Implementation of linear elevator with high riding quality based on Scurve profile

Abstract

The Linear elevators driven by linear motors have recently been widely used because they produce direct motion to transfer people between floors without using ropes, rollers, gears, and counterweights. However, these elevators usually suffer from the production of ripple force when traveling through floors and this makes its application to elevators limited. To minimize the impact of this ripple on the elevator performance, a smooth transition pattern based on a minimum jerk profile is proposed. The elevator cabin speed is controlled via variable frequency driver (VFD), programmed with the best V/f pattern to get the best speed curve profile in order to get a smooth start and smooth stop for the elevator cabin and constant travel speed through the elevator floors with the least jerk possible. A three-floor elevator prototype driven by a permanent magnet synchronous linear motor locally designed and manufactured to lift 25kg payload. The result showed that using the driver leads to reduce the jerk by about 88% compared the that without using the driver. The proposed model achieved convincing results in terms of system control, responsiveness, speed, and smooth and comfortable transition between floors Silos.