Active Vibration Control of an Elevator Car Using Two Rotary Actuators

A new control device is proposed to isolate an elevator cabin from irregularities on a guide rail. The device consists of two rotary electric motors with disks and eccentric masses. One motor produces torque to rotate the eccentric mass according to the command signals from the controller for horizontal control, while the other rotates the mass to eliminate the unwanted vertical force. To design the optimal controller to reduce the horizontal vibration of the cabin, the dynamics of the cabin, including the proposed control device, are described by a linear equation. The performance of the proposed control system is examined through numerical simulations taking into consideration the nonlinear characteristics of the rotating masses, which are neglected in designing the controller, and through experiments with a miniature elevator cabin carrying the proposed actuator. The results indicate the proposed control device reduces the horizontal vibration without producing the unwanted vertical vibration.