Multi-axis AC servo control system and method
AssigneeInternational Rectifier Corporation
InventorToshio Takahashi
Life of this patent
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Abstract
A multiple axis servo control implements a multi-tasking PWM control unit to provide PWM signals for multiple axes in a single unit. A time slice mechanism provides axis selection signals based on a system clock signal to permit control parameters of the selected axis to be processed to control the selected motor drive axis. The single unit PWM control mechanism eliminates complex and costly multiple axis networks typically associated with independent servo motor controls for each axis in a multi-axis system. A single PWM unit implementation also permits the reduction of components for closed loop current control and closed loop velocity control in the multi-axis servo control system.
Claims16
A PWM control unit for producing PWM signals in a multi-axis servo motor drive control, comprising:
- a time slice selection unit for generating a plurality of axis selection signals to select components related to a particular axis in the multi-axis control based on a timing oscillation signal;
- a plurality of storage elements coupled to the time slice selection unit and associated with a phase signal for a motor phase, each of the storage elements being selectably coupled to the associated phase signal based on the axis selection signals generated by the time slice selection unit;
- the storage elements being operable to output a value upon being selected to contribute to generating a PWM control output for the selected axis.
A method for producing PWM signals in a multi-axis servo motor drive control, comprising:
- generating a plurality of axis selection signals for selecting components related to a particular axis in the multi-axis control based on a timing oscillation signal;
- selectably coupling storage elements associated with a motor phase to a motor phase command signal based on the axis selection signals;
- outputting from the storage elements a PWM control output for driving the motor phase for the selected axis.
A multiple axis servo motor drive control system for providing three-dimensional position control of a moving object, comprising:
- a host system for supplying multi-axis servo control commands;
- a processor coupled to the host system for receiving the multi-axis servo control commands, the processor having a PWM control unit for producing PWM signals on the basis of the servo motor control commands;
- the PWM control unit being operable to provide multiple sets of PWM signals to supply a respective set of PWM signals to a motor drive for a selected axis among a plurality of axes;
- the respective set of PWM signals produced by the PWM control unit for said selective axis being selected on the basis of a time slice signal generated in conjunction with a timing oscillation signal;
- and
- wherein:
- the PWM control unit further comprises a plurality of storage elements for storing motor drive command signals for said plurality of motor phases of said plurality of axes, a respective set of storage elements for said plurality of axes being associated with each motor phase;
- and
- said set of storage elements being selectively coupled to the motor drive command signals on the basis of the time slice control signals.
Dependencies are inferred from the claim text.