Abstract :
The purpose of the Advanced Group Rapid Transit (AGRT) Engineering Development System program is to develop, and provide means for testing, the critical technology items associated with the AGRT concepts. Currently, two companies, the Boeing Aerospace Company and the Otis Elevator Company, are under contract to perform the AGRT Engineering Development Program, As stated in the Office of Technology Assessment Report, "There is considerable support at the local level for continuing work on Automated Guideway Transit (AGT) technologies, both among transit users and public officials. Users and nonusers alike are critical of the amenities, frequency of service, reliability, crowding, and inconvenience characteristic of transit services currently available in most cities. Technological innovations encompassed in the AGRT program include new electronic control systems, linear induction motors, magnetic levitation systems, high-speed switching, and emergency braking for short headway operations. These advances in technology offer several potential benefits to transit operators and users: • service flexibility comparable to vans or taxis coupled with the carrying capacity of a trolley car system or a multilane freeway, • lower cost per mile of guideway than for heavy-rail transit systems thus permitting the construction of more extensive guideway networks for a fixed capital investment, • rapid origin-to-destination service with few or no intermediate stops and no transfers, and substantially increased frequency of nonrush hour service." For Otis, the essential subsystem of AGRT is the Command and Control System which controls individual vehicles and groups of vehicles. The approach to verification of the control system and associated subsystems functions involves the use of an engineering test facility to be completed at the Otis Denver, Colorado facility. The equipment configuration is to be functionally representative of equipment which can ultimately be deployed in urban areas. The critical technologies are embodied in the development of the Local (Zone) Control System and in vehicle propulsion for higher speed. Specifically: 1. Local (Zone) Management and Control - This is a minicomputer based hardware/software system - which performs the operational control of all vehicles within an assigned zone for longitudinal speed regulation, merging, diverging, station operations, startup/shut-down, and recovery. This activity involves an extensive development of real-time control software for line headway operations down to 3 seconds for strings of vehicles. 2. Safety Assurance - This function is implemented by using microprocessor based controls on the wayside and the vehicle to assure safe operation (e.g., collision avoidance). The microprocessors are applied to meet the computational speed and data flow requirements of short headway systems. The processors are employed in two-out-of-three voting configurations to give fail-operational safety assurance. This approach represents the technology of the future for safety assurance. 3. Vehicle Development - AGRT requires a vehicle speed of 40 mph. This performance parameter requires a new inverter-linear induction motor (LIM) propulsion system development similar to the Otis system at Duke University. A major effort is being made to minimize vehicle weight, energy consumption, and cost. 4. Verification - The final year of the program will be devoted to operational testing. The tests will serve to verify the critical functional operations of the vehicles under automatic control.
