Kinematic And Workspace Analysis Of A 2-Dof Haptic End-Effector That Carries Out A Developable Haptic Strip

This paper presents the analysis of a 2 DOF end-effector that carries out a haptic tool consisting in a developable servo- actuated plastic strip. To overcome some drawbacks of conven- tional systems related to the use of point based force-feedback, tactile and glove devices we have developed the triangular mesh approach in the developable haptic interface. The developable haptic strip, has evolved as a result of this research. The haptic interface of our system consists of a haptic strip that is inspired by the deformable tape that designers use for creating and mod- ifying aesthetic shapes. The first step for designing the end ef- fector and the haptic strip mechanism has been the assignment of both the total length of the haptic strip and the number of tes- sellation triangles required to control the strip as a developable surface. The strip is aimed at haptically rendering medium sized design objects (vases, lamps, household appliances, etc.). Thus, the total length of the strip has been set to be 160 mm. This length value also ensures the possibility to easily manipulate the strip. Seven triangles have been assigned in order to maintain the haptic strip symmetric; this consideration is particularly im- portant because guarantees an adequate balancing of weight in the mechanism. The device is based on a modular architecture of elements that deform a plastic tape.