Characterization of signal integrity due to pitch-roll-yaw rotation tolerance in magnetic position sensing systems

Abstract

Magnetoresistive sensor is commonly used as a read head to detect sine and cosine waveforms from magnetic patterned medium for determining precision position in engineering applications. The sensor utilizes its magnetoresistivity ability to change its resistance under the influence of magnetic fields. The resistance changes proportionally to square of the sine of the angle between the magnetization vector ( ${M}$ ) and current flow vector ( ${I}$ ). Therefore, the assembly tolerances, such as the pitch, roll, and yaw rotations, between the sensor and the medium would cause angle changes with respect to external magnetic field and magnetization vector, leading to distorted waveforms in microprocessor that result in undesirable subdivision position error. In this paper, parameter studies are conducted with results validated by experiment in determining the characteristic relationship between the assembly tolerances on the measured magnetic signals for manufacturing and real-time dynamic control applications.