Evaluation of the computer simulation model NTVPM for assessing military tracked vehicle cross-country mobility

In the United States and some other NATO (North Atlantic Treaty Organization) countries, the NATO Reference Mobility Model is currently used to evaluate military ground vehicle mobility. The module of the NATO Reference Mobility Model for predicting the cross-country performance of military vehicles is empirically based and was developed using test data collected decades ago. The NATO Reference Mobility Model has inherent limitations, such as the uncertainty whether its empirical relations can be extrapolated beyond the test conditions upon which they were derived or whether it can be used for evaluating new-generation military vehicles. This suggests that there is a need for the development of a physics-based model that takes into account the advancements in terramechanics and modelling/simulation techniques. This paper describes the results of a detailed evaluation of a physics-based model – the Nepean Tracked Vehicle Performance Model – for assessing military tracked vehicle cross-country performance. The performance of a notional tracked vehicle (an armoured personnel carrier) predicted by the latest version of the Nepean Tracked Vehicle Performance Model is compared with test data obtained on sandy terrain, muskeg and snow-covered terrain. The correlations between the predicted and measured performance are evaluated using the coefficient of correlation, coefficient of determination, root mean square deviation and coefficient of variation. The applications of the Nepean Tracked Vehicle Performance Model to predicting the maximum possible vehicle speed (speed-made-good) on a given terrain, the sensitivity of vehicle performance to variations in the values of terrain parameters and the mean maximum pressure are demonstrated. The results of this study indicate that the Nepean Tracked Vehicle Performance Model has potential to form the basis for the development of the next-generation cross-country performance assessment methodology for military tracked vehicles.