Abstract: A system for measuring clearance between a stationary object and a movable object is provided. The system includes at least one sensor configured to be disposed on the stationary object and configured to measure an operating parameter corresponding to the movable object and a controller coupled to the at least one sensor, wherein the controller is configured to control an operating mode of the sensor based upon the measured operating parameter.

Abstract: Two embodiments of closed loop electro-fluidic controlled systems are disclosed for controlling the velocity, acceleration, torque, force of pressure applied to a member. The system includes a source of electrical command signals correlated to the desired magnitude of the parameter being controlled, a transducer responsive to the controlled member for providing an electrical feedback signal correlated to the actual value of the parameter, and a circuit for providing an error signal correlated in magnitude and polarity to the magnitude and sense of the difference between the actual and desired values of the controlled parameter. Also included is a transducer responsive to the error signal for applying a positioning force to a movable valve closure element, which is subjected to no other forces, to regulate the application of pressurized fluid through the valve to the controlled member in dependence upon the error signal.

Abstract: Two embodiments of closed loop electro-fluidic controlled systems are disclosed for controlling the velocity, acceleration, torque, force or pressure applied to the member. The system includes a source of electrical command signals correlated to the desired magnitude of the parameter being controlled, a transducer responsive to the controlled member for providing an electrical feedback signal correlated to the actual value of the parameter, and a circuit for providing an error signal correlated in magnitude and polarity to the magnitude and sense of the difference between the actual and desired values of the controlled parameter. Also included is a transducer responsive to the error signal for applying a positioning force to a movable valve closure element, which is subjected to no other forces, to regulate the application of pressurized fluid through the valve to the controlled member in dependence upon the error signal.