Valve position control method, device and valve positioner

Abstract

The application provides a valve opening degree control method and device and a valve positioner, and relates to the technical field of valve control. The method adjusts the cylinder pressure based on the target valve opening degree and the target air pressure adjustment driving amount to adjust the valve opening degree, obtains the current cylinder pressure and the current valve opening degree, and performs valve position feedback module failure identification based on the current valve opening degree and the current cylinder pressure to obtain a failure identification result. When the failure identification result is that the valve position feedback module is failed, the target cylinder pressure is determined in a preset air pressure adjustment table based on the target valve opening degree, and the valve opening degree is adjusted based on the target cylinder pressure and the target air pressure adjustment driving amount. The valve position feedback module can be identified for failure, and the valve opening degree can be adjusted when the valve position feedback module is failed, so that the reliability and stability of the valve opening degree control can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of valve control, in particular to a valve opening degree control method and device and a valve positioner. BACKGROUND

[0002] The valve positioner is one of the key devices in the modern industrial automation control system, and has been widely used in the fields of petroleum, chemical industry, electric power, metallurgy, pharmaceutical, environmental protection, etc. The valve positioner is mainly used for accurately controlling the opening degree of the pneumatic valve, so as to realize the accurate control of the flow of the medium (such as gas, liquid or steam) in the pipeline.

[0003] The valve positioner generally consists of a control system module, an electrical conversion unit, a pneumatic amplifier module and a valve position feedback module, forming a closed loop system. The sensor of the conventional valve position feedback module adopts a mechanical connection of a resistance potentiometer or a non-contact connection of a Hall sensor, and the control system drives the electrical conversion unit and the pneumatic amplifier to intake or exhaust air according to the deviation between the target valve position control instruction of the main control room and the real-time monitoring of the actual valve position, so as to control the opening degree of the pneumatic valve. Due to the complex environment of the valve positioner, problems such as vibration wear, loose installation or corrosion of the medium may cause the sensor of the valve position feedback module to age or fail, affecting the control reliability and stability. Therefore, there is an urgent need for a valve opening degree control method to improve the reliability and stability of the valve opening degree control. SUMMARY

[0004] In view of the above-mentioned shortcomings of the related art, the present application provides a valve opening degree control method, device and valve positioner to solve the above-mentioned technical problems.

[0005] The valve opening degree control method provided by the present application comprises:

[0006] Obtaining a target air pressure adjustment driving amount, the target air pressure adjustment driving amount being used to adjust the cylinder pressure and in turn adjust the valve opening degree;

[0007] In response to receiving a target valve opening degree, adjusting the cylinder pressure based on the target valve opening degree and the target air pressure adjustment driving amount to adjust the valve opening degree;

[0008] Obtaining the current cylinder pressure and the current valve opening degree, and performing valve position feedback module failure identification based on the current valve opening degree and the current cylinder pressure to obtain a failure identification result;

[0009] When the failure identification result is that the valve position feedback module fails, determining a target cylinder pressure in a preset air pressure adjustment table based on the target valve opening degree, and adjusting the valve opening degree based on the target cylinder pressure and the target air pressure adjustment driving amount, the preset air pressure adjustment table being used to represent the valve opening degree corresponding to different cylinder pressures.

[0010] In an embodiment of the present application, the target valve opening degree is adjusted according to the target air pressure adjustment driving amount and the preset air pressure adjustment table, comprising:

[0011] The valve stroke is determined according to the target valve opening degree and the current valve opening degree, and the valve stroke comprises a positive stroke or a reverse stroke;

[0012] If the valve stroke is a positive stroke, the valve opening degree is adjusted according to the target air pressure adjustment driving amount, the target valve opening degree, and a first preset air pressure adjustment table;

[0013] If the valve stroke is a reverse stroke, the valve opening degree is adjusted according to the target air pressure adjustment driving amount, the target valve opening degree, and a second preset air pressure adjustment table.

[0014] In an embodiment of the present application, the method further comprises:

[0015] When the identification result is that the valve position feedback module is valid, the actual cylinder pressure corresponding to the target valve opening degree is obtained in response to the current valve opening degree being consistent with the target valve opening degree;

[0016] The preset air pressure adjustment table is updated based on the actual cylinder pressure and the target valve opening degree.

[0017] In an embodiment of the present application, the target air pressure adjustment driving amount is obtained, comprising:

[0018] The valve adjustment step: obtaining an initial air pressure adjustment driving amount, an initial valve opening degree, an expected valve opening degree, and a preset air pressure adjustment table, determining a cylinder pressure adjustment value in the preset air pressure adjustment table based on the initial valve opening degree and the expected valve opening degree, and adjusting the valve opening degree based on the cylinder pressure adjustment value and the initial air pressure adjustment driving amount;

[0019] The system parameter updating step: obtaining an actual valve opening degree, and updating the overshoot times or the undershoot times based on the actual valve opening degree and the expected valve opening degree when it is detected that the actual valve opening degree has not changed for three consecutive times;

[0020] The valve parameter updating step: comparing the expected valve opening degree with a preset valve opening degree, if the expected valve opening degree is consistent with the preset valve opening degree, executing the system parameter determining step, if the expected valve opening degree is not consistent with the preset valve opening degree, taking the expected valve opening degree as an updated initial valve opening degree, taking the sum and / or difference between the expected valve opening degree and a preset value as an updated expected valve opening degree, and repeating the valve adjustment step and the value determining step;

[0021] The system parameter determination step is: determining whether the over-adjustment times and the under-adjustment times belong to a preset interval, if the over-adjustment times and the under-adjustment times belong to the preset interval, determining the initial air pressure adjustment driving amount as a target air pressure adjustment driving amount; if the over-adjustment times and the under-adjustment times do not belong to the preset interval, updating the initial air pressure adjustment driving amount based on the over-adjustment times, the under-adjustment times, a preset driving amount adjustment strategy, obtaining an updated initial air pressure adjustment driving amount, and repeatedly executing the valve adjustment step, the system parameter updating step, the valve parameter updating step and the system parameter determination step based on the updated initial air pressure adjustment driving amount.

[0022] In an embodiment of the present application, the initial air pressure adjustment driving amount is updated based on the over-adjustment times, the under-adjustment times, and a preset driving amount adjustment strategy to obtain an updated initial air pressure adjustment driving amount, including:

[0023] If the over-adjustment times are greater than or equal to a first preset value, the initial air pressure adjustment driving amount is reduced based on a first preset driving amount;

[0024] If the over-adjustment times are greater than or equal to a second preset value and less than the first preset value, the initial air pressure adjustment driving amount is reduced based on a second preset driving amount;

[0025] If the over-adjustment times are greater than a third preset value and less than the second preset value, the initial air pressure adjustment driving amount is reduced based on a third preset driving amount;

[0026] If the under-adjustment times are greater than or equal to a first preset value, the initial air pressure adjustment driving amount is increased based on a first preset driving amount;

[0027] If the under-adjustment times are greater than or equal to a second preset value and less than the first preset value, the initial air pressure adjustment driving amount is increased based on a second preset driving amount;

[0028] If the under-adjustment times are greater than a third preset value and less than the second preset value, the initial air pressure adjustment driving amount is increased based on a third preset driving amount.

[0029] In an embodiment of the present application, the valve position feedback module failure identification is performed based on the current valve opening and the current cylinder pressure to obtain a failure identification result, including:

[0030] A first identification result is determined based on the current valve opening and a preset opening interval;

[0031] A pressure interval is determined based on the current valve opening, and a second identification result is determined based on the current cylinder pressure and the pressure interval;

[0032] In a case where the first identification result and the second identification result are both normal identification, the failure identification result is that the valve position feedback module is effective.

[0033] In a case where the first identification result and / or the second identification result is abnormal identification, the failure identification result is that the valve position feedback module is ineffective.

[0034] In an embodiment of the present application, the first identification result is determined based on the current valve opening degree and a preset opening degree interval, including:

[0035] In a case where the current valve opening degree belongs to the preset opening degree interval, the first identification result is normal identification.

[0036] In a case where the current valve opening degree does not belong to the preset opening degree interval, the first identification result is abnormal identification.

[0037] In an embodiment of the present application, a pressure interval is determined based on the current valve opening degree, and a second identification result is determined based on the current cylinder pressure and the pressure interval, including:

[0038] The positive stroke cylinder pressure and the reverse stroke cylinder pressure are obtained based on the current valve opening degree.

[0039] The pressure interval is determined based on the positive stroke cylinder pressure and the reverse stroke cylinder pressure.

[0040] If the current cylinder pressure belongs to the pressure interval, it is determined that the second identification result is normal identification.

[0041] If the current cylinder pressure does not belong to the pressure interval, it is determined that the second identification result is abnormal identification.

[0042] To achieve the above object and other related objects, the present application provides a valve opening degree control device, including:

[0043] A data acquisition module is configured to acquire a target air pressure adjustment driving amount, the target air pressure adjustment driving amount being used to adjust a cylinder pressure and in turn adjust a valve opening degree.

[0044] A first adjustment module is configured to, in response to receiving a target valve opening degree, adjust the cylinder pressure based on the target valve opening degree and the target air pressure adjustment driving amount, so as to adjust the valve opening degree.

[0045] An identification module is configured to acquire a current cylinder pressure and a current valve opening degree, and perform valve position feedback module failure identification based on the current valve opening degree and the current cylinder pressure, to obtain a failure identification result.

[0046] The second adjusting module is configured to, when the failure identification result is that the valve position feedback module is failed, determine a target cylinder pressure based on the target valve opening degree in a preset air pressure adjusting table, and adjust the valve opening degree based on the target cylinder pressure and the target air pressure adjusting driving amount, wherein the preset air pressure adjusting table is used to represent the valve opening degree corresponding to different cylinder pressures.

[0047] To achieve the above object and other related objects, the present application further provides a valve positioner comprising a memory and a processor, wherein the processor is configured to execute program instructions stored in the memory to implement one or more of the above-mentioned valve opening degree control methods.

[0048] As described above, the valve opening degree control method, device and valve positioner provided by the present application have the following beneficial effects:

[0049] The valve opening degree control method provided by the present application comprises the following steps: obtaining a target air pressure adjusting driving amount, adjusting a cylinder pressure based on a target valve opening degree and the target air pressure adjusting driving amount to adjust a valve opening degree in response to receiving the target valve opening degree, obtaining a current cylinder pressure and a current valve opening degree, identifying a failure of a valve position feedback module based on the current valve opening degree and the current cylinder pressure to obtain a failure identification result, determining a target cylinder pressure based on the target valve opening degree in a preset air pressure adjusting table when the failure identification result is that the valve position feedback module is failed, and adjusting the valve opening degree based on the target cylinder pressure and the target air pressure adjusting driving amount. Not only can the failure of the valve position feedback module be identified, but also the target cylinder pressure can be determined based on the target valve opening degree and the preset air pressure adjusting table when the valve position feedback module is failed, and the valve opening degree can be adjusted based on the target cylinder pressure, so that the reliability and stability of the valve opening degree control can be improved.

[0050] It should be understood that the general description above and the following detailed description are only exemplary and explanatory, and cannot limit the present application. BRIEF DESCRIPTION OF DRAWINGS

[0051] The drawings incorporated into the specification and forming a part thereof, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the application. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor. In the drawings:

[0052] Figure 1 is a schematic diagram of an implementation environment of the valve opening degree control method according to an exemplary embodiment of the present application;

[0053] Figure 2is a flow chart of a valve opening degree control method according to an example embodiment of the present application;

[0054] Figure 3 is a flow chart of a target air pressure adjustment driving amount acquisition according to an example embodiment of the present application;

[0055] Figure 4 is a flow chart of a valve opening degree control method according to another example embodiment of the present application;

[0056] Figure 5 is a structural block diagram of a valve opening degree control device according to an example embodiment of the present application. DETAILED DESCRIPTION

[0057] Other advantages and novel features of the present application will become apparent from the following detailed description of the application when considered in conjunction with the drawings. The application can be put into practice / implemented or applied in other different embodiments, and the details in the specification can be modified or changed based on different views and applications, without departing from the spirit of the present application. It should be understood that the preferred embodiments are only for illustrating the present application, and are not intended to limit the protection scope of the present application.

[0058] It should be noted that the diagrams provided in the following embodiments only schematically illustrate the basic concept of the present application, and only show the components related to the present application in the diagrams, rather than being drawn according to the number, shape and size of the components in actual implementation. The shape, number and proportion of the components in actual implementation can be arbitrarily changed, and the layout pattern of the components can be more complex.

[0059] In the following description, a large number of details are discussed to provide a more thorough explanation of the embodiments of the present application, however, it is obvious for those skilled in the art that the embodiments of the present application can be implemented without these specific details, and in other embodiments, the well-known structures and devices are shown in the form of block diagrams rather than in the form of details, to avoid making the embodiments of the present application difficult to understand.

[0060] Please refer to Figure 1 is a schematic diagram of an implementation environment of a valve opening degree control method according to an example embodiment of the present application. The implementation environment can include a valve positioner 110, a valve actuator 120, a pressure sensor 130, and a pneumatic valve 140.

[0061] The valve positioner 110 is composed of a control system module 111, an electrical conversion unit and a pneumatic amplifier module 112, and a valve position feedback module 113, forming a closed loop system. The valve positioner 110 can receive the target valve opening degree output by the field control room, and simultaneously monitor the current valve opening degree in real time through the valve position feedback module 113. The control system module 111 drives the electrical conversion unit and the pneumatic amplifier module 112 to intake or exhaust air, and controls the opening degree of the pneumatic valve 140 through the valve actuator 120.

[0062] The pressure sensor 130 can be installed at the interface of the valve actuator 120, and the signal is transmitted to the valve positioner 110 through a cable. The pressure sensor 130 can also be embedded in the valve positioner 110. The pressure sensor 130 can obtain the cylinder pressure and feed back the cylinder pressure to the valve positioner 110.

[0063] Please refer to Figure 2 , Figure 2 is a flow chart of a valve opening degree control method according to an example embodiment of the present application. The valve opening degree control method can be applied to the implementation environment shown in Figure 1 It can be seen that the valve opening degree control method can include: Figure 2

[0064] Step S210, obtaining a target air pressure adjustment driving amount.

[0065] In a possible implementation, the target air pressure adjustment driving amount can be obtained. The target air pressure adjustment driving amount can drive the positioner output to adjust the cylinder pressure, thereby adjusting the valve opening degree.

[0066] Optionally, in an example embodiment, the step S210 of obtaining the target air pressure adjustment driving amount can include:

[0067] Step S211, valve adjustment step: obtaining an initial air pressure adjustment driving amount, an initial valve opening degree, an expected valve opening degree, and a preset air pressure adjustment table, determining a cylinder pressure adjustment value in the preset air pressure adjustment table based on the initial valve opening degree and the expected valve opening degree, and adjusting the valve opening degree based on the cylinder pressure adjustment value and the initial air pressure adjustment driving amount.

[0068] ​In a possible implementation, the valve adjustment step can be performed after the preset air pressure adjustment table calibration is completed. When the valve adjustment step is performed, the valve adjustment step can be completed by starting from the initial air pressure adjustment driving amount and reaching the target valve opening degree. The initial air pressure adjustment driving amount when the valve adjustment step is performed for the first time can be determined based on expert experience. Since the preset air pressure adjustment table represents the valve opening degrees corresponding to different cylinder pressures, the initial valve opening degree corresponds to the first cylinder pressure, and the expected valve opening degree corresponds to the second cylinder pressure, the difference between the second cylinder pressure and the first cylinder pressure can be the cylinder pressure adjustment value.

[0069] In step S212, a system parameter updating step is performed. The actual valve opening degree is obtained, and when it is detected that the actual valve opening degree does not change for three times in succession, the overshoot times or the undershoot times are updated based on the actual valve opening degree and the expected valve opening degree.

[0070] It should be noted that when the actual valve opening degree does not change for three times in succession, it can be considered that the valve control has reached a stable state. The actual valve opening degree does not change for three times in succession means that the actual valve opening degrees are the same for three times in succession.

[0071] For example, for the case where the expected valve opening degree is greater than the initial valve opening degree, if, during the valve adjustment step, the actual valve opening degree is greater than the expected valve opening degree and the difference (which can be the absolute value of the difference between the actual valve opening degree and the expected valve opening degree) exceeds 1%, the overshoot times are increased by 1; if the final actual valve opening degree is less than the expected valve opening degree and the difference exceeds 1%, the undershoot times are increased by 1. For the case where the expected valve opening degree is less than the initial valve opening degree, if, during the valve adjustment step, the actual valve opening degree is less than the expected valve opening degree and the difference exceeds 1%, the overshoot times are increased by 1; if the final actual valve opening degree is greater than the expected valve opening degree and the difference exceeds 1%, the undershoot times are increased by 1.

[0072] In step S213, a valve parameter updating step is performed. The expected valve opening degree is compared with the preset valve opening degree. If the expected valve opening degree is consistent with the preset valve opening degree, the system parameter determination step is performed; if the expected valve opening degree is not consistent with the preset valve opening degree, the expected valve opening degree is taken as the updated initial valve opening degree, and the sum and / or difference between the expected valve opening degree and the preset value is taken as the updated expected valve opening degree, and the valve adjustment step and the value determination step are repeatedly performed.

[0073] For example, the initial valve opening degree when the valve adjustment step is performed for the first time can be 0%, and the preset valve opening degree can be 0%. That is, the valve opening degree can be increased from 0% to 100%, and then decreased from 100% to 0%, so that the system parameter determination step can be performed. The expected valve opening degree can be obtained by increasing the initial valve opening degree by 10%.

[0074] In step S214, a system parameter determining step is performed. It is determined whether the overshoot times and the undershoot times belong to a preset interval. If the overshoot times and the undershoot times belong to the preset interval, the initial air pressure adjustment driving amount is determined as the target air pressure adjustment driving amount. If the overshoot times and the undershoot times do not belong to the preset interval, the initial air pressure adjustment driving amount is updated based on the overshoot times, the undershoot times, and a preset driving amount adjustment strategy. An updated initial air pressure adjustment driving amount is obtained. The valve adjustment step, the system parameter updating step, the valve parameter updating step, and the system parameter determining step are repeatedly performed based on the updated initial air pressure adjustment driving amount.

[0075] In a possible implementation, if the overshoot times are greater than or equal to a first preset value, the initial air pressure adjustment driving amount is reduced based on a first preset driving amount. If the overshoot times are greater than or equal to a second preset value and less than the first preset value, the initial air pressure adjustment driving amount is reduced based on a second preset driving amount. If the overshoot times are greater than a third preset value and less than the second preset value, the initial air pressure adjustment driving amount is reduced based on a third preset driving amount. If the undershoot times are greater than or equal to the first preset value, the initial air pressure adjustment driving amount is increased based on the first preset driving amount. If the undershoot times are greater than or equal to the second preset value and less than the first preset value, the initial air pressure adjustment driving amount is increased based on the second preset driving amount. If the undershoot times are greater than the third preset value and less than the second preset value, the initial air pressure adjustment driving amount is increased based on the third preset driving amount.

[0076] For example, Figure 3Fig. 2 is a flowchart of a process of obtaining a target air pressure adjustment driving amount, which is shown as an example of the present application. The process of obtaining the target air pressure adjustment driving amount can include: after the valve positioner completes the regular self-tuning, controlling the valve action with a 10% step signal, the valve opening degree positive action from 0% to 100%, and then the negative action from 100% to 0%, the valve position feedback module signal derived from the air cylinder pressure signal, first adjusting the air cylinder pressure with the initial air pressure adjustment driving amount, monitoring the control effect of each valve opening degree of the positive action and the negative action, recording the overshoot number C or the undershoot number Q, every overshoot 1 time, the overshoot number C+1, every undershoot 1 time, the undershoot number Q+1, the valve running a complete round, and the number statistics determining that if the overshoot number is greater than or equal to 10, the initial air pressure adjustment driving amount is reduced by 10%, obtaining the updated initial air pressure adjustment driving amount; if the overshoot number is less than 10 and greater than or equal to 3, the initial air pressure adjustment driving amount is reduced by 6%, obtaining the updated initial air pressure adjustment driving amount; if the overshoot number is less than 3 and greater than 1, the initial air pressure adjustment driving amount is reduced by 2%, obtaining the updated initial air pressure adjustment driving amount; and if the overshoot number is less than or equal to 1, the initial air pressure adjustment driving amount remains unchanged. Similarly, if the undershoot number is greater than or equal to 10, the initial air pressure adjustment driving amount is increased by 10%, obtaining the updated initial air pressure adjustment driving amount; if the undershoot number is less than 10 and greater than or equal to 3, the initial air pressure adjustment driving amount is increased by 6%, obtaining the updated initial air pressure adjustment driving amount; if the undershoot number is less than 3 and greater than 1, the initial air pressure adjustment driving amount is increased by 2%, obtaining the updated initial air pressure adjustment driving amount; and if the undershoot number is less than or equal to 1, the initial air pressure adjustment driving amount remains unchanged. If both the overshoot number and the undershoot number are less than or equal to 1, the self-tuning is completed, and the target air pressure adjustment driving amount is obtained.

[0077] It should be noted that the regular control method based on the valve position feedback module requires stable, accurate and fast valve control. However, the irregular control method based on the air cylinder pressure of the valve actuator as the valve position feedback mainly ensures stability and accuracy, and does not require speed. Within the error allowable range (such as ±2%), overshoot or undershoot is not allowed. The target is to ensure that the valve runs into the control error allowable range of the target valve opening degree once, and no adjustment is made.

[0078] Step S220, in response to receiving the target valve opening degree, adjusting the air cylinder pressure based on the target valve opening degree and the target air pressure adjustment driving amount to adjust the valve opening degree.

[0079] In a possible implementation, in response to receiving the target valve opening degree, the cylinder pressure is adjusted based on the target valve opening degree and the target air pressure to adjust the valve opening degree. When step S220 is performed, the valve opening degree can be adjusted based on the valve position feedback module, that is, the valve position feedback module monitors the actual valve opening degree of the valve in real time, and the control system module drives the electrical conversion unit and the pneumatic amplifier to intake or exhaust air according to the actual valve opening degree and the target valve opening degree to control the size of the pneumatic valve opening degree.

[0080] In step S230, the current cylinder pressure and the current valve opening degree are obtained, and valve position feedback module failure identification is performed based on the current valve opening degree and the current cylinder pressure to obtain a failure identification result.

[0081] In a possible implementation, in the process of adjusting the valve opening degree, the current cylinder pressure and the current valve opening degree can be obtained, and valve position feedback module failure identification is performed based on the current valve opening degree and the current cylinder pressure to obtain a failure identification result.

[0082] It should be noted that when the valve position feedback module is determined to be invalid based on the target valve opening degree adjusting the valve opening degree, in subsequent adjustment of the valve opening degree based on the target valve opening degree, the target cylinder pressure can be determined based on the target valve opening degree in the preset air pressure adjustment table, and the valve opening degree can be adjusted based on the target cylinder pressure and the target air pressure adjustment driving amount.

[0083] Further, the first identification result is determined based on the current valve opening degree and the preset opening degree interval, the pressure interval is determined based on the current valve opening degree, and the second identification result is determined based on the current cylinder pressure and the pressure interval. When the first identification result and the second identification result are both normal, the failure identification result is that the valve position feedback module is valid; when the first identification result and / or the second identification result is abnormal, the failure identification result is that the valve position feedback module is invalid.

[0084] Optionally, in an example embodiment, the process of determining the first identification result based on the current valve opening degree and the preset opening degree interval can include that, when the current valve opening degree belongs to the preset opening degree interval, the first identification result is normal; and when the current valve opening degree does not belong to the preset opening degree interval, the first identification result is abnormal.

[0085] In a possible implementation, the sensor signal of the valve position feedback module is generally a voltage signal, and the valve positioner has identified the voltage signals of the full open position and the full closed position of the valve after self-tuning. After digital processing of the signal, a digital valve opening degree signal of 0%-100% is obtained, and there is generally a valve opening degree safety interval. If the actual detected current valve opening degree is greater than the maximum valve opening degree+the safety interval or less than the minimum valve opening degree-the safety interval, it can be determined that the first identification result is an identification anomaly.

[0086] For example, the valve opening degree safety interval can be 5%, and the preset opening degree interval can be [5%, 105%].

[0087] Optionally, in an example embodiment, based on the current cylinder pressure and the pressure interval, the process of determining the second identification result can include obtaining the positive stroke cylinder pressure and the reverse stroke cylinder pressure based on the current valve opening degree; determining the pressure interval based on the positive stroke cylinder pressure and the reverse stroke cylinder pressure; if the current cylinder pressure belongs to the pressure interval, determining that the second identification result is normal; and if the current cylinder pressure does not belong to the pressure interval, determining that the second identification result is an identification anomaly.

[0088] When controlling the valve opening degree, the cylinder pressure corresponding to the same valve opening degree is generally between the positive stroke and reverse stroke cylinder pressure values corresponding to the valve opening degree, such as PPIN-x% to PPOUT-x% (x% is the current valve opening degree), and there is generally a pressure safety value. If the actual detected current cylinder pressure corresponding to the current valve opening degree is greater than the maximum cylinder pressure corresponding to the current valve opening degree+the maximum cylinder pressure*the pressure safety value or less than the minimum cylinder pressure corresponding to the current valve opening degree-the minimum cylinder pressure*the pressure safety value, it can be determined that the second identification result is an identification anomaly. The maximum cylinder pressure and the minimum cylinder pressure corresponding to the current valve opening degree are determined in the positive stroke cylinder pressure and the reverse stroke cylinder pressure corresponding to the current valve opening degree.

[0089] For example, the pressure safety value can be 20%, and the pressure interval can be [the minimum cylinder pressure corresponding to the current valve opening degree-the minimum cylinder pressure*the pressure safety value, the maximum cylinder pressure corresponding to the current valve opening degree+the maximum cylinder pressure*the pressure safety value].

[0090] Step S240, when the failure identification result is that the valve position feedback module fails, determining a target cylinder pressure based on the target valve opening degree in a preset pressure adjustment table, and adjusting the valve opening degree based on the target cylinder pressure and the target pressure adjustment driving amount 。

[0091] The preset pressure adjustment table is used to represent the valve opening degree corresponding to different cylinder pressures.

[0092] In a possible implementation, when the failure identification result is that the valve position feedback module is failed, the target cylinder pressure can be determined based on the target valve opening in the preset air pressure adjustment table, and the valve opening is adjusted based on the target cylinder pressure and the target air pressure adjustment driving amount.

[0093] Further, the valve stroke is determined according to the target valve opening and the current valve opening, the valve stroke includes a positive stroke or a reverse stroke; if the valve stroke is the positive stroke, the valve opening is adjusted according to the target air pressure adjustment driving amount, the target valve opening and the first preset air pressure adjustment table; if the valve stroke is the reverse stroke, the valve opening is adjusted according to the target air pressure adjustment driving amount, the target valve opening and the second preset air pressure adjustment table.

[0094] It should be noted that when the failure identification result is that the valve position feedback module is failed, the valve opening can be first reset to zero, then the target cylinder pressure is determined based on the target valve opening in the preset air pressure adjustment table, and the valve opening is adjusted based on the target cylinder pressure and the target air pressure adjustment driving amount.

[0095] In an example embodiment, please refer to Figure 4 which is a flowchart of a valve opening control method according to another example embodiment of the present application, and refer to Figure 4 It can be seen that the valve opening control method provided by the embodiments of the present application can further include steps S410 and S420.

[0096] In step S410, when the identification result is that the valve position feedback module is valid, the actual cylinder pressure corresponding to the target valve opening is obtained in response to the current valve opening being consistent with the target valve opening.

[0097] In a possible implementation, when the identification result is that the valve position feedback module is valid, the actual cylinder pressure corresponding to the target valve opening is obtained in response to the current valve opening being consistent with the target valve opening.

[0098] In step S420, the preset air pressure adjustment table is updated based on the actual cylinder pressure and the target valve opening.

[0099] In a possible implementation, the preset air pressure adjustment table is updated based on the actual cylinder pressure and the target valve opening.

[0100] For example, the calibration of the preset air pressure adjustment table is divided into two stages of initial calibration and later running correction with load.

[0101] The initial pressure calibration is completed when the valve positioner is self-tuned in the early stage, and the calibration of the cylinder pressure corresponding to the valve opening is more intensive to improve accuracy, and the positive stroke and the reverse stroke are distinguished. After running online with load in the later stage, offset correction is performed, and the specific method is as follows:

[0102] Firstly, the valve positioner has completed the self-tuning calibration control based on the conventional valve position feedback module sensor, the valve positioner has been able to achieve normal valve opening control, and the full stroke control accuracy is less than 0.5%. At this time, the valve opening and cylinder pressure calibration is carried out, the conventional control means based on the conventional valve position feedback module sensor is adopted, the valve opening is controlled to 0% by the valve positioner, after the valve opening is stable, the value is recorded as V0%, at this time, the cylinder pressure value is recorded as PIN-0%, then the valve opening is controlled to 2%, 5%, 10%, 15%, 20%...95%, 98%, 100% by the valve positioner, after the valve opening is stable, the cylinder pressure corresponding to the valve opening is recorded respectively. Then the valve opening is controlled to 98% by the valve positioner, after the valve opening is stable, the cylinder pressure recorded at this time is recorded as POUT-98%, then the valve opening is controlled to 95%, 90%...10%, 5% and 2% by the valve positioner. After the valve opening is stable, the cylinder pressure corresponding to the valve opening is recorded respectively. The cylinder pressure corresponding to other valve openings is segmented linearized, thereby achieving the pressure calibration of the full stroke with an interval of 1%. Finally, the preset air pressure adjustment table after the calibration is completed can be saved to the EEPROM storage space in the MCU, and is read and called during actual operation.

[0103] When the valve is actually operated with medium in the later stage, at this time, the valve positioner is normally controlled based on the conventional valve position feedback module sensor, due to the influence of the increase of medium force or the change of packing friction, when the positive or negative effect reaches a certain valve opening, the corresponding cylinder pressure may deviate from the initial calibrated value, at this time, the cylinder pressure value of the valve opening needs to be recorded. Because there may be no opportunity to calibrate all valve openings after loading, the corresponding cylinder pressure needs to be tested and recorded according to the actual valve opening, the deviation of the valve opening not tested and recorded is segmented linearized to obtain the full stroke cylinder pressure value combined with the collected data. If used later, the cylinder pressure value with load is used as the valve opening feedback signal. The data is calculated and updated at the same time as the valve positioner is running, and the data is saved to the EEPROM storage space in the MCU in real time, and is read and called when needed during actual operation. The preset air pressure adjustment table is shown in Table 1.

[0104] Table 1: Preset air pressure adjustment table

[0105]

[0106] In summary, the scheme of the embodiment of the present application obtains a target air pressure adjustment driving amount, adjusts the cylinder pressure based on the target valve opening degree and the target air pressure adjustment driving amount to adjust the valve opening degree in response to receiving the target valve opening degree, obtains the current cylinder pressure and the current valve opening degree, and performs valve position feedback module failure identification based on the current valve opening degree and the current cylinder pressure to obtain a failure identification result. When the failure identification result is that the valve position feedback module is failed, the target cylinder pressure is determined in the preset air pressure adjustment table based on the target valve opening degree, and the valve opening degree is adjusted based on the target cylinder pressure and the target air pressure adjustment driving amount. Not only can the valve position feedback module be identified for failure, but also when the valve position feedback module is failed, the target cylinder pressure can be determined through the target valve opening degree and the preset air pressure adjustment table, and the valve opening degree is adjusted through the target cylinder pressure. In this way, the valve opening degree control reliability and stability can be improved.

[0107] Figure 5 is a block diagram of a valve opening degree control device shown by an example embodiment of the present application. As shown in Figure 5 , the example valve opening degree control device 500 includes:

[0108] A data acquisition module 510 is configured to obtain a target air pressure adjustment driving amount, the target air pressure adjustment driving amount being used to adjust the cylinder pressure and in turn adjust the valve opening degree.

[0109] A first adjustment module 520 is configured to adjust the cylinder pressure based on the target valve opening degree and the target air pressure adjustment driving amount to adjust the valve opening degree in response to receiving the target valve opening degree.

[0110] An identification module 530 is configured to obtain the current cylinder pressure and the current valve opening degree, and perform valve position feedback module failure identification based on the current valve opening degree and the current cylinder pressure to obtain a failure identification result.

[0111] A second adjustment module 540 is configured to determine the target cylinder pressure in a preset air pressure adjustment table based on the target valve opening degree when the failure identification result is that the valve position feedback module is failed, and adjust the valve opening degree based on the target cylinder pressure and the target air pressure adjustment driving amount. The preset air pressure adjustment table is used to represent the valve opening degree corresponding to different cylinder pressures.

[0112] It should be noted that the valve opening degree control device provided in the above-mentioned embodiments and the valve opening degree control method provided in the above-mentioned embodiments belong to the same concept, and the specific manner in which each module and unit performs operations has been described in detail in the method embodiments, which will not be repeated here. The valve opening degree control device provided in the above-mentioned embodiments can be used in actual applications, and the above-mentioned functions can be completed by different functional modules according to the needs, that is, the internal structure of the system is divided into different functional modules to complete all or part of the functions described above, and this is not limited herein.

[0113] Embodiments of the present application also provide a valve positioner, comprising: one or more processors; a memory for storing one or more programs, when the one or more programs are executed by the one or more processors, the valve positioner implements the valve opening degree control method provided in each of the above-mentioned embodiments.

[0114] In the embodiments of the present application, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance. "Include" and "comprise" mentioned throughout the specification and claims are open terms, and should be interpreted as "including but not limited to".

[0115] The above-mentioned embodiments only exemplarily illustrate the principles and effects of the present application, and are not used to limit the present application. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical thought of the present application should be covered by the claims of the present application.

Claims

1. A valve opening control method, characterized in that, include: The target air pressure regulation driving amount is obtained, and the target air pressure regulation driving amount is used to adjust the cylinder pressure, thereby adjusting the valve opening. In response to receiving a target valve opening, the cylinder pressure is adjusted based on the target valve opening and the target air pressure regulation drive amount to adjust the valve opening; The current cylinder pressure and current valve opening are obtained, and the valve position feedback module failure is identified based on the current valve opening and current cylinder pressure to obtain the failure identification result; When the failure identification result is that the valve position feedback module has failed, the target cylinder pressure is determined based on the target valve opening in the preset air pressure adjustment table, and the valve opening is adjusted based on the target cylinder pressure and the target air pressure adjustment drive amount. The preset air pressure adjustment table is used to characterize the valve opening corresponding to different cylinder pressures. Obtain the target pressure regulation driving quantity, including: Valve adjustment steps: Obtain the initial air pressure adjustment drive amount, initial valve opening, desired valve opening, and preset air pressure adjustment table; determine the cylinder pressure adjustment value based on the initial valve opening and the desired valve opening in the preset air pressure adjustment table; and adjust the valve opening based on the cylinder pressure adjustment value using the initial air pressure adjustment drive amount. System parameter update steps: Obtain the actual valve opening; when the actual valve opening remains unchanged for three consecutive times, update the overshoot count or undershoot count based on the actual valve opening and the expected valve opening. Valve parameter update steps: Compare the desired valve opening with the preset valve opening. If the desired valve opening matches the preset valve opening, then execute the system parameter determination step. If the desired valve opening does not match the preset valve opening, then use the desired valve opening as the updated initial valve opening, and use the sum and / or difference between the desired valve opening and the preset value as the updated desired valve opening. Repeat the valve adjustment step and the value determination step. System parameter determination steps: Determine whether the number of overshoots and undershoots belong to a preset range. If the number of overshoots and undershoots belong to the preset range, then the initial air pressure regulation driving quantity is determined as the target air pressure regulation driving quantity. If neither the number of overshoots nor the number of undershoots belongs to the preset range, then based on the number of overshoots, undershoots, and the preset driving quantity adjustment strategy, the initial air pressure regulation driving quantity is updated to obtain the updated initial air pressure regulation driving quantity. Based on the updated initial air pressure regulation driving quantity, the valve adjustment step, the system parameter update step, the valve parameter update step, and the system parameter determination step are repeated. Based on the overshoot count, undershoot count, and preset drive quantity adjustment strategy, the initial pressure regulation drive quantity is updated to obtain the updated initial pressure regulation drive quantity, including: If the number of overshoots is greater than or equal to the first preset value, then the initial air pressure regulation driving amount is reduced based on the first preset driving amount; If the number of overshoots is greater than or equal to the second preset value, and the number of overshoots is less than the first preset value, then the initial air pressure regulation driving amount is reduced based on the second preset driving amount. If the number of overshoots is greater than the third preset value and less than the second preset value, then the initial air pressure regulation driving amount is reduced based on the third preset driving amount; If the number of under-adjustment cycles is greater than or equal to the first preset value, then the initial air pressure adjustment driving amount is increased based on the first preset driving amount. If the number of under-adjustment counts is greater than or equal to the second preset value, and the number of over-adjustment counts is less than the first preset value, then the initial air pressure regulation driving amount is increased based on the second preset driving amount. If the number of under-adjustment counts is greater than the third preset value and less than the second preset value, then the initial air pressure adjustment driving amount is increased based on the third preset driving amount.

2. The valve opening control method according to claim 1, characterized in that, Adjusting the valve opening based on the target air pressure regulation drive amount, the target valve opening, and the preset air pressure regulation gauge includes: The valve stroke is determined based on the target valve opening and the current valve opening, and the valve stroke includes forward stroke or reverse stroke; If the valve stroke is a positive stroke, the valve opening is adjusted according to the target air pressure adjustment drive amount, the target valve opening, and the first preset air pressure adjustment table; If the valve stroke is a reverse stroke, the valve opening is adjusted according to the target air pressure adjustment drive amount, the target valve opening, and the second preset air pressure adjustment gauge.

3. The valve opening control method according to claim 1, characterized in that, The method further includes: When the identification result indicates that the valve position feedback module is valid, in response to the current valve opening being consistent with the target valve opening, the actual cylinder pressure corresponding to the target valve opening is obtained; The preset air pressure adjustment table is updated based on the actual cylinder pressure and the target valve opening.

4. The valve opening control method according to claim 1, characterized in that, Based on the current valve opening and the current cylinder pressure, a valve position feedback module failure identification is performed to obtain the failure identification result, including: Based on the current valve opening degree and the preset opening range, a first identification result is determined; The pressure range is determined based on the current valve opening, and a second identification result is determined based on the current cylinder pressure and the pressure range. When both the first identification result and the second identification result are normal, the failure identification result indicates that the valve position feedback module is effective; When the first identification result and / or the second identification result is an identification anomaly, the failure identification result is that the valve position feedback module has failed.

5. The valve opening control method according to claim 4, characterized in that, Based on the current valve opening degree and the preset opening degree range, a first identification result is determined, including: If the current valve opening degree falls within the preset opening degree range, the first identification result is considered normal. If the current valve opening does not belong to the preset opening range, the first identification result is an identification anomaly.

6. The valve opening control method according to claim 5, characterized in that, Based on the current valve opening, a pressure range is determined, and based on the current cylinder pressure and the pressure range, a second identification result is determined, including: The forward stroke cylinder pressure and the reverse stroke cylinder pressure are obtained based on the current valve opening. The pressure range is determined based on the forward stroke cylinder pressure and the reverse stroke cylinder pressure; If the current cylinder pressure falls within the pressure range, then the second identification result is determined to be normal. If the current cylinder pressure does not belong to the pressure range, then the second identification result is determined to be an identification anomaly.

7. A valve opening control device, characterized in that, include: The data acquisition module is used to acquire the target air pressure adjustment driving amount, which is used to adjust the cylinder pressure and thus adjust the valve opening. Obtaining the target air pressure regulation drive quantity includes: Valve adjustment step: obtaining the initial air pressure regulation drive quantity, initial valve opening, desired valve opening, and preset air pressure regulation table; determining the cylinder pressure regulation value based on the initial valve opening and the desired valve opening in the preset air pressure regulation table; adjusting the valve opening based on the cylinder pressure regulation value using the initial air pressure regulation drive quantity; System parameter update step: obtaining the actual valve opening; when the actual valve opening is detected to remain unchanged for three consecutive times, updating the overshoot count or undershoot count based on the actual valve opening and the desired valve opening; Valve parameter update step: comparing the desired valve opening with the preset valve opening; if the desired valve opening... If the valve opening matches the preset valve opening, the system parameter determination step is executed. If the desired valve opening does not match the preset valve opening, the desired valve opening is used as the updated initial valve opening, and the sum / or difference between the desired valve opening and the preset value is used as the updated desired valve opening. The valve adjustment step and the value determination step are repeated. The system parameter determination step: determines whether the overshoot count and the undershoot count belong to a preset range. If the overshoot count and the undershoot count belong to the preset range, the initial air pressure regulation drive quantity is determined as the target air pressure regulation drive quantity. If neither the overshoot count nor the undershoot count belongs to the preset range, the initial air pressure regulation drive quantity is determined based on the overshoot count. The initial air pressure regulation drive quantity is updated based on the overshoot count, undershoot count, and preset drive quantity adjustment strategy to obtain an updated initial air pressure regulation drive quantity. The valve adjustment step, system parameter update step, valve parameter update step, and system parameter determination step are then repeatedly executed based on the updated initial air pressure regulation drive quantity. The update of the initial air pressure regulation drive quantity based on the overshoot count, undershoot count, and preset drive quantity adjustment strategy includes: if the overshoot count is greater than or equal to a first preset value, then the initial air pressure regulation drive quantity is reduced based on the first preset drive quantity; if the overshoot count is greater than or equal to a second preset value, and the overshoot count... If the number of overshoots is less than the first preset value, then the initial air pressure regulation driving amount is reduced based on the second preset driving amount; if the number of overshoots is greater than the third preset value and less than the second preset value, then the initial air pressure regulation driving amount is reduced based on the third preset driving amount; if the number of undershoots is greater than or equal to the first preset value, then the initial air pressure regulation driving amount is increased based on the first preset driving amount; if the number of undershoots is greater than or equal to the second preset value and the number of overshoots is less than the first preset value, then the initial air pressure regulation driving amount is increased based on the second preset driving amount; if the number of undershoots is greater than the third preset value and less than the second preset value, then the initial air pressure regulation driving amount is increased based on the third preset driving amount. The first adjustment module is used to adjust the cylinder pressure based on the target valve opening and the target air pressure adjustment drive amount in response to receiving the target valve opening, so as to adjust the valve opening. The identification module is used to acquire the current cylinder pressure and the current valve opening, and to identify the failure of the valve position feedback module based on the current valve opening and the current cylinder pressure, so as to obtain the failure identification result. The second adjustment module is used to determine the target cylinder pressure based on the target valve opening in a preset air pressure adjustment table when the failure identification result is that the valve position feedback module has failed, and to adjust the valve opening based on the target cylinder pressure and the target air pressure adjustment drive amount. The preset air pressure adjustment table is used to characterize the valve opening corresponding to different cylinder pressures.

8. A valve positioner, characterized in that, The device includes a memory and a processor, the processor being configured to execute program instructions stored in the memory to implement the valve opening control method according to any one of claims 1 to 6.

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