Control device for automatic transmission

A control device for an automatic transmission in which driving power of an engine is transmitted to a gear shift mechanism through a clutch, engaging force of the clutch being adjusted by a motor, the control device comprising:

• a motor control unit for controlling the rotation of the motor, wherein the motor control unit has a motor target current calculating unit for calculating target current in the motor, a current detecting resistor for detecting motor current flowing when the motor rotates, a current detecting unit for sampling a voltage occurring in the current detecting resistor to detect the motor current, and the current detecting unit has a counter for counting a variation number of a rotational position signal output from a rotational position detecting unit for detecting the rotational position of the motor, and an electrical angle 180° judging unit for judging on the basis of the count value of the counter that the motor rotates at 180° in electrical angle, and a current value storing unit for calculating the number of variations of the rotational position signal for the rotation of the electrical angle of 180° of the motor from the electrical angle 180° judging unit and the counter and storing only motor current values which are detected by the current detecting unit and whose number corresponds to an integral multiple of the variation number, and wherein an average value of the motor current values stored in the current value storing unit, and the rotation of the motor is controlled in accordance with the difference between motor target current calculated in the motor target current calculating unit and the average value of the motor current values.

A control device for an automatic transmission in which driving power of an engine is transmitted to a gear shift mechanism through a clutch, engaging force of the clutch being adjusted by a motor, the control device comprising:

• a motor control unit for controlling the rotation of the motor, wherein the motor control unit has a motor target current calculating unit for calculating target current in the motor, a current detecting resistor for detecting motor current flowing when the motor rotates, a current detecting unit for sampling a voltage occurring in the current detecting resistor to detect the motor current, and the current detecting unit has a counter for counting a variation number of a rotational position signal output from a rotational position detecting unit for detecting the rotational position of the motor, an electrical angle 180° judging unit for judging on the basis of the count value of the counter that the motor rotates at 180° in electrical angle, and a current value storing unit for calculating the number of variations of the rotational position signal for the rotation of the electrical angle of 180° of the motor from the electrical angle 180° judging unit and the counter and storing only motor current values which are detected by the current detecting unit and whose number corresponds to an integral multiple of the variation number, and a current ratio calculating unit for setting the current at the count value of the counter to reference current and calculating a ratio of the current stored in the current value storing unit to the reference current every count value, and wherein it is judged whether the current ratio calculation of the current ratio calculating unit is completed or not, and the rotation of the motor is controlled in accordance with the difference between motor target current calculated in the motor target current calculating unit and a value obtained by multiplying the motor current by the calculation result of the current ratio calculating unit.