Comparison of characteristics between an elevator emergency stop device with a magnetic rheological fluid damper and a conventional device

During an elevator emergency stop device operation, a large deceleration is generated at the elevator cage. Passengers in the elevator cage sometimes get injured, because they suffer impact force from the elevator emergency stop device. (Refer to [1] and [2].) Therefore, the authors focused on the passengers´ safety in elevators and proposed an emergency stop device with a spring and a magnetic rheological fluid (hereafter MRF) damper (Fig.1 (a)) which can continuously vary its damping coefficient by controlling the magnetic field. In fact, the damping coefficient of the MRF damper made up in our laboratory varies almost linearly corresponding to the coil current. (See Fig. 1 (b). Refer to [3] and [4].)