Performance of Steering Controllers for Automated Guideway Transit Vehicles

Abstract

Automated Guideway Transit (AGT) is a class of urban transportation system in which vehicles are operated under automatic longitudinal and lateral control on exclusive guideways. This paper discusses the performance of automatically steered rubber-tired vehicles on both straight and curved guideway, subject to the conflicting requirements of tracking accuracy and passenger comfort. The optimal performance for operation on straight guideway containing random lateral reference errors is presented. This performance is the best achievable with any controller of the class considered and provides a standard against which simpler suboptimal controllers can be evaluated. A simple proportional controller using a single displacement sensor is shown to produce near-optimum performance for the typical vehicle studied when operated at the design speed. By appropriate location of the position sensor, steady-state errors in curving can be made small for the practical range of curve radii. Curve entry transients are simulated for a curve having no transition spiral and a steady-state lateral acceleration of 0.223 g at 13.4 m/sec. Acceleration and tracking error overshoots are both less than 13.3% for well-chosen gains.