Mecanum四轮全方位系统的运动性能分析及结构形式优选

Motion Performance Analysis and Layout Selection for Motion System with Four Mecanum Wheels

设计合理的Mecanum四轮系统能够实现平面上3自由度全方位运动,但不是任意组合的Mecanum四轮系统都能实现全方位运动。为求得Mecanum四轮系统实现全方位运动的条件,分析给出一般结构形式的Mecanum四轮系统的运动学模型。通过解析系统速度逆雅可比矩阵的秩,结合系统的驱动性能和可控性要求,得到Mecanum四轮系统实现全方位运动的条件,即系统满足全方位运动的必要条件是逆雅可比矩阵满秩。对于一个具体的四轮系统,能否实现全方位运动还取决于轮结构参数及系统的结构布局形式。列举出六种具有代表性的四轮结构布局形式,通过对其逆运动学速度雅可比矩阵秩的计算,结合具体结构的分析,优选出四轮全方位运动系统的最佳结构布局形式。

A rationally designed motion system with four Mecanum wheels can move in ornni-direction on flat floor, but not any arbitrarily composed system with four Mecanum wheels can do so. In order to find the conditions of the system with four Mecanum wheels to move in omni-direction, the motion model of the general system is put forward and the inverse velocity Jaeobian matrix is analyzed, considering the request of the system driving and controllability. The conclusion is presented that the omi-directional motion conditions not only depend on the full rank of inverses Jacobian matrix, but also depend on the wheel structure and the layout of the four wheels of the system. Then six typical layouts of four Mecanum wheels are illustrated and the optimal layout is picked out by calculating the Jacobian matrix rank of the six typical layouts.