BASIC CONSIDERATION ON PRACTICAL APPLICATION OF SYSTEM IDENTIFICATION BY CHARACTERIS

目前，利用特征矩阵进行系统辨识的研究在各地都在进行。最重要的是，东京工业大学的大沼教授是我们国家的先驱和领导者。许多结果主要与鉴定程序有关。对于设计来说，不仅要进行理论推导，而且要进行误差研究。但在这一领域，却鲜有人开展。然后，进行了实际使用的检验。研究结论如下：在利用模态参数识别机械结构刚体特性的应用中，利用微分迭代法中的模态参数可以获得足够的精度，阐明了激振点和响应点偏差引起的传动点频响函数测量误差对识别的刚体特性的影响。结果表明，在本研究所用试件偏差为20 mm的情况下，最大可能产生约200%的识别误差。此外，在使用该技术识别刚体特性时，为了提高识别精度，有必要尽可能地远离转动振型节点测量频响应函数。

Now, the research of system identification by characteristic matrices is done in various places. Above all, Professor Okuma at Tokyo Institute of Technology is the pioneer of our country and leads. Many of the results are mainly related with procedure of identification. Considering about design, not only procedure of theoretical derivation, but research of error is important. But in this field, it is hardly carried out. Then, examination for practical use has been performed. The conclusion is as follows.In applying MCK identification using modal parameters to obtain the rigid body properties of a mechanical structure, it is shown by using the mode parameters of the differential iteration method that the accuracy is acquired enough, the influence of measurement error of driving point FRF by deviance of exciting point and response point on identified rigid body properties is clarified. Consequentially in the case of 20mm deviance which is assumed to specimen used in this research, it is shown that about 200% of identification error may arise at the maximum. Furthermore, when the rigid body properties are identified using the technique it turns out that it is necessary to measure FRFs keeping away from the node of rotational mode as much as possible in order to improve identification accuracy.