Kinematic properties and control for reconfigurable robotic system

Abstract

This paper presents the kinematic aspects of reconfigurable manipulators such as workspace, manipulability and singularity properties. These properties are calculated and shown in 3D figures. Variable control structures are designed for reconfigurable robotic systems. These robotic systems combine as many properties of different open kinematic structures as possible and can be used for a variety of applications. The kinematic design parameters, i.e., their Denavit-Hartenberg (D-H) parameters, can be modified to satisfy any configuration required to meet a specific task. By varying the joint twist angle parameter (configuration parameter), the presented model is reconfigurable to any desired open kinematic structure, such as ABB, Stanford and SCARA robotic systems. The joint angle and the offset distance of the D-H parameters are also modeled as variable parameters (reconfigurable joint). The resulting self-reconfigurable robotic system hence encompasses different kinematic structures and has a reconfigurable joint to accommodate any required application in medical technology, space exploration and future manufacturing systems among others. A 3-DOF reconfigurable robotic system is constructed and demonstrated as a case study which covers all possible open kinematic structures. SMC controllers were developed based on estimated, bounded models and on computed torque method. This research is intended to serve as a foundation for future studies in reconfigurable control systems.