Horizontal vibration suppression method suitable for super-high-speed elevators

Horizontal vibrations of elevator cars mainly occur because a car swings as roller guides installed at corners of a car frame move on a winding guide rail at high speeds. Rider comfort in high-speed elevators is worsened by these vibrations. Conventional active dampers suppressing horizontal vibrations using ac servomotors make cars heavier so driving power becomes larger, and they are not easily applied to existing elevators. An active damping control method suited to super-high-speed elevators is described which can solve these problems. The method suppresses vibrations by generating only enough magnetic force needed to suppress them only when vibrations of the car frame are produced. The vibrations are detected using acceleration detectors and magnets installed on the left and right sides of the car frame. A computer simulator was made to analyze phenomena of car vibrations and to verify effects of the proposed magnetic damping controller. It was found that the vibrations generated on the cabin floor were remarkably large when the left and right sides at the upper and lower parts of the car frame were swung by sine waves with the same phase. The vibrations had two resonant modes. Results obtained with the computer simulator and a full-scale running simulator showed that the acceleration on the cabin floor, even at the resonant frequencies, could be reduced by the magnetic damping control to around 0.1 m/s2 which would provide a comfortable ride.