A Novel Method for Selecting Inverse Kinematic Solutions Based on Configuration Space Partition for 6R Noncuspidal Manipulators

The selection of an optimal solution from multiple inverse kinematics solutions (IKSs) is a fundamental task in manipulator motion. However, the conventional minimum joint motion criterion (MJM) method suffers from drawbacks such as high computational time and the inability to ensure configuration invariance. With the prevalence of noncuspidal structures in commercial manipulators, a novel IKS selection methodology is exigent. This paper analyzes the limitations of the MJM method by geometric representations of the IKS formal and proposes a novel IKS selection method based on configuration space decomposition. The configuration space of noncuspidal manipulators is partitioned into independent subdomains called uniqueness domains (UD). Subsequently, a bijection between configuration, UD, and IKS is established for selecting IKS, and three important related theorems are proven. The proposed method offers low computational cost, and allows configuration invariance in continuous trajectory tracking or point-to-point planning. Finally, the physical experiment results demonstrate the effectiveness of the proposed method.