A new method for measuring 3D rotation angle of spherical joint

Abstract

A new method for measuring 3D rotation angle of precision spherical joint based on eddy current sensors is proposed in this study. A pseudorandom code is used to generate a 2D plane absolute code and then mapped to the sphere. The 3D absolute code is formed on the ball head through precision cutting, and an eddy current sensor array is arranged in the ball socket to identify the code. The experimental tests were conducted on the parameter-optimized prototype, and the experimental results showed that the mean squared error of the 3D rotation angle measurement was approximately 25′ in the range. The proposed new measurement principle provides a new approach to the precision measurement of spherical rotary motion, which is expected to produce a breakthrough in the theory and technology of spherical-angle sensor measurement. The proposed new principle also provides a theoretical basis and technical experience for the integration and development of intelligent devices.