基于弹性筛网轮地面力学机理的载人月球车月面行驶模拟研究

Lunar roving vehicle (LRV) can travel far from the lunar module and transport astronauts to complete a variety of detection mission more efficiently. In the stage of design, performance optimizing, and driving training, the movement of LRV on the lunar surface needs to be imitated on earth to establish relevant experiments. However, the gravities between earth and moon are different, and the parameters between experimental and real lunar soil may not completely consistent. Hence, these deviations will cause that the imitating experiments on earth cannot use the same LRV on the lunar surface. To address this issue, an approach based on the terramechanics of the wheel with elastic and mesh surface is proposed to imitate an LRV moving on the lunar surface using a terrestrial vehicle on earth. Briefly, the terramechanics model of the wheel with elastic and mesh surface is obtained by the stress distribution research and experiment analyzing. The movement imitation of LRV contains the imitation of straight and steering movement. The coupling terramechanics between the front and rear wheels are deduced, and the imitation method of straight movement is proposed to control the driving motors of the wheels. In addition, the steering dynamic model is established, and the imitation method of steering movement is proposed to control the steering motors based on the H-Infinity theory. With the results of theories, simulations and experiments, the imitation of LRV moving on the lunar surface, which does not use the method of mass equivalent or suspension gravity compensation, will be realized. This research will have special significance for the development of manned lunar exploration engineering.

载人月球车可扩大宇航员月面探索范围，提高行进速度，并能携带更多的样本和仪器。在设计开发、性能优化、宇航员操纵训练等阶段，都需要在地面条件下开展模拟载人月球车月面操纵相关的实验和测试。然而，重力差异以及实验土壤与月壤参数难以完全一致，导致无法直接使用相同的载人月球车进行实验。针对上述问题，本项目拟基于弹性筛网车轮的地面力学机理，研究地面条件下的载人月球车月面行驶模拟问题。通过应力分布研究和实验分析，获得弹性筛网车轮的力学模型。将载人月球车月面行驶模拟分解为直线和转向行驶的模拟：推导整车前后轮的地面力学耦合特征，提出车轮力矩控制的月面直线行驶模拟方法；结合车轮转向力学模型，建立宇航员参考点的操纵动力学模型，基于H-Infinity理论，提出车轮转角控制的月面转向行驶模拟方法。综合理论、仿真和实验结果，实现非质量等效、非悬挂重力补偿方式的载人月球车月面行驶模拟，为我国载人探月工程提供技术基础。

为了在地面条件下开展载人月球车月面运动特性相关的实验和测试，同时训练和提高宇航员驾驶的操纵技术，本研究以消除由月-地重力不同和实验土壤与月壤参数不一致所引起的载人月球车操纵特性差异问题为目的，开展了基于地面力学机理的载人月球车月面行驶模拟研究。首先，通过单轮实验平台，获得了载人月球车弹性筛网车轮与松软地面相互作用的力学模型。然后，将载人月球车月面行驶模拟分解为直线和转向行驶两部分：通过推导整车前后轮的地面力学耦合特征，提出了一种车轮力矩控制的月面直线行驶模拟方法；结合车轮转向运动的力学模型，提出了一种车轮转角控制的月面转向模拟方法。最后，综合理论、仿真和实验结果，实现了较高速、非质量等效、非悬挂重力方式的载人月球车月面行驶模拟。本研究可为载人月球车移动技术提供地面实验依据，为我国载人探月工程提供技术基础。