Study of numeric Saturation Effects in Linear Digital Compensators

Saturation arithmetic is often used in finite precision digital compensators to circumvent instability due to radix overflow. The saturation limits in the digital structure lead to nonlinear behavior during large state transients. It is shown that if all recursive loops in a compensator are interrupted by at least one saturation limit, then there exists a bounded external scaling rule which assures against overflow at all nodes in the structure. Design methods are proposed based on the generalized second method of Lyapunov, which take the internal saturation limits into account to implement a robust dual-mode suboptimal control for bounded input plants. The saturating digital compensator provides linear regulation for small disturbances, and near-time-optimal control for large disturbances or changes in the operating point. Computer aided design tools are developed to facilitate the analysis and design of this class of digital compensators

A Data Fusion Approach to Automated Vehicle Detector Testing

Vehicle presence detectors have become critical elements of traffic management systems, including applications ranging from intersection signal control to freeway congestion monitoring. The need to assess the accuracy and attributes of each of the many types of sensors motivated the California Department of Transportation to construct the Traffic Detector Testbed on I-405 in Southern California. With up to ten detectors of different types under concurrent test in each of six lanes, a means for automating the testing process became imperative, since traditional human-verification methods were not practical. This paper describes the design and implementation of an automated data acquisition and verification system that processes data from all detectors along with that of a reference image processing system, to create a composite ground truth record against which individual detector performance is assessed. The system architecture, data fusion methodology, computer vision methods, operator interface and system performance results are discussed

Evaluation of closed-circuit television technology for application in highway operations. Final report.

California Department of Transportation, SacramentoFederal Highway Administration, Washington, D.C.Mode of access: Internet.Author corporate affiliation: California Polytechnic State University, San Luis ObispoSubject code: CCDSubject code: HCEESubject code: WOJSubject code: XF