Abstract: A method and apparatus for tuning control loop parameters in a motion control system, is provided. In one embodiment, tuning of the proportional and integral gains of a servocontroller's velocity loop compensator is provided, as well as tuning of the cutoff frequencies of the servocontroller's low pass filters. In this embodiment, random noise excitation is added to the velocity command during a plurality of movement types for a machine tool axis. During each movement type, frequency response measurements are taken. Then, a composite frequency response can be selected by concatenating portions of the various frequency response measurements, so as to simulate a worst case scenario for the machine tool axis. From this composite response, an open loop response can be calculated and displayed, as well as bandwidth, phase margin, and gain margin values. The user can then enter the compensator parameters which were used when this data was taken, as well as proposed parameters.

Abstract: A method and apparatus for tuning control loop parameters in a motion control system, is provided. In one embodiment, tuning of the proportional and integral gains of a servocontroller's velocity loop compensator is provided, as well as tuning of the cutoff frequencies of the servocontroller's low pass filters. In this embodiment, random noise excitation is added to the velocity command during a plurality of movement types for a machine tool axis. During each movement type, frequency response measurements are taken. Then, a composite frequency response can be selected by concatenating portions of the various frequency response measurements, so as to simulate a worst case scenario for the machine tool axis. From this composite response, an open loop response can be calculated and displayed, as well as bandwidth, phase margin, and gain margin values. The user can then enter the compensator parameters which were used when this data was taken, as well as proposed parameters.

Abstract: A method and apparatus for tuning control loop parameters in a motion control system, is provided. In one embodiment, tuning of the proportional and integral gains of a servocontroller's velocity loop compensator is provided, as well as tuning of the cutoff frequencies of the servocontroller's low pass filters. In this embodiment, random noise excitation is added to the velocity command during a plurality of movement types for a machine tool axis. During each movement type, frequency response measurements are taken. Then, a composite frequency response can be selected by concatenating portions of the various frequency response measurements, so as to simulate a worst case scenario for the machine tool axis. From this composite response, an open loop response can be calculated and displayed, as well as bandwidth, phase margin, and gain margin values. The user can then enter the compensator parameters which were used when this data was taken, as well as proposed parameters.

Abstract: A method and apparatus for compensating for the effects of compliant elements in a positioning system is provided. The amount of compensation to be applied can be determined by measuring the lost motion errors which are prevalent during continuous motion of the movable member of the system. The compensation value determined can be used to adjust servo control commands, such as position commands for example. Preferably, the compensation is applied when the movable member is in motion and removed when the movable member comes to a stop. Even more preferably, the compensation is applied and removed gradually. The compensation can be used in additional to friction compensation and backlash compensation, and can be implemented in a machine tool system.

Abstract: Compensation for friction affecting motion of moveable machine members is effected in servo control of the member actuators. An estimate of velocity is used in evaluation of a model of frictional force to produce compensation values. Alternative embodiments provide continuous models of estimated velocity and frictional forces and state models of estimated velocity and frictional forces. Compensation values determined according to either embodiment may be produced for application to servo control commands such as position or torque. The compensation accounts for step changes of friction upon reversal of direction of travel.