Generation and Application of Dynamic Lift Kinematics

Performance time is a measure of the time it takes a lift to travel between floors and is crucial to delivering the highest possible handling capacity and lowest passenger waiting times. To calculate performance time and to enable a lift to deliver a comfortable trip leads to a need to understand lift kinematics. Lift kinematics is the study of the motion of a lift car in a shaft without reference to mass or force. When generating lift kinematics, it is normal to consider the travel distance, velocity, acceleration, and jerk; these inputs can be used with well-known equations to determine the time in flight, and a reference speed profile for the lift drive. However, in advanced lift applications, there are additional requirements for the deceleration not to be the same as the acceleration. The jerks may also be different and sometimes it is desirable to change speed part way through a trip. This paper addresses the generation of dynamic lift kinematics to meet these requirements and discusses their application.