Seat belt control device, seat belt retractor, seat belt device, seat belt control method, and program

A seat belt control method for controlling a motor which winds up a seat belt, wherein the method is carried out by a controller and comprises the following steps:

• a storage step of storing a heat generation counter value which represents a temperature variation state of at least one of the motor and a motor driver for driving the motor;
• a count step of making an addition/subtraction of a specified value to/from the heat generation counter value based on operation of the motor driver;
• a decision step of deciding whether or not to shift the controller from a normal operation mode, in which operating power is supplied to the controller to execute seat belt control, to a sleep mode in which the controller has a lower power consumption than when operating in the normal operation mode;
• and
• a control step of shifting the controller to the sleep mode when the decision step decides that a shift to the sleep mode has been made,
• wherein, when the heat generation counter value obtained when the decision step decides that the shift to the sleep mode has been made is equal to or greater than a specified threshold value, the control step stands by until the count step makes a subtraction from the heat generation counter value to the threshold value and then the controller shifts to the sleep mode, and wherein the heat generation counter value functions as a criterion, which is converted from a measured value obtained by pre-measuring variation in temperature of the motor or the motor driver.

A non-transient computer readable storage medium having instructions stored thereon, which, when executed by one or more data processors, cause the one or more data processors to perform operations comprising:

• a storage step of storing a heat generation counter value which represents a temperature variation state of at least one of a motor, which winds up a seat belt, and a motor driver for driving the motor;
• a count step of making an addition/subtraction of a specified value to/from the heat generation counter value based on operation of the motor driver;
• a decision step of deciding whether or not to shift from a normal operation mode, in which operating power is supplied to the computer, to a sleep mode which has a lower power consumption than that of the normal operation mode;
• and
• a control step of shifting to the sleep mode when the decision step decides that a shift to the sleep mode has been made, wherein, when the heat generation counter value obtained when the decision step decides that the shift to the sleep mode has been made is equal to or greater than a specified threshold value, the control step stands by until the count step makes a subtraction from the heat generation counter value to the threshold value and then shifts to the sleep mode, and wherein the heat generation counter value functions as a criterion, which is converted from a measured value obtained by pre-measuring variation in temperature of the motor or the motor driver.