MAGNETIC FLUID ACCELEROMETER EQUIPPED WITH ACTIVE SUSPENSION

PROBLEM TO BE SOLVED: To provide a method for measuring acceleration with a wide dynamic range and a high frequency response. SOLUTION: This method includes suspending an inertial body 202 by using a magnetic fluid 204, generating a magnetic field in the magnetic fluid, balancing a change in position of the inertial body as to a magnetic field generation source owing to acceleration with a modulation of the magnetic field, and calculating acceleration based on the modulation. In the process of the calculation, acceleration is derived from the amount of current, passing through a drive coil 302, required for the modulation. The acceleration comprises linear acceleration and/or angular acceleration. The drive coil comprises a permanent magnet, an electromagnet, or a combination of a permanent magnet and an electromagnet. Displacement of the inertial body can be detected by sensing coils 304 and 306. Each sensing coil can be disposed substantially inside a corresponding drive coil. The inertial body has no or weak magnetism, or else, the inertial body can have a ferromagnetic coating. COPYRIGHT: (C)2006,JPO&NCIPI