This article describes the SYSAL system which presents a unique approach to the subject of vehicle location within the framework of a Fleet Management System. SYSAL integrates three technologies: differential odometer, map matching and differential corrected global positioning satellite systems. Two modes of operation, for fixed route vehicles and random-route vehicles, are described. The distance covered is derived from averaging measurements from two odometer sensors mounted on the two front wheels and changes in heading from the difference between them. Storage of a route map for fixed route vehicles is described. The three major components of the system, the mobile equipment, command centre and communications are briefly outlined. The advantages of SYSAL compared to other systems are considered.
Abstract