Topology and kinematic analysis of color-changing ball

The color-changing ball has two stable configurations. Its mechanism is a multiple loop and polygonal mechanism. This paper investigates the mechanism typology and analyzes its structure and configurations during motion. A three-legged mechanism is extracted from this mechanism. The kinematics model of the mechanism is presented and singularity is discussed. The paper further decomposes the mechanism and investigates the platform structure of the intersection between loops. This leads to investigation of the offset of joint intersection at the intersection and its relevant geometry and kinematics. The paper further focuses on the configuration change between two states of the mechanism and investigates kinematics and singularity between two configurations. Based on the analysis, simulation of the color-changing ball is carried out. The topology and kinematics analysis in this paper helps the analysis of this kind of polyhedral linkage mechanism with radial motion. The research could potentially lead to the development of kinematics for design of this kind of mechanism.