Claims
- 1. A precision servo controlled pneumatic actuator comprising:a pneumatic actuator having a positionable component with a stroke length; and a servo control system operably connected to said pneumatic actuator, wherein said servo control system operates in accordance with a pre-established motion profile to repeatably position said positionable component within a predetermined tolerance at a plurality of programmable positions along said stroke length, wherein said servo control system is programmed with a system of gain parameters, wherein said servo control system performs an adjustment routine to determine an optimal set of said system gain parameters, and wherein said servo control system utilizes said optimal set of gain parameters to modify said pre-established motion profile to an optimal motion profile.
- 2. The pneumatic actuator of claim 1, wherein said stroke length is equal to or greater than twenty-four (24) inches.
- 3. The pneumatic actuator of claim 1, wherein said predetermined tolerance is a fixed value of more precise than +/−0.1 inches regardless of stroke length.
- 4. An automated method of controlling a pneumatic actuator operably connected to a piston in a chamber and to a brake wherein a sensor system generates measurement values representative of a movement of the piston, the method comprising:providing a servo control system that operates to repeatably position to piston; and programming the servo control system utilizing a set of standard loop gain parameters of a servo system for an electrically powered actuator including a proportional gain, (KP); an integral gain, (KI); and a derivative gain, (KV), and one additional control parameter beyond the standard control loop gain parameters of the servo system for said electrically powered actuator wherein said one additional control parameter is a deceleration current constant gain, (KT) that is used to set a minimum brake control signal while the brake is decelerating a load carried by the piston.
- 5. The method of claim 4, further comprising using a deceleration compensation path that enters into effect after a deceleration point, wherein the deceleration compensation path uses the deceleration current constant gain, (KT) to adjust for position overshoot, position undershoot, and deceleration profile linearity when the piston approaches a target position.
- 6. A method of controlling a pneumatic actuator operably connected to a piston in a chamber and to a brake wherein a sensor system generates measurement values representative of a movement of the piston, the method comprising:providing a servo control system that operates to repeatably position the piston in accordance with a pre-established motion profile; and programming the servo control system utilizing a set of system gain parameters; performing an adjustment routine to determine an optimal set of the system gain parameters and automatically utilizing said optimal set of the system gain parameters to modify said pre-established motion profile to an optimal motion profile.
- 7. The method of claim 6, wherein the adjustment routine comprises:specifying a bore size and a usable stroke length of the pneumatic actuator; cycling the piston to positions between ends of the usable stroke length while using a plurality of projected sets of servo parameters; and selecting one of the projected sets of servo parameters that achieves a best result of positioning the piston.
- 8. The method of claim 7, further wherein cycling step is repeated between 6 to 15 cycles.
- 9. The method of claim 7, wherein the selecting step automatically evaluates at least three factors:an overshoot of the position of the piston; an undershoot of the position of the piston; and a velocity following error (overshoot/undershoot) wherein the selecting step operates to minimize these factors.
CLAIM TO PRIORITY
The present invention is a continuation of application Ser. No. 09/699,039, filed Oct. 27, 2000, entitled “Precision Servo Control System for a Pneumatic Actuator,” which claims priority to two U.S. Provisional patent applications, the first of which is Application No. 60/161,875, filed Oct. 27, 1999, entitled “Pneumatic Servo System For A Linear Actuator,” and the second of which is Application No. 60/240,765, filed Oct. 17, 2000, entitled “Pneumatic Servo System,” all of which are hereby incorporated by reference.
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Provisional Applications (2)
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Number |
Date |
Country |
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60/161875 |
Oct 1999 |
US |
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60/240765 |
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US |
Continuations (1)
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Number |
Date |
Country |
Parent |
09/699039 |
Oct 2000 |
US |
Child |
10/288154 |
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US |