Commercialization and Field Distribution of Smart Pedestrian Call Signals

The research on this project resulted in a new design for an accessible pedestrian system (APS) that uses Ethernet communications to implement a distributed control system. Present APS designs represent a safety risk factor by APS systems having undetectable failure modes that may play incorrect audible messages. The systems consists of a controller unit housed in the traffic controller cabinet and interfaces to existing NEMA TS1 and TS2 traffic controller cabinets at the field terminals. It supports from one to 16 pedestrian stations. The controller unit uses a Linux based single board computer with dual Ethernet ports. The pedestrian stations use a resource rich NXP processor reducing the number of components and size of circuit board. All configuration and diagnostics is accomplished using a PC with a standard web browser and an Ethernet connection. This interface reduces the size and cost of the unit mounted in the controller cabinet. The web page provides real-time status of all controller inputs and the state of all pedestrian stations and the audio message currently being played. SNMP and STMP custom objects are used in such a way that each communications transaction is verified. A network protocol is implemented that follows the guidelines for NTCIP custom objects.