Topology based enhancement of the workspace of a reconfigurable parallel haptic interface

The aim of this paper is to increase the geometric workspace of a special class of parallel robots by analyzing the influence of the topology and the joints limits upon the workspace dimensions. Hence, the topology and design modeling of a parallel reconfigurable robotic system used as a haptic interface are presented. More, their influence upon its workspace dimensions are analyzed for several configurations. The reconfigurable robotic system that is presented in this paper has 3,4,5 and 6 degrees of freedom and it is designed to work as a haptic interface with virtual reality. The kinematic chains that connect the fixed and the mobile platform are composed by rotational, universal and spherical joints. The paper illustrates an analysis regarding the influence of the topology and joint limitations upon the dimensions of the workspace. The constant orientation workspace is evaluated for all the configurations.