5: determining the maximum overshoot of the inflation stage, sending 100% PWM wave by the intelligent valve positioner, sending an inflation instruction, adjusting the piezoelectric valve to be in an inflation state, acquiring the valve position in real time by the data acquisition module, and once the valve position reaches P up1 In position, the intelligent microprocessor immediately sends a valve position holding instruction to the piezoelectric valve, and the valve position corresponding AD value P is recorded after 10 seconds of delay up2 Defining the AD value corresponding to the maximum overshoot of the inflation stage as P over1 ＝|P up1 -P up2 |；
Step C6: determining the maximum overshoot of the exhaust stage, continuously sending 100% PWM waves by the intelligent microprocessor, sending an inflation instruction, detecting the speed in real time by the speed detection module, immediately sending an exhaust instruction by the intelligent valve positioner once the speed is 0, adjusting the piezoelectric valve to be in an exhaust state, acquiring the valve position in real time by the data acquisition module, and once the valve position reaches P down1 Position, the intelligent microprocessor immediately sends a valve position holding instruction to the piezoelectric valve, and delays for 10 secondsRecording the corresponding AD value P of the valve position at the time down2 Defining the maximum overshoot corresponding to AD value in the charging stage as P over2 ＝|P down1 -P down2 |；
Step C7: setting the optimal operation PWM in the inflation stage, and specifically realizing the optimal operation PWM comprises the following substeps:
substep C7.1: defining an optimum acceleration distance L ═ λ FSR, λ ranges from 0.1 to 0.3, and H ═ 2 α ═ β × (FSR), p 1 ＝p 2 -β*α*FSR，p 3 ＝p 2 +β*α*FSR，p 2 20% FSR, wherein p 1 、p 2 、p 3 Representing the valve position, and using the corresponding AD value as a specific numerical value;
substep C7.2: initializing a PWM duty ratio, and outputting an initial PWM wave to a piezoelectric valve by a PWM wave output module;
substep C7.3: control regulating valve to run to p 0 At the position, the intelligent microprocessor sends an inflation instruction to the piezoelectric valve, the data acquisition module acquires a real-time valve position signal, and once the valve position reaches p 1 At the position, the intelligent microprocessor immediately sends a holding instruction to the piezoelectric valve, adjusts the piezoelectric valve to be in a holding state, delays for 5 seconds, and records the position of the adjusted valve;
substep C7.4: if the position of the regulating valve is more than p 3 Position, indicating overshoot, the PWM duty cycle is reduced by 10% and substep C7.3 is continued; if the position of the regulating valve is less than p 3 Position, meaning no overshoot, increasing the PWM duty cycle by 10% and continuing to perform substep C7.3;
substep C7.5: if the valve position is overshot when the PWM duty ratio is P1 and the valve position is not overshot when the PWM duty ratio is P2, then the binary search is started, i.e. the PWM duty ratio P is set to P2+ (P1-P2)/2, the substep C7.3 is continuously executed, and P can be obtained after multiple times of circular execution 2 Optimal PWM duty cycle of the valve position;
substep C7.6: performing substeps C7.3-C7.5 in a loop, respectively setting p 2 ＝40％*FSR、p 2 ＝60％*FSR、p 2 Optimal PWM duty cycle at 80% FSR;
substep C7.7: optimal operation PWM duty ratios corresponding to different valve positions in the inflation stage can be obtained through least square linear fitting;
step C8: setting the optimal operation PWM in the exhaust stage, and concretely realizing the method comprises the following substeps:
substep C8.1: defining an optimum acceleration distance L ═ λ FSR, λ is 0.1 to 0.3, and H ═ 2 α ^ β ^ FSR, p represents the product 1 ＝p 2 +β*α*FSR，p 3 ＝p 2 -β*α*FSR，p 2 20% FSR, wherein p 1 、p 2 、p 3 Representing the valve position, and using the corresponding AD value as a specific numerical value;
substep C8.2: initializing a PWM duty ratio, and outputting an initial PWM wave to a piezoelectric valve by a PWM wave output module;
substep C8.3: control regulating valve to run to p 0 At the position, the intelligent microprocessor sends an exhaust instruction to the piezoelectric valve, the data acquisition module acquires a real-time valve position signal, and once the valve position reaches p 1 At the position, the intelligent microprocessor immediately sends a holding state to the piezoelectric valve, adjusts the piezoelectric valve to be in the holding state, delays for 5 seconds, and records the position of the adjusting valve;
substep C8.4: if the position of the regulating valve is less than p 3 Position, indicating overshoot, the PWM duty cycle is reduced by 10% and substep C8.3 is continued; if the position of the regulating valve is more than p 3 If the position indicates no overshoot, increasing the PWM duty ratio by 10 percent, and continuing to execute the step C8.3;
substep C8.5: if the valve position is overshot when the PWM duty ratio is P1 and the valve position is not overshot when the PWM duty ratio is P2, then binary search is started, i.e., the PWM duty ratio P is set to P2+ (P1-P2)/2, the step C8.3 is continuously executed, and P can be obtained after multiple times of circular execution 2 Optimal PWM duty cycle of the valve position;
substep C8.6: substeps C8.3-C8.5 are executed in a circulating manner to respectively set p 2 ＝40％*FSR、p 2 ＝60％*FSR、p 2 Optimal PWM duty cycle at 80% FSR;
substep C8.7: obtaining optimal operation PWM duty ratios corresponding to different valve positions in the exhaust stage through least square linear fitting;
step A3: the LCD module displays the highest control precision epsilon allowed by the intelligent valve positioning device, a user manually inputs a target valve value, and the intelligent microprocessor receives the target valve value and compares the target valve value with a real-time valve value acquired from the valve position acquisition module; if the difference value between the target valve position and the current valve position is larger than the precision requirement set by the user, the step A4 is carried out; otherwise, no operation is carried out;
step A4: calling self-set parameters by the intelligent microprocessor, performing closed-loop control, calculating a real-time PWM duty ratio and the working state of the piezoelectric switch valve, outputting the PWM and a control instruction to the piezoelectric switch valve, controlling the air intake and exhaust amount of the piezoelectric switch valve to realize the control of the valve position, and performing the step A3 in a circulating manner;
the method comprises the following specific steps:
step D1: definitions ε ═ β FSR, e 1 ＝S over1 ，e 2 ＝S over2 Receiving a target valve position value r (t) input by a user, acquiring a real-time valve position feedback value c (t), a valve position error e (t), r (t) -c (t), and dividing a control process into a coarse adjustment area, a fine adjustment area and a dead area according to the size of the valve position error; wherein t represents time, beta represents control precision, the system default of factory adopts 0.5% precision, beta value range is 0-1, and represents product, epsilon and e 1 、e 2 Representing the valve position, and representing the specific numerical value by using the corresponding AD value;
step D2: the intelligent microprocessor collects a real-time valve position through the data collection module, calculates a valve position error, and executes the step D6 if the error is in the coarse adjustment area 1;
step D3: the data acquisition module acquires the valve position in real time, if the error is in the fine adjustment area 1, the data acquisition module detects the real-time speed, and once the speed is greater than zero, the step D7 is executed, otherwise, the step D6 is executed;
step D4: the intelligent microprocessor collects real-time valve positions through the data acquisition module, calculates valve position errors, and if the errors are in the fine adjustment area 1,
step D5: the intelligent microprocessor acquires a real-time valve position through the data acquisition module, calculates a valve position error, immediately outputs a compensation PWM wave if the error is in a dead zone, and controls the valve position to stay in the dead zone;
step D6: outputting a given 100% PWM wave to the switch type piezoelectric valve, and sending an inflation instruction to the piezoelectric valve, and executing the step D1;
step D7: the intelligent microprocessor immediately calculates the corresponding real-time optimal operation PWM at the moment according to the real-time valve position, outputs the real-time optimal operation PWM + the compensation PWM to the piezoelectric valve, controls the valve position to move and executes the step D1;
step D8: the intelligent microprocessor immediately calculates the corresponding real-time minimum driving PWM according to the real-time valve position, outputs the minimum driving PWM + the compensation PWM to the piezoelectric valve and executes the step D1;
finally, detecting a valve position which is finally stopped through a valve position feedback value acquired in real time, recording the times of overshoot if the valve position is overshot, and when the times of overshoot are equal to 5, reducing the PWM by the compensation PWM by 0.5 and updating the compensation PWM to a closed-loop control algorithm; if the dead zone is not reached, recording the times, and when the times is equal to 5, increasing the compensation PWM by the amplitude of 0.5; if the PWM duty ratio is over-adjusted when the PWM duty ratio is P1 and the PWM duty ratio does not reach the dead zone when the PWM duty ratio is P2, the binary search is started, namely the compensation PWM duty ratio P is equal to P2+ (P1-P2)/2, and finally the compensation PWM duty ratio is updated into a closed-loop control algorithm.
CN202011563520.5A 2020-12-25 2020-12-25 Control method of switch type intelligent valve positioner based on environment self-learning Active CN112650062B (en)

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102080735A (en) * 2011-02-23 2011-06-01 合肥工业大学 Piezoelectric switch type valve positioner control method and piezoelectric switch type valve positioner control system
CN108181812A (en) * 2017-12-28 2018-06-19 浙江工业大学 BP neural network-based valve positioner PI parameter setting method
CN110173589A (en) * 2019-04-30 2019-08-27 杭州电子科技大学 A kind of Valve Positioner System Based on ARM Microcontroller based on switching regulator piezo electric valve
CN110645395A (en) * 2019-08-01 2020-01-03 杭州电子科技大学 Intelligent valve positioner control system and control method
CN110985738A (en) * 2019-11-13 2020-04-10 杭州电子科技大学 Self-learning valve positioning device and positioning method thereof
CN111043379A (en) * 2019-12-26 2020-04-21 杭州电子科技大学 Accurate control method for switch type intelligent valve positioner

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102080735A (en) * 2011-02-23 2011-06-01 合肥工业大学 Piezoelectric switch type valve positioner control method and piezoelectric switch type valve positioner control system
CN108181812A (en) * 2017-12-28 2018-06-19 浙江工业大学 BP neural network-based valve positioner PI parameter setting method
CN110173589A (en) * 2019-04-30 2019-08-27 杭州电子科技大学 A kind of Valve Positioner System Based on ARM Microcontroller based on switching regulator piezo electric valve
CN110645395A (en) * 2019-08-01 2020-01-03 杭州电子科技大学 Intelligent valve positioner control system and control method
CN110985738A (en) * 2019-11-13 2020-04-10 杭州电子科技大学 Self-learning valve positioning device and positioning method thereof
CN111043379A (en) * 2019-12-26 2020-04-21 杭州电子科技大学 Accurate control method for switch type intelligent valve positioner

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
智能阀门***的仿人积分规则自学习模糊控制算法;梁开喜 等;《新技术新工艺》;20041231(第8期);第4-6页 *
智能阀门***阀位自适应控制算法研究;刘军 等;《仪表技术与传感器》;20121231(第12期);第151-152页 *

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