Semi-active operation assist control device for manual conveyance of flexible parts — Control system design via bilinear optimal control theory

This paper proposes an assist-handle for manual conveyance of flexible part and its semi-active operation assist control. The assist-handle consists of a handle, a variable damper and a mechanical spring. The variable damper and the mechanical spring are connected in parallel. The assist-handle can be attached to a general hand cart, through which a human operates the hand cart. In order to suppress the vibration of the flexible part, the operating force is shaped by changing the viscosity of variable damper. Then the shaped force is transmitted to the hand cart through the assist-handle. The controlled system, which consists of the assist-handle, a hand cart and a flexible part, is represented as a bilinear system. The semi-active operation assist control is designed by using the bilinear optimal control theory. The performance index of bilinear optimal control involves the vibration of the flexible part and the control input. The effectiveness of the assist-handle and the semi-active operation assist control is verified by simulations.