Patent ID: 8131428
Filing Date: 2012-03-06
Classification: B60R

Abstract:
1. A control module for a seat belt retractor that includes a winding mechanism having a rotational shaft that winds a seat belt for a vehicle; a motor that generates a power to rotate the rotational shaft; and a gear mechanism that mechanically couples the motor with the rotational shaft, the control module comprising: a control unit that controls motor current that flows through the motor using a preset control parameter value; a change unit that changes, based on the motor current and an output torque value of the rotational shaft, the preset control parameter value; wherein, the control module further includes a current sensor; the control unit takes feed-back control of the motor current so as to reduce a difference between a target current calculated based on a target torque for the motor and the motor current detected by the current sensor; the preset control parameter value comprises an apparent torque constant for each of a plurality of seat belt retractors; and the control unit calculates the target current, based on the target torque and the apparent torque constant for each of the seat belt retractors.