Determination of Required Positioning Integrity Parameters for Design of Vehicle Safety Applications
Yanming Feng and Charles Wang, Queensland University of Technology, Australia; Charles Karl, Australian Road Research Board, Australia
Location: Grand Ballroom F
Date/Time: Tuesday, Jan. 30, 4:30 p.m.
Most connected vehicle safety and traffic applications depend on communication and position and velocity information to function. However, road users may have different vehicle communicating and positioning capabilities. Further, the performance of communicating and positioning could vary from time to time and location to location. It is important for the vehicle safety system to be fully aware of the performance of vehicle positioning outputs and warn the drivers when the positioning system cannot be used for intended level of safety applications. However, unlike aviation and Maritime navigation, minimum operational performance standards about positioning have not been established in the road community. In this work, we review and develop the required navigation performance parameters for vehicle positioning capability in terms of accuracy, integrity, timeliness and interrogability of positioning solutions. We attempt to adjust the integrity performance parameters for vehicle safety positioning and provide the analysis for integrity risk, protection level and different alert limits. Based on these discussions, we introduce the error ellipse representation to visualize the protection bubble area of each vehicle on the road. The results from a vehicle experiment demonstrate how well different levels of vehicle positioning capabilities meet the different integrity alarm limits. The results emphasize that the positioning system can inform the protection level achievable at any time instant and serve the safety application at that level accordingly.