| 摘要 |
<p>The braking command is triggered, particularly in a lift drive, in dependence on two guide curves (VS1, VS2) which correspond to two voltages (Usoll, Ucomp) and on a third voltage (UX). The first guide curve represents the start-up variation, that is to say the speed of travel as a function of time. The second guide curve is the nominal braking variation in the same type of representation. The said third voltage is obtained by integrating the difference between these two guide curves in that the voltages corresponding to the guide curves are supplied to the input of an integrating section and the third voltage appears as output voltage at the output of this section. The voltages corresponding to the guide curves and the said output voltage are supplied to a comparator. The output signal of the comparator is used as braking command. This braking command delays the initiation of the braking process to a time (t1) so that a maximum speed is reached at the switch-over point. In this manner, the so-called crawling distance can be kept to an optimum shortness. <IMAGE></p> |
