Semi-active Acceleration Control System for In-Car Crib with Joint Application of Regular and Inverted Pendulum Mechanisms

In order to reduce the collision shock and risk of injury to an infant in an in-car crib (or in a child safety bed) during a car crash, it is necessary to limit the force acting on the crib below a certain allowable value. To realize this objective, we propose a semi-active in-car crib system with the joint application of regular and inverted pendulum mechanisms. The crib is supported by arms similar to a pendulum, and the pendulum system itself is supported by arms similar to an inverted pendulum. In addition, the arm acting as a regular pendulum is joined with the arm acting as an inverted pendulum through a linking mechanism for simplicity, and the friction torque of the joint connecting the base and the latter arm is controlled using a brake mechanism, which enables to maintain the deceleration of the crib at around the target value. The present work focuses on the semi-active control with the absolute crib horizontal acceleration feedback derived using the sliding mode control theory for the high performance control. Further, a control experiment using scale model is conducted to confirm the effectiveness, and some results are reported.