四驱全地形车可变直径轮软土牵引特性分析

为解决常规地面车辆及传统车轮在沙地、滩涂等松软地域行驶或作业时存在通过性差、效率低、能耗大甚至无法行驶的问题,自主创新设计出四驱可变直径轮轻型全地形探测车,车轮具有可张开成为弹性步行轮和合拢成为刚性圆车轮2种工作轮态.基于贝克模型的经典地面力学理论,分别建立了可变直径轮张开轮及合拢轮态时与3种典型松软沙土交互作用关系的力学简化模型,计算并对比分析了可变直径轮两种工作轮态的挂钩牵引力和驱动力矩、牵引效率等随滑转率的变化关系及车轮接近角与沉陷量关系.结果表明车轮的挂钩牵引力、驱动力矩和牵引效率等均受到车轮滑转率及软土特性参数的制约,在松软路面上可变直径轮张开步行轮比合拢圆轮能产生更大的挂钩牵引力、驱动力矩、牵引效率和更小的沉陷量,更有利于提高车轮的软土牵引通过性.分析结果可作为后续实验研究对比的参考.

Tractive performance analysis of diameter-variable wheel for 4WD all-terrain vehicle on soft soil

Four-wheel drive all-terrain light exploration vehicle with diameter-variable wheels was innovatively designed out to solve the problems when conventional ground vehicles and wheels driving on soft terrain, such as poor trafficability, low efficiency, big energy consumption and even can-t drive. The wheel has two extreme working status: elastic extended walking-wheel and folded rigid wheel. Based on classical terramechanics theory, the dynamics models of interactions between two types of working wheel status and three kinds of typical soft soils were established. The drawbar pull, driving torque and driving efficiency as well as sinkage of diameter-variable wheel were analyzed under the condition of different slip. The results indicate that traction trafficability indexes are limited by wheel slip and soft soil parameters. The simulation provides theoretical basis for that the elastic extended wheel can improve significantly bigger drawbar pull, driving efficiency and soft soil traction trafficability, and reduce sinkage compared with that of rigid folded wheel’s, and can be used as the reference for further experimental investigation.