Representative AWD System Evaluation by High-Function Dyno—New Simulation Model of Sand Road

Previously, AWD system evaluations have taken place using actual vehicles on real roads. However, there have always been concerns regarding inaccuracies from test to test due to seasonal differences in road conditions and weather. This problem is especially prevalent on sand road tests, these tests are particularly affected due to the sinking behavior of tires in soft sand. Therefore, when a comparative evaluation is implemented on a vehicle with changes made to the AWD control logics and specification, it is difficult to identify whether any phenomenon observed between tests is a result of the adjustment made to the AWD specification or a change in the road conditions. To solve this problem a new simulation model replicating a sand road has been developed. The model is able to simulate driving a car on sand using Dynamos with low inertia and high response motors. To create this simulation model, 4 characteristics of sand, which are “the running resistance”, “the static and dynamic sinkage characteristic of the tires” and “the traction coefficient” were identified and calculated by carrying out full-scale test with an actual vehicle running on sand.