Actuator control providing linear and continuous force output
US6762745B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 5, 2000 |
| Grant date | Jul 13, 2004 |
| Priority date | — |
| Expiry date | May 5, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/0383
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Methods and apparatus for controlling an actuator to provide linear and continuous force output to a user of a force feedback device. To provide continuous and smooth force output in a zero crossover region of operation, two drive signals are used, each causing current to flow in a different direction in the actuator. When a desired output force is in the crossover region, the two drive signals are alternated to cause the output force to quickly switch directions. When the desired force is outside the crossover region, only one drive signal is used to cause output force in one direction. To compensate for a nonlinear output of the actuator, a desired command current is correlated with an approximated point of a characterization curve of the actuator, where the curve includes points determined in a previously performed actuator characterization. The approximated point is determined between two successive points using a linear approximation, and a drive signal duty cycle is determined from the approximated point. Other features can be implemented to compensate for power supply voltage variation, back EMF effect, and temperature.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.