Application of self-sensing actuator to control of a soft-handling gripper

The self-sensing actuator (SSA) is a new concept for intelligent materials, where a single piezoelectric element simultaneously performs as both a sensor and an actuator. This concept is very advantageous in many aspects of control, and it makes it possible to reduce the size and weight of the structures. The bimorph piezoceramics are very useful for the soft-handling miniature gripper to control the minute grasping force. Our aim is to realize such a gripper making the most of the properties of SSA, that is to develop a method to detect the grasping force without a force sensor. The proposed method does not need the complete electric bridge circuit which is generally used to detect the strain information. The experimental result proved that the grasping force provides some desired trajectories irrespective of the rigidity of the grasping object