Patent · US Expired

Open-loop electric drive with corrective controller

US4163928A · kind A · utility

9Cited by
2References
16Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 9, 1978
Grant dateAug 7, 1979
Priority date
Expiry dateFeb 9, 1998

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG05B2219/42182
  • WIPO fieldControl
  • WIPO sectorInstruments

Abstract

A controller minimizes periodic torque or force perturbations in an inductor-type synchronous motor drive by supplying current waveforms to each motor phase that contain a fundamental frequency component and selected harmonic components. The harmonic components in the phase currents heterodyne with the periodic permanent magnet flux fundamental frequency to create periodic torques or forces which subtract from the unwanted torques or forces perturbing the moving portion of the motor. The controller, which includes an interpolator, a memory, and a converter, provides for smooth incremental movement of a member such as a plot head, at substantially constant velocity, by applying selected continuous periodic waveform signals as phase currents to the windings of inductor-type synchronous motors.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.