CN203979570U - Control valve assembly - Google Patents

Abstract

A control valve assembly is described. An exemplary control valve assembly disclosed herein includes: a valve having a flow control element; an actuator mechanically connected to the flow control element; and a controller communicatively coupled to the actuator wherein the actuator moves the flow control element in response to a control signal received from the controller; wherein when the control valve assembly is operating, the controller The position value is self-calibrating during operation of the control valve assembly, and the single point position value represents the position of the flow control element when the controller is placed in a control mode.

Description

control valve assembly

technical field

The utility model generally relates to a valve, and more specifically, relates to a control valve assembly.

Background technique

A process plant element, such as a valve, typically has associated installed instrumentation, such as a valve position controller and/or position transmission that controls the element and/or communicates information about the element to achieve one or more required processes and/or operations in the process plant device. Exemplary valve assemblies include diaphragm-type or piston-type pneumatic actuators controlled by electropneumatic valve position controllers. An exemplary electropneumatic valve position controller receives one or more control signals (eg, 4-20 milliamp (mA) control signal, 0-10 volt direct current (VDC) control signal, digital control signal, etc.) and converts the control signal The air pressure supplied to one or more pneumatic actuators to open, close or maintain the corresponding valve position. For example, if the process control program determines that a pneumatically actuated, normally closed stroke valve will allow the passage of a relatively large volume and/or flow rate of process fluid, assuming the current type of control signal is used, the The amplitude of the control signal can be increased from 4mA to 8mA.

In certain embodiments, the electropneumatic valve position controller uses a feedback signal generated via a feedback sensing system or element, such as a position sensor. This feedback signal represents the position of the pneumatic actuator and corresponding valve. The valve position controller compares the feedback signal with a control signal representative of a desired set point or desired valve position (eg, 35% open) and determines whether to adjust one or more air pressures supplied to the actuator. In order for a position controller, actuator and valve combination to function as intended within a process plant, the position controller needs to be calibrated against the feedback sensing element.

Utility model content

In order to solve the technical problem in the prior art that the valve needs to stop working or be offline to fully drive the valve when calibrating the valve, the utility model provides a control valve assembly that can use a single externally set position value for self-calibration.

A control valve assembly is disclosed, comprising: a valve having a flow control element; an actuator mechanically connected to the flow control element; and a controller communicatively coupled to the flow control element. an actuator, wherein the actuator moves the flow control element in response to a control signal received from the controller; wherein when the control valve assembly is operated, the controller operates according to the position sensor sensitivity value and A single point position value is self-calibrating during operation of the control valve assembly, the single point position value representing the position of the flow control element when the controller is placed in a control mode.

Advantageously, further comprising removing another controller from said control valve assembly while said control valve assembly is in place and operating with a process control system prior to installing said controller.

Advantageously, said single point position value represents an initial position of said flow control element when said controller is initially installed in said control valve assembly.

Advantageously, said single point position value represents a percentage of travel span of said flow control element.

Advantageously, said self-calibration is also based on a first estimated calibration value and a second estimated calibration value, wherein said first estimated calibration value and said second estimated calibration value respectively represent an upstroke span limit of said flow control element and downstroke span limit.

Advantageously, further comprising obtaining a first estimated calibration value and a second estimated calibration value from said controller, said controller determining said first estimated calibration value and said second estimated calibration value from a single point calibration position and a position sensor sensitivity value Estimate the calibration value.

Advantageously, placing said controller in a control mode includes activating said controller to cause said control valve assembly to control fluid flow to a process system.

Advantageously, placing said controller in control mode comprises activating the controller without prior to placing said controller in control mode between one end of travel of said flow control element and the other end of travel of said flow control element drive the control valve assembly between.

Advantageously, further comprising selecting a calibration procedure for said controller via a user interface.

A control valve assembly is disclosed, characterized in that it includes: a controller coupled to the control valve assembly when the control valve assembly is operated with or on-line with a process control system, wherein the controller includes; a position sensor sensitivity value; a single point position value representing the current position of the flow control element of the control valve assembly; based on the position sensor sensitivity value and the single point position value representing the first travel span limit of the flow control element an estimated upper stroke limit value and an estimated lower stroke limit value representing a second stroke span limit of the flow control element; and wherein the controller estimates the upper stroke limit value based on the position sensor sensitivity value, the single point position value, Limits and estimated downstroke limits are self-calibrating during operation of the control valve assembly.

Advantageously, the current position of the flow control element is fixed against movement of the flow control element.

Advantageously, said single point position value represents an estimate of the current position of said flow control element relative to the entire travel span of said flow control element when said flow control element is fixed.

Advantageously, further comprising releasing said flow control element and activating said controller.

Advantageously, the position sensor sensitivity value and the single point position value are input to the controller via an input interface.

Advantageously, determining the estimated up-travel limit and the estimated down-travel limit comprises causing the controller to calculate the estimated up-travel limit and the estimated down-travel limit based on the position sensor sensitivity value and the single point position value.

A control valve assembly is disclosed, characterized in that it includes: a controller, when the control valve assembly is located in a fluid system, the controller determines the position of the flow control element of the valve in the control valve assembly; a predetermined position a sensor sensitivity value; a single point position value representing the initial position of the flow control element relative to the span of travel of the flow control element when the controller is placed in control mode; based on the position sensor sensitivity value and estimated upper and lower calibration values of the single-point position value; and wherein the controller self-calibrates based on the single-point position value, the position sensor sensitivity value, and the estimated upper and lower calibration values .

Advantageously, said single point position value represents a visual estimate of the position of said flow control element before said control valve is placed in control mode.

Advantageously, said single point position value is expressed as a percentage of the travel span of said flow control element.

Advantageously, said single point position value is obtained by measuring the position of said flow control element by means of a position sensor of said control valve assembly.

Advantageously, when the control valve assembly is on-line or operating with a fluid system, the controller self-calibrates without actuating the flow control element or bypassing the control valve assembly.

Based on the provided measured or estimated current position value, the control valve assembly of the present invention learns, adapts and/or self-calibrates during subsequent operation of the valve assembly within the running process plant. Control valve assemblies in accordance with the present invention can be used without taking the relevant part of the process plant offline or shutting down, without the need to actuate, adjust or reposition valves, without bypass lines, and without the need for benches, testing or calibration of valves components.

Description of drawings

FIG. 1 illustrates an example valve apparatus with a valve position controller that can be calibrated using the example methods and apparatus described herein.

2A-2C depict example states of the example valve assembly of FIG. 1 .

3 , 4 and 5 illustrate example calibration operations that may be accomplished by the example valve position controller of FIG. 1 .

FIG. 6 illustrates an example manner of implementing the example valve position controller of FIG. 1 .

FIG. 7 illustrates an example process that may be performed to install the example valve position controller of FIGS. 1 and 6 .

8-11 illustrate an example process that may be performed to calibrate and/or implement the example valve position controller of FIGS. 1 and 6 .

FIG. 12 illustrates an example valve apparatus with a position transmitter that can be calibrated using the example methods and apparatus described herein. .

FIG. 13 illustrates an example manner of implementing the example position transmitter in FIG. 12 .

FIG. 14 illustrates an example process that may be performed to install the example position transmitters of FIGS. 12 and 13 .

FIG. 15 illustrates an example process that may be performed to calibrate and/or implement the example position transmitters of FIGS. 12 and 13 .

16 is a schematic diagram of an exemplary processor platform that may be used and/or programmed to implement the exemplary processes in FIGS. 7-11, 14 and 15, and/or, more generally, Implement the example valve position controller in FIGS. 1 and 6 and/or the example position transmitter in FIGS. 12 and 13 .

Detailed ways

In order to calibrate certain valves, the valve must be stroked between one end-of-stroke end point or position (eg, fully open position) and another end-stroke end-point or position (eg, fully closed position). However, this approach is disadvantageous because it requires shutting down or taking the valve offline to fully actuate the valve. In some cases, however, the process system cannot be interrupted or shut down to allow for valve position controller and/or position transmitter calibration. Even when a process system can be disrupted, such disruption can have undesirable monetary and/or efficiency impacts. While bypass lines can be used to isolate valves and keep process systems online, bypass lines are not always desirable, efficient, or feasible.

Additionally or alternatively, certain valve position controllers and/or position transmitters may be calibrated using bench, test or calibration valves, actuators and position sensors that The sensor has generally similar or identical characteristics (eg, stroke length, stroke end points, etc.) to the valve, actuator, and position sensor to which the valve position controller and/or position transmitter is mounted. For example, test valves, actuators and position sensors are located in maintenance workshops or laboratories located far from the actual process plant. In the laboratory or workshop, test valves, actuators and position sensors can be fully or fully actuated in order 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 rig and operatively connected or installed to the target valve actuator within the process plant. Although effective, this calibration method is time consuming and requires the availability of suitable test equipment.

To overcome at least these deficiencies, the example valve position controllers and position transmitters described herein may self-calibrate using a single, externally set position value indicating that the valve position controller is installed, was installed, and/or will An estimate of the current position (eg 70% closed) of the installed valve assembly (ie valve, actuator and position sensor considered in combination). In the embodiments described herein, no further position values need be provided to the valve position controller or position transmitter before the valve position controller or position transmitter is operational in the process plant. Individual position values can be easily and/or easily determined and/or estimated by the installer, for example by visually verifying and/or measuring the current position of the valve assembly during installation of the valve position controller. The installer inputs and/or provides the measured or estimated current position value to the valve position controller or position transmitter, eg, using the user interface. Based on the provided measured or estimated current position values, the example valve position controllers and position transmitters described herein learn, adapt and/or self-calibrate during subsequent operations of operating the valve assembly within the process plant. Thus, the methods and apparatus described herein for calibrating valve position controllers and position transmitters can be used without taking the relevant part of the process plant offline or shutting down, without actuating, adjusting or repositioning valves, without bypassing through-line without the need for benches, testing, or calibration of valve assemblies.

FIG. 1 illustrates an exemplary valve apparatus 100 including a valve assembly 102 and a valve position controller 104 constructed in accordance with the teachings of the present disclosure. Although the exemplary method and apparatus for calibrating a valve position controller are described with reference to the exemplary valve assembly 102 in FIG. and/or type of other or optional valve assembly for use with valve position controllers. For example, although valve 106 is depicted in FIG. 1 as a sliding stem control valve, the exemplary method and apparatus for calibrating a valve position controller can be used with any other type of valve, including but not limited to rotary control valves. valves, quarter-turn control valves, and more. Additionally or alternatively, while the exemplary actuator 108 in FIG. 1 is depicted as a double-acting piston actuator, any other type of actuator, such as a rotary actuator, a single-acting spring return Either diaphragm or piston actuators can be used. It should be further understood that the single position value calibration methods and apparatus described herein may be used with any number and/or type of other controllable devices including, but not limited to, buffers, elevators, lifting equipment, balances, wait. Therefore, the embodiment of FIG. 1 is merely an exemplary embodiment for the purpose of discussion, and the scope covered by this patent is not limited thereto.

The exemplary valve assembly 102 in 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 therein that defines an aperture 114 providing a fluid flow passage within the valve 106 between openings 116 and 118 . The exemplary actuator 108 in FIG. 1 can be operably connected to a flow control element 120 by a valve stem 122, which can move the flow control element 120 in a first direction (eg, away from the valve seat 112) to allow openings 116 and 118. greater fluid flow between openings 116 and 118, and moving flow control element 120 in a second direction (eg, toward valve seat 112) to further restrict or prevent fluid flow between openings 116 and 118.

The example pneumatic actuator 108 in FIG. 1 includes a piston 130 disposed within a housing 132 to define a first chamber 136 and a second chamber 137 . An actuator output rod 138 is connected to the piston 130 and is operatively connected to the valve stem 122 through a connector 139 with an associated travel indicator 140 . The flow rate through valve 106 is controlled by adjusting the position of piston 130 relative to housing 132 to adjust the position of flow control element 120 relative to valve seat 112 and the position of valve 106 .

To control the position of the example piston 130, the example electropneumatic valve position controller 104 of FIG. 136, and is supplied to the second chamber 137 through the second channel 154. The differential pressure, if any, that exists across the exemplary piston 130 determines whether the piston 130 is stationary or moving. For example, to move piston 130 in a first direction (eg, downward in FIG. 1 ), valve position controller 104 supplies control fluid to first chamber 136 at a pressure greater than that supplied to second chamber 137, thereby A net downward force is exerted on the piston 130 . Movement of piston 130 in a first downward direction moves actuator output rod 138 , valve stem 122 , and flow control element 120 toward valve seat 112 , thereby further preventing or restricting fluid flow through bore 114 . Conversely, to move piston 130 in a second direction (eg, upward in FIG. 1 ), valve position controller 104 supplies control fluid to first chamber 136 at a pressure less than that supplied to second chamber 137, by This exerts a net upward force on piston 130 . Movement of piston 130 in the second upward direction moves actuator output rod 138 , valve stem 122 , and flow control element 120 away from valve seat 112 , thus allowing greater fluid flow through bore 114 .

In the illustrated embodiment of FIG. 1 , actuator 108 includes travel stops 160 and 162 . An exemplary travel stop 160 corresponds to the fully open or 100% travel span position (see FIG. 2A ) of the actuator 108 , ie, the maximum or highest travel end point. An exemplary travel stop 162 corresponds to the fully closed or 0% travel position (see FIG. 2C ) of the actuator 108 , ie, the minimum or lowest travel end point. FIG. 2B depicts the piston 130 intermediate the stops 160 and 162, thus corresponding to the 50% stroke position. In some embodiments, travel stops 160 and/or 162 are adjustable.

Turning 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 exemplary position sensor 110 in FIG. 1 measures and/or senses the position of the travel indicator 140 relative to the stationary position sensor 110 and outputs and/or provides a signal 170 indicative of the current position of the travel indicator 140 and the position of the valve 106. Position (e.g. opening or span as a percentage). An exemplary position sensor 110 is a linear array of Hall effect sensors that outputs an analog signal 170 having different values (eg, voltage or current) corresponding to different positions of the travel indicator 140 . The exemplary analog signal 170 in FIG. 1 represents the absolute travel or position of the travel indicator 140 . For example, assuming that the actuator 108 has a stroke length of 100 millimeters (mm), and the position signal 170 transitions between 0 and 40 millivolts (mV), when the valve stem 122 moves 10%, the analog signal 170 changes by 4 mV , ie 10% of 40mV. The analog signal 170 has a first travel value and/or voltage (PTV) when the travel indicator 140 is in the first position corresponding to the piston 130 contacting the stopper 162 ( FIG. 2C ), and when the travel indicator 140 is in contact with the piston 130 There is a second PTV when the contact limiter 160 corresponds to the second position (FIG. 2A), and there is a possibility of being between the first PTV and the second PTV when the travel indicator 140 is between the first and second positions PTV range. For example, if piston 130 is at the midpoint between stops 160 and 162 (FIG. 2B), analog signal 170 has a PTV at the midpoint between the first and second PTVs. In some embodiments, the position sensor 110 may measure a greater range of motion than the actuator 108 physically supports, that is, the length of the position sensor 110 is greater than the total travel length of the actuator 108 . While the exemplary position sensor 110 in FIG. 1 outputs an analog signal 170 , the position sensor may additionally or alternatively output a digital signal having a count value representing the relative position of the travel indicator 140 . Further, the analog signal 170 output by the position sensor 110 may be converted into a digital signal by the valve position controller 104 before being processed.

The example valve position controller 104 in FIG. 1 may self-calibrate based on a single externally provided position value PPP or an estimate and/or approximation thereof representing the current position of the actuator 108 (eg, 70% open). As described here, the valve position controller 104 does not require additional externally provided position values before the valve position controller 104 starts operating in the process plant. Further, the position of the actuator 108 need not be adjusted, changed, or actuated prior to operation of the exemplary valve apparatus 100 of FIG. 1 in a process plant. For example, a single position value PPP may be easily and/or readily determined by an installer by, for example, visually verifying (e.g., estimating) and/or measuring the current position of position indicator 140 during installation of valve position controller 104 and/or estimates. An installer provides and/or inputs the estimated or measured position value PPP to and/or enters the valve position controller 104 , for example, via an input device 640 ( FIG. 6 ) of the valve position controller 104 . While the exemplary valve position controller 104 may self-calibrate based on a single estimated position value when additional position values are available, or based on an estimate or measurement provided by the installer and/or determined by actuating the valve 106 Calibration, this added value can be used, for example, to improve calibration accuracy.

Based on a single estimated position value PPP and a sensitivity value SENSITIVITY representing the change in PTV 170 on each travel unit of position indicator 140 and the overall travel distance value of the valve, the exemplary valve position controller 104 in FIG. 1 estimates the desired and/or Or predict the PTV 170 corresponding to the end-of-travel of the valve actuator 108 . Alternatively, the value SENSITIVITY represents a count value indicating the entire travel of the valve 106 . Further, the value SENSITIVITY represents the change in PTV 170 over the travel of valve 106 . Referring to FIG. 3, at time point T1, the exemplary valve assembly 102 of FIG. 1 is 75% open and has a PTV 170 corresponding to the current 75% position, with a HI_ACT of HI_ACT when the actuator 108 is in the fully open 100% position. PTV 170 and PTV 170 with LO_ACT when actuator 108 is in the fully closed 0% position. At time T2, valve position controller 104 calculates a first value HI_CAL corresponding to the estimated or expected fully open position of actuator 108 and calculates a second value LO_CAL corresponding to the estimated or expected fully closed position of actuator 108 . 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 reality, however, the value of PPP is an estimate (eg, a measurement with error) of the position of the actuator 108 and/or the SENSITIVITY value is inaccurate due to manufacturing tolerances and/or mounting orientation variations. Therefore, in some embodiments, the example valve position controller 104 of FIG. The travel range, as shown at time point T3.

The values of HI_ACT and LO_ACT can be calculated using the following mathematical expressions, assuming that the feedback signal 170 increases when the valve 104 is open:

HI_CAL=PTV+(100-PPP)*(1+RAF)*SENSITIVITY, equation (1), and

LO_CAL=PTV-PPP*(,1+RAF)*SENSITIVITY, equation (2)

where RAF is a range adjustment factor, such as 0.1, that results in a 10% increase in the value of HI_CAL and a 10% decrease in the value of LO_CAL, and a value of PPP expressed as a percentage of the travel range of the actuator 108 . If, in turn, the feedback signal 170 decreases when the valve 104 is open, then the values of HI_ACT and LO_ACT are calculated using the following mathematical expressions:

HI_CAL=PTV+PPP*(1+RAF)*SENSITIVITY, equation (3), and

LO_CAL=PTV-(100-PPP)*(1+RAF)*SENSITIVITY, equation (4)

Using numerous and/or various types of methods, algorithms, and/or logic, the example valve position controller 104 in FIG. Control signal 180 of position and/or set point (SP) (eg, 40% open) to determine how the pressure of the control fluid supplied to chambers 136 and 137 should be adjusted and/or maintained based on estimated endpoint values HI_CAL and LO_CAL . For example, based on HI_CAL and LO_CAL, the example valve position controller 104 calculates a value TARGET of the position signal 170 corresponding to the desired position of the valve 106 . The valve position controller 104 then regulates the pressure in the chambers 136 and 137 until the actual PTV 170 substantially meets or equals the value TARGET. The value TARGET can be calculated using the following mathematical expression:

TARGET=LO_CAL+SP*(HI_CAL-LO_CAL)／100, equation (5)

While the example valve apparatus 100 of FIG. 1 is operating in a process plant, the example valve position controller 104 adapts, adjusts and/or modifies the estimated position using numerous and/or various types of algorithms, logic, criteria and/or methods The endpoint values HI_CAL and LO_CAL. When the piston 130 reaches either of the physical travel stops 160 , 162 during plant operation, the example valve position controller 104 adjusts the corresponding calibrated endpoint values HI_CAL, LO_CAL. The detection of when the piston 130 has reached the stops 160, 162 can be done by detecting that the pressure applied to the piston 130 no longer changes even though the pressure applied to the piston 130 should cause the piston 130 to move. For example, at time point T4 in FIG. 3 , the 100% fully open limiter 160 is reached, and the valve position controller 104 modifies the HI_CAL value to match the current PTV 170 value, which is equal to HI_ACT. Likewise, at time T5, when the 0% fully closed stop 162 is reached, the valve position controller 104 modifies the LO_CAL value to match the current PTV 170 value, which is equal to LO_ACT.

Under certain circumstances, using the exemplary calibration method illustrated in FIG. 3 , adverse valve positioning effects may occur. In the illustrated embodiment of FIG. 3 , the calibration values HI_CAL and LO_CAL are fully adjustable so long as the piston 130 reaches the respective travel stops 160 , 162 , potentially causing the valve 106 to move away from the respective end points 160 , 162 . For example, if the piston 130 reaches the fully closed stop 162 at the 5% open position SP180, and the value of LO_CAL is immediately fully adjusted as described above, the valve position controller 104 will immediately proceed by opening the valve 106 to 5%. response, causing a sudden change in process fluid flow. This change in valve position can interrupt work in progress and/or have other negative consequences.

Turning to Figure 1, to reduce the likelihood of this effect, another exemplary automatic calibration method adjusts the calibration value only when the program controller 104 moves SP 180 beyond a certain value, at which point valve 106 reaches one of its travel limits HI_CAL and LO_CAL. In this case, the appropriate HI_CAL or LO_CAL value can be adjusted without causing a change in the position of valve 106 . When the SP signal 180 actually reaches 0% and 100%, the calibration of the corresponding endpoints HI_CAL, LO_CAL is completed. Otherwise, the calibration of the endpoints HI_CAL, LO_CAL is still 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. Up to stop 162, the value of LO_CAL can be corrected using the following mathematical expression:

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). In order to reduce reasonable control errors due to, for example, inaccurate signal offsets present in the position feedback signal 170, the following mathematical expression is used to modify the value of LO_CAL to include a 1% safety factor:

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 physical stop of 100% open, for example by detecting that the actuator pressure has loaded the piston 130 to the stop 160, the value of HI_CAL can similarly use the following mathematical expression One of them is corrected.

HI_CAL=LO_CAL+(PTV-LO_CAL)*100/SP, equation (8)

HI_CAL=LO_CAL+(PTV-LO_CAL)*101/SP, equation (9)

Like equation (7), equation (9) includes a 1% safety factor.

FIG. 4 illustrates an example modification of LO_CAL using the example expressions of Equation (6) or Equation (7). In the embodiment of Figure 4, the actuator pressure 405 decreases during normal operation. At some time 410, SP 180 drops below the value at which actuator 108 reaches the fully closed 0% position. However, due to inaccurate calibration, SP180 is still above 0%. Due to controller gain, actuator pressure 405 decreases rapidly as SP180 continues to decrease. The example valve position controller 104 in FIG. 1 recognizes that the actuator 108 is fully closed from the low actuator pressure 405 and modifies LO_CAL using one of the mathematical expressions in Equation (6) or Equation (7). to the new minimum, thus improving the accuracy of the LO_CAL value by 5% in the embodiment of FIG. 4 . If the SP180 has been fully driven to the 0% position, the calibration of LO_CAL is basically ideal. In some embodiments, equation (6) or equation (7) is repeated when actuator 108 is held in the fully closed 0% position and SP 180 is varied. Additionally or alternatively, equation (6) or equation (7) is used for the minimum value of SP 180 that occurs when the actuator 108 is in the fully closed 0% position.

Turning to FIG. 1 , in some embodiments, any one of the equations (6)-(9) shown in Eqs. fix.

In yet another embodiment, the example valve position controller 104 of FIG. 1 records the PTV 170 when the SP 180 reaches a value at which the valve 106 reaches one of its travel limits. Thereafter, whenever SP 180 is changed by an amount to eliminate noise activation, the example valve position controller 104 applies a small correction to the corresponding calibration values LO_CAL, HI_CAL, which will reduce the recorded PTV 170 from the corresponding calibration values LO_CAL, HI_CAL. The difference between HI_CAL. By slowly changing the calibration values LO_CAL and HI_CAL over a period of time during which SP 180 is changed, any interruption to an ongoing process can be reduced, reduced and/or eliminated. In some embodiments, the usage rate of the calibration correction is limited to 0.1% of the total stroke span per minute or one stroke count per minute. Depending on the dynamics of the SP 180 (eg, how much and/or at what speed the SP 180 changes), the rate of calibration corrections may need to be decreased and/or increased.

While the embodiments described above are based on initial, purposefully expanded calibration values HI_CAL and LO_CAL, alternatively, valve position controller 104 may initially underestimate the range of travel of actuator 108, as shown in FIG. 5 . For example, the compressed calibration values HI_CAL and LO_CAL can be calculated using equations (1)-(4) with a RAF of -0.1. At time T4, the actuator 108 is still moving due to the differential pressure of the chambers 136, 137, but the value of PTV 170 has exceeded the current HI_CAL value, and the HI_CAL value is adjusted to reflect the current PTV value. The underestimated stroke limit LO_CAL is also adjusted, as indicated at time T5. Without SP 180 exceeding a value corresponding to a valve position of 0% to 100%, valve 106 may not have reached the end of its stroke, so calibration of the HI_CAL and LO_CAL values as shown in FIG. 5 is not possible.

Additionally or alternatively, the HI_CAL and LO_CAL calibration values may be adjusted by detecting when SP 180 exceeds the 0 to 100% range, provided SP 180 exceeds a value corresponding to a 0% to 100% valve position. In some embodiments, the valve position controller 104 implements a cutout, which is to intentionally fully load the actuator 108 to the set of mechanical stops 160 when the SP 180 reaches a corresponding respective predetermined value (eg, 5% or 95%). , one of 162. In such an embodiment, it may be advantageous to undo the cutout when using the originally compressed calibration values HI_CAL and LO_CAL. When SP 180 is out of range and moved by an amount to eliminate the effects of noise, and the actuator pressure is not loading the piston 130 against the respective stops 160, 162, the example valve position controller 104 adjusts the respective calibrated values HI_CAL, HI_CAL, LO_CAL, moves the actuator 108 toward and/or loads the stops 160 , 162 . After a period of time, one or more of the above conditions will no longer be met and the calibration will be substantially complete. In some embodiments, the calibration values HI_CAL, LO_CAL are repeatedly adjusted when the piston 130 is unloaded and the SP 180 varies and is outside the range of 0 to 100%. Additionally or alternatively, the calibration values HI_CAL, LO_CAL are adjusted using the maximum SP 180 range value that occurs when the piston 130 is unloaded.

In yet another embodiment, the example valve position controller 104 of FIG. 1 records the PTV 170 when the SP 180 reaches a value at which the valve 106 reaches one of its travel limits. Thereafter, whenever SP 180 is changed by an amount to eliminate noise activation, the example valve position controller 104 applies a small correction to the corresponding calibration values LO_CAL, HI_CAL, which will reduce the recorded PTV 170 from the corresponding calibration values LO_CAL, HI_CAL. The difference between HI_CAL. By slowly changing the calibration values LO_CAL, HI_CAL over a period of time during which SP 180 is changed, any interruption to an ongoing process can be reduced, reduced and/or eliminated. In some embodiments, the usage rate of the calibration correction is limited to 0.1% of the total stroke span per minute or one stroke count per minute. Depending on the dynamics of the SP 180 (eg, how much and/or at what speed the SP 180 changes), the rate of calibration corrections may need to be decreased and/or increased.

While any of the exemplary valve calibration methods described above may automatically apply and/or initiate new LO_CAL and HI_CAL values at calculation time, additionally or alternatively, the new LO_CAL and/or HI_CAL values are stored and The valve position controller 104 is activated and/or used when explicitly commanded and/or directed. For example, valve position controller 104 may display a flag on display 645 (FIG. 6) indicating that one or more new calibration values LO_CAL, HI_CAL may be enabled. For example, when the user indicates via the exemplary input device 640 that new and/or revised calibration values LO_CAL, HI_CAL are to be used, the valve position controller 104 begins using the activated calibration values LO_CAL, HI_CAL during subsequent valve control operations. .

In yet another embodiment, a combination of the calibration methods described above is possible. For example, a calibration method as described above for the initial extended range may be used when it is detected that the piston 130 is loaded to the stops 160, 162 by the SP 180 in the range of 0 to 100%. However, when SP180 is detected not in the 0 to 100% range, a calibration method as described above for the initial compression range can be used. In other further embodiments, the calibration values HI_CAL and LO_CAL are estimated and/or calculated as accurately as possible using an appropriate calibration method as described above depending on the detection conditions used, rather than purposefully expanding or compressing the initial calibration Values HI_CAL and LO_CAL.

Turning to FIG. 1, the exemplary apparatus 100 of FIG. 1 includes any number and/or type of Retainers, one of which is designated by reference numeral 190, are used to secure, hold and/or maintain the current position of the valve assembly. Exemplary retainers 190 include, but are not limited to, clips, stops, and/or fluid traps.

FIG. 6 illustrates an example manner of using the example valve position controller 104 of FIG. 1 . To receive the feedback position signal 170 , the example valve position controller 104 in FIG. 6 includes a position sensor interface 605 . Using any number and/or type of circuits, components, and/or devices, the exemplary position sensor interface 605 of FIG. 6 conditions and/or converts the feedback signal 170 into a form suitable for processing by the valve controller 610 and/or calibrator 615 . For example, position sensor interface 605 may convert analog feedback signal 605 into count value 607 representing the current position PTV of travel indicator 140 . Additionally or alternatively, if the feedback signal 170 has a different polarity due to the travel indicator 140 being positioned above or below the centerline of the position sensor 110, the position sensor interface 605 may compensate the feedback signal 170 so that, for example, only has a positive value.

To receive the control signal 180 , the example valve position controller 104 in FIG. 6 includes a control signal interface 620 . The example control signal interface 620 in FIG. 6 conditions and/or converts the control signal 180 into a form suitable for processing by the example valve controller 610 using any number and/or type of circuits, components and/or devices. For example, the control signal interface 620 may convert the control signal 180 into a digital control value 622 representing a desired setpoint 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 in FIG. 6 includes a pressure controller 625 . Using any number and/or type of circuits, components, and/or devices, and based on the pressure control value 627 provided by the example valve controller 610, the example pressure controller 625 determines whether to increase or decrease the air pressure supplied through lines 152 and 154 .

Using any number and/or type of methods, algorithms, and/or logic, the exemplary valve controller 610 of FIG. 6 compares a digital position value 607 with a desired set point and/or position value 622 to determine a pressure control value 627, That is, how the control fluid pressure supplied to chambers 136 and 137 should be adjusted. As described above in connection with FIG. 1 and equation (5), valve controller 610 determines pressure control value 627 based on estimated endpoint values HI_CAL and LO_CAL.

To determine and correct estimates HI_CAL and LO_CAL of count value 607 corresponding to expected end-of-travel of actuator 108 , example valve position controller 104 in FIG. 6 includes example calibrator 615 . To calculate an initial pair of estimated values HI_CAL and LO_CAL from a single externally provided position value PPP, the example calibrator 615 includes an endpoint estimator 617 . For example, using the mathematical expressions of equations (1)-(4), the example endpoint estimator 617 calculates initial values HI_CAL and LO_CAL.

The example calibrator 615 includes an end point adjuster 619 in order to correct the values HI_CAL and LO_CAL corresponding to the expected end points of travel of the actuator 108 during operation of the example valve apparatus 100 in FIG. 1 in a process plant. For example, using any one of the exemplary methods described above in connection with FIGS. The HI_CAL and LO_CAL values are corrected during on-line operation of the controller 104. It should be understood that, additionally or alternatively, the exemplary end point regulator 619 may be used to calculate and/or correct HI_CAL and LO_CAL valve 106 is purposefully actuated for calibration purposes.

To store control variables, the example valve position controller 104 of FIG. 6 includes a memory 630 . Control variables are stored in memory 630 using any number and/or type of data structures, and memory 630 may use any number and/or type of non-permanent and/or permanent memory, memory devices, and/or storage device implementation. Exemplary control variables stored in the exemplary memory 630 include, but are not limited to, an externally provided position value PPP, a sensitivity value SENSITIVITY, and estimated trip endpoint values HI_CAL and LO_CAL.

To allow a user to provide a position value PPP and/or a sensitivity value SENSITIVITY, the example valve position controller 104 in FIG. 6 includes any type of user interface 635, any number and/or type of input devices 640, and any type of display 645. In some embodiments, user interface 635 prompts via display 645 that instructs and/or prompts the user to provide and/or enter a value for PPP and/or SENSITIVITY. Exemplary input devices 640 include, but are not limited to, digital communication interfaces and/or keypads. In some embodiments, a touch screen may be used as both display 645 and input device 640 .

Although an exemplary manner of implementing the exemplary valve position controller 104 in FIG. 1 has been illustrated in FIG. 6, one or more interfaces, data structures, elements, procedures, and/or devices illustrated in FIG. Combine, divide, rearrange, omit, remove and/or implement. Further, an example position sensor interface 605, an example calibrator 615, an example endpoint estimator 617, an example endpoint regulator 619, an example control signal interface 620, an example pressure controller 625, an example memory 630, an example An exemplary user interface 635, an exemplary input device 640, an exemplary display 645, and/or, more broadly, the valve position controller 104 in FIG. or any combination of firmware implementations. Thus, for example, an example position sensor interface 605, an example calibrator 615, an example endpoint estimator 617, an example endpoint regulator 619, an example control signal interface 620, an example pressure controller 625, an example memory 630, an exemplary user interface 635, an exemplary input device 640, an exemplary display 645, and/or, more broadly, the valve position controller 104, any of which may be controlled by one or more electronic circuits, programmable processors , Application Specific Integrated Circuit (ASIC), Programmable Logic Device (PLD), Field Programmable Logic Device (FPLD), and/or Field Programmable Gate Array (FPGA), etc. Exemplary position sensor interface 605, exemplary calibrator 615, exemplary endpoint estimator 617, an example endpoint regulator 619, an example control signal interface 620, an example pressure controller 625, an example memory 630, an example user interface 635, an example input device 640, an example display 645, and/or, more generally In other words, at least one of the valve position controllers 104 is expressly defined herein as comprising a tangible computer readable medium. Exemplary tangible computer readable media include, but are not limited to, flash memory, compact disc (CD), DVD, floppy disk, read only memory (ROM), random access memory (RAM), programmable read only memory (PROM), electronically programmable Read-Only Memory (EPROM) and/or Electrically Erasable Programmable Read-Only Memory (EEPROM), optical storage disks, optical memory devices, magnetic disks, magnetic storage, and/or any of the following tangible media, which may be used to store programs The instructions are in the form of code and/or machine readable instructions or data structures and are accessible by a processor, computer and/or other device having a processor, such as the exemplary processor platform P100 discussed next in connection with FIG. 16 . Combinations of the above elements are also included within the scope of tangible computer readable media. Still further, the exemplary valve position controller 104 includes interfaces, data structures, elements, programs and/or devices instead of or in addition to those shown in FIG. 6, and/or includes graphical interfaces, Any number or all of more than one data structure, element, program, and/or device.

FIG. 7 illustrates an example procedure that may be used to install the example valve position controller 104 of FIGS. 1 and 6 . 8-11 illustrate exemplary routines for implementing the exemplary calibrator 615 of FIG. 6 and/or, more broadly, the valve position controller 104 of FIGS. 1 and 6 . A processor, controller, and/or any other suitable processing device may be used and/or programmed to perform the example routines of FIGS. 7-11. For example, the programs in FIGS. 7-11 may be embodied as code and/or machine-accessible instructions stored on any article of manufacture such as a tangible computer readable medium such as flash memory, CD , DVD, floppy disk, ROM, RAM, PROM, EPROM and/or EEPROM, optical storage disk, optical storage device, magnetic disk, magnetic storage and/or any other tangible medium that can be used to store program code and/or be machine-readable The instructions are in the form of instructions or data structures and are accessible by a processor, computer, and/or other device having a processor, such as the exemplary processor platform P100 discussed next in connection with FIG. 16 . Combinations of the above are also included within the scope of tangible computer-readable media. Machine-readable instructions include, for example, instructions and data that cause a processor, a computer, and/or a device having a processor to execute one or more specific programs. Alternatively, some or all of the exemplary operations in FIGS. 7-11 may be implemented using any combination of ASICs, PLDs, FPLDs, FPGAs, discrete logic elements, hardware, firmware, and the like. Also, one or more of the exemplary operations in FIGS. 7-11 may be implemented manually or in any combination of any of the aforementioned techniques, such as any combination of firmware, software, discrete logic elements, and/or hardware. Further, many other methods may be used to implement the exemplary operations in Figs. 7-11. For example, the order of execution of the modules may be changed, and/or one or more modules may be changed, eliminated, subdivided, or combined. Additionally, any or all of the exemplary process routines in FIGS. 7-11 may be executed sequentially and/or in parallel, eg, by separate processing threads, processors, devices, discrete logic elements, circuits, and the like.

The example procedure of FIG. 7 begins with the operator and/or installer determining or fixing (eg, manually fixing) the position of the valve assembly 102 with the example holder 190 (block 705 ). For example, an operator may manually secure the valve 106 using clips and/or stops, or secure the position of the actuator 108 by preventing movement of control fluid within the actuator 108 (eg, trapping).

The valve position controller 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) and accesses the user interface 635 (block 720). For example, the installer enters configuration data such as the sensitivity value SENSITIVITY of the position sensor 110 (eg, obtained from a nameplate or label on the position sensor 110) (block 725). The installer then enters the single point position PPP of the position indicator 140 (block 730). In some embodiments, position PPP is entered as a percentage of the travel span of actuator 108 (eg, 50% open).

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

The installer activates the valve position control 104 (block 745) and unclamps or releases the position of the valve assembly 102 (block 750).

The example routines of FIGS. 8-11 are executed each time valve position controller 104 is instructed to change the position of valve assembly 102 via control signal 180 , and valve position controller 104 changes the position of valve assembly 102 in accordance with such instructions. The exemplary procedure in FIG. 8 corresponds to the illustrated embodiment of FIGS. 3 and 5 . The example routine in FIG. 9 corresponds to correction of calibration values based on example equations (6)-(9). The exemplary routine in FIG. 10 corresponds to a correction of the calibration value based on the stored PTV 170 when the travel limit is reached. The example routine in Figure 11 corresponds to calibration value corrections outside the SP180 range. Before executing the example routines of FIGS. 8-11 for the first time (e.g., when the valve position controller 104 initiates into automatic control mode), the example endpoint estimator 617 in FIG. 6 calculates an initial estimated HI_CAL and LO_CAL, as above As described in conjunction with Figures 1 and 6.

In the exemplary routine of FIG. 8, a pair of 0% and 100% correction status bits and a single point calibration status bit are discussed. When the one-point calibration is complete, the 0% and 100% correction status bits are cleared and the one-point calibration status bits are set. Because a single point calibration is performed, the 0% and 100% trim status bits indicate whether the valve 106 and actuator 108 have reached the 0% and 100% travel stops, respectively. The single-point calibration status bit indicates that a single-point calibration (possibly inaccurate) was performed (eg, block 740 in FIG. 7 ) but not yet corrected. In the embodiment of FIG. 8, the NEW_LO_CAL and NEW_HI_CAL values are new calibration values that have been calculated and/or set but not used until the user chooses to use them. The example routine in FIG. 8 begins with the example valve controller 610 determining whether the actuator 108 has reached the fully closed 0% position (block 805 ). If the fully closed 0% position has been reached (e.g., the 0% travel stop 162 has been reached) (block 805), the end point adjuster 619 determines whether the status bit corresponding to the fully closed or 0% position has been set (e.g., 0 % Correction Status Bits) (block 810). If the fully closed 0% status bit has been set (Block 810), control returns to Block 805 to check whether the 0% travel stop has been reached.

If the fully closed status bit has not been set (e.g., the NEW_LO_CAL value has not been set) (block 810), the endpoint regulator 619 records the current LO_ACT value of the feedback signal 170 as NEW_LO_CAL (block 815) and sets the fully closed status bit (block 815) module 820). The calibrator 615 notifies the user (eg, via the exemplary display 645 ) that new and/or corrected calibration data is ready to use (block 835 ). If the user does not use the new value (block 840), the user will be repeatedly informed of the available correction data and control returns to block 805 to check whether the 0% travel stop has been reached.

If the user is only using a new value (block 845), the user will be repeatedly informed of the corrective data available and control returns to block 805 to check whether the 0% travel stop has been reached. If NEW_LO_CAL and NEW_HI_CAL were used (block 845), the corrected endpoint values LO_CAL, HI_CAL are stored in the example memory 630 and the single point calibration status bit is cleared, indicating that all possible errors have been corrected (block 845). Operation of the example calibrator 615 is stopped (block 850 ), and control exits from the example routine of FIG. 8 .

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

If the fully open 100% travel stop has been reached (block 860), the end point adjuster 619 determines whether the fully open 100% status bit has been set (block 865). If the fully open 100% status bit has been set (block 865), control returns to block 805 to check whether the 0% travel stop has been reached.

If the fully open 100% status bit has not been set (e.g., the NEW_HI_CAL value has not been set) (block 865), the endpoint regulator 619 records the current HI_ACT value of the feedback signal 170 as NEW_HI_CAL (block 870) and sets fully open 100% status bit (block 875). Control then passes to block 835, where the user is notified of the new calibration data.

The example routine of FIG. 9 begins with the example end point adjuster 619 waiting for the piston 130 to load on either stop 160 , 162 (block 905 ). When the piston 130 is loaded (block 905), the end point adjuster 619 determines whether the SP 180 is shifting toward the stops 160, 162 (block 910). If the SP 180 changes toward the loaded stop 160, 162 (block 910), the end point adjuster 619 modifies the corresponding calibration value HI_CAL, LO_CAL using a corresponding one of equations (6)-(9) (block 915).

When the SP 180 is no longer changing toward the loaded stop 160 , 162 (block 910 ), the control return module 905 determines whether the piston 130 is loaded on the mechanical stop 160 , 162 . In the embodiment of FIG. 9, the revised calibration values HI_CAL and LO_CAL are applied automatically. Additionally or alternatively, if the revised calibration values HI_CAL, LO_CAL cannot be automatically applied, a notification and new calibration data application procedure substantially similar to that described above in connection with blocks 835, 840, 845, 850, and 855 in FIG. 8 is performed.

The example routine of FIG. 10 begins with the example end point adjuster 619 determining whether the piston 130 is loaded into 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 if the SP 180 is changing toward the stops 160, 162 (block 1015). If the SP 180 changes towards the loaded stop 160, 162 (block 1015), the endpoint adjuster 619 modifies the corresponding calibration values HI_CAL, LO_CAL to be close to but not necessarily equal to the respective stored PTV 170 (block 1020). For example, the calibration values HI_CAL, LO_CAL are corrected as a percentage difference between the calibration values HI_CAL, LO_CAL and the respective stored PTV 170 . When the revised calibration values HI_CAL and LO_CAL equal their respective saved PTV values (block 1025 ), control exits the example routine of FIG. 10 because no further calibration value adjustments are possible and/or required. If neither of the revised calibration values HI_CAL and LO_CAL is equal to its respective saved 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 SP 180 has changed.

In the embodiment of FIG. 10, the revised calibration values HI_CAL and LO_CAL are applied automatically. Additionally or alternatively, if revised calibration values cannot be automatically applied, a notification and new calibration data application procedure substantially similar to that described above in connection with blocks 835, 840, 845, 850, and 855 in FIG. 8 is performed.

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

If the piston 130 is unloaded (block 1110 ), the end point adjuster 619 adjusts the respective calibration values HI_CAL, LO_CAL so that the piston 130 moves toward the respective stop 160 , 162 (block 1120 ).

When SP180 has not changed (block 1115), the piston 130 loads to the mechanical stops 160, 162 (block 1110), or when SP180 returns to within the 0-100% range (block 1105), control returns to block 1105 to wait for SP180 to again Move outside the 0-100% range.

In the embodiment of Figure 11, the corrected calibration values are applied automatically. Additionally or alternatively, if revised calibration values cannot be automatically applied, a notification and new calibration data application procedure substantially similar to that described above in connection with blocks 835, 840, 845, 850, and 855 in FIG. 8 is performed.

FIG. 12 illustrates an example valve apparatus 1200 that includes an example valve assembly 1202 and a position transmitter 1205 constructed in accordance with the teachings of the present disclosure. Because the elements of the exemplary device 1200 in FIG. 12 are consistent with those discussed above in connection with the exemplary device 100 in FIG. 1 , descriptions of the same elements are not repeated here. Instead, like elements are designated with like reference numerals in FIGS. 1 and 12, and the interested reader is referred back to the description given above in connection with FIG. 1 for a complete description of like numbered elements.

The exemplary valve apparatus of FIG. 1200 includes an example location transmitter 1205 . The example position transmitter 1205 of FIG. 12 calculates and/or determines the value of POS_SIG 1200 by the PTV 170 . For example, position transmitter 1205 may calculate POS_SIG 1200 using the following mathematical expression:

$\mathrm{POS}\_\mathrm{SIG}=\frac{\mathrm{PTV}-\mathrm{LO}\_\mathrm{CAL}}{\mathrm{HI}\_\mathrm{CAL}-\mathrm{LO}\_\mathrm{CAL}}(\mathrm{MAX}-\mathrm{MIN})+\mathrm{MIN}$ Equation (10)

where MAX is the value of POS_SIG1210 corresponding to a fully open valve and MIN is the value of POS_SIG1200 corresponding to a fully closed valve. In some embodiments, MIN is 4 mA and MAX is 20 mA. The values of LO_CAL and HI_CAL are calculated, selected and/or modified by the position transmitter 1205 as described below.

The example position transmitter 1205 in FIG. 12 may self-calibrate based on a single externally provided position value PPP or an estimate and/or approximation thereof representing the current position of the actuator 108 (eg, 70% open). As described here, the position transmitter 1205 does not require an additional externally provided position value before the valve system 1200 in the processing plant starts to operate. Further, the position of the actuator 108 need not be adjusted, changed or actuated prior to operation of the example valve apparatus 1200 in FIG. 12 in a process plant. For example, a single position value PPP may be easily and/or readily determined and/or estimated by the installer, for example by visually verifying (e.g., estimating) and/or measuring the position indicator 140 during installation of the position transmitter 1205. current location. For example, the installer provides and/or inputs the estimated or measured position value PPP to the position transmitter 1205 via the input device 640 of the position transmitter 1205 (FIG. 13). While the exemplary position transmitter 1205 may self-calibrate based on a single estimated position value PPP, an estimate or measurement provided by the installer and/or determined by actuating the valve 106 when additional position values are available, such additional values as Can be used to improve calibration accuracy.

Based on a single estimated position value PPP and a sensitivity value SENSITIVITY representing the change in PTV 170 per travel unit of position indicator 140, and the total travel distance of the valve and actuator, the exemplary position transmitter 1205 in FIG. 12 estimates The PTV 170 corresponding to the end-of-travel of the valve actuator 108 is expected and/or projected. Alternatively, the value SENSITIVITY represents a count value indicating the entire travel of the valve 106 . Further, the value SENSITIVITY represents the change in PTV 170 over the travel of valve 106 . Referring to FIG. 5, at time point T1, the exemplary valve assembly 102 of FIG. 12 is 75% open and has a PTV 170 corresponding to the current 75% position, with a HI_ACT of HI_ACT when the actuator 108 is in the fully open 100% position. PTV 170 with the PTV value 170 of LO_ACT when the actuator 108 is in the fully closed 0% position. At time T2, position transmitter 1205 calculates a first value HI_CAL corresponding to the estimated or expected fully open position of actuator 108 and calculates a second value LO_CAL corresponding to the estimated or expected fully closed position of actuator 108 . If the values of PPP and SENSITIVITY are substantially accurate, the value of HI_CAL is approximately equal to HI_ACT and the value of LO_CAI is approximately equal to LO_ACT. In reality, however, the PPP value is an estimate of the actuator 108 position (eg, a measurement with error) and/or the SENSITIVITY value is inaccurate due to manufacturing tolerances and/or mounting orientation variations. Therefore, in some embodiments, the example position transmitter 1205 in FIG. range, as shown at time point T3 in FIG. 5 .

The values of HI_ACT and LO_ACT can be calculated using the following mathematical expressions, assuming that the feedback signal 170 increases when the valve 104 is open:

HI_CAL=PTV+(100-OFF-PPP)*SENSITIVITY*TRAVEL*(100-GAIN), equation (11), and

LO_CAL=PTV-(PPP-OFF)*SENSITIVITY*TRAVEL*(100-GAIN), equation (12)

Wherein, OFF is the tolerance in the PPP estimate (as a percentage of the travel span), TRAVEL is the actual travel length or rotation angle of the valve 106 in engineering units, and GAIN is the sensor 140 calibration, sensor 140 perturbation, sensor output 170 gain and Tolerance (as a percentage of travel span) in/or filtering and/or analog-to-digital conversion of sensor output 170 .

Using the exemplary mathematical expressions in equations (10)-(12), the exemplary position transmitter 1205 attempts to output values corresponding to 0% and 100% valve positions during subsequent operation of the exemplary valve apparatus 1200 in a process plant. The value of POS_SIGN1210. In the illustrated embodiment of FIG. 12, the exemplary position transmitter 1205 transmits MAX as the output 1210 indicating a 100% open valve before the valve 106 actually reaches the fully open 100% position, and transmits MIN as the valve 106 actually reaches the fully closed 100% position. The 0% position precedes the output 1210 indicating 0% open valve.

The example position transmitter 1205 of FIG. 12 adapts, adjusts, and/or corrects the estimated endpoint values HI_CAL and LO_CAL as it operates within the processing plant. During plant operation, software within the position transmitter 1205 calculates values of POS_SIG 1210 that lie outside the range [MIN, MAX], and the example position transmitter 1205 adjusts the corresponding calibration endpoint values HI_CAL, LO_CAL. For example, when the calculated POS_SIG 1200 is greater than MAX, the position transmitter 1205 modifies the HI_CAL value to match the current PTV 170 value. Likewise, when the calculated POS_SIG 1210 is less than MIN, the position transmitter 1205 modifies the LO_CAL value to match the current PTV 170 . The calibration of the exemplary position transmitter 1205 is corrected over a period of time by updating the HI_CAL and LO_CAL values each time the calculated POS_SIG 1210 is outside the range [MIN, MAX]. When the valve 106 actually reaches the fully open 100% or fully closed 0% position, the corresponding HI_CAL or LO_CAL calibration values are substantially perfect. Preferably, position feedback 170 is filtered to reduce noise effects so that calibration errors are not introduced and/or caused by noise.

The example location transmitter 1205 of FIG. 12 can automatically apply and/or enable new LO_CAL and HI_CAL values at calculation time, as described in the previous paragraph, and/or the new LO_CAL and/or HI_CAL values can be stored and Transmitter 1205 is enabled and/or used when expressly instructed and/or directed. For example, position transmitter 1205 may display a flag on display 645 (FIG. 13) indicating that one or more new calibration values LO_CAL, HI_CAL may be used. For example, when the user indicates via the exemplary input device 640 (FIG. 13) that new and/or revised calibration values LO_CAL, HI_CAL are to be used, the position transmitter 1205 begins calculating a subsequent value POS_SIG 1210 using the enabled calibration values LO_CAL, HI_CAL.

FIG. 13 illustrates an exemplary manner of implementing the exemplary position transmitter 1205 of FIG. 12 . Because the elements of the example position transmitter 1205 in FIG. 13 are consistent with those discussed above in connection with the example valve position controller 104 in FIG. 6 , descriptions of the same elements are not repeated here. Instead, like elements are designated with like reference numerals in FIGS. 6 and 13 , and the interested reader is referred back to the description given above in connection with FIG. 6 for a complete description of like numbered elements.

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

To correct the values HI_CAL and LO_CAL during operation of the example valve apparatus 1200 in FIG. 12 within a process plant, the example calibrator 1305 of FIG. 13 includes an end point adjuster 1315 . The example endpoint adjuster 1315 of FIG. 13 modifies the values HI_CAL and LO_CAL during on-line operation of the position transmitter 1205 . During operation, the POS_SIG 1210 is calculated to be outside the range [MIN,MAX], the example endpoint adjuster 1315 adjusts the corresponding calibration endpoint values HI_CAL, LO_CAL to the current value of the count value 607 . It should be understood that the example end point adjuster 1315 may additionally or alternatively be used to calculate and/or correct HI_CAL and LO_CAL valve 106 is purposely actuated for calibration purposes.

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 of the digital signal 1320 from the calibration values HI_CAL and LO_CAL, for example, by employing the example mathematical expression of Equation (10).

To transmit and/or provide POS_SIG 1210 to program controller 185 and/or program interlock 1215 , the example position transmitter 1205 of FIG. 13 includes any transmitter or transceiver 1330 . The example transmitter 1330 of FIG. 13 converts the count value 1320 to an analog signal, such as a 4-20 mA signal, using any number and/or type of circuits, devices, and/or methods. Additionally or alternatively, transceiver 1330 may digitally and/or wirelessly transmit count value 1320 as signal 1210 .

Although an exemplary manner of implementing the exemplary position transmitter 1205 in FIG. 12 has been illustrated in FIG. 13, one or more of the interfaces, data structures, elements, procedures, and/or devices illustrated in FIG. 13 may be combined in any manner , split, rearrange, omit, remove and/or enforce. Further, an example position sensor interface 605, an example calibrator 1305, an example endpoint estimator 1310, an example endpoint regulator 1315, an example memory 630, an example user interface 635, an example input device 640, an example display 645. Exemplary location value determiner 1325, exemplary transmitter/transceiver 1330, and/or, more broadly, location transmitter 1205 in FIG. and/or any combination of firmware implementations. Thus, for example, an example position sensor interface 605, an example calibrator 1305, an example endpoint estimator 1310, an example endpoint regulator 1315, an example memory 630, an example user interface 635, an example input device 640, Exemplary display 645, exemplary position value determiner 1325, exemplary transmitter/transceiver 1330 and/or, more broadly, position transmitter 1205, any of which may be controlled by one or more circuits, programmable Processors, Application Specific Integrated Circuits (ASICs), Programmable Logic Devices (PLDs), Field Programmable Logic Devices (FPLDs), and/or Field Programmable Gate Arrays (FPGAs), etc. Exemplary position sensor interface 605, exemplary calibrator 1305, exemplary endpoint estimator 1310, an example endpoint adjuster 1315, an example memory 630, an example user interface 635, an example input device 640, an example display 645, an example position value determiner 1325, an example transmitter/transceiver 1330, and/or , and more broadly, at least one of location transmitters 1205 is expressly defined herein as comprising a tangible computer-readable medium. Exemplary tangible computer readable media include, but are not limited to, flash memory, compact disc (CD), DVD, floppy disk, read only memory (ROM), random access memory (RAM), programmable read only memory (PROM), electronically programmable Read-Only Memory (EPROM) and/or Electrically Erasable Programmable Read-Only Memory (EEPROM), optical storage disks, optical memory devices, magnetic disks, magnetic storage, and/or any of the following tangible media, which may be used to store programs The instructions are in the form of code and/or machine readable instructions or data structures and are accessible by a processor, computer and/or other device having a processor, such as the exemplary processor platform P100 discussed next in connection with FIG. 16 . Combinations of the above are also included within the scope of tangible computer readable media. Still further, the exemplary location transmitter 1205 includes interfaces, data structures, elements, programs, and/or devices instead of or in addition to those shown in FIG. 12 , and/or includes graphical interfaces, data One or more of any or all of structures, elements, procedures, and/or devices.

FIG. 14 illustrates an example program that may be executed to install the example location transmitter 1205 of FIGS. 12 and 13 . FIG. 15 illustrates an example program that may be executed to implement the example calibrator 1305 of FIG. 13 and/or, more broadly, the example position transmitter 1205 of FIGS. 12 and 13 . A processor, controller, and/or any other suitable processing device may be used and/or programmed to carry out the example routines of FIGS. 14 and 15 . For example, the programs of FIGS. 14 and 15 are embodied as code and/or machine-accessible instructions stored on any article of manufacture, such as a tangible computer-readable medium, which can be accessed by a processor, a computer, and/or Other devices having a processor access, such as the exemplary processor platform P100 discussed next in connection with FIG. 16 . Alternatively, some or all of the exemplary operations in FIGS. 14 and 15 may be implemented using any combination of ASICs, PLDs, FPLDs, FPGAs, discrete logic elements, hardware, firmware, and the like. Also, one or more of the exemplary operations in FIGS. 14 and 15 may be implemented manually or in any combination of any of the aforementioned techniques, such as any combination of firmware, software, discrete logic elements, and/or hardware. Further, many other methods may be used to implement the exemplary operations in FIGS. 14 and 15 . For example, the order of execution of the modules may be changed, and/or one or more of the modules described may be changed, eliminated, subdivided, or combined. Additionally, any or all of the exemplary process routines in FIGS. 14 and 15 may be executed sequentially and/or in parallel, eg, by separate processing threads, processors, devices, discrete logic elements, circuits, and the like.

The example procedure of FIG. 14 begins with the operator and/or installer determining or fixing (eg, manually fixing) the position of the valve assembly 102 with the example holder 190 (block 1405 ). For example, an operator may manually secure the valve 106 using clips and/or stops, or secure the position of the actuator 108 by preventing movement of control fluid within the actuator 108 (eg, trapping).

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 (eg, provides power to) the location transmitter 1205 and accesses the user interface 635 (block 1420). For example, the installer enters configuration data such as the sensitivity value SENSITIVITY of the position sensor 110 (eg, obtained from a nameplate or label on the position sensor 110) (block 1425). The installer then enters the single point position PPP of the position indicator 140 (block 1430). In some embodiments, position PPP is entered as a percentage of the travel span of actuator 108 (eg, 50% open).

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

The installer activates the position transmitter 1205 (block 1445) and unclamps or releases the position of the valve assembly 102 (block 1450).

The example routine of FIG. 15 begins with the example endpoint regulator 1315 waiting for the calculated value of POS_SIG 1210 to fall outside the range [MIN, MAX] (block 1505). When the calculated value of POS_SIG 1210 falls outside the range [MIN, MAX] (block 1505) and the calibration correction is to be applied automatically (block 1510), the endpoint adjuster 1315 corrects the corresponding calibration values HI_CAL, LO_CAL to the current PTV 170 value ( module 1515).

If the calibration correction has not been automatically applied (block 1510), the endpoint adjuster 1315 notifies the user (e.g., via the exemplary display 645) that new and/or corrected calibration data is readily available (block 1520), and determines whether the PTV 170 is at the above NEW_CAL value Out of range (block 1525). If the PTV 170 is outside the above range (block 1525), the endpoint regulator 1315 stores the revised calibration values NWE_HI_CAL, NEW_LO_CAL for subsequent recovery and/or enabling (block 1530). Control then returns to block 1505 to wait for POS_SIG 1210 to fall outside the range [MIN, MAX].

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

Processor platform P100 in the embodiment of FIG. 16 includes at least one programmable processor P105. Processor P105 executes coded instructions P110 and/or P112 residing in the main memory of processor P105 (eg, RAM P115 and/or ROM P120). Processor P105 may be any kind of processing component, such as a processor core, processor and/or microcontroller. Processor P105 may, among other things, execute the example routines of FIGS. 7-11, 14 and/or, more broadly, implement the example valve position controller 104 of FIGS. An exemplary location transmitter 1205 for .

Processor P105 is coupled to any number and/or type of tangible computer-readable storage media (including ROM P120 and/or RAM P115) via bus P125. RAMP 115 can be implemented by dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM) and/or any other type of RAM device, and ROM can be implemented by flash memory and/or any other required type of storage device to achieve. Access to memory P115 and memory P120 may be controlled by a memory controller (not shown). Example memories P115 and P120 may be used, for example, to implement example memory 630 of FIGS. 6 and 13 .

The processor platform P100 also includes an interface circuit P130. Any interface standard, such as external storage interface, serial port, general-purpose input/output, etc., can 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 the example input device 640, while output device P140 may be used to implement the example display 645 of FIGS. 6 and 13 .

Although certain exemplary methods, devices, and systems have been described herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all methods, apparatus, systems and articles of manufacture fairly falling within the scope of the appended claims either literally or under the doctrine of equivalents.

Claims (20)

1. a control valve assembly, is characterized in that, comprising:

Valve, it has flow control element;

Actuator, it is mechanically connected to described flow control element; And

Controller specific integrated circuit, it can be couple to described actuator communicatedly, and wherein said actuator moves described flow control element with the control signal in response to receiving from described controller specific integrated circuit;

Wherein, when described control valve assembly work, described controller specific integrated circuit is carried out self-calibrating according to position transducer Sensitirity va1ue and single-point positional value at described control valve assembly duration of work, described single-point positional value represent when described controller specific integrated circuit is placed in control mode described in the position of flow control element.

2. control valve assembly as claimed in claim 1, it is characterized in that, before being further included in the described controller specific integrated circuit of installation, when described control valve assembly installation in position and while moving, from described control valve assembly, remove another controller specific integrated circuit together with process control system.

3. control valve assembly as claimed in claim 1 or 2, is characterized in that, described single-point positional value represent when described controller specific integrated circuit is arranged in described control valve assembly at first described in the original position of flow control element.

4. control valve assembly as claimed in claim 1 or 2, is characterized in that, described single-point positional value represents the stroke span percentage of described flow control element.

5. control valve assembly as claimed in claim 1 or 2, it is characterized in that, described self-calibrating is also based on the first estimation calibration value and the second estimation calibration value, wherein, described the first estimation calibration value and described the second estimation calibration value represent respectively up stroke span limit and the down stroke span limit of described flow control element.

6. control valve assembly as claimed in claim 5, it is characterized in that, further comprise from described controller specific integrated circuit and obtain the first estimation calibration value and the second estimation calibration value, described controller specific integrated circuit is determined described the first estimation calibration value and described the second estimation calibration value according to single-point calibration position and position transducer Sensitirity va1ue.

7. control valve assembly as claimed in claim 1 or 2, it is characterized in that, described controller specific integrated circuit is placed in to control mode and comprises that to make described controller specific integrated circuit in running order, so that the fluid flow of described control valve assembly control procedure system.

8. control valve assembly as claimed in claim 1 or 2, it is characterized in that, described controller specific integrated circuit is placed in to control mode and comprises and enable controller specific integrated circuit, and before described controller specific integrated circuit is placed in to control mode, between an end point of travel of described flow control element and another end point of travel of described flow control element, do not drive described control valve assembly.

9. control valve assembly as claimed in claim 1 or 2, is characterized in that, further comprises the calibration of selecting described controller specific integrated circuit via user interface specific integrated circuit.

10. a control valve assembly, is characterized in that, comprising:

Controller specific integrated circuit, when control valve assembly moves or be online together with process control system, controller specific integrated circuit is coupled to control valve assembly, and wherein said controller specific integrated circuit comprises;

Position transducer Sensitirity va1ue;

Single-point positional value, it represents the current location of the flow control element of described control valve assembly;

Based on described position transducer Sensitirity va1ue and described single-point positional value, represent the estimation up stroke limiting value of the first stroke span limit of described flow control element and the estimation down stroke limiting value of the second stroke span limit of the described flow control element of expression; And

Wherein, described controller specific integrated circuit is carried out self-calibrating according to described position transducer Sensitirity va1ue, described single-point positional value, estimation up stroke limiting value and estimation down stroke limiting value at described control valve assembly duration of work.

11. control valve assemblies as claimed in claim 10, is characterized in that, the current location of described flow control element is fixed to stop described flow control element to move.

12. control valve assemblies as described in claim 10 or 11, it is characterized in that, described single-point positional value represents that, when described flow control element is fixed, described flow control element is with respect to the estimation of the current location of the whole stroke span of described flow control element.

13. control valve assemblies as described in claim 10 or 11, is characterized in that, further comprise and unclamp described flow control element and enable described controller specific integrated circuit.

14. control valve assemblies as described in claim 10 or 11, is characterized in that, described position transducer Sensitirity va1ue and described single-point positional value are inputted described controller specific integrated circuit via input interface specific integrated circuit.

15. control valve assemblies as described in claim 10 or 11, it is characterized in that, definite estimation up stroke limiting value and estimation down stroke limiting value comprise makes described controller specific integrated circuit estimate up stroke limiting value and estimation down stroke limiting value according to position transducer Sensitirity va1ue and the calculating of single-point positional value.

16. 1 kinds of control valve assemblies, is characterized in that, comprising:

Controller specific integrated circuit, when control valve assembly is arranged in fluid system, the position of the flow control element that described controller specific integrated circuit is determined valve in described control valve assembly;

Preposition transducer sensitivity value;

Single-point positional value, it represents that described flow control element is with respect to the original position of the stroke span of described flow control element when described controller specific integrated circuit is placed in control mode;

Upper calibration value and lower calibration value based on described position transducer Sensitirity va1ue and the estimation of described single-point positional value; And

Wherein, described controller specific integrated circuit is carried out self-calibrating according to the upper calibration value of described single-point positional value, described position transducer Sensitirity va1ue and estimation and lower calibration value.

17. control valve assemblies as claimed in claim 16, is characterized in that, described single-point positional value is illustrated in described controller specific integrated circuit and is placed in the position that control mode is visually estimated described flow control element before.

18. control valve assemblies as described in claim 16 or 17, is characterized in that, described single-point positional value is expressed as the stroke span percentage of described flow control element.

19. control valve assemblies as described in claim 16 or 17, is characterized in that, described single-point positional value obtains by measure the position of described flow control element by means of the position transducer of described control valve assembly.

20. control valve assemblies as described in claim 16 or 17, it is characterized in that, when described control valve assembly is online or move together with fluid system, described controller specific integrated circuit is carried out self-calibrating, and does not need to drive control valve assembly described in described flow control element or bypass.