Static Balancing of a 2 Degree-of-Freedom Serial Manipulator with Torsional Wrapping Cams

Abstract

In robotic applications where a robot is designed to assist humans performing manual labor, the robotic systems must be placed in close proximity to the human counterparts they work alongside. Thus, for these collaborative robots, it is essential to employ mechanisms that are capable of bearing heavy loads while also operating within safety restraints. In order to assess the potential of a passive, purely mechanical system that can bear variable loads, a two degree-of-freedom statically balancing serial manipulator is designed. The linkages of the manipulator are kinematically controlled by linear springs and wrapping cams, which operate in conjunction to produce a non-linear torsional output in response to loadings applied to the end-effector arm. The accuracy of using the methods described by Kilic et al. to generate wrapping cam profiles that result in a desired torque-displacement function and the general functionality of using spring-cam mechanisms for passive load-bracing in a serial manipulator are evaluated by performing loading experiments on the a physical mock-up of the static balancing system.