On the simultaneous realization of virtually zero-power and zero-compliance controls

A virtually zero-power and zero-compliance mechanism is presented in this paper. A zero-compliance system using an integral control accompanies power consumption to cancel disturbances on the system. On the other hand, systems using a zero-power control can avoid power consumption at steady-state. However, the zero-power control causes a negative deflection of the system in the presence of disturbance. Therefore, in a conventional controlled system, zero-power and zero-compliance characteristics simultaneously are incompatible to each other. This study proposes a new mechanism to obtain zero-power and zero-compliance states simultaneously in a controlled system. The proposed mechanism comprises a zero-power control magnetic suspension system connected with a normal spring (positive stiffness) in series, where the stiffness of the magnetic suspension and the normal spring are equal in absolute magnitude.