Method and apparatus for acceleration limiting a position command for motion control
OwnerJeffrey G. Knirck, Paul A. Swansoninventors
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Abstract
An acceleration limiting electronic filter for a position motion control system is disclosed. The filter is used in conjunction with a position control system to precisely control the position of a device. The present invention limits the acceleration content of a position command signal to some value less than what the control system can execute so that the control system does not clip the acceleration and degrade control.
Claims12
An electronic signal filter apparatus, for use with a motion control system, that filters an input position command signal to produce a resultant filtered position command signal with a limited acceleration content comprising:
- a feedback signal;
- an error signal which is a combination of the input position command signal and the feedback signal;
- a means to limit the amplitude of the error signal which limits the acceleration amplitude of the resultant filtered position command signal;
- a gain stage to amplify the error signal;
- and
- two integrators to convert the amplified error signal to the resultant filtered position command signal.
An electronic signal filtering method, for use with a motion control system, that filters an input position command signal to produce a resultant filtered position command signal, comprising the steps of:
- limiting the acceleration amplitude to what the motion control system can execute;
- and
- limiting the acceleration bandwidth to what the motion control system can execute.
An electronic signal filtering method, for use with a motion controller, that filters an input position command signal to produce a resultant filtered position command signal with a limited acceleration content comprising the steps of:
- combining the input position command signal and a feedback signal to form an error signal;
- limiting the amplitude of the error signal which limits the acceleration amplitude of the resultant filtered position command signal;
- and
- double integrating the limited error signal to produce the resultant filtered position command signal.
An electronic signal filtering method, for use with a motion controller, that filters an input position command signal to produce a resultant filtered position command signal with a limited acceleration content comprising the steps of:
- determine a position error based on a difference between the input position command signal and the resultant filtered position command signal;
- calculate a switch point based on the limited acceleration and the position error;
- accelerate with a limited acceleration for a time t by incrementing the resultant filtered position command at a rate equal to the double integral of acceleration;
- and
- at the switch point, accelerate with the limited acceleration of the opposite polarity by incrementing the resultant filtered position command at a rate equal to the double integral of acceleration until the position error is zero.
Dependencies are inferred from the claim text.