Patent ID: 6590366
Filing Date: 2003-07-08
Classification: F16C

Abstract:
A system for suspending a movable member, the system comprising:at least one magnetic bearing operable to suspend the movable member in response to a control signal; at least one sensor disposed to detect displacement of the movable member from a desired position, the sensor providing a sensing signal; and a control system connected to the magnetic bearing and the sensor, the control system including a control unit for processing the sensing signal and producing at least a portion of the control signal so that the magnetic bearing responds to the control signal to maintain the movable member in the desired position, the control unit further including a unifying plant compensation filter which isolates a negative stiffness characteristic, wherein the control unit further comprises: a resonance controller connected between the sensor and the compensation filter for adaptively filtering a negated sensing signal; a PID controller connected to the compensation filter, the PID controller operable to produce a PID controller output signal; a narrowband controller operating on the sensing signal, and connected to a tachometer signal input, the narrowband controller removing at least in part noise caused by imbalances and loading of the movable member, the narrowband controller operable to produce a narrowband controller output signal; and a summer connected to the PID controller and the narrowband controller, so as to be operable to produce at least a portion of the control signal from the narrowband controller output signal and the PID controller output signal.