A dual quaternion approach to efficient determination of the maximal singularity-free joint space and workspace of six-DOF parallel robots

作者：Yang, XiaoLong^*; Wu, HongTao; Chen, Bai; Li, Yao; Jiang, SuRong

来源：Mechanism and Machine Theory, 2018, 129: 279-292.

DOI：10.1016/j.mechmachtheory.2018.08.002

• Singularity-free joint space
• Singularity-free workspace
• Dual quaternion
• Six-DOF parallel robot
• 6-U(P)under-barS
• 6-(P)under-barUS

The avoidance of singularities is critical to design and control of parallel robots. This paper aims at efficient determination of the maximal singularity-free joint space and workspace of a class of six-DOF parallel robots with six kinematic chains of same type. We represent the singularity-free joint space by a 6-cube and determine it firstly. The singularity-free workspace is generated by continuous motion of all active joints in the singularity-free joint space. As a result, the boundary of the workspace can be obtained with simultaneous consideration of position and orientation of the mobile platform. The size relation between the maximal singularity-free joint space and workspace is discussed. To efficiently determine the singularity-free joint space and workspace, we propose dual quaternion-based Jacobian matrices and construct an efficient algorithm. The algorithm detects singularities in a given joint space and simultaneously calculates its corresponding workspace. The computational costs of the proposed algorithm and the traditional one are compared using a 6-U (P) under barS parallel robot, leading to 9 seconds and 458 seconds respectively. Finally, both the maximal singularity-free joint space and workspace of a 6-(P) under bar US parallel robot are determined to further demonstrate the effectiveness of the new approach.

• 出版日期2018-11
• 单位南京航空航天大学