| 摘要 |
Actuators and corresponding methods and systems for controlling such actuators offer efficient, fast, flexible control with large forces. In an exemplary embodiment, an fluid actuator includes a housing having first and second fluid ports, an actuation cylinder in the housing defining a longitudinal axis and having first and second ends in first and second directions, an actuation piston in the cylinder with first and second surfaces moveable along the longitudinal axis, a spring subsystem biasing the actuation piston to a neutral position, a first fluid space defined by the first end of the actuation cylinder and the first surface of the actuation piston, a second fluid space defined by the second end of the actuation cylinder and the second surface of the actuation piston; and a flow bypass that short-circuits the first and second fluid spaces when the actuation piston is not proximate to the second end of the actuation cylinder. A first flow mechanism controls fluid communication between the first fluid space and the first port, whereas a second flow mechanism controls fluid communication between the second fluid space and the second port. The first flow mechanism is always wide-open, whereas the second flow mechanism is open and closed when the flow bypass is closed and open, respectively. The system is able to latch the actuation piston at its second direction end position while making it possible for the actuation piston not to dwell at its first direction end position, thus reducing the overall actuation time.
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