| This paper presents ferrofluid acceleration sensor according to a new principle of ferrofluid sensor, magnetic core is made up with a permanent magnet levited by ferrofluids, and its restoring force is derived from a couple of permanent magnets, signal is detected by a couple of inductive coils.According to the magnetic surface stress tensor of ferrofluid, ferrofluid levitation force is theoretical studied, the expression of self-levitaion of ferrofluid is obtained, self-levitation of magnet in ferrofluid is theortical proved, the relative permeability of ferrofluid, which used in experimental research, should be greater than1.02. According to magnetic force calculation principle, based on model of disc stack of cylindrical magnet and equivalent current coil model of cylindrical magnet, the magnetic field of cylindrical magnet is calculated, magnetic force between two cylindrical magnets is obtained, the relationship between restoring force and magnetic core displacement is studied by numerical computation, the relationship between magnetic force and magnetic core displacement is obtained under different restore distance, and the relationship between acceleration and magnetic core displacement is obtained under different restore distance. Output voltage of differential inductive sensor is theoretical studied, the output voltage of sensor is obtained.Structural parameters of coil are designed. Magnetic core material is selected. Supply voltage and frequency are confirmed. Differential bridge circuit is designed, which is signal detected circuit of sensor. Electionic circuit of signal processing is designed, signal processing electionic circuit has amplification and rectifier functions. Interface program between data acquisition card and computer is designed by Labview soft. Differential bridge circuit, electionic circuit of signal processing, data acquisition card, Labview soft and computer are assembled in sensor experimental platform.The relationships between structural parameters of sensor and output characteristics are analysed. The relationships among output voltage and restoring distance, type of ferrofluid, volume of ferrofluid, physical parameters of ferrofluid, dimension of magnetic core of ferrofluid acceleration sensor are studied on sensor experimental platform, expermential data are in good agree with numerical simulation, the partial static and dynamic performances are studied, expermential data are in good agree with theory analysis. There are95figures,22tables,126references on this paper.
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