Portable Loop Fault Diagnosis Tool Development for Control Cabinet Level

This paper presents preliminary results in the research and development of a Portable Loop Fault Detection Tool for use at the control cabinet level. This work is complementary to most previous work focusing on macroscopic faulty loop data. Part of the project is to develop a real-time vision-based multi-lane multi-vehicle tracking algorithm for freeways to use as baseline measurements to compare with the lower level loop signal for direct loop fault detection. The system is primarily developed for both freeways and arterials. It is composed of a mobile trailer, a retractable pole with a video camera mounted on top to look at the suspicious loop detector on the ground, a computer running the vehicle tracking algorithm, and another computer at the control cabinet interfacing with a loop detector card though RS232 serial port. Both computers run IEEE 802.11b wireless for information passing and synchronization. A small data packet of the virtual loop information passes from the trailer computer to the cabinet computer through a UDP protocol. Information from the virtual and the physical loops are then compared which can be viewed on a visual display. Preliminary tests have been conducted and the results are analyzed.