Direct current command generation for a stepper motor drive
US5914579A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 2, 1997 |
| Grant date | Jun 22, 1999 |
| Priority date | — |
| Expiry date | Oct 2, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P8/12
- 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 is of the type having memory wherein the memory includes two transfer tables. The microprocessor, in accordance with software-selectable current magnitude parameter values and microstepping parameter values, determines a sequence of digital words to populate a first one of the tables. The stepper motor is a two-phase motor and the digital words correspond to the phase current commands are generated by the microprocessor using sine, and cosine law function tables. A DMA (Direct Memory Access) controller in the microprocessor outputs the populated transfer table to a drive circuit to energize the stepper motor while the main control software executing in the microprocessor populates the second-transfer table. Once the first transfer table has been completely output to the drive circuit, the roles of the transfer tables are reversed and the process is repeated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.