Lift Performance Time

Performance time is a measure of how long it takes for a lift to travel between two floors, including opening and closing of the doors. Performance time has a major effect on handling capacity and passenger waiting times. Performance time can be modelled in traffic analysis and simulation through the application of lift kinematics. Formulae can be used to calculate travel times and to plot the distance travelled, velocity, acceleration and jerk against time. Measurements of these parameters can be derived from accelerometer readings. Measurements of start and levelling delays are more difficult to make, but are necessary to model a lift trip completely. Site measurements and ideal lift kinematics are plotted together for comparison. Performance time assumptions typically made in lift traffic analysis and simulation are compared with site measurements. The difference between assumed performance times and measurement are considered in the context of their impact on handling capacity and waiting times. Proposals are made which help designers to avoid discrepancies compromising the traffic design.