Station stop and speed regulation system for trains

• US 4,005,838 A
• Filed: 05/27/1975
• Issued: 02/01/1977
• Est. Priority Date: 05/27/1975
• Status: Expired due to Term

• Current Assignee: Union Switch & Signal, Inc. (Hitachi, Ltd.)
• Original Assignee: Westinghouse Air Brake Technologies Corporation
• Inventors: Grundy, Reed H.
• Primary Examiner(s): Kunin, Stephen G.
• Application Number:
  US05/581,369
• Time in Patent Office: 616 Days
• Field of Search: 104/149, 104/1 R, 104/152, 235/150.2, 235/150.24, 246/63 C, 246/182 R, 246/182 B, 246/182 C, 246/187 R, 246/187 B, 246/187 A
• US Class Current: 246/182.00B
• CPC Class Codes: B60L 15/20 for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed
• CPC Class Codes: B60L 2200/26 Rail vehicles
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

Abstract

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 from the existing base level in accordance with under or over speed conditions. Each full cycle of ATL operation drives the PTL apparatus to the next higher or lower base level. A propulsion error signal PE drives a comparator-clock network to generate clock pulses and an up/down signal to step the ATL register and thus the PTL encoder to bring speed within the desired range. A speed control, brake error signal SCBE controls normal train braking effort but is inhibited while propulsion control remains effective to reduce speed. When the PTL encoder counts down to the zero propulsion level, the clamp on signal SCBE is removed 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. Each trigger signal applies a scaled value of train speed and a distance-to-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.

Claims

1. A station stop and speed regulation system for a train, each car of which is equipped with braking control means interconnected for common operation of brakes throughout the train, and with variable propulsion control means capable of providing a plurality of propulsion effort conditions, comprising in combination,

a. a desired velocity source for supplying a desired speed signal,

b. a train speed measuring means coupled for measuring velocity of the train and for generating separate signals representing actual train speed and actual train acceleration,

i. said measuring means also supplying pulses, each representing a unit of distance traveled by that train,

c. a speed and brake regulating means coupled for receiving said desired speed, actual speed, and actual acceleration signals, and responsive to the difference between said desired and actual speed signals for generating a series of first clock pulses in accordance with the magnitude of said difference and an error direction signal having a first or a second condition as said actual speed is less than or more than said desired speed, respectively,

i. said speed and brake regulating means further responsive to said difference for generating a brake error signal to jointly actuate said braking control means, said brake error signal normally inhibited from execution while a propulsion effort exists,

d. an advance train line register means connected for receiving said series of first clock pulses and said direction signal and responsive thereto for varying the propulsion level of the train by preselected steps including a preselected number of cars less than the total cars in the train, one step for each clock pulse, increasing or decreasing from the train base propulsion level as said direction signal is in said first or second condition, respectively,

i. said advance train line register means responsive to the completion of each full train cycle of propulsion variation for generating a second clock pulse,

e. a propulsion train line encoder means coupled for receiving second clock pulses and said direction signal and responsive thereto for establishing a new base propulsion level for the train upon reception of each second clock pulse, increased or decreased from the former base level in accordance with the first or second condition of said direction signal,

i. said propulsion train line encoder means connected, when in its zero count condition during a count-down action, for removing the inhibiting clamp on said braking error signal to actuate a train braking action and for resetting said advance train line register means,

f. a trigger detection means responsive to passage by a station stop actuating device, positioned along the track wayside a predetermined distance in approach to a station stop location, for registering a station stop trigger signal,

g. an acceleration computer means, connected to said trigger detection means and to said speed measuring means, responsive to said trigger signal, said distance traveled pulses, and actual train speed signal for computing a signal representing the deceleration rate required to stop that train at said station stop location, and further coupled to supply the required deceleration signal to said speed and brake regulating means,

h. a source of a desired acceleration/deceleration rate signal, coupled to supply that signal to said speed and brake regulating means,

i. said speed and brake regulating means responsive to said desired deceleration signal and said required deceleration signal in a preset ratio for driving said propulsion train line encoder means to the lowest propulsion level for that train,

j. said speed and brake regulating means also responsive to said desired and required deceleration signals when equal for interrupting the normal speed control of the train braking control means and for actuating a train braking action at said desired deceleration rate until that train has stopped at said station stop location.

2. A station stop and speed regulation system as defined in claim 1, in which said trigger detection means is responsive to passage by subsequent wayside station stop devices, each positioned a different lesser distance in approach to said station stop location, for resetting said acceleration computer means, rescaling said actual train speed signal and the distance signal, and reactuating the computing of said required deceleration signal using the rescaled values.

3. A station stop and speed regulation system as defined in claim 2 in which three successive wayside station stop actuating devices are used to control the station stop operation with increased accuracy.

4. A speed regulation system for a rapid transit train, each car of which is equipped with variable propulsion control means providing a plurality of propulsion effort conditions, comprising in combination,

a. a desired velocity source responsive to one or more speed limit detectors for supplying a single desired speed signal,

b. a train speed measuring means coupled for producing a signal representing actual train speed and further operable for producing another signal representative of train acceleration,

c. a velocity brake error means coupled for receiving said desired and actual train speed signals and said train acceleration signal, and responsive thereto for producing a first series of clock pulses having a frequency determined by the magnitude of any difference between the actual and desired train speeds, and a direction signal having a first or a second condition as said actual speed is less than or more than said desired speed, respectively,

d. advance train line register apparatus connected for receiving said first clock pulses and said direction signal and responsive thereto for varying the propulsion effort of the train in steps of a selected number of cars, one such step for each received clock pulse, increasing or decreasing from a base level the propulsion level of each car included in a step in accordance with the first or second condition of said direction signal,

i. said advance train line register apparatus further responsive to the completion of each cycle of propulsion steps for generating a second clock pulse, and

e. a propulsion train line encoder coupled for receiving said second clock pulses and also said direction signal, and responsive thereto for establishing a new base level of train propulsion effort upon reception of each second clock pulse, increasing or decreasing from the previous base level as said direction signal has a first or a second condition, respectively,

f. said propulsion train line encoder further connected to said velocity brake error means for inhibiting train braking except when the propulsion base is reduced to a zero level from a higher level.

5. A station stop system for rapid transit trains, each car of a train having individual propulsion control and braking control apparatus, comprising in combination,

a. a register means on the train responsive to passage by an actuating device along the track wayside, marking a preselected distance in approach to the station stop position, for actuating a station stop procedure and registering said preselected distance.

b. a train speed measuring means connected for generating a signal representing actual train speed,

i. said speed measuring means also operable for generating a signal representing actual train acceleration/deceleration,

ii. said speed measuring means also generating a series of pulses each representing a preselected unit of distance traveled,

c. a deceleration computer means coupled for receiving said actual speed signal and said successive distance pulses and controlled by said register means for computing a signal representing the deceleration rate required to stop the train at the station in accordance with existing speed and distance-to-go conditions,

d. a source of a desired deceleration signal to provide maximum passenger comfort,

e. a first comparator means coupled for comparing said required deceleration signal with a predetermined percentage of said desired deceleration signal and connected for driving each car propulsion control apparatus to its lowest propulsion condition when the compared signals are equal, and

f. a second comparator means coupled for comparing said required and desired deceleration signals and further coupled for applying the difference between said actual and required deceleration signals to control said braking control means to stop the train at said station.

6. A station stop system as defined in claim 5, in which,

a. subsequent actuating devices are positioned along the track wayside, each a different lesser preselected distance in approach to said station stop position, and

b. said register means is responsive to passage by each subsequent actuating device for reactuating the station stop procedure and for registering each lesser preselected distance to the station stop,

c. said register means further controlling said deceleration computer means to rescale the actual train speed signal and said distance pulses used to compute required deceleration in accordance with each registered lesser distance.

7. A station stop system as defined in claim 6, in which three wayside actuating devices are positioned in spaced succession along the track in approach to the station stop position.