基于相似理论的星球车牵引通过性模型

深空探测车辆在星球表面巡视过程中,应避免过度沉陷,保障其可靠的通过性能具有重要意义。月球和火星表面重力加速度分别约为地球表面重力加速度的1/6和2/5,地面实现低重力环境的模拟具有一定局限性,因此基于相似理论进行轮壤相互作用系统的量纲分析,研制二分之一缩比模型车;开展缩比模型车轮壤试验,重点研究滑转条件下车轮沉陷行为和牵引特性;基于地面力学理论,结合轮壤接触应力分布的线性化方法,建立与沉陷和滑转率相关联的星球车挂钩牵引力预测模型。通过土槽试验数据对模型进行验证,结果表明该模型具有较高的准确性。能够为星球车通过性评估提供一定的理论技术基础。

Planetary rover's tractive performance model based on similarity theory

It is important to ensure reliable mobility performance and avoid excessive sinkage for planetary rover. Gravity acceleration on the moon and mars is about one-sixth and two-fifths of the earth, respectively; however, there are certain limitations to simulate low gravity environment on the earth. Therefore, based on similarity principle and terramechanics theory, we present a dimensional analysis on wheel-soil system. A scaling planetary rover has been developed, which is used for eliminating the equivalent influence of the low gravity in the ground experiments. Soil bin tests of the planetary rover are conducted on two different terrains, and the sinkage and tractive characteristics of planetary model rover have also been analyzed. By combining the linearization approach on contact stress distribution between wheel and soil interface, a simplified drawbar pull model is established, which is related to the wheel sinkage and slip ratio. The model is validated through the soil bin testing data and results indicate that the proposed model has a higher accuracy in the mobility performance assessment, including wheel sinkage and drawbar pull.