Abstract: A dynamic degaussing system includes a magnetic field sensor for generating a sensor signal in response to a sensed magnetic field. The magnetic sensor is coupled to a controller that produces an output signal based on the sensor signal. The controller may include feedforward and feedback control loops. The output signal of the controller controls a magnetic field generator which generates a magnetic field so as to attenuate the sensed magnetic field. According to one aspect of the invention, a vessel is provided with a reduced magnetic signature and a control system for controlling magnetic fields about a podded electric motor. The control system employs feed-forward and feedback control in tandem. The control system may be dynamically adapted to changing physical characteristics of the motor. Control signals are generated in response to sensed or predicted magnetic fields internal to, or external to, the motor.

Abstract: A multi-sensor, multi-actuator control system for controlling vibration in a mechanical structure. The system employs feedforward and feedback control strategies in tandem. Outputs from adaptive feedforward and modal feedback control loops are added to each other. The control system may be dynamically adapted to the changing physical characteristics of the controlled structure. For example, the plant transfer function estimates for the feedforward unit and the gain for the feedback unit may be calculated as functions of sensed physical parameters (location, mass, etc.), and the plant transfer function estimates may be dynamically modified to reflect time-varying feedback control gains. If desired, the control system may be used to cancel low frequency vibrations (<20 Hz) in industrial processes. The actuators may be formed of electromagnets, fixed armatures and interposed flux sensors. In a preferred embodiment of the invention, the robust actuators are sealed so as to be impervious to fluids and dust.

Abstract: A dynamic degaussing system includes a magnetic field sensor for generating a sensor signal in response to a sensed magnetic field. The magnetic sensor is coupled to a controller that produces an output signal based on the sensor signal. The controller may include feedforward and feedback control loops. The output signal of the controller controls a magnetic field generator which generates a magnetic field so as to attenuate the sensed magnetic field. According to one aspect of the invention, a vessel is provided with a reduced magnetic signature and a control system for controlling magnetic fields about a podded electric motor. The control system employs feed-forward and feedback control in tandem. The control system may be dynamically adapted to changing physical characteristics of the motor. Control signals are generated in response to sensed or predicted magnetic fields internal to, or external to, the motor.

Abstract: A compliant structure, such as a rubber pad, is used to simplify the resonance pattern of a vibrating object. According to one aspect of the invention, a support system is provided with a device for applying electromagnetic forces to the vibrating object, and the compliant structure is used to support the electromagnetic device. The electromagnetic device is positively controlled as a function of (A) the position of the vibrating object and (B) the position of the electromagnet. The compliant structure may also be used to further attenuate high frequency vibration transmission. According to one aspect of the invention, the compliant structure permits some rocking and/or rotational motion of the electromagnet to simplify the vibration transmission mechanism. According to another aspect of the invention, the compliant structure operates as a slightly-damped stiff spring in the axial direction of the electromagnet.

Abstract: A compliant structure, such as a rubber pad, is used to simplify the resonance pattern of a vibrating object. According to one aspect of the invention, a support system is provided with a device for applying electromagnetic forces to the vibrating object, and the compliant structure is used to support the electromagnetic device. The electromagnetic device is positively controlled as a function of (A) the position of the vibrating object and (B) the position of the electromagnet. The compliant structure may also be used to further attenuate high frequency vibration transmission. According to one aspect of the invention, the compliant structure permits some rocking and/or rotational motion of the electromagnet to simplify the vibration transmission mechanism. According to another aspect of the invention, the compliant structure operates as a slightly-damped stiff spring in the axial direction of the electromagnet.

Abstract: A multi-sensor, multi-actuator control system for controlling vibration in a mechanical structure. The system employs feedforward and feedback control strategies in tandem. Outputs from adaptive feedforward and modal feedback control loops are added to each other. The control system may be dynamically adapted to the changing physical characteristics of the controlled structure. For example, the plant transfer function estimates for the feedforward unit and the gain for the feedback unit may be calculated as functions of sensed physical parameters (location, mass, etc.), and the plant transfer function estimates may be dynamically modified to reflect time-varying feedback control gains. If desired, the control system may be used to cancel low frequency vibrations (<20 Hz) in industrial processes. The actuators may be formed of electromagnets, fixed armatures and interposed flux sensors. In a preferred embodiment of the invention, the robust actuators are sealed so as to be impervious to fluids and dust.