关键词: 低重力, 轮压, 摇臂转向架式星球车, 重力补偿

Abstract: The crucial problems encountered in gravity compensation (GC) for rocker-bogie rovers through single string tension are examined and tackled to enable easy and precise low gravity simulation. A GC approach utilizing single string and counterweights on rockers is developed to simulate all the wheel contact forces of rovers in all configurations. The contact force model of four and six wheeled rovers is constructed, through which the equivalence between ensuring contact force and defined contact force (wheel pressure), the special case when the horizontal components of all contact force is nil, is proved. The approach is proved by showing compensated wheel pressure is identical with that in low gravity. The advantage and validity of such approach is future proved by software simulation. To equivalently apply compensation force onto the inner point of the carriage (a sealed body), the similarly suspension mechanism is developed. The mechanism is such that the relative position between surface points and inner points of the sealed body is exactly identical with those of the suspension body; compensation force on the suspension body is equivalently applied to corresponding inner point of the sealed body. To avoid dismantling of rover for the center of mass measurement, an algorithm is established to relate the position and magnitude of compensation force system with wheel pressure. The method and equipment are established to measure the wheel pressure. These researches provide a precise and feasible plan for rocker-bogie rovers’ gravity compensation, which is proved by their application in experiment.

Key words: Gravity compensation, Low gravity, Rocker-bogie planetary rover, Wheel pressure