Apparatus and method for determining presence or absence of foreign object or the like caught in power-open-and-closure mechanism
First Claim
1. An apparatus for a power open-and-closure mechanism, comprising:
- a fixed member of the power open-and-closure mechanism;
a movable member of the power open-and-closure mechanism;
a reversible motor for driving, in response to a receipt of a power supply, the power open-and-closure mechanism to move the movable member in directions toward the fixed member to a closed position and away from the fixed member to an open position;
a current detector for detecting a current flowing through the reversible motor;
a voltage detector for detecting a terminal voltage across the reversible motor;
a motor angular velocity detector for detecting an angular velocity of the reversible motor;
an external disturbance torque calculator for calculating an external disturbance torque imposed on the reversible motor on the basis of at least two of three parameters of the detected current flowing through the reversible motor, the detected terminal voltage across the reversible motor, and the detected angular velocity of the reversible motor;
a differentiator for differentiating the calculated external disturbance torque to derive a change rate at which the calculated external disturbance torque is changed with time; and
,a comparator for comparing the derived change rate of the calculated external disturbance torque with a predetermined threshold value so as to determine whether a foreign object is caught in the power open-and-closure mechanism on the basis of a result of comparison thereby while the movable member is driven by the reversible motor to be moved in the direction toward the fixed member to the closed position.
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Accused Products
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 ω. 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.
178 Citations
20 Claims
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1. An apparatus for a power open-and-closure mechanism, comprising:
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a fixed member of the power open-and-closure mechanism; a movable member of the power open-and-closure mechanism;
a reversible motor for driving, in response to a receipt of a power supply, the power open-and-closure mechanism to move the movable member in directions toward the fixed member to a closed position and away from the fixed member to an open position;a current detector for detecting a current flowing through the reversible motor; a voltage detector for detecting a terminal voltage across the reversible motor; a motor angular velocity detector for detecting an angular velocity of the reversible motor; an external disturbance torque calculator for calculating an external disturbance torque imposed on the reversible motor on the basis of at least two of three parameters of the detected current flowing through the reversible motor, the detected terminal voltage across the reversible motor, and the detected angular velocity of the reversible motor; a differentiator for differentiating the calculated external disturbance torque to derive a change rate at which the calculated external disturbance torque is changed with time; and
,a comparator for comparing the derived change rate of the calculated external disturbance torque with a predetermined threshold value so as to determine whether a foreign object is caught in the power open-and-closure mechanism on the basis of a result of comparison thereby while the movable member is driven by the reversible motor to be moved in the direction toward the fixed member to the closed position. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. An apparatus for a power open-and-closure mechanism, comprising:
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a fixed member; a movable member; a reversible motor for driving the movable member toward the fixed member and to a closed position; external disturbance torque calculating means for calculating an external disturbance torque and imposed on the reversible motor on the basis of at least two of three parameters of a detected current flowing through the reversible motor, a detected terminal voltage across the reversible motor, and a detected angular velocity of the reversible motor; differentiating means for differentiating the calculated external disturbance torque to derive a change rate at which the calculated external disturbance torque is changed with time; and
,comparing means for comparing the derived change rate of the calculated external disturbance torque with a predetermined threshold value; and a determining unit which determines whether a foreign object is caught in the power open-and-closure mechanism on the basis of a result of a comparison performed by the comparing means while the movable member is driven by the reversible motor toward the closed position.
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20. A method for determining whether a foreign object is caught in a power open-and-closure mechanism, the open-and-closure mechanism including a fixed member, a movable member, and a motor for driving in response to a receipt of a power supply, the power open-and-closure mechanism to move the movable member in directions toward the fixed member to a closed position and away from the fixed member to an open position,
the method comprising the steps of: -
detecting a current flowing through the reversible motor; detecting a terminal voltage across the reversible motor; detecting an angular velocity of the motor; calculating an external disturbance torque imposed on the motor on the basis of at least two of three parameters of the detected current flowing through the motor, the detected terminal voltage across the motor, and the detected angular velocity of the motor; differentiating the calculated external disturbance torque to derive a change rate at which the calculated external disturbance torque is changed with time; comparing the derived change rate of the calculated external disturbance torque with a predetermined threshold value; and determining whether the foreign object is caught in the power open-and-closure mechanism on the basis of a result of comparison at the comparing step while the movable member is driven by the motor to be moved in the direction toward the fixed member to the closed position.
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Specification