Pressure-sinkage model and experimental research of interaction between rigid-wheel and simulant lunar soil

It is important to evaluate the behavior of rover on the moon. An experiment was conducted in an indoor soil bin for obtaining necessary data on the interaction between rigid-wheel and soft terrain so as to investigate the pressure-sinkage characteristics of the simulant lunar soil. A series of pressure-sinkage models are discussed of which the parameters were fitted based on the measured data from soil bin tests in order to select suitable model for describing the pressure- sinkage characteristics of the simulant lunar soil under the rigid wheel. Then the comparison between results of computation by the selected model and simulation by Distinct Element Method (DEM) under the lunar gravity was made. It was found from the comparison that there exists a fairly close agreement between calculation without gravity parameter and simulation with lunar gravity in tendency. But simulated sinkage in lunar gravity is 22.5% to 57.6% larger than that calculated sinkage by selected model under the same pressure condition. This work is of great benefit for evaluating the behavior of lunar rover with rigid wheels over the soft lunar soil.