Apparatus and method for determining presence or absence of foreign object or the like caught in power-open-and-closure mechanism
US5977732A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 4, 1998 |
| Grant date | Nov 2, 1999 |
| Priority date | — |
| Expiry date | Feb 4, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H3/44
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Disclosed are apparatus and method for determining whether a foreign object or the like is caught in an open-and-closure mechanism such as a power window of an automotive vehicle. An external disturbance torque T imposed on a the open-and-closure mechanism motor as its load is calculated on the basis of at least two of three parameters of a terminal voltage Em across the motor, a current flowing through the motor Im, and a motor angular velocity .omega.. Furthermore, the calculated external disturbance torque is differentiated to derive a change rate at which the external disturbance torque T is changed with time as dT/dt (T'). Since dT/dt (T')=dTs'/dt (Ts')+dTd'/dt (Td') and dTd/dt (Td')=0 (Td: a dynamic friction resistance force and dTd/dt: the change rate of the dynamic friction resistance force per time), dT/dt=dTs'/dt (Ts: an external disturbance force imposed on the motor by the caught foreign object and dTs/dt (Ts'): the differentiation value of the external disturbance force). When the change rate (dT/dt or T') of the external disturbance torque T is compared with a predetermined threshold value (Kw in a second embodiment), an accurate determination of whether the foreign o…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.