Simulation of a high performance PRT control system

In connection with the second phase of the Advanced Group Rapid Transit (AGRT) project sponsored by UMTA, General Railway Signal Company has refined the design of a control system for a high-performance (3-second headway) Personal Rapid Transit (PRT) system. The control system utilizes a variable length moving block control algorithm, and features a combination of multiple wayside and vehicle-borne computers that are connected by a wide bandwidth data link to achieve the desired performance. In this phase of the project, a major effort was directed toward developing a highly detailed simulation of the entire control system. This simulation was undertaken to verify that the deployed system would meet previously defined performance specifications. This paper will discuss the implementation of the simulation and describe its use in verifying system operation at both macroscopic and microscopic levels. Examples of microscopic operations studied include effects of communication delays and errors on system operation and scheduling of different processes on the same computer. Examples of macroscopic operations studied include the operation of several vehicles merging at a junction, the response of several vehicles in a string during normal station stopping maneuvers, and responses to various failures that require emergency action.