Active deflection compensator

Abstract

An active deflection compensator for use with an antenna system that comprises a linear scanner ridge that projects into a waveguide cavity coupled to an antenna array. Linear actuators are coupled to the linear ridge at opposite ends thereof and adjacent its center. Transducers are coupled to the linear ridge at opposite ends thereof adjacent the actuators that are adapted to provide signals indicative of the linear and angular displacement of the linear scanner ridge. A transducer is disposed adjacent the center linear actuator that is adapted to provide signals indicative of the amount of bending of the linear scanner ridge. A servo control system is coupled to the actuators and transducers that executes a control algorithm that processes information regarding the location, angular displacement and deflection of the linear scanner ridge and that provides correction signals to the actuators to maintain the linear scanner ridge parallel to the waveguide cavity and provide signals to the center actuator to dynamically correct for deflection of the linear scanner ridge to keep it relatively flat or straight. The active deflection compensator thus compensates for deflections of a slender body or beam (the linear scanner ridge) when it is subjected to dynamic loads. Throughout its range of motion, the oscillating beam is commanded to positions that are to be reached at specific times. The time and position commands produce accelerations on the beam that interact with its mass producing forces and deflections on the beam. The use of the center actuator provides an active response by adding (when the point lags behind) or subtracting (when the point moves ahead) to actively compensate for beam deflections.