Self-sensing active damping guide roller for elevators

A theoretical and experimental study of an active isolation system for the control of lateral vibrations in elevators is presented. The control system consists of a linear, electromagnetic motor, which is arranged to act on the elevator via a lever system. Direct feedback is implemented using the measured actuator coil current as error sensor (self-sensing actuator). It is shown that active damping can then be achieved up to a characteristic actuator frequency. H 2 optimal control is investigated to enhance the active damping behaviour to higher frequencies. The experimentally achievable performance of a reduced current feedback controller is compared to an acceleration feedback PI controller at a test elevator. It is found that the solf-sensing active control system may reduce vibrations up to 40% at the first mechanical natural frequency with this type of control system.