Closure member control device and method for limiting positional deviation of closure member

1. A closure member control device connected to an external power supply, wherein the closure member control device comprising:

a closure member that is movable between a first mechanical limit position at a closing travel end of the closure member and a second mechanical limit position at an opening travel end of the closure member;

a drive motor that drives the closure member to move the closure member between the first mechanical limit position and the second mechanical limit position;

a position detecting means for:

incrementing and decrementing a count value based on rotation of the drive motor; and

detecting an operational position of the closure member between the first mechanical limit position and the second mechanical limit position based on the count value;

a storage device that stores position information of the closure member, which indicates the operational position of the closure member obtained by the position detecting means;

a position information judging means for determining whether the position information stored in the storage device is erroneous when a voltage of the power supply falls below a predetermined voltage and thereafter returns to the predetermined voltage;

a motor operational state determining means for determining whether the drive motor is turned on at a point in time just before the voltage of the power supply falls below the predetermined voltage; and

a positional deviation determining means for determining whether a deviation of the detected operational position of the closure member exists, wherein the positional deviation determining means determines that the deviation of the detected operational position of the closure member exists upon satisfaction of a first set of the following conditions:

the position information judging means determines that the position information stored in the storage device is non-erroneous; and

the motor operational state determining means determines that the drive motor is turned on at the point in time just before the voltage of the power supply falls below the predetermined voltage.

2. A closure member control device according to claim 1 , wherein when the positional deviation determining means determines that the deviation of the detected operational position of the closure member exists upon satisfaction of the first set of the conditions, the count value is set to a predetermined count value while the closure member is placed in a predetermined operational position.

3. A closure member control device according to claim 2 , wherein the predetermined operational position of the closure member is the first mechanical limit position.

4. A closure member control device according to claim 1 , further comprising at least one relay that is arranged between the external power supply and the drive motor such that electric power is supplied to the drive motor through at least one of the at least one relay, wherein the motor operational state determining means determines whether the drive motor is turned on by determining whether at least one of the at least one relay is turned on at the point in time just before the voltage of the power supply falls below the predetermined voltage.

5. A closure member control device according to claim 1 , wherein the positional deviation determining means also determines that the deviation of the detected operational position of the closure member exists upon satisfaction of a second set of the following conditions:

the position information judging means determines that the position information stored in the storage device is erroneous; and

the motor operational state determining means determines that the drive motor is turned on at the point in time just before the voltage of the power supply falls below the predetermined voltage.

6. A closure member control device according to claim 5 , further comprising a reference point setting state indicating means for indicating a need for setting a reference point of the closure member when the positional deviation determining means determines that the deviation of the detected operational position of the closure member exists upon satisfaction of the second set of the conditions.

7. A closure member control device according to claim 6 , wherein the reference point setting state indicating means indicates the need for setting the reference point of the closure member by inching the closure member toward one of the first mechanical limit position and the second mechanical limit position.

8. A closure member control device according to claim 5 , wherein when the positional deviation determining means determines that the deviation of the detected operational position of the closure member exists upon satisfaction of the second set of the conditions, the count value is set to a predetermined count value while the closure member is placed in a predetermined operational position.

9. A closure member control device according to claim 8 , wherein the predetermined operational position of the closure member is the first mechanical limit position.

10. A closure member control device according to claim 5 , further comprising at least one relay that is arranged between the external power supply and the drive motor such that electric power is supplied to the drive motor through at least one of the at least one relay, wherein the motor operational state determining means determines whether the drive motor is turned on by determining whether at least one of the at least one relay is turned on at the point in time just before the voltage of the power supply falls below the predetermined voltage.

11. A closure member control device according to claim 5 , wherein the storage device is a volatile storage device.

12. A method for limiting a deviation of a detected operational position of a closure member, which is movable between a first mechanical limit position at a closing travel end of the closure member and a second mechanical limit position at an opening travel end of the closure member, the method comprising:

detecting an operational position of the closure member between the first mechanical limit position and the second mechanical limit position based on a count value, which is incremented and decremented based on rotation of a drive motor that is powered by a power supply and drives the closure member to move the closure member between the first mechanical limit position and the second mechanical limit position;

storing position information of the closure member in a storage device, wherein the position information indicates the operational position of the closure member obtained through the detecting of the operational position of the closure member;

determining whether the position information stored in the storage device is erroneous when a voltage of the power supply falls below a predetermined voltage and thereafter returns to the predetermined voltage;

determining whether the drive motor is turned on at a point in time just before the voltage of the power supply falls below the predetermined voltage; and

determining whether a deviation of the detected operational position of the closure member exists, wherein the deviation of the detected operational position of the closure member is determined to exist upon satisfaction of a first set of the following conditions:

the position information stored in the storage device is determined to be non-erroneous in the determining of whether the position information stored in the storage device is erroneous; and

the drive motor is determined to be turned on in the determining of whether the drive motor is turned on at the point in time just before the voltage of the power supply falls below the predetermined voltage.

13. A method according to claim 12 , further comprising setting the count value to a predetermined count value while the closure member is placed in a predetermined operational position upon satisfaction of the first set of the conditions in the determining of whether the deviation of the detected operational position of the closure member exists.

14. A method according to claim 13 , wherein the predetermined operational position of the closure member is the first mechanical limit position.

15. A method according to claim 12 , wherein the determining of whether the drive motor is turned on further includes determining whether at least one of at least one relay, which is arranged between the power supply and the drive motor, is turned on at the point in time just before the voltage of the power supply falls below the predetermined voltage.

16. A method according to claim 12 , wherein the deviation of the detected operational position of the closure member is determined to exist in the determining of whether the deviation of the detected operational position of the closure member exists upon satisfaction of a second set of the following conditions:

the position information stored in the storage device is determined to be erroneous in the determining of whether the position information stored in the storage device is erroneous; and

the drive motor is determined to be turned off in the determining of whether the drive motor is turned on at the point in time just before the voltage of the power supply falls below the predetermined voltage.

17. A method according to claim 16 , further comprising indicating a need for setting a reference point of the closure member when the deviation of the detected operational position of the closure member is determined to exist upon satisfaction of the second set of the conditions in the determining of whether the deviation of the detected operational position of the closure member exists.

18. A method according to claim 17 , wherein the indicating of the need for setting the reference point of the closure member includes inching the closure member toward one of the first mechanical limit position and the second mechanical limit position.

19. A method according to claim 16 , further comprising setting the count value to a predetermined count value while the closure member is placed in a predetermined operational position upon satisfaction of the second set of the conditions in the determining of whether the deviation of the detected operational position of the closure member exists.

20. A method according to claim 19 , wherein the predetermined operational position of the closure member is the first mechanical limit position.

21. A method according to claim 16 , wherein the determining of whether the drive motor is turned on includes determining whether at least one of at least one relay, which is arranged between the power supply and the drive motor, is turned on at the point in time just before the voltage of the power supply falls below the predetermined voltage.

22. A method according to claim 16 , wherein the storage device is a volatile storage device.