Method for controlling a holding force against, and limiting impact with travel limit positions
US7855525B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 30, 2007 |
| Grant date | Dec 21, 2010 |
| Priority date | — |
| Expiry date | Sep 26, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05B2219/43058
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
An actuator includes a motor operated by a controller through a pulse width modulation drive signal applied to a drive circuit that drives the motor. The actuator has an output shaft connected to a coupling structure for manipulating a device such as a variable geometry turbine (VGT) or an exhaust gas recirculation (EGR) valve. The device has a range of motion limited by first and second mechanical stops located at opposing low and high ends of the range. The controller learns the location of the mechanical stops during calibration. An external control unit transmits a desired position to the actuator. A protocol allows the external control unit to implicitly request a positioning mode by virtue of what value range the desired position falls into. The controller is configured to limit the drive signal to a non-harmful level when one of the positioning modes calls for pushing the device against one of the stops.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.