Dynamic Modeling of Planetary Vehicle’s Fall on Soft Soil

The objective of future planetary mission is to explore more new zones on Mars planet. This goal may be achieved by using high speed planetary vehicle, (Rover). The motion of planetary vehicles at high speed and on unknown terrain increases the number of possible risks. One risk is a sudden change of ground level in the vehicle path causes a fall down onto a low ground. This paper presents a study and simulation of the dynamic response of a free fall of a quarter vehicle (rover) model with rigid wheel on a soft soil. A simplification of Bekker’s equation is derived and used in the numerical solution of the two coupled dynamic equations of motion. The Dynamic response of the unsprung mass, rigid wheel, shows a three stages; the sinkage stage, the equilibrium stage, and the pulling out stage from soil. The simulation shows that having rigid body mode helps in pulling out the vehicle wheel from the soil. It shows that the first three stages of the first fall are the most significant ones. They have the largest sinkage, largest impulsive force, and largest amplitude of the system dynamic response during interaction of the rigid wheel and the soft soil following the free fall. The existence of a damping reduces the dynamic response magnitude and prevent the unsprung mass from pulling out the wheel from soil after sinkage.

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Opracowanie ze środków MNiSW w ramach umowy 812/P-DUN/2016 na działalność upowszechniającą naukę.