Workspace Analysis and Stiffness Optimization of Snake-Like Cable-Driven Redundant Robots

Snake-like cable-driven redundant robots (SCDRR) have great application prospects in narrow and complex environments, thus are being widely research in recent years. However, the effect of links length distribution on workspace is rarely studied. Meanwhile, the stiffness optimization of SCDRR is an important issue, due to its relatively poor stiffness performance compared with industrial robots. This paper first analyzes the relationship between workspace area, workspace volume and manipulability to illustrate the effect of links length distribution on workspace. Then stiffness optimization model with and without the variation of the Jacobian matrix can be established by statics and stiffness model. Lastly, simulations show that the optimization result between two models is not much different when cables tension are relatively low, while the simplify one has less computational complexity. The workspace analysis in this paper can provide guidance for SCDRR design. And the comparison of two proposed optimization model can provide a basis for the research of variable stiffness control.