Abstract: Process controllers, methods, and systems provide for frequency control to account for the effects of periodic disturbances in the feedback signal of closed loop control systems. The frequency components of the feedback signal are determined, including the magnitude and phase of each. Waveforms for each frequency component are generated with substantially the same magnitude and substantially the opposite phase of each frequency component. The waveforms are then summed to produce a compensating waveform that is summed within the output of the control system so that the effects of the periodic disturbances are cancelled from the control system output being provided to the system under control.

Abstract: Process controllers, methods, and systems provide for frequency control to account for the effects of periodic disturbances in the feedback signal of closed loop control systems. The frequency components of the feedback signal are determined, including the magnitude and phase of each. Waveforms for each frequency component are generated with substantially the same magnitude and substantially the opposite phase of each frequency component. The waveforms are then summed to produce a compensating waveform that is summed within the output of the control system so that the effects of the periodic disturbances are cancelled from the control system output being provided to the system under control.

Abstract: An adaptive closed-loop controller is described that reduces repetitive speed variations of precision rotatable mechanical components, such as rollers, casting wheels, pulleys, gears, pull rollers, extruders, gear pumps, and the like. A system is illustrated in which the controller is coupled to a motor for driving a rotatable mechanical component in response to a motor control signal. A sensor is mounted to the shaft of the mechanical component, and generates a speed signal representing angular velocity of a mechanical component. The controller receives the speed signal, and generates a set of data elements to relate speed variations of the mechanical component to a plurality of angular positions of the mechanical component over one or more revolutions. The controller generates an error signal based on the data elements and introduces the error signal into closed-loop control circuitry to provide adaptive control over the mechanical component.

Abstract: An adaptive closed-loop controller is described that reduces repetitive speed variations of precision rotatable mechanical components, such as rollers, casting wheels, pulleys, gears, pull rollers, extruders, gear pumps, and the like. A system is illustrated in which the controller is coupled to a motor for driving a rotatable mechanical component in response to a motor control signal. A sensor is mounted to the shaft of the mechanical component, and generates a speed signal representing angular velocity of a mechanical component. The controller receives the speed signal, and generates a set of data elements to relate speed variations of the mechanical component to a plurality of angular positions of the mechanical component over one or more revolutions. The controller generates an error signal based on the data elements and introduces the error signal into closed-loop control circuitry to provide adaptive control over the mechanical component.