Design of high precision magnetic grid displacement sensor

A new kind of magnetic grid displacement sensor is designed in this paper, which is composed of magnetic head and magnetic grid. The magnetic head contains arrays of linear hall element, and the magnetic grid is made of arrays of permanent magnet. In order to enhance the quality of original voltage signal, the signal generator adopts three-phase and six components. The errors caused by assemble and zero drift is eliminated through difference. Otherwise, the electromagnetic field of magnetic signal generator is analyzed with ANSYS. The assemblage gap of magnetic head can be chosen better according to the analysis result, which can improve the signal quality also. A look-up table technique is presented when dealing with magnetic grid signal, which can decreases the computational complexity of the processing chip. And the method is realized through the flush type SCM(dsPIC33FJ64MC706) with 16 bits. The peripheral circuit is simplified, which meets the requirement of miniaturization and increases the resolution and reliability of the magnetic grid displacement sensor.