Joint Stiffness and Link Deflection Identification of Serial Robotic Manipulators and End-Effectors

Abstract

This research work aims to evaluate the joint-stiffness and link deflection of any 6-Degree of Freedom revolute serial manipulator. The reduced stiffness inherent in serial robots hinders its application to perform machining operations due to its reduced accuracy imparted through deformations within the links and joints. The current focus is on identifying the stiffness values at each joint considering the translational and rotational movement of the End-Effector with an applied force/torque. Additionally, the paper focuses on identifying the deflections inherent in links of the robot due to both bending and torsional effects. Identifying these parameters could help realise the effects of various forces/torques acting on the End-Effector in three-dimensional space. The high repeatability, extended workspace reachability and alacrity of serial manipulators make them appealing to perform machining operations as opposed to its competitor, the CNC machine. Consequently, from an economic perspective, manufacturers will notice an increased throughput rate of finished goods. This identification and optimization procedure will significantly improve the future of machining with serial robots. The outcome of enhancing the stiffness parameters could result in high precision of workpieces. Manufacturers of the future will be able to identify the true potential of their manipulators to perform machining operations.