@techreport{oai:jaxa.repo.nii.ac.jp:00044899,
 author = {滝沢, 実 and 大月, 正男 and 鈴木, 孝雄 and TAKIZAWA, Minoru and OOTSUKI, Masao and SUZUKI, Takao},
 month = {Dec},
 note = {In the last few years, in order to develop more precise inertial sensors, such as floated gyros and floated accelerometers used in the inertial navigation system, a passive magnetic suspension with an eight-pole stator, that can be applied to support the output axes of the sensors, has been theoretically and experimentally studied at NAL (National Aerospace Laboratory). In our previous reports, 7)～10)29) a theoretical analysis and an experimental study of the magnetic suspension were described. In this study, an application of the magnetic suspension to a floated pendulum accelerometer is used in order to develop a more precise accelerometer. This report describes the principle of the magnetically suspended accelerometer (MSA); the design of the three-axis magnetic suspension, the torque generator and the signal generator; and the design of the damping, the analog torque rebalance loop and the magnetic suspension. Furthermore this report describes the experiments on the performances and characteristics of the new accelerometer. The main results obtained from this study are as follows: (1)The performances of the new accelerometer (MSA-1) are measuring range ±15G (G:gravity), threshold 3.3×10(exp -7) G, non-linearity coefficient 3.4×10(exp -5)G/G2, and short term bias stability ±5.6×10(exp -6)G. These performances are compared with those of a former floated pendulum accelerometer4)～6) with high precision pivot-jewel bearings, which had been developed at NAL. In this comparison, with respect in particular to the threshold and the short term bias stability, each value of the above mentioned accelerometer is less than one hundredth compared to that of the former accelerometer. (2)The transfer function of the MSA is expressed by second order systems and the measured cut-off frequency of the MSA-1 is about 40 Hz when the accelerometer is abjusted to nearly optimal conditions. This measured value is in close accordance with theoretical value(41 Hz). (3)The magnetic suspension system can act normally at high levels of constant acceleration (±15G). The suitable material of the magnetic suspension rotor core is ferrite, which has such properties as high permeability, high saturation of magnetic flux density and minimum eddy current loss. (4)The magnetic suspension was successfully applied to a floated pendulum accelerometer. It is considered that the magnetic suspension will also be effectively applied to a floated gyroscope., 資料番号: NALTR0644000, レポート番号: NAL TR-644},
 title = {Study of a Floated Pendulum Accelerometer with Passive Magnetic Suspension},
 year = {1980}
}