Patent Grant
10077789
The present invention relates to a pneumatic actuation system. More specifically, the invention relates to a system and method for linear actuation of an industrial device.
Industrial control systems are commonly employed to provide control and monitoring of industrial facilities and processes, such as oil refining processes, oil and gas transportation facilities, chemical processing, pharmaceutical processing, and power generation facilities. Industrial control systems rely on actuators to position control elements, such as valves, to effectuate control actions. For reasons of safety and efficiency, some industrial control systems rely on pneumatically driven actuators to position control elements. Many industrial facilities and processes operate continuously for extended periods of time because shutting down and starting up facilities and processes can be costly. Unplanned shut down of a facility or process can be especially disruptive and expensive. Thus, highly reliable pneumatically actuated control elements are desired to prevent costly facility or process downtime.
In Example 1, an apparatus for providing linear actuation to a device having a moveable portion and an immoveable portion includes a plurality of pneumatic linear actuator modules, a dynamic actuator linkage, and a static actuator linkage. Each of the plurality of pneumatic linear actuator modules includes a static portion and a dynamic portion, wherein the dynamic portion is moveable in a linear fashion relative to the static portion. The dynamic actuator linkage is configured to connect the dynamic portion of each of the plurality of pneumatic linear actuator modules to the moveable portion of the device. The static actuator linkage is configured to connect the static portion of each of the plurality of pneumatic linear actuator modules to the immoveable portion of the device. A number of pneumatic linear actuator modules one less than the plurality of pneumatic linear actuator modules are configured to provide linear actuation to the device. Each of the plurality of actuator modules is configured to selectively couple and decouple to the dynamic actuator linkage and the static actuator linkage.
In Example 2, the apparatus of Example 1, wherein the device is a control valve, the moveable portion of the device is a valve stem, and the immoveable portion is a bonnet.
In Example 3, the apparatus of Example 2, wherein the static actuator linkage is integral with the bonnet.
In Example 4, the apparatus of any of Examples 2-3, wherein the dynamic actuator linkage is integral with the valve stem.
In Example 5, the apparatus of any of Examples 1-4, wherein each of the plurality of actuator modules includes a first member, a second member, a plurality of linear guides connecting the first member to the second member, a plurality of linear bearings configured to move along the plurality of linear guides, a translating member connected to the plurality of linear bearings, a fluidic actuator connecting the translating member to the first member, and a pneumatic fitting connected to the fluidic actuator. The pneumatic fitting is configured to connect the fluidic actuator to a pneumatic line. The translating member is the dynamic portion of the pneumatic linear actuator module and the second member is the static portion of the pneumatic linear actuator module.
In Example 6, the apparatus of Example 5, further including a pneumatic controller configured to selectively couple and decouple to each of the plurality of pneumatic linear actuator modules. The controller is configured to control actuation of the plurality of pneumatic linear actuator modules.
In Example 7, the apparatus of Example 6, wherein the pneumatic controller includes a processor configured to receive a control input, a position transducer electrically connected to the processor, and a pneumatic control mechanism electrically connected to the processor. The position transducer is configured to sense a position of the movable portion of the device relative to the immoveable portion of the device. The pneumatic control mechanism is configured to connect a compressed gas supply to the plurality of pneumatic linear actuators and configured to modulate a pressure of the compressed gas supplied to the plurality of pneumatic linear actuators in response to an electrical signal from the processor. The electrical signal from the processor is function of at least the control input and the sensed position of the moveable portion of the device relative to the immoveable portion of the device.
In Example 8, the apparatus of Example 7, wherein the pneumatic controller further includes a pressure transducer electrically connected to the processor and configured to sense the pressure of the compressed gas supplied to the plurality of pneumatic linear actuators, and wherein the electrical signal from the processor is additionally a function of the sensed pressure of the compressed gas supplied to the plurality of pneumatic linear actuators.
In Example 9, the apparatus of Example 6, wherein the first member is a first plate, a second member is a second plate, and the translating member is a translating plate, and wherein each of the plurality of actuator modules further includes a biasing member configured to apply a biasing force countering a force applied between the first plate and the translating plate by the fluidic actuator.
In Example 10, the apparatus of Example 9, wherein each of the plurality of actuator modules further includes a threaded cylindrical column and a nut. The threaded column is connected on one end to the translating plate and projects toward the first plate. The column includes a hollow interior extending the length of the column, and an exterior including threads extending at least a portion of the length of the column. The nut is configured to threadedly engage the threads of the column. The biasing member is disposed between the nut and the first plate such that the biasing force is adjustable by threading the nut along the column.
In Example 11, the apparatus of any of Examples 9-10, wherein each of the plurality of actuator modules further includes a position transducer electrically connected to the pneumatic controller and configured to sense a position of the translating plate.
In Example 12, the apparatus of Example 11, wherein the pneumatic controller includes a processor and a pneumatic control mechanism. The processor is configured to receive a control input and is electrically connected to the position transducer of each of the plurality of actuator modules. The pneumatic control mechanism is electrically connected to the processor. The pneumatic control mechanism is configured to connect a compressed gas supply to the plurality of pneumatic linear actuators, and is configured to modulate a pressure of the compressed gas supplied to the plurality of pneumatic linear actuators in response to an electrical signal from the processor. The electrical signal from the processor is function of at least the control input and the sensed position of the translating plate of each of the plurality of pneumatic linear actuator modules.
In Example 13, the apparatus of Example 12, wherein the each of the plurality of actuator modules further includes a pressure transducer electrically connected to the processor and configured to sense the pressure of the compressed gas supplied to the pneumatic linear actuator, and wherein the electrical signal from the processor is additionally a function of the sensed pressure of the compressed gas supplied to each of the plurality of pneumatic linear actuators.
In Example 14, the apparatus of Example 1, wherein each of the plurality of actuator modules includes a first member, a second member, a plurality of linear guides connecting the first member to the second member, a plurality of linear bearings configured to move along the plurality of linear guides, a translating member connected to the plurality of linear bearings, a fluidic actuator connecting the translating member to the first member, a first pneumatic fitting connected to the fluidic actuator, and a pneumatic controller. The first pneumatic fitting is configured to selectively couple the pneumatic linear actuator module to a compressed gas supply. The pneumatic controller is configured to selectively couple the pneumatic linear actuator module to a control input. The pneumatic controller includes a processor configured to receive the control input, a position transducer electrically connected to the processor and configured to sense a position of the translating member, and a pneumatic control mechanism electrically connected to the processor. The pneumatic control mechanism is configured to connect a compressed gas supply from the pneumatic line to the plurality of pneumatic linear actuators. The pneumatic control mechanism is also configured to modulate a pressure of the compressed gas supplied to the pneumatic linear actuator in response to an electrical signal from the processor. The electrical signal from the processor is function of at least the control input and the sensed position of the translating member.
In Example 15, the apparatus of Example 14, wherein the first member is a first plate, a second member is a second plate, and the translating member is a translating plate, and wherein each of the plurality of actuator modules further includes a biasing member configured to apply a biasing force countering a force applied between the first plate and the translating plate by the fluidic actuator.
In Example 16, the apparatus of Example 15, wherein each of the plurality of actuator modules further includes a threaded cylindrical column and a nut. The threaded cylindrical column is connected on one end to the translating plate and projects toward the first plate. The column includes a hollow interior extending the length of the column, and an exterior including threads extending at least a portion of the length of the column. The nut is configured to threadedly engage the threads of the column. The biasing member is disposed between the nut and the first plate such that the biasing force is adjustable by threading the nut along the column.
In Example 17, the apparatus of any of Examples 14-16, wherein the each of the plurality of pneumatic linear actuator modules further includes a pressure transducer electrically connected to the processor and configured to sense the pressure of the compressed gas supplied to the fluidic actuator, and wherein the electrical signal from the processor is additionally a function of the sensed pressure of the compressed gas supplied to the fluidic actuator.
In Example 18, the apparatus of any of Examples 14-17, wherein the processors of each of the plurality of pneumatic linear actuator modules are electrically connected to the local control loop to receive the control input.
In Example 19, the apparatus of Example 18, wherein one of the plurality of pneumatic linear actuator modules provides the control input to each of the remaining plurality of pneumatic linear actuator modules.
In Example 20, the apparatus of any of Examples 14-19, further including a common header configured to pneumatically connect to the fluidic actuators of each of the plurality of actuator modules. Each of the plurality of actuator modules further includes a second pneumatic fitting connected to the fluidic actuator, the second pneumatic fitting configured to selectively couple the pneumatic linear actuator module to the common header. The pneumatic controller further includes a first pneumatic valve to selectively connect the fluid actuator to the compressed gas supply, and a second pneumatic valve to selectively connect the fluid actuator to the common header.
Example 21 is a method for providing linear actuation of a device having a moveable portion and an immoveable portion includes coupling a plurality of pneumatic linear actuation modules to the device, connecting a compressed gas supply to each of the plurality of pneumatic linear actuation modules, and modulating a pressure of the compressed gas supplied to the plurality of pneumatic linear actuators to provide linear actuation of the device. Coupling the plurality of pneumatic linear actuation modules to the device includes connecting a dynamic portion of each of the pneumatic linear actuator modules to the moveable portion of the device, and connecting a static portion of each of the pneumatic linear actuator modules to the immoveable portion of the device. A number of pneumatic linear actuator modules one less than the plurality of pneumatic linear actuator modules are able to provide linear actuation of the device.
In Example 22, the method of Example 21, further including replacing a one of the plurality of pneumatic linear actuation modules while modulating the pressure of the remainder of the plurality of pneumatic linear actuation modules to provide uninterrupted linear actuation of the device.
In Example 23, the method of Example 22, wherein the one of the plurality of pneumatic linear actuation modules comprise a failed or failing one of the plurality of pneumatic linear actuation modules and wherein the replacing includes identifying the failed or failing one of the plurality of pneumatic linear actuation modules to be replaced, disconnecting the compressed gas supply from the identified pneumatic linear actuation module, decoupling the identified pneumatic linear actuation module from the device, coupling a replacement pneumatic linear actuation module to the device, and connecting the compressed gas supply to the replacement pneumatic linear actuation module. Decoupling the identified pneumatic linear actuation module from the device includes disconnecting the dynamic portion of the pneumatic linear actuator module from the moveable portion of the device, and disconnecting the static portion of the pneumatic linear actuator module from the immoveable portion of the device. Coupling a replacement pneumatic linear actuation module to the device includes connecting a dynamic portion of the replacement pneumatic linear actuator module to the moveable portion of the device, and connecting a static portion of the replacement pneumatic linear actuator module to the immoveable portion of the device.
While multiple embodiments are disclosed, still other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive.
While the invention is amenable to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are described in detail below. The intention, however, is not to limit the invention to the particular embodiments described. On the contrary, the invention is intended to cover all modifications, equivalents, and alternatives falling within the scope of the invention as defined by the appended claims.
A more complete understanding of the present invention is available by reference to the following detailed description of numerous aspects and embodiments of the invention. The detailed description of the invention which follows is intended to illustrate, but not limit, the invention.
Each of the pneumatic linear actuator modules 14 may be substantially the same, as shown in the embodiment of
As also shown in
The fluidic actuator 40 may connect the translating member 38 to the first member 30. The pneumatic fitting 42 may selectively connect the fluidic actuator 40 to a controlled pressure, as described below. The pneumatic fitting 42 may be any type of fitting suitable for reliably connecting and disconnecting the pneumatic linear actuator module 14 to a pneumatic line, for example, a quick disconnect fitting or a threaded fitting. The bleed valve 44 may selectively connect the fluidic actuator 40 to an ambient environment. The fluidic actuator 40 may be a tensile actuator, such as a Fluidic Muscle available from the Festo Corporation. The fluidic actuator 40 may also be referred to as air muscle. The fluidic actuator 40 may be a hollow tubular structure having walls that are flexible, but substantially inelastic. As pressure within the flexible walls of the fluidic actuator 40 increases, the flexible walls are forced outward. As the flexible walls are forced outward, a tensile force is generated between opposite ends of the fluidic actuator 40. The fluidic actuator 40 is able to provide significant tensile force in a form factor that has a relatively small cross-sectional area in a direction perpendicular to the tensile force.
As also shown in
In some embodiments, the pneumatic control mechanism 50 may include a current-to-pressure (I/P) transducer 58 and a volume booster 60. The I/P transducer 58 is electrically connected to the processor 46 and pneumatically connects the compressed gas supply S to the volume booster 60. The volume booster 60 is also directly pneumatically connected to the compressed gas supply S and to the pneumatic control line 54.
In some embodiments, the position transducer 48 may be, for example, a linear potentiometer physically connected to the dynamic actuator linkage 16 and the static actuator linkage 18 to produce an electrical signal indicative of a position of the dynamic actuator linkage 16 relative to the static actuator linkage 18. In other embodiments, the position transducer 48 may be, for example, a capacitive sensing device or an electromagnetic flux sensing device (Hall Effect sensor) physically connected to one of the dynamic actuator linkage 16 and the static actuator linkage 18, and configured to capacitively sense a relative position of the other of the dynamic actuator linkage 16 and the static actuator linkage 18.
In some embodiments including the optional pressure transducer 56, the pressure transducer 56 may employ any of a number of known pressure sensing technologies, including, for example, piezoresistive strain gauge, capacitive, or electromagnetic. The pressure transducer 56 may be pneumatically connected to the pneumatic control line 54 to produce an electrical signal indicative of a pressure in the pneumatic control line 54. In some embodiments, the pressure transducer 56 may be an absolute pressure transducer and the electronic signal may be indicative of the absolute pressure in the pneumatic control line 54. In other embodiments, the pressure transducer 56 may be a gauge pressure transducer, and the electrical signal may be indicative of a difference between the pressure in the pneumatic control line 54 and a pressure of the ambient environment.
In operation, the processor 46 of pneumatic controller 20 may receive the control signal from the control input C indicating a desired level of actuation of the device 12, for example increasing the level of actuation by moving the stem 26 away from the fully closed position. The processor 46 sends an electrical signal to the I/P transducer 58 of the pneumatic control mechanism 50. The electrical signal may be a function of the signal from the control input C, the electrical signal from the position transducer 48, and optionally the signal from the pressure transducer 56. The I/P transducer 58 modulates a pressure from the compressed gas supply S in response to the electrical signal from the processor 46 to provide a pneumatic control signal to the volume booster 60. The pneumatic control signal from the I/P transducer 58 increases the pressure supplied by volume booster 60 from the compressed gas supply S to the pneumatic control line 54.
Each of the plurality of header isolation valves 52 may be in an open position such that the increased pressure from the pneumatic control mechanism 50 is supplied from the pneumatic control line 54 to the fluidic actuator 40 of each of the pneumatic linear actuator modules 14 by way of the pneumatic fitting 42. Within each of the pneumatic linear actuator modules 14, the increased pressure supplied from the pneumatic control line 54 increases the pressure within the fluidic actuator 40, generating a tensile force between opposite ends of the fluidic actuator 40. As noted above, the fluidic actuator 40 may connect the translating member 38 to the first member 30. Thus, the tensile force generated by the fluidic actuator 40 pulls the translating member 38 toward the first member 30 and away from the second member 32. Movement of the translating member 38 toward the first member 30 and away from the second member 32 for each of the plurality of pneumatic linear actuator modules 14 also moves the dynamic actuator linkage 16 away from the static actuator linkage 18. The tensile force produced by the plurality of pneumatic linear actuator modules 14 is sufficient to overcome the biasing force of the valve spring 28 and move the valve stem 26 away from the fully closed position.
Fine adjustment of the position of the stem 26 may be accomplished through the electrical signal from the position transducer 48. This is a feedback signal indicative of the position of the dynamic actuator linkage 16 relative to the static actuator linkage 18. The processor 46 may adjust the electrical signal sent to the I/P transducer 58 to increase or decrease the pressure supplied to the plurality of pneumatic linear actuator modules 14, adjusting the position of the stem 26 accordingly.
Optionally, additional fine control of the pressure supplied to the fluidic actuator 40 may be accomplished through the electrical signal from the pressure transducer 56. This is a feedback signal indicative of the pressure in the pneumatic control line 54. The processor 46 may adjust the electrical signal sent to the I/P transducer 58 to further modulate the pressure supplied by volume booster 60 from the compressed gas supply S to the pneumatic control line 54.
The embodiment of the linear actuation apparatus 10 shown in
Installing a replacement pneumatic linear actuator module 14 is done by connecting the second member 32 to the static actuator linkage 18, and connecting the translating member 38 to the dynamic actuator linkage 16 to physically couple the replacement pneumatic linear actuator module 14. Then the pneumatic fitting 42 of the replacement pneumatic linear actuator module 14 may be connected to the pneumatic control line 54 and the bleed valve 44 closed. Next, the header isolation valve 52 for the replacement pneumatic linear actuator module 14 may be opened to connect the replacement pneumatic linear actuator module 14 to the compressed gas supplied by the pneumatic controller 20. The result is as shown in
In the embodiment of
In some embodiments, it may not be beneficial to operate the linear actuation apparatus 10 for an extended period of time with a number of pneumatic linear actuator modules 14 one less than n. However, for relatively short periods of time, for example, time sufficient to detect a failure of one of the plurality of pneumatic linear actuator modules 14 and replace it as describe above, operating with a number of pneumatic linear actuator modules 14 one less than n may not result in significant stress on the pneumatic linear actuator modules 14.
Each of the pneumatic linear actuator modules 114 may be substantially the same. The pneumatic linear actuator module 114 may be identical to the pneumatic linear actuator module 14 described above, except that each of the pneumatic linear actuator modules 114 may further include a biasing element 128, a position transducer 148, a pressure transducer 156, a threaded column 170, and a threaded nut 172.
The position transducer 148 may be identical to the position transducer 48 described above in reference to
The pressure transducer 156 may be identical to the pressure transducer 56 described above in reference to
The biasing element 128 may be a spring, such as a coil spring, or an elastomeric device. The biasing element 128 may be configured to apply a biasing force between the translating member 38 and the first member 30 in opposition to the tensile force generated by the fluidic actuator 40.
As shown in
The pneumatic controller 120 may be identical to the pneumatic controller 20 described above in reference to
In operation, the processor 46 of pneumatic controller 120 may receive a signal from the control input C indicating a desired level of actuation of the device 12, for example increasing the level of actuation by moving the stem 26 away from the fully closed position. The processor 46 sends an electrical signal to the I/P transducer 58 of the pneumatic control mechanism 50. The electrical signal may be a function of the signal from the control input C, the electrical signals from each of the position transducers 148, and the electrical signals from each of the pressure transducers 156. The I/P transducer 58 modulates a pressure from the compressed gas supply S in response to the electrical signal from the processor 46 to provide a pneumatic control signal to the volume booster 60. The pneumatic control signal from the I/P transducer 58 increases the pressure supplied by volume booster 60 from the compressed gas supply S to the pneumatic control line 54.
Each of the plurality of header isolation valves 52 may be in an open position such that the increased pressure from the pneumatic control mechanism 50 is supplied from the pneumatic control line 54 to the fluidic actuator 40 of each of the pneumatic linear actuator modules 114 by way of the pneumatic fitting 42. Within each of the pneumatic linear actuator modules 114, the increased pressure supplied from the pneumatic control line 54 increases the pressure within the fluidic actuator 40, generating a tensile force between opposite ends of the fluidic actuator 40. The tensile force generated by the fluidic actuator 40 pulls the translating member 38 toward the first member 30 and away from the second member 32. Movement of the translating member 38 toward the first member 30 and away from the second member 32 for each of the plurality of pneumatic linear actuator modules 114 also moves the dynamic actuator linkage 16 away from the static actuator linkage 18. The tensile force produced by the plurality of pneumatic linear actuator modules 114 is sufficient to overcome the biasing force of the biasing elements 128 in each of the pneumatic linear actuator modules 114 and move the valve stem 26 away from the fully closed position.
Fine adjustment of the position of the stem 26 may be accomplished through the electrical signals from each of the position transducers 148 to the processor 46. Fine control of the pressure supplied to the fluidic actuator 40 may be accomplished through the electrical signals from each of the pressure transducers 156 to the processor 46.
As with the embodiment of the linear actuation apparatus 10 described above in reference to
The linear actuation apparatus 110 may be more reliable than the linear actuation apparatus 10 described above in reference to
Each of the plurality of isolation valves 252 is disposed between the compressed gas supply S and a corresponding one of each of the pneumatic linear actuator modules 214. By selectively opening or closing one of the plurality of header isolation valves 252, a corresponding one of the plurality of pneumatic linear actuator modules 214 may be selectively connected to, or isolated from, the compressed gas supply S.
Each of the pneumatic linear actuator modules 214 may be substantially the same. The pneumatic linear actuator module 214 may be identical to the pneumatic linear actuator module 14 described above in reference to
As shown in
In operation, for each of the plurality of pneumatic linear actuator modules 214, the processor 246 of pneumatic controller 220 may receive a signal from the control input C indicating a desired level of actuation of the device 212, for example increasing the level of actuation by moving the stem 26 away from the fully closed position. The processor 246 sends an electrical signal to the I/P transducer 58 of the pneumatic control mechanism 50. The electrical signal may be a function of the signal from the control input C, the electrical signal from the position transducers 148, and the electrical signal from the pressure transducer 156. The I/P transducer 58 modulates a pressure from the compressed gas supply S in response to the electrical signal from the processor 246 to provide a pneumatic control signal to the volume booster 60. The pneumatic control signal from the I/P transducer 58 increases the pressure supplied by volume booster 60 from the compressed gas supply S to the pneumatic control line 254. The increased pressure supplied from the pneumatic control line 254 increases the pressure within the fluidic actuator 40, generating a tensile force between opposite ends of the fluidic actuator 40. The tensile force generated by the fluidic actuator 40 pulls the translating member 38 toward the first member 30 and away from the second member 32. Movement of the translating member 38 toward the first member 30 and away from the second member 32 for each of the plurality of pneumatic linear actuator modules 214 also moves the dynamic actuator linkage 16 away from the static actuator linkage 18. The tensile force produced by the plurality of pneumatic linear actuator modules 214 is sufficient to overcome the biasing force of the biasing elements 128 in each of the pneumatic linear actuator modules 214 and move the valve stem 26 away from the fully closed position.
Fine adjustment of the position of the stem 26 may be accomplished through the electrical signal from the position transducer 148 to the processor 246. Fine control of the pressure supplied to the fluidic actuator 40 may be accomplished through the electrical signals from the pressure transducer 156 to the processor 246.
As with the embodiments of the linear actuation apparatus 10 and the linear actuation apparatus 110 described above, the linear actuation apparatus 210 is configured such that a number of pneumatic linear actuator modules 214 one less than the plurality of pneumatic linear actuator modules 214 are able to provide linear actuation to the device 112. Should one of the plurality of pneumatic linear actuator modules 214 fail, it may be replaced without any downtime in the operation of the linear actuation apparatus 210 and its control of device 112. For example, once one of the pneumatic linear actuator modules 214 has been identified as failed or failing, replacement begins by disconnecting or isolating the pneumatic linear actuator module 214 from the compressed gas supply S by closing the isolation valve 252 corresponding to the pneumatic linear actuator module 214 to be replaced. The bleed valve 44 may then be opened to relieve any pressure within and pneumatic fitting 242 may be disconnected from the isolation valve 252. The pneumatic controller 220 may also be electrically disconnected from the control input C. The pneumatic linear actuator module 214 to be replaced may then be physically decoupled from the linear actuation apparatus 210 by disconnecting the translating member 38 from the dynamic actuator linkage 16, and disconnecting the second member 32 from the static actuator linkage 18.
Installing a replacement pneumatic linear actuator module 214 is done by connecting the second member 32 to the static actuator linkage 18, and connecting the translating member 38 to the dynamic actuator linkage 16 to physically couple the replacement pneumatic linear actuator module 214. Then the pneumatic fitting 242 of the replacement pneumatic linear actuator module 214 may be connected to the isolation valve 252 and the bleed valve 44 closed. Next, the header isolation valve 252 may be opened to connect the replacement pneumatic linear actuator module 214 to the compressed gas supply S. In this way, a failed or failing pneumatic linear actuator module 214 may be replaced with no downtime in the operation of device 112.
The linear actuation apparatus 210 may be more reliable than the linear actuation apparatus 10 or the linear actuation apparatus 110 described above because if one of the pneumatic controllers 220 fails, its functions are duplicated in the each of the remaining plurality of pneumatic linear actuators 214. In addition, replacing a failed pneumatic controller 220 requires no downtime because they are part of the pneumatic linear actuator modules 214, which may be replaced without any system downtime, as described above.
In some embodiments, each of the plurality of pneumatic linear actuator modules 214a, 214b, 214c, and 214d may receive the same control signal from control input C by way of the local control loop 380. One of the plurality of pneumatic linear actuator modules 214a, 214b, 214c, and 214d, for example, the pneumatic linear actuator module 214a, may be designated a primary control module, and the remaining of pneumatic linear actuator modules 214b, 214c, and 214d may be designated as secondary control modules. So configured, the pneumatic linear actuator module 214a may act as the primary control module and may send a loop control signal to each of the secondary control modules, the pneumatic linear actuator modules 214b, 214c, and 214d, in response to the control signal from control input C. As secondary control modules, the pneumatic linear actuator modules 214b, 214c, and 214d may actuate in response to the loop control signal and may ignore the control signal from control input C. In this way, one of the plurality of pneumatic linear actuator modules, the pneumatic linear actuator module 214a, may control and coordinate the actuation of all of the pneumatic linear actuator modules of linear actuation apparatus 310.
As with the embodiments of the linear actuation apparatus 210 described above, the linear actuation apparatus 310 is configured such that a number of pneumatic linear actuator modules 214 one less than the plurality of pneumatic linear actuator modules 214 are able to provide linear actuation to the device 112. As shown in
In this way, one of the plurality of pneumatic linear actuator modules 214a, 214b, 214c, and 214d may control and coordinate the actuation of all of the pneumatic linear actuator modules of linear actuation apparatus 310 while a failed or failing pneumatic linear actuator module may be replaced without any downtime in the operation of the linear actuation apparatus 310.
Each of the plurality of isolation valves 252 is disposed between the compressed gas supply S and a corresponding one of each of the pneumatic linear actuator modules 414. By selectively opening or closing one of the plurality of header isolation valves 252, a corresponding one of the plurality of pneumatic linear actuator modules 414 may be selectively connected to, or isolated from, the compressed gas supply S.
Each of the pneumatic linear actuator modules 414 may be substantially the same. The pneumatic linear actuator module 414 may be identical to the pneumatic linear actuator module 214 described above in reference to
As shown in
As shown in
In operation, for each of the plurality of pneumatic linear actuator modules 414, the processor 446 of pneumatic controller 420 may receive a signal from the control input C indicating a desired level of actuation of the device 112, for example increasing the level of actuation by moving the stem 26 away from the fully closed position. The pneumatic controller 420 may also receive a signal from the control input C indicating one of four alternative states for control of each of the pneumatic linear actuator modules 414. In a first state, the pneumatic linear actuator module 414 is directed to operate as a stand-alone unit, operating as described above for the pneumatic linear actuator module 214 in reference to
In a second state, the pneumatic linear actuator module 414 is directed to control the other pneumatic linear actuator modules 414. In the second state, the processor 446 sends electrical signals to open both the control line pneumatic valve 466 and the common header pneumatic valve 468. The processor 446 sends an electrical signal to the I/P transducer 58 of the pneumatic control mechanism 50. The electrical signal may be a function of the signal from the control input C, the electrical signal from the position transducers 148, and the electrical signal from the pressure transducer 156. The I/P transducer 58 modulates a pressure from the compressed gas supply S in response to the electrical signal from the processor 446 to provide a pneumatic control signal to the volume booster 60. The pneumatic control signal from the I/P transducer 58 increases the pressure supplied by volume booster 60 from the compressed gas supply S to the pneumatic control line 454 and to the other pneumatic linear actuator modules 414 by way of their connection to the common header 462. The increased pressure supplied from the pneumatic control line 454 increases the pressure within the fluidic actuator 40 of each of the plurality of pneumatic linear actuator modules 414, generating a tensile force between opposite ends of the fluidic actuator 40. The tensile force produced by the plurality of pneumatic linear actuator modules 414 is sufficient to overcome the biasing force of the biasing elements 128 in each of the pneumatic linear actuator modules 414 and move the valve stem 26 away from the fully closed position.
In a third state, the pneumatic linear actuator module 414 is directed to be controlled by one of the other pneumatic linear actuator modules 414. In the third state, the processor 446 sends electrical signals to close the control line pneumatic valve 466 and open the common header pneumatic valve 468. In this state, increased pressure is supplied to the pneumatic control line 454 exclusively from the common header 462, which is controlled by the one of the other pneumatic linear actuator modules 414. The increased pressure supplied from the pneumatic control line 454 increases the pressure within the fluidic actuator 40 of each of the plurality of pneumatic linear actuator modules 414, generating a tensile force between opposite ends of the fluidic actuator 40. The tensile force produced by the plurality of pneumatic linear actuator modules 414 is sufficient to overcome the biasing force of the biasing elements 128 in each of the pneumatic linear actuator modules 414 and move the valve stem 26 away from the fully closed position.
In a fourth state, the pneumatic linear actuator module 414 is directed to isolate the pneumatic control line 454 from both the output of the pneumatic control mechanism 50 and the common header 462. In the fourth state, the processor 446 sends electrical signals to close the control line pneumatic valve 466 and the common header pneumatic valve 468. In this “hold” state may be employed, for example, when no change in the pressure within the fluidic actuator 40 is desired, or as in intermediate state prior to entering any of the first, second, or third states.
As with the embodiments of the linear actuation apparatus 10, the linear actuation apparatus 110, and the linear actuation apparatus 210 described above, the linear actuation apparatus 410 is configured such that a number of pneumatic linear actuator modules 414 one less than the plurality of pneumatic linear actuator modules 414 are able to provide linear actuation to the device 112. Should one of the plurality of pneumatic linear actuator modules 414 fail, it may be replaced without any downtime in the operation of the linear actuation apparatus 410 and its control of device 112. For example, if one of the plurality of pneumatic actuator modules 414 is in the state two and identified as failed or failing, another one of the plurality of pneumatic linear actuator modules 414 may receive a signal from the control input C to go to state two to take over control of the other of the pneumatic linear actuator modules 414. Once the failed pneumatic linear actuator module 414 is not controlling, it may be replaced and a new pneumatic linear actuator module 414 installed as described above in reference to
Various modifications and additions can be made to the exemplary embodiments discussed without departing from the scope of the present invention. For example, while the embodiments described above refer to particular features, the scope of this invention also includes embodiments having different combinations of features and embodiments that do not include all of the above described features. And further, use of the term “may” within the description of the various embodiments is intended to mean may as opposed to must, may only, can only, necessarily or another absolute term.
This application claims priority to Provisional Application No. 62/118,623, filed Feb. 20, 2015, which is herein incorporated by reference in its entirety.
| Number | Name | Date | Kind |
|---|---|---|---|
| 3598019 | Killian | Aug 1971 | A |
| 3766835 | Kobelt | Oct 1973 | A |
| 3967809 | Skantar | Jul 1976 | A |
| 4373334 | Carlander | Feb 1983 | A |
| 4577654 | Pringle | Mar 1986 | A |
| 5052273 | Sakaguchi | Oct 1991 | A |
| 5067390 | Negishi | Nov 1991 | A |
| 5197328 | Fitzgerald | Mar 1993 | A |
| 5431182 | Brown | Jul 1995 | A |
| 5975492 | Brenes | Nov 1999 | A |
| 6209443 | Perez | Apr 2001 | B1 |
| 7104182 | Reininger | Sep 2006 | B2 |
| 7617874 | Ocalan | Nov 2009 | B2 |
| 8820342 | Do et al. | Sep 2014 | B2 |
| 20040035181 | DeRuiter et al. | Feb 2004 | A1 |
| 20090100962 | Uracz et al. | Apr 2009 | A1 |
| 20090173178 | Okazaki | Jul 2009 | A1 |
| Number | Date | Country |
|---|---|---|
| 796582 | Apr 1936 | FR |
| 37412 | Jan 1962 | JP |
| S42017216 | Sep 1967 | JP |
| S5256194 | Apr 1977 | JP |
| S53147178 | Dec 1978 | JP |
| S58181981 | Oct 1983 | JP |
| S6024905 | Feb 1985 | JP |
| S60146909 | Aug 1985 | JP |
| 6235405 | Aug 1994 | JP |
| H09196006 | Jul 1997 | JP |
| 2000257604 | Sep 2000 | JP |
| 2004197769 | Jul 2004 | JP |
| Entry |
|---|
| Festo. “Fluidic Muscle DMSP/MAS.” 2013, 36 pages. |
| International Search Report and Written Opinion issued in PCT/US2016/018183, dated Apr. 19, 2016, 14 pages. |
| Norgren. “Integrating Valves and Actuators Optimizes Pneumatic Motion Control Efficiency: Integrated Valve and Actuator Control (IVAC) Simplifies, Enhances Pneumatic Control Systems.” pp. 516.01-516.08, 2012. |
| Number | Date | Country | |
|---|---|---|---|
| 20160245312 A1 | Aug 2016 | US |
| Number | Date | Country | |
|---|---|---|---|
| 62118623 | Feb 2015 | US |
