Sensor systems and thermal imaging equipment manufacturer, FLIR Systems Inc., has revealed details of the incident detection technology that it has provided for the Brynglas tunnels on the UK’s motorway network in South Wales.
The 1,181 feet (360m) long twin-bored Brynglas tunnels are located on the M4 motorway at Newport. With about 80,000 vehicles passing through them on peak days, the tunnels are of major economic importance to the region. Incidents in the tunnels have immediate effects on traffic congestion and overall accessibility, which is why it is of crucial importance that vehicle-related accidents are detected and reported as soon as possible, so that response teams can intervene, and secondary accidents can be avoided. During the tunnels’ most recent upgrade, lead contractor CCSL required a new incident detection system that would notify tunnel operators of any potential hazard or traffic issues within the bores.
After a thorough market appraisal, CCSL selected a combination of FLIR’s smart visual and thermal incident detection cameras, together with the company’s Flux video detection management software. The Brynglas tunnels now use 13 FLIR TrafiBot HD visual cameras with built-in automatic incident detection (AID) functionality. The video feeds are analyzed locally at the camera before relevant alarms/events are generated and sent to the redundant Flux video management servers. An additional eight FLIR FC-Series ITS thermal imaging cameras are installed at the entrances and exits of both tunnel bores.
A visible-light camera can possibly suffer from sun glare if it is positioned to point outwards at the tunnel portal. As a result, the image for the portal areas would be blank due to light contrast and the camera would not be able to detect any potential incident around the portal areas. To avoid this, the first visual camera is pointed into the tunnel, while the blind spot underneath the camera and at the portal exit area are covered by the FLIR FC-Series ITS thermal cameras.
To enable rapid identification and notification of an incident, FLIR’s AID cameras and Flux video management system provide traffic control room operators with an alarm within seconds of an incident occurring. The Flux server acts as a management and storage unit in the AID system. Flux filters information generated from all cameras on the network and exposes only the relevant data to the SCADA via a Modbus TCP Interface. A Flux web client provides a user-friendly view of all cameras on the network.
“A tunnel refurbishment is usually a long and challenging process,” explained Carl Cheetham, CCSL’s technical director “Hence, it is important to have a reliable partner along for the journey who can give you the required support. We had previously received excellent service and support from FLIR and this made the choice of supplier/partner a simple one. Their incident detection cameras have been performing very well since installation. Thanks to a smart combination of visual and thermal camera technologies, FLIR has been able to reduce the false alarm rate to a minimum without missing real alarms.”