Abstract

Moment of inertia measurement based on displacement sensor

Author(s): Chunfu Zhang, Jianguo Miao, Song Tang, Guangwu He

Moment of inertia (MI) is a significant characteristic parameter of spacecraft and MI measurement of the spacecraft during ground testing is of prime importance. There are various techniques to measure MI, on the basis of analyzing the MI measuring principle, the mathematical function of period and moment of inertia is deduced in torsional pendulum method, then a measuring method based on inductive displacement sensor is proposed. In a torsional pendulum procedure, the changes of displacement follow the physical laws, and the displacement acquired from the sensor are discrete electrical signals; direct comparison or median filtering algorithm are commonly used to process the signals, but these two methods have large errors and low precision. According to those characteristics, a local linear optimal fitting algorithm based on least square is presented to determine the period of torsional pendulum, all the theoretical analysis and experimental results indicates that this algorithm has higher resolving precision.