Correlation Between Open and Closed Loop Vehicle Handling Measurements

This paper describes correlation between open and closed loop measurements of vehicle response time in transient steer maneuvers. Open loop tests were conducted by negotiating ramp steer and reverse ramp steer maneuvers. The response time values were determined at five levels of lateral acceleration. Closed loop tests were conducted by negotiating lane change maneuvers. The response time values were determined by using cross-correlation function. It was found that correlation between closed and open loop test data is greatly influenced by the selection of response time criteria, test procedure, and level of lateral acceleration used for determination of response time in open loop tests. The best correlation (R = .958) was obtained for lateral acceleration response time determined by using reverse ramp steer and measuring the response time at zero lateral acceleration.