Kinematically redundant parallel robots for high performance applications

Baron, Nicholas (2021) Kinematically redundant parallel robots for high performance applications. Doctoral thesis (PhD), University of Sussex.

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Abstract

This thesis addresses the development of kinematically redundant parallel robots for high performance applications and methods of kinematic analyses tailored towards them. Parallel robot manipulators are well known to hold various advantages over serial manipulators, including having better speeds, accuracies, and power-to-weight ratios. However, a major disadvantage they have is that they suffer from limited workspaces and rotational capabilities; indeed, it can be argued that this is the main reason serial robots are used more frequently in many industries. This thesis aims to address this major shortcoming of parallel robots, whilst maintaining all of their advantages, by concentrating on the solution of kinematic redundancy.

Firstly, an introduction to the topic of kinematically redundant parallel robots for high performance applications is presented and a review of the relevant literature is given. In the second section, a novel kinematically redundant architecture of parallel robot is presented. The kinematic redundancy of the mechanism allows it to achieve full cycle rotations of the end-effector without encountering kinematic singularities, a feat that is not possible for non-redundant systems. The third section addresses the issue with current methods of singularity analyses of parallel robots when applied to kinematically redundant architectures. It is shown that conventional Jacobian-based methods of singularity analysis are unreliable when applied to kinematically redundant architectures. In the fourth section a novel, more robust, method of singularity analysis is presented, which is then used to develop a method of singularity avoidance. The fifth section presents a kinematically redundant architecture that is dynamically balanced, meaning that the shaking forces and moments imposed on the base by the manipulator are nullified. An issue for manipulators moving at high speeds is that shaking forces and moments generated can cause vibration and inhibit the performance of the system. By dynamically balancing the system, the manipulator is able to move at high speeds without experiencing these drawbacks.

The aim of this PhD thesis is that the work presented here can provide some of the building blocks for developers of robot manipulators to create high performance parallel robots which exhibit high speed, strength, and dexterity, through the use of kinematic redundancy.

Item Type: Thesis (Doctoral)
Schools and Departments: School of Engineering and Informatics > Informatics
Subjects: T Technology > TJ Mechanical engineering and machinery > TJ0210.2 Mechanical devices and figures. Automata. Ingenious mechanisms. Robots (General)
Depositing User: Library Cataloguing
Date Deposited: 03 Feb 2021 09:00
Last Modified: 03 Feb 2021 09:00
URI: http://sro.sussex.ac.uk/id/eprint/96867

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