Magnetic field-based sensing method for spherical joint

This paper presents a sensing method that harnesses the capacity of modern sensors to measure vector fields. This approach directly maps distributed independent field measurements to the instantaneous orientation of a spherical joint embedded with low-cost permanent magnets. Unlike existing methods which require a priori and precise field models, this direct method engages an artificial neural network to associate a collection of measurements to joint orientation. The operation of both bipolar and unipolar single and multi-axis sensors were considered and evaluated experimentally.