The vehicle coast-down test

This report investigates the analysis of vehicle coast-down results. Two analytical models are investigated, and one is chosen as the basis for a derivative based correction technique to account for changes in the ambient conditions. A vehicle coefficient extraction algorithm, based on a parameter optimization technique, is developed. A FORTRAN program is developed to implement the correction and coefficient extraction algorithms, and also to carry out a statistical analysis on the extracted vehicle coefficients. The statistical analysis utilizes 'weights' (based on RHS curve fitting error) in order to account for random error in the input coast-down data. An investigation into the effect of measurement error on the extracted values of the coefficients was carried out, and it was recomended that the vehicle speed and wind velocity measurements should be improved. A large number of actual test were obtained and analyzed, but the results were inconclusive, except that it was clear that the measurement accuracy must be improved. Finally, recomendations for future work were made based on experience gained during the course of this work.