Software compensation of magnetic crosstalk on hall-effect-based rotary encoders close together

Abstract

In the process of developing human-like robotic hands, engineers are looking for robust and accurate sensors that can fit in very confined spaces. Rotary encoders that measure joint angles of a multi-fingered hand must be of very small size and yet provide reliable and repetitive data. Hall-effect sensors combined with ring magnets fit in narrow spaces and have proved to be durable rotary magnetic position sensors due to their contact-less features. However, when several sensors of this kind are packed closely together in a finger, magnetic crosstalk effects appear and can lead to important errors/shifts in nearby sensor readings. This paper describes magnetic crosstalk effects in nearby joints and proposes a compensation method directly linked with the software calibration process.