Elevator door stall mode with hysteresis
US4300661A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 27, 1979 |
| Grant date | Nov 17, 1981 |
| Priority date | — |
| Expiry date | Dec 27, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05B2219/45242
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
An elevator system includes a microprocessor-based cab controller which controls door motion and which controls the generation of stall forces in the door. The disclosed embodiment includes a dictated velocity, high-speed door profile, and a position-controlled dictated velocity profile, door motion being controlled as the difference between actual door velocity and dictated velocity. A stall mode, in which the door motor is provided with currents required to provide a desired force on the door, is invoked with the door velocity is less than a predetermined stall velocity, provided that the door is at an extreme position of traverse, the previous cycle was a stall cycle, or a hysteresis time period has elapsed with the velocity consistently less than the stall velocity. An exemplary elevator control system and microprocessor-based cab controller, as well as an exemplary overall door control program and details of the present invention are disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.