针对轮式全方位移动平台在负重、振动等方面的不足,基于全方位履带结构设计了向心型全方位移动平台,并对平台进行了运动特性分析.列举三履带、四履带平台布局形式,建立了平台运动学和动力学模型.分析平台运动的各向相异性,得到最大速度和最大加速度分布规律,确定了两种平台合理的辊轮偏置角分别为α≥π/3rad和α≥π/4rad.选取相同辊轮偏置角进行对比分析后可知,四履带平台相对于三履带平台在速度和加速度方面都有较大的提升,但三履带平台的运动均衡性较好.比较了两种平台在体积、质量、控制等方面的优点和缺点.利用ADAMS软件建立了两种平台的虚拟样机,针对横向、纵向和中心转向3种典型全方位运动及其各向相异性进行了仿真.仿真结果表明,所建平台具备全方位移动性能,同时验证了该平台的运动特性.%For the deficiencies of current wheeled omnidirectional platform in loading capability and vibration, centripetal tracked omnidirectional mobile platforms are designed based on the structure of omnidirectional mobile track, and their motion characteristics are analyzed. The layout forms of three-and four-track omnidirectional platforms are presented, and the kinematics and dynamics models are established. Anisotropies of omnidirectional platforms are analyzed to achieve the distribution rules of maximum speed and maximum acceleration, and determine the most suitable offset angles of α ≥π/3 rad and α≥π/4 rad. Selecting same roller offset angle to compare the motion characteristics of mobile platforms, the four-track platform has greater improvements than the three-track platform in speed and acceleration, but the three-track platform has better motion balance. The advantages and disadvantages of two platforms in volume, weight, control and other aspects are compared. The virtual prototypes of two platforms are developed using ADAMS, and three kinds of typical motions are simulated: longitudinal motion, lateral motion, central steering motion. The motion characteristics of the platforms are verified. The simulated results show that the centripetal platforms have omnidirectional mobile ability.
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