Dynamic parameter estimation of velocity sensors using an indirect measurement approach

An indirect measurement method is proposed for the dynamic parameter estimation of velocity sensors. This approach makes use of data processing abilities of computers and does not require high precision devices. Under the indirect measurement mode, the relationship between the input voltage and the output current of the testing system can be described by a third-order transfer function including physical parameters of the sensor. An identification method for transfer functions with a two step algorithm is presented based on the spectral analysis. The spectral density functions are first obtained from input-output signals of a system, then the dynamic parameters can be estimated from frequency response data. Some parameter estimation algorithms are derived by minimizing a unified loss function with different weight selections and the estimation errors are analyzed. By use of the indirect measurement approach and the modeling algorithms, we can get enough precision results. When the transfer function under the indirect measurement mode is determined, the transfer function in the working state can be obtained through the relationship between the models in the measuring state and in the working state. The methods suggested in the paper can be widely used in the modeling of mechanic-electric systems