The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 16, 1997
Filed:
Oct. 12, 1995
James C Spall, Ellicott City, MD (US);
The Johns Hopkins University, Baltimore, MD (US);
Abstract
A method and apparatus for model-free, real-time, system-wide signal timing for a complex road network is provided. It provides timings in response to instantaneous flow conditions while accounting for the inherent stochastic variations in traffic flow through the use of a simultaneous perturbation stochastic approximation (SPSA) algorithm. This is achieved by setting up several (M) parallel neural networks, each of which produces optimal controls (signal timings) for any time instant (within one of the M time periods) based on observed traffic conditions. The SPSA optimization technique is critical to the feasibility of the approach since it provides the values of weight parameters in each of the neural networks without the need for a model of the traffic flow dynamics.