The Study of a Novel Tilt Sensor Using Magnetic Fluid and Its Detection Mechanism

This paper presents a novel tilt sensor using magnetic fluid, and the influence of the structural parameters on its detection performance is studied. This sensor comprises a core body and a shell. The core body as a sensing pendulum, which is composed of two permanent magnet rings and an iron core, is placed in the interior of the shell. The magnetic fluid, which produces the magnetic buoyancy and makes the core body suspension, is injected between the ends of the core body and the inner wall of the shell. There is a magnetic repulsion force between the permanent magnet rings placed at the ends of the shell and the core body, which provides an axial restoring force and makes the core body balance in the axial direction. When the sensor deviates from the horizontal position, the core body is displaced in the axial direction. The displacement reflects the tilt angle and can be measured by inductance coils wound on the shell. In our laboratory, a tilt sensor prototype was assembled, and some performance tests were carried out. The results show that its measurement sensitivity can reach 0.004° in the interval −10°–10°, and its detection performance can be further improved by adjusting the structural parameters. This sensor has the advantages of low cost, easy implementation, no-mechanical abrasion, and strong anti impact ability. It is flexible and can meet the different requirements of engineering applications.