The Inverse Kinematics for Control of a New Class of Robots for Computer-Integrated Flexible Manufacturing

当前的六自由度机器人系统可以满足在工作空间中访问广泛位置和位置的要求，但它们经常存在以次优方式完成这一任务的缺点。具体地说，为了在特定类别的操作或动作(即，弧焊)期间保持恒定速度，经常会遇到致动器超速效应。未能保持恒定速度可能会导致性能降低，即焊接质量下降。戴维森教授设计了一类七自由度机器人，它们具有避免超速奇点的潜力。这个项目利用了这类机器人，并开发了使用这种机器人的机床的设计和合成。机床被定义为包括机器人、放置在机器人末端执行器连杆上的某个角度和位置的一个或多个工具以及夹具的单元。研究通过五个步骤完成，包括(1)建立机械手的代数量纲分析方程，(2)探索合成方程的替代公式以扩大设计变量的数量，(3)确定用于近似任务的最大精度位置数，(4)根据机械手的尺寸和关节处的偏移范围来规定机械手的工作空间，以及(5)提取附加的设计条件，以使本研究中所考虑的这类机器人的工作空间的体积最大化。这项研究的影响将在未来的工业机器人技术领域。具体地说，这些结果可以减少制造安装所需的工程时间，为在机床中放置工具和夹具的计算机自动设计程序的开发提供了准备，并构成了机器人完成特定制造任务的计算机自动编程的重要步骤。*

Current six degree of freedom robot systems can meet the requirement of accessing a broad range of locations and positions in a workspace, but they frequently have the disadvantage of doing this in a suboptimal way. In particular, actuator overspeeding effects are often encountered in an attempt to maintain a constant speed during a particular class of operations or maneuvers, i.e., arc welding. Failure to maintain constant speed can result in reduced performance, i.e., degraded weld quality. Professor Davidson has designed a class of seven degree of freedom robots which have the potential of avoiding the overspeeding singularities. This project exploits that class of robots and develops the design and synthesis of workcells which use such robots. Workcell is defined as a unit comprising a robot, one or more tools placed at some angle and position on the end effector link of the robot, and a fixture. The research is accomplished through five steps including (1) developing the equations for algebraic dimensional analysis of the manipulators, (2) exploring alternative formulations of the synthesis equations to expand the number of design variables, (3) determining the maximum number of precision locations used to approximate a task, (4) prescribing the manipulator workspace in terms of manipulator dimensions and excursion ranges at the joints, and (5) extracting additional design conditions to enable maximizing the volume of workspace for the class of robots considered in this study. The research's impact will be in the area of future industrial robot technology. Specifically, the results could reduce the engineering time required for manufacturing setup, provide for the development of computer automated procedures of design for the placement of tools and fixtures in workcells, and constitute an important step in the computer automated programming of a robot to accomplish a specific manufacturing task. *