Using GPS-based Data Acquisition to Evaluate Vehicle and Driver Performance

Abstract

GPS systems, a common aerospace application, have become widely available over the last ten years. Most data acquisition systems used for flight or ground testing of vehicles in the past were very expensive and hard to setup. This paper looks at the recently available low cost GPS-based systems for ground vehicle data acquisition and investigates their ability to evaluate vehicle and driver performance. An SCCA Spec Miata racecar was used at two different race tracks to evaluate the system. The data acquisition system acquires GPS position and calculates speed; in addition the system uses internal accelerometers to record lateral and longitudinal acceleration. Speed versus location on the track plots were most effective evaluating driver performance. Both longitudinal acceleration and velocity/time plots were effective determining acceleration, braking, and the effect of shift points on acceleration. Lateral acceleration was used to compare cornering forces and friction circle transitions from braking/acceleration. Race track segment analysis was used to measure changes to driving line through complex corners on the track in order to determine the optimal driving line. The effect of late braking was measured and determined to have minimal effect on overall lap times. It was concluded that GPS-based data acquisition systems are easy to use and with proper data reduction can provide accurate vehicle and driver performance measures.