JP2015535061A - How to calibrate an instrument attached to a valve - Google Patents

Abstract

A method for calibrating an instrument attached to a valve, such as a position controller and / or position transmitter, is described. An example method disclosed herein includes fixing the position of the flow control member of the control valve assembly to prevent movement of the flow control member and installing a controller in the control valve assembly. The method activates a user interface of the controller after the controller is coupled to the control valve assembly, and inputs a position sensor sensitivity value and a single point position value that represents a fixed position of the flow control member. Applying a single-point calibration value, placing the controller in control mode, and releasing the position of the flow control member so that the controller can detect position sensor sensitivity values and single values while the control valve assembly is in operation. Self-calibrating during operation of the control valve assembly based on the single point position value.

Description

  This disclosure relates generally to valves and, more particularly, to methods, apparatus and products for calibrating instruments attached to valves.

  A process plant element, such as a valve, is typically an attached instrument such as a valve position controller and / or position transmitter that controls the element and / or transmits information about the element, Associated with an instrument that performs one or more desired process (s) and / or operations (s) within the process plant. Exemplary valve assemblies include diaphragm or piston type pneumatic actuators that are controlled by an electropneumatic valve position controller. An electropneumatic valve position controller example receives one or more control signals (e.g., a 4-20 milliamp (mA) control signal, a 0-10 volt direct current (VDC) control signal, a digital control signal, etc.), The control signal (s) is converted into one or more pneumatic pressures provided to the pneumatic actuator to open, close or hold the corresponding valve position. For example, if a process control routine determines that an air-operated normally closed stroke valve will allow a larger amount and / or rate of process fluid flow to pass, it is associated with the valve. The magnitude of the control signal supplied to the selected electropneumatic valve position controller can be increased from 4 mA to 8 mA, assuming the use of the current type of control signal.

In some examples, the electropneumatic valve position controller uses a feedback signal generated by a feedback sensing system or element, eg, a position sensor. Such a feedback signal represents the position of the pneumatic actuator and the corresponding valve. The valve position controller compares the feedback signal with a control signal representing a desired set point or desired valve position (eg, 35% opening) to determine whether to adjust one or more of the air pressures provided to the actuator. decide. In order for the valve position controller, actuator and valve combination to operate as intended in the process plant, the valve position controller may need to be calibrated to the feedback sensing element.

  Disclosed are methods, apparatus and product examples for calibrating instruments attached to valves, such as position controllers and / or position transmitters. Example methods disclosed herein include fixing the position of the flow control member of the control valve assembly to prevent movement of the flow control member and installing a controller in the control valve assembly. The method inputs a controller user interface after the controller is coupled to the control valve assembly, a position sensor sensitivity value, and a single point position value representing a fixed position of the flow control member. Applying a single point calibration value, placing the controller in control mode, and releasing the position of the flow control member so that the controller can detect the position sensor sensitivity value while the control valve assembly is operating. And self-calibrating during operation of the control valve assembly based on the single point position value.

An example method disclosed herein couples a controller to a control valve assembly while the control valve assembly is in service or inline using a process control system and provides position sensor sensitivity values to the controller. Providing a single point position value representative of the current position of the flow control member of the control valve assembly, and based on the position sensor sensitivity value and the single point position value, a first travel span limit of the flow control member And an estimated lower stroke limit value representative of the second travel span limit of the flow control member, and the operation of the control valve assembly causes fluid flow in the process control system. Operate the controller to enable control so that the controller Including, the method comprising calibrated during operation of the control valve assembly based sensitivity values and a single point position value.

  The example method disclosed herein locks the position of the flow control member of the control valve assembly while the valve control assembly is in the fluid system and initiates calibration of the controller that operates the control valve assembly. Inputting a predetermined position sensor sensitivity value to the controller via a user interface; inputting a single point position value representing a locked position of the flow control member relative to the movement span of the flow control member; Obtaining upper and lower calibration values estimated from the controller based on the position sensor sensitivity value and the single point position value; and inputting the estimated upper and lower calibration values via a user interface; Activating the controller and the flow control member Unlocking, allowing the control valve assembly to control the fluid system, allowing the controller to calibrate based on single point position values, position sensor sensitivity values, and estimated upper and lower calibration values; ,including.

1 illustrates an example valve device having a valve position controller that can be calibrated using the methods and example devices described herein. 2 depicts an example state of the example valve assembly of FIG. 2 depicts an example state of the example valve assembly of FIG. 2 depicts an example state of the example valve assembly of FIG. 2 illustrates an example calibration operation that may be performed by the example valve position controller of FIG. 2 illustrates an example calibration operation that may be performed by the example valve position controller of FIG. 2 illustrates an example calibration operation that may be performed by the example valve position controller of FIG. 2 illustrates an example technique for implementing the example valve position controller of FIG. FIG. 7 illustrates an example process that may be performed to install the example valve position controller of FIGS. 7 illustrates an example process that may be performed to calibrate and / or perform the example valve position controller of FIGS. 7 illustrates an example process that may be performed to calibrate and / or perform the example valve position controller of FIGS. 7 illustrates an example process that may be performed to calibrate and / or perform the example valve position controller of FIGS. 7 illustrates an example process that may be performed to calibrate and / or perform the example valve position controller of FIGS. 1 illustrates an example valve device having a position transmitter that can be calibrated using the methods and example devices described herein. 13 illustrates an example technique for implementing the example position transmitter of FIG. 14 illustrates an example process that may be performed to install the example position transmitter of FIGS. 14 illustrates an example process that may be performed to calibrate and / or perform the example position transmitter of FIGS. To implement the example processes of FIGS. 7-11, 14 and 15, and / or more generally, the example valve position controller of FIGS. 1 and 6 and / or the example of position transmitter of FIGS. FIG. 6 is a schematic diagram of an example processor platform that can be used and / or programmed for.

  To calibrate some valves, between one extreme travel end point or position (eg fully open position) and the other extreme travel end point or position (eg fully closed position) It is necessary to stroke the valve. However, such methods are disadvantageous because they require that the valve be taken out of service or taken offline to stroke the valve sufficiently. However, in some instances, the process system cannot be interrupted or shut down to facilitate calibration of the valve position controller and / or position transmitter. Even when the process system can be interrupted, such interruptions can have undesirable monetary and / or efficiency effects. While the bypass line can be used to isolate the valve and keep the process system online, the bypass line is not necessarily desirable, available, or suitable.

  Additionally or alternatively, some valve position controllers and / or position transmitters are valves, actuators and position sensors, with which the valve position controller and / or position transmitter will be installed. Valves, actuators and position sensors can be calibrated using benches, test or calibration valves, actuators and position sensors having substantially similar or identical characteristics (eg, stroke length, end of travel, etc.). Test valves, actuators and position sensors can be located, for example, in a maintenance shop or laboratory located remotely from the actual process plant. In a laboratory or store, test valves, actuators, and position sensors can be fully or fully stroked to calibrate new and / or replacement valve position controllers and / or position transmitters. After calibration, the calibrated valve position controller and / or position transmitter is removed from the test setup and operably coupled or attached to the target valve actuator in the process plant. While effective, such calibration methods can be time consuming and require the availability of appropriate test devices.

In order to overcome at least these drawbacks, the example valve position controller and position transmitter described herein provides the current position (e.g., valve, actuator and position sensor considered collectively) of the valve assembly (e.g., A single externally provided position value representing an estimate of the current position at which the valve position controller is installed, installed and / or will be installed. Can be self-calibrated. In the examples described herein, additional position values need not be provided to the valve position controller or position transmitter prior to operation of the valve position controller or position transmitter in the process plant. The single position value can be easily and / or easily determined by the installer, eg, by visually inspecting and / or measuring the current position of the valve assembly during installation of the valve position controller, and Or may be estimated. The installer inputs and / or provides the measured or estimated current position value to the valve position controller or position transmitter, for example using a user interface. Based on the measured or estimated current position value provided, the example valve position controller and position transmitter described herein can be used during subsequent operation of the valve assembly in an operating process plant. Learn, fit and / or self-calibrate. Accordingly, the method and apparatus for calibrating a valve position controller and position transmitter described herein can stroke, adjust or reposition a valve without taking the relevant parts of the process plant offline or out of service. It can be used with no need, no need for bypass lines, and no need for bench, test or calibration valve assemblies.

  FIG. 1 illustrates an example valve device 100 that includes a valve assembly 102 configured in accordance with the teachings of this disclosure and a valve position controller 104. Although an example method and apparatus for calibrating a valve position controller will be described with reference to the example valve assembly 102 of FIG. 1, the example methods and apparatus described herein may include any number and / or (multiple It should be understood that it can be used to calibrate a valve position controller for use with additional or alternative valve assemblies. For example, the valve 106 depicted in FIG. 1 is a slide-type stem control valve, but the method and apparatus for calibrating the valve position controller is not limited, but includes a rotation control valve, 1/4 rotation control. It may be used with any other type (s) of valves including valves and the like. Additionally or alternatively, the example actuator 108 of FIG. 1 is depicted as a double-acting piston actuator, but any other type of actuator, such as a rotary actuator, a single-acting spring return diaphragm Or a piston actuator or the like may alternatively be used. The single position value calibration methods and apparatus described herein may be any number and / or type (s), such as, but not limited to, dampers, elevators, lifting devices, instruments, etc. It should be further understood that it can be used in connection with other controllable devices. Accordingly, the example of FIG. 1 is merely an illustrative example for purposes of description, and the scope of subject matter of this patent is not limited thereto.

  The example valve assembly 102 of FIG. 1 includes a valve 106, a pneumatic actuator 108 and a position sensor 110. The example valve 106 of FIG. 1 has a valve seat 112 disposed on the valve to define a hole 114 between the openings 116 and 118 that provides a fluid flow passage in the valve 106. The example actuator 108 of FIG. 1 is operably coupled to the flow control member 120 by a valve stem 122 that moves the flow control member 120 in a first direction (eg, away from the valve seat 112). The flow control member 120 can be moved in a second direction (e.g., toward the valve seat 112) to allow greater fluid flow between the openings 116 and 118. Further restrict or prevent fluid flow between them.

  The example pneumatic actuator 108 of FIG. 1 includes a piston 130 disposed within a housing 132 that defines a first chamber 136 and a second chamber 137. Actuator stem 138 is operatively coupled to valve stem 122 by a connector 139 connected to piston 130 and having an associated movement indicator 140. The flow rate allowed through the valve 106 is controlled by adjusting the position of the piston 130 relative to the housing 132 to adjust the position of the flow control member 120 relative to the position of the valve seat 112 and hence the valve 106. To do.

In order to control the position of the example piston 130, the electropneumatic valve position controller example 104 of FIG. 1 uses a first passage 152 to control fluid (eg, pressurized air, hydraulic fluid, etc.) from a fluid source 150. One chamber 136 and a second passage 154 to the second chamber 137. If there is a pressure differential present across the example piston 130, it determines if the piston 130 is stationary or moving. For example, in order to move the piston 130 in a first direction (eg, a downward direction in the orientation of FIG. 1), the valve position controller 104 has a first pressure greater than the control fluid provided to the second chamber 137. A control fluid is supplied to chamber 136, thereby applying a net downward force to piston 130. This movement of the piston 130 in the first downward direction results in moving the actuator stem 138, the valve stem 122, and hence the flow control member 120, toward the valve seat 112, thereby passing through the hole 114. Further block or limit fluid flow. Conversely, to move the piston 130 in a second direction (e.g., an upward direction in the orientation of FIG. 1), the valve position controller 104 has a pressure less than the control fluid provided to the second chamber 137. A control fluid is supplied to the chamber 136 thereby applying a net upward force to the piston 130. This movement of the piston 130 in the second upward direction causes the actuator stem 138, the valve stem 122, and hence the flow control member 120, to move away from the valve seat 112, thereby allowing more fluid to pass through the hole 114. Allow flow.

  In the illustrated example of FIG. 1, the actuator 108 includes movement stops 160 and 162. The example travel stop 160 corresponds to a fully open or 100% travel span position of the actuator 108 (see FIG. 2A), ie, the maximum or maximum travel end point. The movement stop example 162 corresponds to a fully closed or 0% movement position of the actuator 108 (see FIG. 2C), ie, the minimum or minimum movement end point. FIG. 2B depicts the piston 130 positioned midway between the stops 160 and 162 and thus corresponding to a 50% travel position. In some examples, the movement stops 160 and / or 162 are adjustable.

  Returning to FIG. 1, to measure the position of the actuator 108, the example valve assembly 102 of FIG. 1 includes an example position sensor 110. The position sensor example 110 of FIG. 1 measures and / or senses the position of the movement indicator 140 relative to the stationary position sensor 110 to provide the current position of the movement indicator 140, and thus (eg, open or spanned). A signal 170 representing the position of the valve 106 (as a percentage) is output and / or provided. The example position sensor 110 is a linear array of Hall effect sensors that output an analog signal 170 having different values (eg, voltage or current) for different positions of the movement indicator 140. The example analog signal 170 of FIG. 1 represents the absolute movement or position of the movement indicator 140. For example, assuming that the actuator 108 has a stroke length of 100 millimeters (mm) and the position signal 170 varies between 0 millivolts (mV) and 40 millivolts (mV), the valve stem When 122 is moved 10%, the analog signal 170 changes by 4 mV, which is 10% of 40 mV. The analog signal 170 is the first current travel value and / or voltage (PTV) when the travel indicator 140 is in a first position corresponding to the piston 130 in contact with the stop 162 (FIG. 2C). And when the movement indicator 140 is in the second position corresponding to the piston 130 in contact with the stop 160 (FIG. 2A), the movement indicator 140 has a second PTV. When between the first position and the second position, it has a range of possible PTVs between the first PTV and the second PTV. For example, if the piston 130 is in the middle between the stops 160 and 162 (FIG. 2B), the analog signal 170 has a PTV in the middle between the first PTV and the second PTV. In some examples, the position sensor 110 may measure a range of motion that is greater than the range of motion physically supported by the actuator 108, ie, the length of the position sensor 110 is greater than the full stroke length of the actuator 108. Can also be long. The example position sensor 110 of FIG. 1 outputs an analog signal 170, but the position sensor may additionally or alternatively output a digital signal having a digital value that represents the relative position of the movement indicator 140. Further, the analog signal 170 output by the position sensor 110 can be converted to a digital signal by the valve position controller 104 prior to processing.

  The example valve position controller 104 of FIG. 1 self-calibrates from a single externally provided position value PPP representing the current position (eg, 70% opening) of the actuator 108, or an estimate and / or approximation thereof. be able to. As described herein, additional externally provided position values are not required by the valve position controller 104 prior to the start of operation of the valve position controller 104 within the process plant. Further, the position of the actuator 108 is adjusted before the operation of the example valve device 100 of FIG. 1 in the process plant and need not be changed or stroked. The single position value PPP can be obtained by, for example, visually inspecting (eg, estimating) and / or measuring the current position of the position indicator 140 during installation of the valve position controller 104, for example. Can be easily and / or easily determined and / or estimated. The installer provides and / or inputs the estimated or measured position value PPP to the valve position controller 104, eg, via the input device 640 (FIG. 6) of the valve position controller 104. While the example valve position controller 104 may self-calibrate based on a single estimated position value, additional position values are available, provided by the installer, and / or by stroking the valve 106 Such additional values can be utilized, for example, to improve calibration accuracy, when determined or measured values are determined.

  Based on a single estimated position value PPP, a sensitivity value SENSITIVITY representing the change in PTV 170 per unit of distance traveled by the position indicator 140, and the full stroke distance value for the valve, the example valve position controller 104 of FIG. Estimates the PTV 170 that is expected and / or predicted to correspond to the travel endpoint of the valve actuator 108. Alternatively, the value SENSITIVITY represents a count number representing the full stroke of the valve 106. Still further, the value SENSITIVITY can represent the change in PTV 170 over the full stroke of valve 106. Referring to FIG. 3, at time T1, the example valve assembly 102 of FIG. 1 is 75% open, has a PTV 170 corresponding to the current 75% position, and the actuator 108 is fully open 100. It will have a PTV 170 of HI_ACT when in the% position and a PTV value 170 of LO_ACT when the actuator 108 is in the fully closed 0% position. At time T2, the valve position controller 104 calculates a first value HI_CAL corresponding to the estimated or expected fully opened position of the actuator 108, and the actuator 108's estimated or expected sufficient A second value LO_CAL corresponding to the closed position is calculated. If the values of PPP and SENSITIVITY are substantially accurate, the value of HI_CAL is substantially equal to HI_ACT, and the value of LO_CAL is substantially equal to LO_ACT. In practice, however, the value of PPP is an estimate of the position of actuator 108 (eg, a measured value with an error) and / or the value of SENSITIVITY is due to manufacturing tolerances and / or installation alignment deformations. Can be inaccurate. Accordingly, in some examples, the example valve position controller 104 of FIG. 1 adjusts the estimated end point value in an objective manner, and thus is estimated and / or predicted represented by HI_ACT and LO_ACT. The moving range includes a larger moving range of the actuator 108 as shown at time T3.

The values of HI_ACT and LO_ACT can be calculated using the following equations, assuming that the feedback signal 170 increases as the valve 104 opens.
HI_CAL = PTV + (100-PPP) * (1 + RAF) * SENSITIVITY, and equation (1)
LO_CAL = PTV-PPP * (1 + RAF) * SENSITIVITY Equation (2)
Here, RAF is, for example, a range adjustment factor of 0.1 resulting in an increase in the value of HI_CAL by 10% and a decrease in the value of LO_CAL by 10%. Expressed as a percentage of the travel range. Alternatively, if the feedback signal 170 decreases as the valve 104 opens, the following formula can be used to calculate the values of HI_ACT and LO_ACT:
HI_CAL = PTV + PPP * (1 + RAF) * SENSITIVITY, and
Equation (3)
LO_CAL = PTV− (100−PPP) * (1 + RAF) * SENSITIVITY Equation (4)

Using any number and / or type (s) of method (s), algorithm (s) and / or logic, the example valve position controller 104 of FIG. , Based on the estimated endpoint values HI_CAL and LO_CAL as compared to a control signal 180 received from the process controller 185, representing the desired position and / or set point (SP) (eg, 40% opening) of the valve 106 Thus, it is determined how the pressure (s) of the control fluid provided to chambers 136 and 137 should be adjusted and / or maintained. For example, based on HI_CAL and LO_CAL, the example valve position controller 104 calculates a value TARGET for the position signal 170 corresponding to the desired position of the valve 106. The valve position controller 104 then adjusts the pressure in the chambers 136 and 137 until the actual PTV 170 substantially matches or is equal to the value TARGET. The value TARGET can be calculated using the following formula:
TARGET = LO_CAL + SP * (HI_CAL-LO_CAL) / 100
Equation (5)

  When the example valve device 100 of FIG. 1 operates in a process plant, the example valve position controller 104 may include any number and / or type (s) of algorithm (s), logic, criteria, and / or ) Method is used to adapt, adjust and / or update the estimated endpoint values HI_CAL and LO_CAL. During operation of the process plant, when the piston 130 reaches any of its physical movement stops 160, 162, the example valve position controller 104 adjusts the corresponding calibrated endpoint values HI_CAL, LO_CAL. . The detection of when the piston 130 reaches the stop 160, 162 is to detect that the PTV 170 no longer changes, even if the pressure applied to the piston 130 may result in movement of the piston 130. Can be executed by. For example, at time T4 in FIG. 3, when reaching the fully open stop 160, the valve position controller 104 updates the value of HI_CAL to match the current value PTV 170 equal to HI_ACT. Similarly, at time T5, when a stop 162 that is 0% fully closed is reached, valve position controller 104 updates the value of LO_CAL to match the current PTV 170 equal to LO_ACT.

  In some situations, deleterious valve position effects can occur using the example calibration method illustrated in FIG. In the illustrated example of FIG. 3, the calibration values HI_CAL and LO_CAL are sufficiently adjusted each time the piston 130 reaches the corresponding movement stop 160, 162, causing the valve 106 to move away from the corresponding end point 160, 162. Potentially resulting in For example, if the piston 130 reaches the fully closed stop 162 at the 5% open position SP180, and if the LO_CAL value is adjusted immediately and completely as described above, the valve position Controller 104 will respond immediately by opening valve 160 to 5%, resulting in a sudden change in process fluid flow. Such changes in valve position may interrupt ongoing processes and / or have other negative consequences.

  Returning to FIG. 1, to reduce the likelihood of such an effect, another example self-calibration method is that the process controller 104 causes the SP 180 to exceed SP 180 when it reaches one of its travel limits. Only when it is moved, the calibration values HI_CAL and LO_CAL are adjusted. Under such circumstances, the appropriate HI_CAL or LO_CAL value can be adjusted without changing the position of the valve 106. When the SP signal 180 actually reaches both 0% and 100%, the calibration of the corresponding end points HI_CAL, LO_CAL is complete. If not, the calibration of the end points HI_CAL and LO_CAL is partially incomplete.

Assuming that the initial values of LO_CAL and HI_CAL are calculated to represent an extended travel range, as described above in connection with FIG. When detecting that the valve 106 has reached 0% by detecting that the piston 130 is loaded, the value of LO_CAL may be updated using the following formula:
LO_CAL = HI_CAL- (HI_CAL-PTV) * 100 / (100-SP)
Equation (6)
If the value of SP180 is less than 0%, the value of SP180 should be set to 0% in equations (6)-(9). For example, to reduce possible control errors due to inaccurate signal bias present in the position feedback signal 170, the following formula is used to update the value of LO_CAL to include a 1% safety factor: Can be done.
LO_CAL = HI_CAL- (HI_CAL-PTV) * 101 / (100-SP)
Equation (7)
When the valve controller 104 detects that the valve 106 has reached its 100% open physical stop, for example by detecting that the actuator pressure has loaded the piston 130 against the stop 160. , The value of HI_CAL may be similarly updated using one of the following equations:
HI_CAL = LO_CAL + (PTV-LO_CAL) * 100 / SP Equation (8)
HI_CAL = LO_CAL + (PTV-LO_CAL) * 101 / SP Equation (9)
Similar to equation (7), equation (9) includes a 1% safety factor.

  FIG. 4 illustrates an example of updating LO_CAL using the example equation of equation (6) or equation (7). In the example of FIG. 4, the actuator pressure 405 decreases during the normal operation. At some time 410, SP 180 is below the value at which the actuator 108 reaches a fully closed 0% position. However, due to inaccurate calibration, SP180 is still above 0%. Due to the controller gain, the actuator pressure 405 decreases rapidly as SP 180 continues to decrease. The example valve position controller 104 of FIG. 1 recognizes from the low actuator pressure 405 that the actuator 108 is fully closed and uses one of equations (6) or (7). Update LO_CAL to a new minimum, thereby improving the accuracy of the value of LO_CAL by 5% in the example of FIG. If the SP 180 was driven all the way to the 0% position, the LO_CAL calibration would have been substantially ideal. In some examples, equation (6) or equation (7) is applied repeatedly while the actuator 108 remains in the fully closed 0% position and the SP 180 is changing. Additionally or alternatively, equation (6) or equation (7) applies to the minimum value of SP 180 that occurs while the actuator 108 is in the fully closed 0% position.

Returning to FIG. 1, in some examples, whenever the appropriate update of equations (6)-(9) is in the corresponding travel stop 160, 162 and / or Or apply in the meantime.

  In yet another example, the valve position control example 104 of FIG. 1 records a PTV 170 when the SP 180 reaches a value where the valve 106 reaches one of its travel limits. Thereafter, whenever the SP 180 changes by an amount that hinders operation due to noise, the example valve position controller 104 corresponds to reduce the difference between the recorded PTV 170 and the corresponding calibration values LO_CAL, HI_CAL. A small correction is applied to the calibration values LO_CAL and HI_CAL. By slowly changing the calibration values LO_CAL and HI_CAL over time while the SP 180 is changing, interruptions to any ongoing process (s) can be reduced, minimized, and / Or can be eliminated. In some examples, the rate of application of calibration correction is limited to 0.1% of the total movement span per minute or one movement count per minute. Depending on the dynamic nature of SP 180 (eg, how much and / or at what rate SP 180 changes), the rate of calibration correction may need to be reduced and / or increased. .

  Although the above example is based on initially and purposely expanded calibration values HI_CAL and LO_CAL, alternatively, the valve position controller 108 determines the range of movement of the actuator 108 as shown in FIG. It can be estimated low initially. The compressed calibration values HI_CAL and LO_CAL can be calculated using equations (1)-(4), for example, with a RAF of −0.1. At time T4, the actuator 108 is still moving due to the pressure difference across the chambers 136, 137, but when the value PTV 170 exceeds the current value of HI_CAL, the value of HI_CAL reflects the current value PTV. To be adjusted. The lower estimated travel limit LO_CAL is similarly adjusted as depicted at time T5. In the case where SP 180 cannot exceed a value corresponding to a valve position from 0% to 100%, valve 106 cannot reach its travel end point and therefore HI_CAL and LO_CAL as illustrated in FIG. Value calibration may not be possible.

  Assuming that SP180 may exceed values corresponding to 0% and 100% valve positions, the calibration values for HI_CAL and LO_CAL may additionally or alternatively be when SP180 exceeds the 0-100% range. Can be adjusted by detecting. In some examples, the valve position controller 104 performs a shut-off, which causes the actuator 108 to move to a set of mechanical stops 160 when the SP 180 reaches a respective predetermined value (eg, 5% or 95%). , 162 intentionally fully loaded. In such an example, it may be beneficial not to activate the block when using the initially compressed calibration values HI_CAL and LO_CAL. When the SP 180 is moving beyond this range by an amount that prevents operation due to noise, and when the actuator pressure is not loading the piston 130 into the corresponding stop 160, 162, the valve position controller example 104 is The corresponding calibration values HI_CAL, LO_CAL are adjusted by a small amount that moves 108 towards the stops 160, 162 and / or loads the stops 160, 162. Eventually, one or more of the above conditions will no longer be met and the calibration will be substantially complete. In some examples, the calibration values HI_CAL, LO_CAL are repeatedly adjusted while the piston 130 is not loaded and while the SP 180 is changing and is outside the 0-100% range. Additionally or alternatively, the calibration values HI_CAL, LO_CAL are adjusted using the maximum of the SP180 range values that occurred while the piston 130 was not loaded.

  In yet another example, the valve position control example 104 of FIG. 1 records a PTV 170 when the SP 180 reaches a value where the valve 106 reaches one of its travel limits. Thereafter, whenever the SP 180 changes by an amount that prevents operation due to noise, the example valve position controller 104 causes the corresponding calibration to reduce the difference between the recorded PTV 170 and the corresponding calibration values LO_CAL, HI_CAL. A small correction is applied to the action values LO_CAL and HI_CAL. By slowly changing the calibration values LO_CAL, HI_CAL over time while the SP 180 is changing, interruptions to any ongoing process (s) can be reduced, minimized, and / Or can be eliminated. In some examples, the rate of application of calibration correction is limited to 0.1% of the total movement span per minute, or one movement count per minute. Depending on the dynamic nature of SP 180 (eg, how much and / or at what rate SP 180 changes), the rate of calibration correction may need to be reduced and / or increased.

  Any of the example valve calibration methods described above may apply and / or activate new LO_CAL and HI_CAL values as they are calculated, while additionally or alternatively The LO_CAL and / or HI_CAL values are stored and activated and / or applied only when the valve position controller 104 is specifically commanded and / or commanded. For example, the valve position controller 104 may display an indicator on the display 645 (FIG. 6) indicating that one or more new calibration values LO_CAL, HI_CAL are available for operation. For example, when the example input device (s) 640 indicates that the user will be applying new and / or updated calibration values LO_CAL, HI_CAL, the valve position controller 104 may Start using the calibration values LO_CAL, HI_CAL activated during the valve control operation.

  In still further examples, combinations of the calibration methods described above may be implemented. For example, if it is detected that the piston 130 is loaded on the stops 160, 162 by the SP 180 within a range of 0 to 100%, one of the calibration methods described above is applied to the first expanded range. obtain. However, if it is detected that SP 180 is outside the 0-100% range, one of the calibration methods described above for the initially compressed range may be applied. In yet a further example, rather than expanding or compressing the initial calibration values HI_CAL and LO_CAL with purpose, the calibration values HI_CAL and LO_CAL are applied according to the detected condition (multiple And) are estimated and / or calculated as accurately as possible using the appropriate calibration procedure (s).

  Returning to FIG. 1, the valve position controller 104 is installed, configured, activated, and / or to fix the position of the valve assembly 102 while calculating the initial estimated endpoint values HI_CAL and LO_CAL of FIG. The example apparatus 100 includes any number and / or types of holders for fixing, holding and / or maintaining the current position of the valve assembly, one of which is a reference The number 190 is designated. The example holder 190 includes, but is not limited to, clamps, blocks, and / or fluid traps.

FIG. 6 illustrates an example technique for implementing the example valve position controller 104 of FIG. To receive the feedback position signal 170, the example valve position controller 104 of FIG. 6 includes a position sensor interface 605. Using any number and / or type (s) of circuit (s), component (s) and / or device (s)
The example position sensor interface 605 of FIG. 6 adjusts and / or converts the feedback signal 170 into a form suitable for processing by the valve controller 610 and / or the calibrator 615. For example, the position sensor interface 605 may convert the analog feedback signal 605 to a digital value 607 representing the current position PTV of the movement indicator 140. Additionally or alternatively, if the feedback signal 170 has a different polarity depending on whether the movement indicator 140 is above or below the midline of the position sensor 110, the position sensor interface 605 may be, for example, prior to conversion to a digital value 607. The feedback signal 170 may be offset to have only a positive value at.

  To receive the control signal 180, the example valve position controller 104 of FIG. 6 includes a control signal interface 620. Using any number and / or type (s) of circuit (s), component (s) and / or device (s), the example control signal interface 620 of FIG. Control signal 180 is adjusted and / or converted to a form suitable for processing by 610. For example, the control signal interface 620 may convert the control signal 180 into a digital control value 622 that represents the desired set point and / or position SP of the actuator 108.

  To control the air pressure supplied to chambers 136 and 137, the example valve position controller 104 of FIG. 6 includes a pressure controller 625. Pressure control using any number and / or type (s) of circuit (s), component (s) and / or device (s) and by example valve controller 610 Based on the value 627, the example pressure controller 625 determines whether to increase or decrease the air pressure provided via lines 152 and 154.

  Using any number and / or type (s) of method (s), algorithm (s) and / or logic, the example valve controller 610 of FIG. 622 and the digital position value 607 are compared to determine how the pressure control value 627, ie, the pressure (s) of the control fluid provided to chambers 136 and 137 should be adjusted. As described above in connection with FIG. 1 and equation (5), the valve controller 610 determines the pressure control value 627 based on the estimated endpoint values HI_CAL and LO_CAL.

  To determine and update the estimated values HI_CAL and LO_CAL of the digital value 607 corresponding to the expected end point of movement of the actuator 108, the example valve position controller 104 of FIG. The calibrator example 615 includes an endpoint estimator 617 to calculate an initial pair of values HI_CAL and LO_CAL estimated based on a single externally provided position value PPP. For example, the end point estimator example 617 calculates initial values HI_CAL and LO_CAL using equations (1) to (4).

  The calibrator example 615 includes an end point adjuster 619 to update the values HI_CAL and LO_CAL corresponding to the expected travel end point of the actuator 108 during operation of the example valve apparatus 100 of FIG. For example, using any of the method examples described above in connection with FIG. 1 and FIGS. The values of HI_CAL and LO_CAL are updated during the 104 online operation. The end point adjuster example 619 can additionally or alternatively be used to calculate and / or update HI_CAL and LO_CAL if the valve 106 is stroked for purposes of calibration. It should be understood.

In order to store the control variables, the example valve position controller 104 of FIG.
Contains zero. The control variables may be stored in the storage device 630 using any number and / or type (s) of data structures, which may be any number and / or type (s) of volatile. And / or can be implemented using non-volatile memory (s), memory device (s) and / or storage device (s), such as a hard disk drive. Examples of control variables that may be stored in the example storage device 630 include, but are not limited to, an externally provided position value PPP, a sensitivity value SENSITIVITY, and estimated movement endpoint values HI_CAL and LO_CAL.

  In order to allow the user to provide the position value PPP and / or the sensitivity value SENSITIVITY, the example valve position controller 104 of FIG. 6 includes any type of user interface 635, any number and / or type ( A plurality of) input devices 640, as well as any type of display 645. In some examples, the user interface 635 presents a prompt via a display 645 shown to the user and / or prompts the user to provide and / or enter the values PPP and / or SENSITIVITY. The example input device 640 includes, but is not limited to, a digital communication interface and / or a keypad. In some examples, the touch screen may be used to implement both the display 645 and the input device 640.

Although an example technique for implementing the example valve position controller 104 of FIG. 1 is illustrated in FIG. 6, one or more of the interfaces, data structures, elements, processes, and / or devices illustrated in FIG. 6 may be combined. Can be split, rearranged, omitted, eliminated, and / or implemented in any other manner. Further, a position sensor interface example 605, a calibrator example 615, an end point estimator example 617, an end point adjuster example 619, a control signal interface example 620, a pressure controller example 625, a storage device example 630, a user interface example 635, input (s). Example device 640, display example 645, and / or more generally, valve position controller 104 of FIG. 6 is implemented by hardware, software, firmware, and / or any combination of hardware, software, and / or firmware. Can be done. Therefore, for example, position sensor interface example 605, calibrator example 615, end point estimator example 617, end point adjuster example 619, control signal interface example 620, pressure controller example 625, storage device example 630, user interface example 635, (plurality) Any of the example input devices 640, the example displays 645, and / or more generally, the valve position controller 104 may include one or more (multiple) circuits, (multiple) programmable processors, (multiple) Application specific integrated circuit (multiple ASICs), programmable logic devices (multiple) PLDs, field programmable logic devices (multiple FPLDs), and / or Field programmable gate array ((multiple It may be implemented by) FPGA) or the like. When any claim of this patent that incorporates one or more of these elements is read as purely encompassing a software and / or firmware implementation, example position sensor interface 605, example calibrator 615 , End point estimator example 617, end point adjuster example 619, control signal interface example 620, pressure controller example 625, storage device example 630, user interface example 635, input device example 640, display example 645, at least One and / or more generally, the valve position controller 104 is explicitly defined herein to include a tangible computer readable medium. Examples of a tangible computer readable medium include, but are not limited to, flash memory, compact disk (CD), DVD, floppy disk, read only memory (ROM), random access memory (RAM), programmable ROM ( PROM), electronically programmable ROM (EPROM), and / or electronically erasable PROM (EEPROM), optical storage disk, optical storage device, magnetic storage disk, magnetic storage device, and / or program Any other tangible medium that can be used to store code and / or instructions in the form of machine-readable instructions or data structures, which is related to the processor, computer, and / or FIG. Processor described in That may be accessed by other machines having a processor such as a platform example P100, or any other tangible media. Combinations of the above are also included within the scope of tangible computer readable media. Still further, the example valve position controller 104 may include interfaces, data structures, elements, processes and / or devices instead of or in addition to those illustrated in FIG. 6 and / or the illustrated interfaces, It may include two or more of any or all of data structures, elements, processes and / or devices.

  FIG. 7 illustrates an example process that may be used to install the example valve position controller 104 of FIGS. FIGS. 8-11 illustrate example processes that may be performed to implement the example calibrator 615 of FIG. 6 and / or more generally the example valve position controller 104 of FIGS. A processor, controller and / or any other suitable processing device may be used and / or programmed to perform the example processes of FIGS. For example, the processes of FIGS. 7-11 may be performed by, for example, a tangible computer readable medium such as flash memory, CD, DVD, floppy disk, ROM, RAM, PROM, EPROM, and / or EEPROM, optical storage disk, optical A storage device, magnetic storage disk, magnetic storage device, and / or any other tangible medium that can be used to store program code and / or instructions in the form of machine-readable instructions or data structures. Any, such as a processor, computer, and / or any other tangible medium that can be accessed by other machines having a processor, such as the processor platform example P100 described below in connection with FIG. Remembered on the product May be embodied accessible instructions coded instructions and / or machines. Combinations of the above are also included within the scope of computer-readable media. Machine readable instructions include, for example, instructions and data which cause a processor, a computer, and / or a machine having a processor to perform one or more specific processes. Alternatively, some or all of the example operations of FIGS. 7-11 include: (multiple) ASICs, (multiple) PLDs, (multiple) FPLDs, (multiple) FPGAs, discrete logic, hardware, It can be implemented using any combination (s) such as firmware. Also, one or more of the example operations of FIGS. 7-11 may be implemented manually or as any combination of any of the above techniques, eg, any combination of firmware, software, discrete logic and / or hardware. obtain. In addition, many other ways of implementing the example operations of FIGS. 7-11 can be utilized. For example, the order of execution of the blocks can be changed and / or one or more of the described blocks can be changed, eliminated, subdivided, or combined. Additionally, any or all of the example machine processes of FIGS. 7-11 may be executed sequentially and / or, for example, separate processing threads, processors, devices, discrete logic, circuits, etc. May be executed in parallel.

  The process example of FIG. 7 begins with an operator and / or installer locating or securing (eg, manually securing) the valve assembly 102 using the example holder 190 (block 705). For example, an operator can manually clamp valve 106 using a clamp and / or block, or position of actuator 108 by preventing (eg, trapping) movement of control fluid within actuator 108. May be determined.

The valve position controller that is to be replaced is removed (block 710) and a replacement and / or new valve position controller 104 is installed (block 715). The installer activates the valve position controller 104 (eg, provides power to the valve position controller 104) to access the user interface 635 (block 720). The installer inputs configuration data, such as the sensitivity value SENSITIVITY of the position sensor 110 (eg, taken from a plate or label on the position sensor 110) (block 725). The installer then inputs the single point position PPP of the position indicator 140 (block 730). In some examples, the position PPP is entered as a percentage of the travel span of the actuator 108 (eg, 50% open).

  Based on the entered information, valve position controller 104 calculates calibration values LO_CAL and HI_CAL, and the installer applies these values (block 740).

  The installer places the valve position controller 104 in an active state (block 745) and unlocks or releases the position of the valve assembly 102 (block 750).

  The example processes of FIGS. 8-11 are each time the valve position controller 104 is commanded to change the position of the valve assembly 102 via the control signal 180 and the valve position controller 104 responds to such a command. This is performed while the position of the valve assembly 102 is being changed. The process example of FIG. 8 corresponds to the illustrated example of FIGS. The process example of FIG. 9 corresponds to updating calibration values based on equation examples (6) to (9). The example process of FIG. 10 corresponds to updating the calibration value based on the stored PTV 170 when the movement stop is reached. The example process of FIG. 11 corresponds to updating the calibration value for an SP 180 that is out of range. Prior to the example processes of FIGS. 8-11 performed at a first time (eg, when the valve position controller 104 is activated in automatic control mode), the example endpoint estimator 617 of FIG. Calculate the initial estimated HI_CAL and LO_CAL as described above in connection with.

  In the example process of FIG. 8, a pair of correction status bits 0% and 100% and a single point calibration status bit are described. The 0% and 100% correction status bits are cleared and the single point calibration status bit is set when the single point calibration is complete. Since single point calibration has been performed, the 0% and 100% correction status bits indicate whether the valve 106 and actuator 108 have reached the 0% and 100% travel limits, respectively. The single point calibration status bit indicates that a (potentially incorrect) single point calibration has been performed (eg, block 740 of FIG. 7) and has not been improved. In the example of FIG. 8, the values NEW_LO_CAL and NEW_HI_CAL are new calibration values that have been calculated and / or set, but are not applied until the user chooses to do so. . The example process of FIG. 8 begins with the example valve controller 610 determining whether the actuator 108 has reached a fully closed 0% position (block 805). If a fully closed 0% position has been reached (eg, 0% movement stop 162 has been reached) (block 805), the endpoint adjuster 619 can perform a fully closed or 0% position calibration. It is determined whether a corresponding status bit (eg, 0% correction status bit) has been set (block 810). If a sufficiently closed 0% status bit is set (block 810), control returns to block 805 to check if a 0% travel stop has been reached.

If the fully closed status bit has not been set (eg, the NEW_LO_CAL value has not yet been set) (block 810), the endpoint adjuster 619 determines that the NEW_LO_CA
Record the current value LO_ACT of the feedback signal 170 as L (block 815) and set the fully closed status bit (block 820). The calibrator 615 notifies the user that new and / or improved calibration data is ready to be applied (eg, via the example display 645) (block 835). If the user does not apply the new value (s) (block 840), the user will be repeatedly informed about the improved data available, and control returns to block 805, where 0% stop moving Check whether the part has been reached.

  If the user applies only one of the new values (block 845), the user will be repeatedly informed about the improved data available, and control returns to block 805, where 0% stop moving Check if the part has been reached. If both NEW_LO_CAL and NEW_HI_CAL apply (block 845), the updated endpoint values LO_CAL, HI_CAL are stored in the example storage device 630, the single point calibration status bit is cleared, and any potential The actual inaccuracy has been corrected (block 845). Execution of example calibrator 615 is terminated (block 850) and control then exits from the example process of FIG.

  Returning to block 805, if the fully closed 0% travel stop has not been reached (block 810), the valve controller 610 determines whether a fully open 100% travel stop has been reached (block 810). Block 860).

  If the fully open 100% position has not been reached (block 860), the endpoint adjuster 619 determines whether the fully open 100% status bit has been set (block 865). If the fully open 100% status bit is set (block 865), control returns to block 805 to check if a 0% travel stop has been reached.

  If the fully open 100% status bit is not set (eg, the NEW_HI_CAL value is not yet set) (block 865), the endpoint adjuster 619 records the current value HI_ACT of the feedback signal 170 as NEW_HI_CAL. (Block 870), the fully open 100% status bit is set (block 875). Control then proceeds to block 835 and notifies the user of new calibration data.

  The example process of FIG. 9 begins with the endpoint adjuster 619 waiting for the piston 130 to be loaded against either of the stops 160, 162 (block 905). When the piston 130 is to be loaded (block 905), the end point adjuster 619 determines whether the SP 180 is changing toward the stops 160, 162 (block 910). If SP 180 is changing towards loaded stops 160, 162 (block 910), endpoint adjuster 619 responds using the corresponding one of equations (6)-(9). The calibration values HI_CAL and LO_CAL to be updated are updated (block 915).

  When the SP 180 is no longer changing toward the loaded stop 160, 162 (block 910), control returns to block 905 to determine whether the piston 130 is loaded against the mechanical limits 160, 162. decide. In the example of FIG. 9, the updated calibration values HI_CAL and LO_CAL are automatically applied. Additionally or alternatively, those described above in connection with blocks 835, 840, 845, 850 and 855 of FIG. 8 if the updated calibration values HI_CAL, LO_CAL are not to be automatically applied. As well as a new calibration data application process can be performed.

  The example process of FIG. 10 begins with the example endpoint adjuster 619 determining whether the piston 130 is loaded against either of the stops 160, 162 (block 1005). If the piston 130 is loaded (block 1005), the end point adjuster 619 saves the current PTV 170 (block 1010) and determines whether the SP 180 is changing towards the stops 160, 162 (block). 1015). If the SP 180 is changing towards the loaded stop 160, 162 (block 1015), the end point adjuster 619 is directed toward each stored PTV 170, however, that (s). The calibration values HI_CAL, LO_CAL corresponding to and not necessarily equal to the PTV 170 are updated (block 1020). For example, the calibration values HI_CAL, LO_CAL are updated with the percentage difference between the calibration values HI_CAL, LO_CAL and their respective stored PTVs 170. When the updated calibration values HI_CAL and LO_CAL are equal to their respective stored PTV values (block 1025), no further calibration value adjustments are possible and / or necessary so that the control The process example of FIG. If any of the updated calibration values HI_CAL and LO_CAL are not equal to their respective stored PTV (block 1025), control returns to block 1015.

  Returning to block 1005, if the piston 130 is not loaded (block 1005), control proceeds to block 1015 to determine if the SP 180 has changed.

  In the example of FIG. 10, the updated calibration value is automatically applied. Additionally or alternatively, as described above in connection with blocks 835, 840, 845, 850 and 855 of FIG. 8 if the updated calibration value (s) are not to be automatically applied. As well as a new calibration data application process can be performed.

  The process example of FIG. 11 begins with endpoint adjuster 619 waiting for SP 180 to be outside the range of 0-100% (block 1105). When SP 180 is outside the 0-100% range (block 1105), endpoint analyzer 619 determines whether piston 130 is loaded against either stop 160, 162 (block 1110). ). If the piston 130 is loaded (block 1110), control returns to block 1105.

  If the piston 130 is not loaded (block 1110), the end point adjuster 619 adjusts the corresponding calibration values HI_CAL, LO_CAL so that the piston 130 moves toward the corresponding stop 160, 162 (block 1120).

  When SP 180 has not changed (block 1115), piston 130 will be loaded against mechanical limits 160, 162 (block 1110), or SP 180 will be reversed within the range of 0-100%. Returning to block 1105, control returns to block 1105 and waits for SP 180 to move again beyond the 0-100% range.

  In the example of FIG. 11, the updated calibration value is automatically applied. Additionally or alternatively, if the updated calibration value (s) will not be automatically applied, the one described above in connection with blocks 835, 840, 845, 850 and 855 of FIG. A substantially similar notification as well as a new calibration data application process may be performed.

FIG. 12 illustrates an example valve device 1200 including an example valve assembly 102 and a position transmitter 1205 configured in accordance with the teachings of this disclosure. The elements of example apparatus 1200 of FIG. 12 are the same as those described above in relation to example apparatus 100 of FIG. 1, and therefore description of the same elements will not be repeated here. Instead, the same elements are designated with the same reference numerals in FIGS. 1 and 12, and the interested reader is associated with FIG. 1 for a complete description of those identically numbered elements. Then, refer back to the explanation presented above.

ここで、ＭＡＸは、十分に開いたバルブに対応するＰＯＳ＿ＳＩＧ１２１０の値であり、ＭＩＮは、十分に閉じたバルブに対応するＰＯＳ＿ＳＩＧ１２１０の値である。いくつかの例において、ＭＩＮは４ｍＡであり、ＭＡＸは２０ｍＡである。ＬＯ＿ＣＡＬとＨＩ＿ＣＡＬの値が、以下に説明されるように位置トランスミッタ１２０５によって計算され、選択され、および／または更新される。 To provide a position signal (POS_SIG) 1210 representative of the position of valve assembly 102 to, for example, process controller example 185 and / or monitoring system, monitoring device, automatic shutdown system, and / or process interlock 1215 of FIG. The example valve device 1200 includes an example position transmitter 1205. The example position transmitter 1205 of FIG. 12 calculates and / or determines the value of POS_SIG 1210 from the PTV 170. For example, the position transmitter 1205 may calculate POS_SIG 1210 using the following formula:

Here, MAX is a value of POS_SIG 1210 corresponding to a fully opened valve, and MIN is a value of POS_SIG 1210 corresponding to a sufficiently closed valve. In some examples, MIN is 4 mA and MAX is 20 mA. The values of LO_CAL and HI_CAL are calculated, selected and / or updated by the position transmitter 1205 as described below.

  The example position transmitter 1205 of FIG. 12 is self-calibrating from a single externally provided position value PPP representing the current position (eg, 70% opening) of the actuator 108, or an estimate and / or approximation thereof. Can do. As described herein, additional externally provided position values are not required by position transmitter 1205 prior to the start of operation of valve device 1200 within the process plant. Further, the position of the actuator 108 is adjusted before the operation of the example valve device 1200 of FIG. 12 in the process plant and need not be changed or stroked. The single position value PPP can be determined by the installer, for example, by visually inspecting (eg, estimating) and / or measuring the current position of the position indicator 140, for example, during installation of the position transmitter 1205. Can be easily and / or easily determined and / or estimated. The installer provides and / or inputs the estimated or measured position PPP to the position transmitter 1205, eg, via the input device 640 of the position transmitter 1205 (FIG. 13). While the example position transmitter 1205 may self-calibrate based on a single estimated position value PPP, additional position values are available, provided by the installer and / or stroke the valve 106. Such additional values can be utilized, for example, to improve the accuracy of the calibration when the estimated or measured value is determined by.

Based on a single estimated position value PPP, a sensitivity value SENSITIVITY representing the change in PTV 170 per unit of distance of movement of position indicator 140, and the total distance of movement of valves and actuators, example position transmitter 1205 of FIG. Estimates the PTV 170 that is expected and / or predicted to correspond to the travel endpoint of the valve actuator 108. Alternatively, the value SENSITIVITY represents a count number representing the full stroke of the valve 106. Still further, the value SENSITIVITY can represent a change in PTV 170 beyond the full stroke of valve 106. Referring to FIG. 5, at time T1, the example valve assembly 102 of FIG. 12 is 75% open, has a PTV 170 corresponding to the current 75% position, and the actuator 108 is fully open. It will have a PTV 170 of HI_ACT when in the% position and a PTV value 170 of LO_ACT when the actuator 108 is in the fully closed 0% position. At time T2, the position transmitter 1205 calculates a first value HI_CAL corresponding to the estimated or expected fully opened position of the actuator 108 to close the estimated or expected fully closed position of the actuator 108. A second value LO_CAL corresponding to the determined position is calculated. If the values of PPP and SENSITIVITY are substantially accurate, the value of HI_CAL is substantially equal to HI_ACT and the value of LO_CAL is substantially equal to LO_ACT. In practice, however, the value of PPP is an estimate of the position of actuator 108 (eg, a measured value with an error) and / or the value of SENSITIVITY is due to manufacturing tolerances and / or installation alignment deformations. Can be inaccurate. Accordingly, in some examples, the example position transmitter 1205 of FIG. 12 adjusts the estimated endpoint value in an objective manner, and thus is estimated and / or predicted represented by HI_ACT or LO_ACT. The movement range includes a smaller movement range of the actuator 108, as shown at time T3 in FIG.

The values of HI_ACT and LO_ACT can be calculated using the following equation, assuming that the feedback signal 170 increases as the valve 104 opens.
HI_CAL = PTV + (100−OFF−PPP) * SENSITIVITY * TRAVEL * (100−GAIN), and equation (11)
LO_CAL = PTV− (PPP−OFF) * SENSITIVITY * TRAVEL * (100−GAIN) Equation (12)
Where OFF is the tolerance (in percentage of travel span) in PPP estimation, TRAVEL is the physical stroke length or degree of rotation of valve 106 in engineering units, and GAIN is the calibration of sensor 140 Permissible (percentage of moving span) in excitation of sensor 140, amplification and / or filtering of sensor output 170 and / or analog-to-digital conversion of sensor output 170.

  Using the example equations of Equations (10)-(12), the example position transmitter 1205 is configured for the POS_SIGN 1210 corresponding to 0% and 100% valve positions during subsequent operation of the example valve device 1200 in the process plant. It is intended to output a value. In the illustrated example of FIG. 12, the example position transmitter 1205 transmits MAX as an output 1210 representing a 100% open valve before the valve 106 actually reaches the fully open 100% position, and the valve 106 Transmits MIN as an output 1210 representing a valve that is 0% open before actually reaching the fully closed 0% position.

When the example position transmitter 1205 of FIG. 12 operates within the process plant, the example position transmitter 1205 matches, adjusts and / or updates the estimated endpoint values HI_CAL and LO_CAL. During operation of the process plant, when the software in the position transmitter 1205 calculates a value for the POS_SIG 1210 that is outside the range [MIN, MAX], the position transmitter example 1205 has a corresponding calibrated endpoint value HI_CAL, Adjust LO_CAL. For example, when POS_SIG 1210 is calculated to exceed MAX, position transmitter 1205 updates the value of HI_CAL to match the current value PTV 170. Similarly, when POS_SIG 1210 is calculated to be less than MIN, position transmitter 1205 updates the value of LO_CAL to match the current PTV 170. By updating the values of HI_CAL and LO_CAL each time POS_SIG 1210 is calculated to be outside the range [MIN, MAX], the calibration of the example position transmitter 1205 is improved over time. When the valve 106 actually reaches a fully open or fully closed 0% position, the corresponding HI_CAL or LO_CAL calibration value becomes substantially ideal. Preferably, the position feedback 170 is filtered to reduce the effects of noise so that calibration errors are not introduced and / or caused by noise.

  The example position transmitter 1205 of FIG. 12 may automatically apply and / or operate as new LO_CAL and HI_CAL values are calculated as described in the preceding paragraph, and / or The LO_CAL and / or HI_CAL values can be stored and can be activated and / or applied only when the position transmitter 1205 is specifically commanded and / or indicated. For example, the position transmitter 1205 may display an indicator on the display 645 (FIG. 13) indicating that one or more new calibration values LO_CAL, HI_CAL are available for operation. For example, when the example input device (s) 640 (FIG. 13) indicates that the user will be applying new and / or updated calibration values LO_CAL, HI_CAL, the position transmitter 1205 may be activated. The calculated calibration values LO_CAL, HI_CAL are used to begin calculating subsequent values of POS_SIG 1210.

  FIG. 13 illustrates an example technique for implementing the example position transmitter 1205 of FIG. The elements of the example position transmitter 1205 of FIG. 13 are the same as those described above in connection with the example valve position controller 104 of FIG. 6, and therefore description of the same elements will not be repeated here. Instead, the same elements are designated with the same reference numerals in FIGS. 6 and 13, and interested readers can refer to FIG. 6 for a complete description of those identically numbered elements. Reverting to the description presented above in relation.

  The example position transmitter 1205 of FIG. 13 includes a calibrator 1305 to determine, calculate, and update the estimated values HI_CAL and LO_CAL. To calculate an initial pair of estimated values HI_CAL and LO_CAL based on a single externally provided position value PPP, the example calibrator 1305 of FIG. 13 includes an endpoint estimator 1310. For example, using the equations (11) and (12), the example endpoint estimator 1310 of FIG. 13 calculates initial values HI_CAL and LO_CAL.

  To update the values HI_CAL and LO_CAL during operation of the example valve device 1200 of FIG. 12 within the process plant, the example calibrator 1305 of FIG. 13 includes an end point adjuster 1315. The example end point adjuster 1315 of FIG. 13 updates the values of HI_CAL and LO_CAL during online operation of the position transmitter 1205. During operation, when the POS_SIG 1210 is calculated to be outside the range [MIN, MAX], the end point adjuster example 1315 sets the corresponding calibrated end point value HI_CAL, LO_CAL to the current value of the digital value 607. Adjust to. The end-point adjuster example 1315 may additionally or alternatively be used to calculate and / or update HI_CAL and LO_CAL if the valve 106 is stroked for purposes of calibration. It should be understood.

  To calculate the digital representation 1320 of POS_SIG 1210, the example position transmitter 1205 of FIG. 13 includes a position value determiner 1325. The example position value determiner 1325 of FIG. 13 calculates the value (s) of the digital signal 1320 based on the calibration values HI_CAL and LO_CAL, for example by implementing the example equation of equation (10).

To transmit and / or provide POS_SIG 1210 to process controller 185 and / or process interlock 1215, example position transmitter 1205 in FIG. 13 includes any type of transmitter or transceiver 1330. The example transmitter 1330 of FIG. 13 uses any number and / or type (s) of circuit (s), device (s), and / or method (s) to provide digital value (s). 1320 is converted into an analog signal, for example, a signal of 4 to 20 mA. Additionally or alternatively, the transceiver 1330 may transmit the digital value (s) 1320 as a signal 1210 digitally and / or wirelessly.

  Although an example technique for implementing the example position transmitter 1205 of FIG. 12 is illustrated in FIG. 13, one or more of the interfaces, data structures, elements, processes and / or devices illustrated in FIG. 13 may be combined, It can be split, rearranged, omitted, eliminated, and / or implemented in any other manner. Further, a position sensor interface example 605, a calibrator example 1305, an end point estimator example 1310, an end point adjuster example 1315, a storage device example 630, a user interface example 635, an input device example 640, a display example 645, a position value determination Example instrument 1325, example transmitter / transceiver 1330, and / or more generally, position transmitter 1205 of FIG. 13 may be any piece of hardware, software, firmware, and / or hardware, software, and / or firmware. It can be implemented by a combination. Thus, for example, position sensor interface example 605, calibrator example 1305, endpoint estimator example 1310, endpoint adjuster example 1315, storage device example 630, user interface example 635, input device example 640, display example 645, Any of the example position value determiner 1325, any example transmitter / transceiver 1330, and / or more generally, the position transmitter 1205 may include one or more (multiple) circuits, (multiple) programmable processors, (multiple). Application specific integrated circuit (several ASIC), programmable logic device (s) (plld) PLD, field programmable logic device (s) (FPLD), and / or Multiple field programmable gate arrays It may be carried out by (multiple) FPGA) or the like. When any claim of this patent that incorporates one or more of these elements is read purely as including software and / or firmware implementations, an example position sensor interface 605, an example calibrator 1305, Of example end point estimator 1310, example end point adjuster 1315, example storage device 630, example user interface 635, example input device (s) 640, example display 645, example position value determiner 1325, example transmitter / transceiver 1330 At least one, and / or more generally, the position transmitter 1205 is explicitly defined herein to include a tangible computer readable medium. Examples of a tangible computer readable medium include, but are not limited to, flash memory, compact disk (CD), DVD, floppy disk, read only memory (ROM), random access memory (RAM), programmable ROM ( PROM), electronically programmable ROM (EPROM), and / or electronically erasable PROM (EEPROM), optical storage disk, optical storage device, magnetic storage disk, magnetic storage device, and / or machine Any other tangible medium that can be used to store program code and / or instructions in the form of instructions or data structures readable by a processor, computer and / or for example in connection with FIG. The process described in That may be accessed by other machines having a processor such as service platforms example P100, or any other tangible media. Combinations of the above are also included within the scope of tangible computer readable media. Still further, example position transmitter 1205 may include and / or examples of interfaces, data structures, elements, processes and / or devices instead of or in addition to those illustrated in FIG. May include two or more of any or all of the interface, data structure, element, process and / or device.

  FIG. 14 illustrates an example process that may be performed to install the example position transmitter 1205 of FIGS. FIG. 15 illustrates an example process that may be performed to implement the example calibrator 1305 of FIG. 13 and / or, more generally, the example position transmitter 1205 of FIGS. A processor, controller and / or any other suitable processing device may be used and / or programmed to perform the example processes of FIGS. For example, the processes of FIGS. 14 and 15 may be read by a processor, a computer, and / or a tangible computer that may be accessed by other machines having a processor, such as the processor platform example P100 described below in connection with FIG. It can be embodied in coded and / or machine-accessible instructions stored on any product, such as possible media. Alternatively, some or all of the example operations of FIGS. 14 and 15 may include: (multiple) ASICs, (multiple) PLDs, (multiple) FPLDs, (multiple) FPGAs, discrete logic, hardware, firmware, etc. Can be implemented using any combination of (s). Also, one or more of the example operations of FIGS. 14 and 15 may be implemented manually or as any combination of any of the above techniques, for example, any combination of firmware, software, discrete logic and / or hardware. obtain. In addition, many other ways of implementing the example operations of FIGS. 14 and 15 can be utilized. For example, the order of execution of the blocks can be changed and / or one or more of the described blocks can be changed, eliminated, subdivided, or combined. Additionally, any or all of the example machine processes of FIGS. 14 and 15 may be executed sequentially and / or in parallel, eg, by separate processing threads, processors, devices, individual logic, circuits, etc. Can be executed.

  The process example of FIG. 14 begins with an operator and / or installer locating or securing (eg, manually securing) the valve assembly 102 using the example holder 190 (block 1405). For example, the operator can manually clamp the valve 106 using a clamp and / or block, or by preventing (eg, trapping) movement of the control fluid within the actuator 108, The position may be determined.

  The position transmitter to be replaced is removed (block 1410) and a replacement and / or new position transmitter 1205 is installed (block 1415). The installer activates the position transmitter 1205 (eg, provides power to the position transmitter 1205) to access the user interface 635 (block 1420). The installer inputs configuration data such as, for example, the sensitivity value SENSITIVITY of the position sensor 110 (eg, retrieved from a plate or label on the position sensor 110) (block 1425). The installer then inputs the single point position PPP of the position indicator 140 (block 1430). In some examples, the position PPP is entered as a percentage of the travel span of the actuator 108 (eg, 50% open).

  Based on the entered information, the position transmitter 1205 calculates calibration values LO_CAL and HI_CAL, and the installer applies these values (block 1440).

  The installer places the position transmitter 1205 in an active state (block 1445) to unlock or release the position of the valve assembly 102 (block 1450).

The example process of FIG. 15 begins with the endpoint adjuster 1315 waiting for the calculated value of POS_SIG 1210 to be outside the range [MIN, MAX] (block 1505). When the calculated value of POS_SIG 1210 is outside the range [MIN, MAX] (block 1505) and a calibration improvement is to be applied automatically (block 1510), the endpoint adjuster 1315 receives the corresponding calibration. The action values HI_CAL, LO_CAL are updated to the current values of the PTV 170 (block 1515).

  If a calibration improvement will not be automatically applied (block 1510), the endpoint adjuster 1315 will inform the user that new and / or improved calibration data is ready to be applied (eg, , Via the example display 645 (block 1520) to determine if the PTV 170 is outside the range of the previous NEW_CAL value (block 1525). If the PTV 170 is outside the previous range (block 1525), the endpoint adjuster 1315 stores the calibration values NEW_HI_CAL, NEW_LO_CAL updated for subsequent retrieval and / or activation (block 1530). Control then returns to block 1505 and waits for the value of POS_SIG 1210 to be outside the range [MIN, MAX].

  FIG. 16 is a schematic diagram of an example processor platform P100 that can be used and / or programmed to implement any of the apparatus and / or example methods for calibrating the barre position controller disclosed herein. For example, one or more general purpose processors, processor cores, microcontrollers, etc. may implement the processor platform P100.

  The processor platform P100 in the example of FIG. 16 includes at least one programmable processor P105. Processor P105 executes coded instructions P110 and / or P112 that reside in main memory of processor P105 (eg, in RAM P115 and / or ROM P120). The processor P105 may be any type of processing unit, such as a processor core, a processor and / or a microcontroller. The processor P105 may perform, among other things, the example processes of FIGS. 7-11, 14 and / or more generally the example valve position controller 104 of FIGS. 1 and 6 and / or the position transmitter of FIGS. Example 1205 may be performed.

  The processor P105 is in communication with any number and / or types of tangible computer readable storage media (including ROM P120 and / or RAM P115) via bus P125. RAM P115 may be implemented by dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM) and / or any other type of RAM device, ROM may be flash memory and / or any other Can be implemented by any desired type of memory device. Access to the memory P115 and the memory P120 can be controlled by a memory controller (not shown). Memory examples P115 and P120 may be used, for example, to implement the example storage device 630 of FIGS.

  The processor platform P100 also includes an interface circuit P130. Any type of interface standard, such as an external memory interface, serial port, general purpose input / output, etc. may implement the interface circuit P130. One or more input devices P135 and one or more output devices P140 are connected to the interface circuit P130. Input device P135 may be used to implement example input device (s) 640, and output device P140 may be used to implement example display 645 of FIGS.

  Although certain methods, apparatus, and system examples are described herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent includes all methods, devices, systems, and products that fall within the scope of the appended claims, either literally or under an equivalent theory.

Claims (20)

Fixing the position of the flow control member of the control valve assembly to prevent movement of the flow control member;
Installing a controller in the control valve assembly;
Activating a user interface of the controller after the controller is coupled to the control valve assembly;
Inputting a position sensor sensitivity value and a single point position value representing the fixed position of the flow control member;
Applying a single point calibration value;
Placing the controller in control mode;
The position of the flow control member is released so that the controller can operate during operation of the control valve assembly based on the position sensor sensitivity value and the single point position value while the control valve assembly is in operation. Self-calibrating.   The method further comprises removing another controller from the control valve assembly prior to installing the controller while the control valve assembly is in the field and in service using a process control system. The method according to 1.   The method according to claim 1, wherein inputting the single point position value comprises visually estimating the fixed position of the flow control member.   4. The method of any of claims 1-3, wherein inputting the single point position value comprises inputting the single point position value as a percentage of a travel span of the flow control member.   Applying the single point calibration includes inputting a first estimated calibration value and a second estimated second calibration value, the first and second estimated values The method according to claim 1, wherein calibration values represent upper and lower travel span limits of the flow control member, respectively.   Obtaining the estimated first and second calibration values from the controller, the controller determines the first and second estimated values based on the single point calibration position and the position sensor sensitivity value. 6. The method according to any of claims 1-5, further comprising determining a calibration value.   7. Placing the controller in the control mode includes placing the controller in an active state to allow the control valve assembly to control fluid flow in a process system. The method of crab.   Placing the controller in the control mode means that the control between one movement end point of the flow control member and the other movement end point of the flow control member before placing the controller in the control mode. 8. A method as claimed in any preceding claim, including actuating the controller without stroking a valve assembly.   9. A method according to any preceding claim, further comprising selecting a calibration routine for the controller via the user interface. Coupling a controller to the control valve assembly while the control valve assembly is in service or in-line with a process control system;
Providing a position sensor sensitivity value to the controller;
Providing a single point position value representative of a current position of the flow control member of the control valve assembly;
Based on the position sensor sensitivity value and the single point position value, an estimated upper stroke limit value representing the first movement span limit of the flow control member and a second movement span limit of the flow control member are obtained. Entering an estimated lower stroke limit value to represent;
Actuating the controller to allow operation of the control valve assembly to control fluid flow of the process control system, the controller based on the position sensor sensitivity value and the single point position value Calibrating during operation of the control valve assembly.   The method of claim 10, further comprising fixing the current position of the flow control member to prevent movement of the flow control member.   The providing of the single point position value comprises estimating the current position of the flow control member relative to a total travel span of the flow control member when the flow control member is fixed. The method in any one of 10-11.   13. The method according to any of claims 10-12, further comprising releasing the flow control member and activating the controller.   14. A method according to any of claims 10 to 13, wherein providing the position sensor sensitivity value and the single point position value comprises inputting the value to the controller via an input interface.   Determining an estimated upper stroke limit value and an estimated lower stroke limit value is based on the provided position sensor sensitivity value and the single point position value, and the estimated upper and lower strokes. 15. A method according to any of claims 10 to 14, comprising causing a limit value to be calculated by the controller. Locking the position of the flow control member of the control valve assembly while the valve control assembly is in the fluid system;
Initiating calibration of a controller that operates the control valve assembly;
Inputting a predetermined position sensor sensitivity value to the controller via a user interface;
Inputting a single point position value representing the locked position of the flow control member with respect to a travel span of the flow control member;
Obtaining upper and lower calibration values estimated from the controller based on the position sensor sensitivity value and the single point position value;
Inputting the estimated upper and lower calibration values via the user interface;
Activating the controller;
Unlocking the flow control member to allow the control valve assembly to control the fluid system so that the controller can control the single point position value, the position sensor sensitivity value and the estimated upper and Calibrating based on the subordinate calibration value.   The method of claim 16, wherein inputting the single point position value includes visually estimating the position of the flow control member after the control valve is secured.   18. A method according to any of claims 16 to 17, wherein entering the single point position value comprises entering a value as a percentage of the travel span of the flow control member.   19. A method according to any of claims 16-18, wherein inputting the single point position comprises measuring the position of the flow control member via a position sensor of the control valve assembly.   By operating the controller while the control valve assembly is in-line or in service with the fluid system and without stroking the flow control member or bypassing the control valve assembly 20. A method according to any of claims 16 to 19, further comprising calibrating the controller.

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