Recent applications of microprocessor technology to people mover systems

During the past decade the performance requirements of train control equipment have consistently increased particularly in terms of reduced headways, unattended operation, improved availability and better ride quality. The increased functional complexity of the control equipment has resulted in the broad application of microprocessor-based hardware. This, in turn, has generated new potential problems associated with safety considerations, adequate training of maintenance personnel, special test equipment, and increased diagnostic and repair time. The microprocessor, however, also provides opportunities to solve these problems by incorporating additional features such as self-diagnostics, dual processor control for safety and switching head-end control of a train to a different car when a failure occurs in the normal head-end control equipment. The micro-processor-based approach also provides additional flexibility by allowing modification of the system operation and diagnostic capability through changes in software rather than in hardware as was the case with previous designs. In other words, the micro-processor-based approach allows more standardization of the system hardware than was previously possible.