Direct current command generation for a stepper motor drive
US6121745A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 5, 1999 |
| Grant date | Sep 19, 2000 |
| Priority date | — |
| Expiry date | Jan 5, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P8/00
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A system for controlling a stepper motor is disclosed that includes a microprocessor for directly generating current command signals. The microprocessor has a memory wherein the memory includes a function table, a first function table address, and a second function table address. A velocity signal (indicating a rotational position change per unit time) is calculated by the microprocessor during each update interval. Each update interval comprises a plurality of interrupt intervals. The microprocessor, in accordance with software-selectable current magnitude parameter values and microstepping parameter values, determines a first and second current value by accessing the function table at the first and second function table addresses, during each interrupt interval. The first and second current values generated by the microprocessor correspond to a pair of digital words representing a pair of phase current commands. The microprocessor outputs the pair of digital words to a drive circuit during each interrupt interval to energize a two-phase stepper motor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.