To detect the accelerated variable of an automobile with a smaller number of sensor by arranging an acceleration sensor at the specified angle against a motor shaft of an automobile having a measuring surface of the sensor.

A control circuit for controlling an adjusting device 9 response to the only one acceleration sensor 17. Namely, a measuring surface 19 of the acceleration sensor 17 is extended at an angle β against a space, which is extended in the direction for crossing a long axis X, or against a lateral axis Y of the movement, and the measuring surface 19 is extended at an angle γagainst a space, which is extended vertically to the long axis X and vertically to the lateral axis Y, or against a Z axis of the movement. The angle is effectively selected at 45 degree. Angle in relation to the long axis X is practically set at any degree. Influence of the acceleration in the long axis X direction is measured in response to the degree of angle. An instantaneous value of the acceleration of an automobile body, which is supplied from the acceleration sensor, includes and acceleration component in relation to the long axis X, the lateral axis Y and the movement vertical axis Z.