| 摘要 |
<p>Train speed is controlled by propulsion train line (PTL) apparatus, which sets a base level of propulsion effort, and by an advance train line (ATL) apparatus, which varies the propulsion effort up or down fro the existing base level in accordance with under or over speed condition. Each full cycle of ATL operation drive the PTL apparatus to the next high r or lower base level. A propulsion error signal PE drive a comparator-clock network to generate clock pulses and an up/down signal to step the ATL register and this the PTL encoder to bring speed within the desired range. A speed control, brake error signal SCBE control normal train braking effort but is inhibited while propulsion control remains effective to reduce speed. When the PTL encoder counts down to the rero propulsion level, the clamp on signal SCBE is remove to activate braking to further reduce speed. Station stops are controlled by a first trigger signal a preset distance in approach to the station and two subsequent triggers at shorter distances to improve the accuracy of the stop Bach trigger signal applies a scaled value of train speed and a distanceto-go indication to an acceleration computer which continually computes the deceleration rate required to stop at the station When a comparison of the computed deceleration rate with a desired rate results in a preset ratio, the PTL encoder is driven down to zero to reduce speed in preparation for the station stopping action. The apparatus finds use in rapid transit systems. Novelty resides in the combination of apparatus to provide accurate speed control and station stopping.</p> |
