| 摘要 |
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 object or the like is caught in the open-and-closure mechanism can be made since an aged deterioration and/or a temperature variation in the dynamic friction resistance Td are almost not included in the change rate (dT/dt, T') at which the external disturbance torque T is changed with time.
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