Gradeability of ‘Zhu Rong’ Mars rover based on the simulated Martian terrain

Due to the long-term weathering and erosion climate, many craters terrains on the surface of Mars are covered with loose weathered sedimentary debris, and Mars rovers traversing these slope-like terrains with soft soils will easily slip or even sink, and may affect the survey missions. Therefore, it is important to study the climbing ability of Mars rovers for Mars exploration missions. This work testes the climbing capability of 'Zhurong' Mars rover based on active–passive suspensions under the simulated Martian terrain and soil parameters were adequately measured. The maximum climbing distance (MCD), slip rate, power, current, energy, and efficiency are analyzed to explore the climbing abilities under different climbing methods, soil states and dynamic parameters (speeds, angular velocity) settings. The test results show that the peristaltic mode is able to continue climbing after a direct climb failure, and the MCD per period is influenced by angular velocity. The power and current data can effectively reflect the difficulty of the rover climbing. Under the same dynamic parameters, the greater the slip rate of the rover, the larger the output power and current. In addition, the speed should be minimized to prolong the climbing distance, no matter it is direct or peristaltic climbing.