A Design-To-Task Approach for Wire Robots

Abstract

Wire robots consist of a moveable end-effector which is connected to the machine frame by motor driven wires. Since wires can transmit only tension forces, at least m = n + 1 wires are needed to tense a system having n degrees-of-freedom. This leads to a kinematical redundancy and am–n dimensional solution space for the wire force distribution. For their calculation, sophisticated mathematical methods are required. Nevertheless workspace analysis is an important task in applications. Discrete methods do not produce satisfying results, since intermediate points on the discrete calculation grids are neglected. To overcome this problem, intervals instead of points can be used. On the one hand, this leads to reliable results, on the other hand, the approach can be extended to solve synthesis tasks, which is even more important in practical applications. In this paper, a Design-to-Workspace approach using interval analysis is presented, i.e. calculation of an optimal robot layout for a given workspace. Furthermore, a first extension of this approach to a Design-to-Task approach is presented. Design-to-Task denotes the problem of calculating the optimal robot for a specific task.