Guido Korlath, Dipl. -lng.Dr.techn.The Human Factor in Off-Road Mobility A Simulation Approach to Assess the Influence of Human Reactions and Mission Planning Strategies on Off-Road Mobility

Even vehicles of highest development level equipped with all available features for perfect off-road capability are still driven – active by driver or programmed to act autonomous – by human beings. All technical aids to enhance off-road mobility are developed and validated for or under more or less ideal circumstances. In most of the cases, when a skilled driver operates a vehicle, they proof to work perfect. But what would be the result, if subjective driver decisions, especially when they are obviously wrong, can not be compensated by the vehicle, or, if a mission strategy brings an operator in situations, where he will be forced to act knowingly against given algorithms of the driving aids in order to maintain motion of the vehicle.
The presented paper shows a first simulation approach to analyze subjective operator decisions on mobility behavior of off-road vehicles. Exemplary results show, what could be expected, if it comes to a very individual situation-dependent decision for braking, accelerating, stopping etc.
Another important field of interest is mission planning. If mission planning forces a driver to undertake reactions, which turned out to have a negative influence on mobility performance, parameter varying simulation runs can help to set action in the run-up to be prepared for such situations or even avoid them.
Using the simulation program WINMAKU? in its newest release, it will be possible to simulate such influences of subjective human reactions. Based on standardized reaction patterns, mobility parameters are calculated. In the form of speed vs. distance – diagrams, the speed characteristic over a mission profile is predicted and critical situations due to driver’s reactions can be identified. Corrective reactions on wrong reactions – i. e. a driver realizes, that an action seems to lead the vehicle to a fatal mobility behavior and sets therefore another reaction – have not been taken into account. This simplification is well reasonable, because in reality, there is often not time enough to compensate or overcome totally a wrong decision by an other one.
The presented simulation approach takes into account a wide range of possible human influences on off-road vehicle performance for perfect planning of tactical missions and for operational mission passing and shows the significant impact of human reactions and decisions on off-road mobility.