Patent · US Expired

Digital robot control having pulse width modulator operable with reduced noise

US4980838A · kind A · utility

17Cited by
4References
8Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJan 31, 1989
Grant dateDec 25, 1990
Priority date
Expiry dateJan 31, 2009

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH02P7/04
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

A pulse width modulation (PWM) control circuit provides for improved implementation of position, velocity and current feedback loops for digital servo control of a multi axis robot. The PWM circuit utilizes a single resistor for sensing joint motor drive current. Circuitry is also disclosed for reducing audible noise and motor heating in large servo motors used for joint arms operated at relatively low PWM frequencies by reducing the motor ripple current.

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