A New Method for the Analysis of the Motion of Quasi-Static Systems of Bodies in Contact

本研究针对准静态运动进行分析 接触物体的系统。 一个机器人系统 与当地环境的关系在某种意义上可以被描述为 动态地作为相互作用的刚性和柔性体的系统。 其中一些身体受到主动控制，而另一些则做出反应 以被动的方式。 如果这些物体的加速度 很小，那么假设加速度 在分析被动体的运动时， 这种类型的系统被称为准静态的，并且 假设保持静态平衡。 机械系统 适合于准静态建模的是那些运动 是由接触的影响所支配的，即，机器人手 将工件装配到夹具中。 这里使用的方法是 根据Peshkin的最小权力原则， 被动体的瞬时运动是 同时最大限度地降低功耗， 与活动物体接触所施加的运动学约束。 应用这一原理产生一种算法， 确定系统被动体的速度， 作为时间函数的接触力。 算法比较少 比系统的传统解决方案计算密集 微分方程，并将算法集成到 现有的机械装配CAD/CAM系统将允许建议 组装程序将评估接触力，接头 所需的扭矩，以及稳定性和干扰条件， 开始组装。

This research addresses the analysis of the quasi static motion of systems of contacting bodies. A robotic system in contact with the local environment can in some sense be characterized dynamically as a system of interacting rigid and flexible bodies. Some of these bodies are actively controlled while others respond in a passive manner. If the accelerations of these bodies are very small, then it is often useful to assume that acceleration to be zero in the analysis of the motion of the passive bodies. This type of system is said to be quasi static, and the law of static equilibrium is assumed to hold. Mechanical systems amenable to quasi static modeling are those for which the motion is dominated by the effects of contacts, i.e., a robot hand assembling workpieces into a fixture. The approach used here is based on Peshkin's Minimum Power Principle which states that the instantaneous motion of the passive bodies is that which simultaneously minimizes power dissipation and satisfies kinematic constraints imposed by contact with active bodies. Application of this principle results in an algorithm which can determine the velocities of the system's passive bodies and the contact forces as functions of time. The algorithm is less computationally intensive than traditional solution of the system differential equations, and integration of the algorithm into existing mechanical assembly CAD/CAM systems will allow proposed assembly procedures to be evaluated for contact forces, joint torques required, and stability and jamming conditions before beginning assembly.