초록 ▼

A pair of on-board processing units, operating in parallel, are supplied with input signals representing actual train speed, advance traffic conditions, and selected train parameters. Each unit continuously calculates a maximum train speed from which emergency braking will stop the train within the

A pair of on-board processing units, operating in parallel, are supplied with input signals representing actual train speed, advance traffic conditions, and selected train parameters. Each unit continuously calculates a maximum train speed from which emergency braking will stop the train within the indicated clear track distance ahead. Each unit also compares the calculated maximum speed with actual train speed and emits a preselected distinctive frequency signal or a d.c. signal as actual speed is less than, or equals, or exceeds maximum speed, respectively. A logic network with parallel filter-rectifier circuit paths passes the unit outputs, if of the preselected frequencies, to a two-input AND gate whose output holds emergency braking released. If a preselected frequency output is absent from either or both units, due to actual speed equaling or exceeding maximum speed or to a fault condition in the apparatus, the corresponding lack of an AND gate output actuates emergency braking. Each processing unit monitors operation of the other unit so that, if a malfunction is detected, the operable unit, when input speed signals are within limits, also emits a second signal of the other unit frequency. This is passed through a separate filter rectifier circuit within the logic network and applied to the second input of the AND gate to maintain train movement.

대표청구항 ▼

Speed control apparatus for a railroad train, which is provided with brake control means, track signal repeater means for indicating advance traffic conditions along the stretch of track over which the train moves, and means for measuring actual train speed, comprising in combination, (a) a first an

Speed control apparatus for a railroad train, which is provided with brake control means, track signal repeater means for indicating advance traffic conditions along the stretch of track over which the train moves, and means for measuring actual train speed, comprising in combination, (a) a first and a second processing unit, each coupled for receiving advance traffic condition and actual train speed signals and responsive thereto for individually calculating a maximum train speed which permits stopping said train by train braking controlled by said brake control means within the unoccupied track distance indicated by the received advance traffic condition signal, (b) each processing unit further responsive for comparing the calculated speed signal with the received actual speed signal and for producing an alternating current output signal, having a preselected frequency different from that of the other processing unit, only when said actual train speed is less than the corresponding calculated maximum speed, each unit otherwise producing a signal having a direct current characteristic, (c) a first and a second band pass filter and rectifier circuit path coupled to said first and second processing units, respectively, each circuit path tuned for producing an output signal only when the associated processing unit output is of the proper preselected distinctive frequency, and (d) a two-input AND logic gate with one input coupled to receive the output signal from one filter and rectifier circuit path, the other input coupled to receive the output from the other filter and rectifier circuit path, and an output coupled to said brake control means for withholding or actuating train braking as an AND gate output signal is produced or is absent, respectively.