单一可动叶片车轮和砂土的交互作用力学特性

Interaction characteristics between an active lugged wheel with a single lug and sand soil

摘要:

为评估本课题组研发的新型可动叶片车轮ALW(Active Lugged Wheel)与土壤交互作用的力学特性，搭建了ALW-土壤交互作用力学测量平台，测量了采用不同叶片运动轨迹的ALW机构与砂土间相互作用所产生的牵引力和垂直升力，将其与光滑车轮和单个叶片产生的土壤反作用力分别进行比较，辨识了车轮表面和叶片与砂土的耦合作用影响.根据测量结果进一步分析了叶片倾斜角度和沉陷长度对土壤反作用力的影响，并通过最小二乘法构建了叶片沉陷长度与土壤反作用力相关性的数学模型.结果表明：当车轮转角处于一定范围内时，ALW产生的牵引力和垂直升力比光滑车轮和单个叶片产生的作用力的总和更大，因此推断车轮表面和叶片与砂土的耦合作用会影响砂土的变形形式，ALW可以利用砂土的这种变形特性增大土壤反作用力；ALW受到的牵引力和竖直升力与叶片的倾斜角度没有明显关系，而与叶片的沉陷长度呈二次函数关系，因此可以通过主动调节叶片的沉陷长度来提高ALW机构在软土上的运动性能.

Abstract:

To evaluate the interaction characteristics between the soil and the Active Lugged Wheel (ALW) developed in our lab, an ALW-soil interaction testbed has been developed. The drawbar pull and the vertical force generated by the ALW mechanism in various trajectories are measured and compared with forces generated by a smooth wheel and a single lug, respectively, to identify the interference between the wheel rim and lugs. In addition, based on the experimental results, the effects of lug inclination angle and lug sinkage length on soil reaction forces are analyzed, and the relationship between the lug sinkage length and the soil reaction forces is established by the least square method. It has been confirmed that the ALW generates a larger soil reaction forces than the sums of the respective forces generated by the smooth wheel and the single lug as the wheel rotates within a certain range, thus the ALW can exploit the deformation property of the sandy soil to gain larger soil reaction forces due to the interference between the wheel rim and the lugs. Moreover, it has been found that the lug inclination angle has no regular influence on the soil reaction force, while both drawbar pull and vertical force are quadratic functions of lug sinkage. Thus, it is possible to improve the traveling performance of the ALW mechanism by adjusting the lug sinkage length.