履带式移动机器人车体跌落碰撞仿真分析

移动机器人本体与地面冲击碰撞过程属于高度非线性结构问题，数值仿真与模拟试验技术为其求解提供了有效的解决方法。文中应用非线性有限元分析法对小型履带式移动机器人机动平台的跌落碰撞过程进行仿真计算。采用ProE软件建立机器人平台机架的三维实体模型，从中获得零件准确的质量、质心位置和惯性矩等计算参数。两侧塑料履带轮和橡胶履带简化成四个超弹性橡胶轮，地面被简化为一刚体材料，地面与平台机体接触刚度川橡胶轮弹性等效代替，忽略箱体上轴孔，对箱体中的零件质量采用等效质量方法分摊到简化的箱体上。利用ANSYS／LS-DYNA模块分析平台在不同高度、不同着地姿态下跌落碰撞过程，获得跌落碰撞过程中的应力、变形值，仿真结果清楚显示出平台本体内部应力、应变及变形随时间变化的详细分布情况。与试验法相比，有限元数值仿真法节省时间、降低费用、提高设计质量。对机器人本体设计、研究工作具有重要的参考意义。

DROP IMPACT SIMULATION OF TRACKED MOBILE ROBOT BODY

The impact of mobile robot body dropping on ground is a high nonlinear structure problem. The dynamic process of drop impact of the body can be effectively investigated by means of numerical and test simulation technique. Drop impact of the small tracked mobile robot body was simulated by nonlinear finite element method. The robot 3D solid model was established with application of the ProE software to obtain the accurate mass, position of center of mass and inertia moment. The plastic track wheels and rubber tracks in two sides were simplified to four hyperelastic rubber wheels and the ground was simplified to rigid body. The contact stiffness between them was substituted for that of impact drop between ground and the robot equivalently. The holes of housing bear seat were neglected and the mass of the parts in the case were allocated to the case by equivalent mass method. The drop impact process of the body in different heights and different touchdown attitudes was analyzed with ANSYS/LS-DYNA. The stress and deformation of the drop impact body was obtained. The distribution of internal stress-time, stains and deformation-time of the body was obviously indicated by the result of simulation. Compared with test method, nonlinear finite element method could save the time consumption, the test cost and improve the design quality significantly. It is referred to design and research mobile robot.