Opening/closing control device and opening/closing control method

1. An opening/closing control device for controlling an opening/closing operation of an opening/closing body driven by a motor, the opening/closing control device comprising:

a current detector configured to detect a current flowing to the motor;

a voltage detector configured to detect a voltage supplied to the motor;

a processor; and

a memory storing program instructions that cause the processor to:

detect a position of the opening/closing body based on rotation of the motor;

calculate a load of the opening/closing body in the opening/closing operation based on the current detected by the current detector;

set a pinch threshold value that defines an upper limit of the calculated load;

determine that an object is pinched by the opening/closing body in a case where the calculated load exceeds the upper limit defined by the pinch threshold value; and

perform a pinch prevention control process in response to determining that the object is pinched, the pinch prevention control process reversing the rotation of the motor,

wherein the processor calculates a speed of the opening/closing body based on a change in the detected position of the opening/closing body, and decreases the pinch threshold value in a case where a state, in which the calculated speed of the opening/closing body is less than or equal to a first predetermined threshold value, and a temporal change in the calculated load is greater than or equal to a second predetermined threshold value and less than or equal to a third predetermined threshold value, continues for a certain period of time or greater.

2. The opening/closing control device as claimed in claim 1 , wherein the processor decreases the pinch threshold value by a constant value in the case where the state, in which the speed of the opening/closing body is less than or equal to the first predetermined threshold value, and the temporal change in the calculated load is greater than or equal to the second predetermined threshold value and less than or equal to the third predetermined threshold value, continues for the certain period of time.

3. The opening/closing control device as claimed in claim 1 , wherein the processor detects the position of the opening/closing body based on a ripple included in the current detected by the current detector.

4. The opening/closing control device as claimed in claim 1 , wherein in response to detecting that the position of the opening/closing body is within a predetermined area near an upper end position, the processor increases the pinch threshold value by an increment value that increases as the position of the opening/closing body approaches the upper end position.

5. The opening/closing control device as claimed in claim 1 , wherein in response to detecting that the calculated load does not increase linearly, a voltage change is generated in the voltage detected by the voltage detector, or a disturbance affecting the calculated load is generated, the processor increases the pinch threshold value.

6. An opening/closing control device for controlling an opening/closing operation of an opening/closing body driven by a motor, the opening/closing control device comprising:

a current detector configured to detect a current flowing to the motor;

a voltage detector configured to detect a voltage supplied to the motor;

a processor; and

a memory storing program instructions that cause the processor to:

detect a position of the opening/closing body based on rotation of the motor;

calculate a load of the opening/closing body in the opening/closing operation based on the current detected by the current detector;

set a pinch threshold value that defines an upper limit of the calculated load;

determine that an object is pinched by the opening/closing body in a case where the calculated load exceeds the upper limit defined by the pinch threshold value; and

perform a pinch prevention control process in response to determining that the object is pinched, the pinch prevention control process reversing the rotation of the motor,

wherein the processor calculates a speed of the opening/closing body based on a change in the detected position of the opening/closing body, and determines that the object is pinched, in a case where a state, in which the calculated speed of the opening/closing body is less than or equal to a first predetermined threshold value, and a temporal change in the calculated load is greater than or equal to a second predetermined threshold value and less than or equal to a third predetermined threshold value, continues for a certain period of time or greater.

7. An opening/closing control method for controlling an opening/closing operation of an opening/closing body driven by a motor, the opening/closing control method comprising:

detecting a position of the opening/closing body based on rotation of the motor;

calculating a load of the opening/closing body in the opening/closing operation based on a current flowing to the motor;

setting a pinch threshold value that defines an upper limit of the calculated load;

determining that an object is pinched by the opening/closing body in a case where the calculated load exceeds the upper limit defined by the pinch threshold value; and

performing a pinch prevention control process in response to determining that the object is pinched, the pinch prevention control process reversing the rotation of the motor,

wherein the setting of the pinch threshold value includes calculating a speed of the opening/closing body based on a change in the detected position of the opening/closing body, and decreasing the pinch threshold value in a case where a state, in which the calculated speed of the opening/closing body is less than or equal to a first predetermined threshold value, and a temporal change in the calculated load is greater than or equal to a second predetermined threshold value and less than or equal to a third predetermined threshold value, continues for a certain period of time or greater.

8. An opening/closing control method for controlling an opening/closing operation of an opening/closing body driven by a motor, the opening/closing control method comprising:

detecting a position of the opening/closing body based on rotation of the motor;

calculating a load of the opening/closing body in the opening/closing operation based on a current flowing to the motor;

setting a pinch threshold value that defines an upper limit of the calculated load calculated in the load calculating step;

determining that an object is pinched by the opening/closing body in a case where the calculated load calculated in the load calculating step exceeds the upper limit defined by the pinch threshold value; and

performing a pinch prevention control process in response to determining that the object is pinched, the pinch prevention control process reversing the rotation of the motor,

wherein the determining includes calculating a speed of the opening/closing body based on a change in the detected position of the opening/closing body, and determining that the object is pinched, in a case where a state, in which the calculated speed of the opening/closing body is less than or equal to a first predetermined threshold value, and a temporal change in the calculated load is greater than or equal to a second predetermined threshold value and less than or equal to a third predetermined threshold value, continues for a certain period of time or greater.