拖挂式自行车机器人机构设计与非完整约束分析

Mechanism Design and Nonholonomic Constraintan Analysis for A Tractor-Trailer Bicycle Robot

负载能力是评测自行车机器人机构性能的1个重要指标,针对现有的两轮自行车机器人机构负载能力不足的问题,提出1种由两轮自行车（牵引车）和单轮挂接车构成的新型自行车机器人机构,重点对机构的非完整约束特性进行研究。以车轮纯滚动为基础,结合相对运动原理分析系统的运动约束特性,结果发现牵引车驱动速度与挂接车速度存在着一定的函数关系。通过物理样机骑行试验的方法,给出系统相关运动变量关系的验证算例。所得结果表明,约束计算得到的变量曲线和测量得到的变量曲线基本一致,验证了非完整约束分析的可靠性。研究结果可为该新型自行车机器人机构的动力学建模和驱动优化设计提供理论参考。

Load capacity is an important index to evaluate the performance of a bicycle robot,and in view of the load capacity deficiency of the traditional two-wheel bicycle robot,a tractor-trailer bicycle robot with a two-wheel tractor and a single-wheel trailer is presented. The work in this paper focuses on the nonholonomic constraints of this system. By considering the precondition of the pure rolling contact between the ground and wheels,the constraints of the system are analysed by the principle of relative motion theory. The results show that,there is an explicit function relationship for the speed of the tractor and that of the trailer. Physical prototype experiments are performed,which shows the calculated curve of the nonholonomic constraint is basically consistent with the measured ones of the experiments. The experiments testify reliability of the developed nonholonomic constraint. The work in this paper can be taken as the theory foundation for the system＇s drive optimization and dynamics analyses.