Vehicle control unit

A control unit for a track-bound vehicle capable of exchanging data telegrams with a control center via transmitting and receiving equipment comprising:

• two computers coupled to said receiving equipment, said transmitting equipment and on-board units, each of said two computers delivering as an output a life signal at regular intervals and each of said two computers, independent of each other, process data telegrams received by said receiving equipment to generate control commands for said on-board units and compile data telegrams concerning the condition, location and speed of said vehicle for said control center from data received from said on-board units, said control commands being delivered to said on-board units and said compiled data being transmitted to said control center only when said control commands and said compiled data telegrams produced by each of said two computers are identical;
• a comparator coupled to each of said two computers to compare said control commands and said compiled data telegrams from each of said two computers to determine whether they are identical, operation of said comparator being automatically checked from time to time by intentionally falsifying said control commands and said compiled data telegrams delivered by one of said two computers;
• two clock generators each coupled to and controlling a different one of said two computers;
• a direct connection between said two clock generators for synchronization of the clock frequency thereof;
• and
• two emergency brake circuits each coupled to a different one of said two computers responsive to said life signals to initiate emergency braking if said life signals from the associated one of said two computers is not received within a given period of time.