Adaptive IdentificationAlgorithms of Nonlinear Systems with their Applications

非线性系统的辨识在基于模型的非线性控制系统设计和无线通信非线性信号处理中起着重要的作用。该项目的主要目的是构建和评估针对特定类别系统的有效和系统的非线性识别算法，通过在非线性系统识别框架中制定这些算法来解决复杂的建模问题。结果表明：(1)提出了一种新的全自适应隔振控制方案，该方案采用安装在地面和一楼之间的半主动磁流变阻尼器，该阻尼器由两个自适应控制器组成。一种是自适应逆控制器，它可以为磁流变阻尼器提供必要的输入电压，从而产生作用于被控结构的特定参考阻尼力。另一种是自适应参考控制器，它可以将结构的第一层动力学与期望的参考动力学相匹配。本文提出的自适应方法既能处理磁流变阻尼器模型的不确定性，也能处理结构的不确定性。讨论了包括两种自适应机制在内的整个体系的稳定性，并明确了稳定性条件。实验结果验证了该自适应方案的有效性。(2)由于OFDM传输的信息是在复幅上获取的，因此功率放大器的非线性补偿是一个重要的问题。该方案提出了一种新的自适应预失真器，可以补偿非线性失真，并能最大限度地提高功率效率。提出了一种新的自适应耦合抵消算法，该算法识别了所有传输路径的动态特性，并明确了收敛条件。(3)将城市多径环境下使用阵列天线的移动站定位制定为一个新的非线性参数识别问题，通过阵列信号处理估计移动站产生的散射源的方向和角度传播，并估计源的位置，使射线追迹法计算的方向和角度传播与阵列天线估计的方向和角度传播之间存在误差。通过室外实验验证了其有效性。将阵列天线的自定标视为一个非线性辨识问题，并将该思想应用于Capon方法。研究了阵列天线对相关信号数的检测，提出了一种基于QR分解改进的简单有效的检测方法。少

Identification of a nonlinear system plays an important role in model-based approaches in nonlinear control system design and nonlinear signal processing for wireless communication. The main purpose of the project is to construct and evaluate effective and systematic nonlinear identification algorithms for a specific class of systems to solve complicated modeling issues by formulating them in a nonlinear system identification framework. The results are summarized as follows :(1)A new fully adaptive control scheme is proposed for vibration isolation using a semi-active MR damper installed between ground and first floor, which is composed of two adaptive controllers. One is an adaptive inverse controller which can give necessary input voltage to MR damper so as to generate specified reference damping force acted on a controlled structure. The other is an adaptive reference controller which can match the dynamics of the first floor of structure to a desired reference dynamics. The propose … More d fully adaptive approach can deal with both uncertainties in models of MR damper and structure. The stability of the total system including the two adaptation mechanisms is discussed and the stability conditions are clarified. Experimental results are also shown to validate the effectiveness of the proposed adaptive scheme.(2)Since the information is taken on the complex amplitude in the OFDM transmission, compensation of the nonlinearity of power amplifier is a significant issue. The project proposed the new adaptive predistorter which can compensate for nonlinear distortion as well as can maximize the power efficiency. The new adaptive coupling cancellation algorithm was also proposed in which all of the transmission path dynamics are identified and convergence conditions are clarified.(3)Localization of mobile station in urban multipath environments by using an array antenna is formulated as a new nonlinear parameter identification issue, where the direction and angle spread of scattered sources produced by the station are estimated by the array signal processing, and the source location can also be estimated so that the error between the direction and angle spread calculated by the ray tracing method and those estimated by the array antenna. Its effectiveness was validated by outdoor experiments. Autocalibration of array antenna is also regarded as a nonlinear identification problem, and the idea was applied to Capon method. Detection of the number of correlated signals by array antenna is also investigated and a simple but effective method was proposed based on improvements of QR decomposition. Less