Dragana Popovic Renella, Thomas Kaltenbacher, Sasa Spasic, Andrea Cavelti, Giorgio Valsecchi, Lennart Nachtigall, Marco Hutter
Novel 3D Hall sensor and its application in inspection robots
This paper describes a novel CMOS magnetic field sensor that can measure all three magnetic field components (Bx, By, and Bz) simultaneously at a single location. The sensor employs three groups of mutually orthogonal horizontal and vertical Hall-effect elements, each with dedicated biasing circuits and amplifiers. The field sensitive volume of the 3D sensor is very compact, only 100 x 100 μm2, which enables high spatial resolution. The use of CMOS technology ensures high angular accuracy and orthogonality of the three measurement axes. The sensor also employs a spinningcurrent technique that effectively mitigates issues such as offset, low-frequency noise, and planar Hall effect. The wide analog bandwidth from DC to 300 kHz and built-in temperature sensor make the sensor suitable for various applications, including 3D positioning sensors, proximity sensors, current sensors, and magnetometry. As an example, the paper discusses an application of the 3D sensor for improved adhesion control in inspection robots.