Vulnerable Road User Detection System For City Buses
Kristofer Flodström, Erika Strömberg · Epubl LTU · 2011
The purpose of this work has been to develop a prototype system for pedestrian detection on city buses, based on a wide angle camera with an image processing unit for object detection delivered by one of the suppliers to Scania. A warning algorithm was developed and optimized for the application area. The wide-angle lens of the camera made it possible to cover about two-three meters in front and along the whole right side of the bus, however it complicated the detection and distorted the object information. The performance of the object detection was very dependent on the current weather conditions and contrasts of the detected objects. The camera system could not distinguish between pedestrians and objects, therefore a pedestrian filtering procedure was made. The warning algorithm was developed in two parts, where the first one was designed to be sensor specific which converted the object information from the camera to an adapted format. That information was then used in the latter part of the algorithm where the warning level was evaluated. Due to the performance variation of the camera sensor the first part of the warning algorithm became much more complicated than expected. The covered area is large for one sensor and works to detect pedestrians in a static mode. However, if the system is to be used during driving, the covered distance in front of the bus is to small for detecting pedestrians and warn the driver to avoid a collision. The cameras large coverage area is positive both for the cost efficiency and installation aspects. The performance of the complete system can be significantly increased by using additional sensors and a collaboration with the supplier to develop a custom designed system.