Research And Analysis Of Dynamic Measurement System And Its Error

Now the dynamic measurement technology has became the mainstream, the research of dynamic measurement system is becoming more and more important. The dynamic measurement system is a complex system everywhere, it can be seen as a combination of a class of measurement systems under dynamic measurement conditions,either as a single measuring instrument or as a complete system of numerous links; or as a component or unit that compose a measurement system such as sensors, data acquisition cards etc; there even can be simpler unit circuits such as amplifiers, RC filters. The dynamic measurement system has four characteristics, and it is often considered that the process of measurement is a random process, which is different from the relation of the input and output in the static measurement system. It is also not a time-varying function relationship. So the methods of processing traditional static system are not suitable for analyzing error and data processing in the dynamic system.Therefore, it is important to study the dynamic measurement system.At present, with the development of science and technology, the accuracy of dynamic measurement is getting higher and higher, the related dynamic accuracy assessment, the research of dynamic measurement uncertainty, the dynamic error traceability and the precision loss diagnosis theory, and the dynamic error correction and compensation of the whole system dynamic precision theory and so on, are constantly improving the dynamic measurement system theory. system dynamic precision theory as a mainstream of dynamic accuracy theory, describe the system inside and outside the factors on the system accuracy comprehensive. However, the dynamic/static characteristics of the measurement system still can not be clearly defined by these mainstream research directions and theories, and the error measurement and separation of the dynamic measurement system different from the traditional static measurement system are also not defined clearly.In this paper, it based on the whole system precision theory "ashing" models,according to the theory of the whole-system precision, build the "whitening" or"quasi-whitening" model of real measurement system. Through the analysis and identification of the system is characterized by the second order Taylor series, so as to analyze the systematic error and its change of the measurement system more accurately,that is, realizing the "quasi-whitening" analysis of the system. Based on the study of the characteristics of the dynamic measurement system, there put forward creatively the method of identifying the dynamic/ static characteristics of the measurement system.there proposes a new method to express the system error; adapting the different method of data processing to the different measurement system, under the unstable or stable conditions, the random error can be separated by the Taylor series approximation method or the standard amount of insertion method and be predicted by the autoregressive model AR(M). Finally, the whole process of dynamic / static characteristic identification, experimental data processing, system error characterization,random error prediction and error separation are realized by simulation and verification of the theoretical method by means of the second order amplifier circuit.