考虑磁流变减振器阻尼力和悬架弹性元件非线性特性，建立车辆半主动悬架非线性动力学模型。应用微分几何非线性控制，经过适当的非线性状态和反馈变换，实现半主动悬架非线性系统的精确线性化，并对系统实施非线性状态反馈控制；根据预定的控制目标及模糊控制策略调节控制参数，设计模糊控制器, 对悬架系统进行了控制仿真研究；利用神经网络模式识别能力对输入数据处理辨别，设计控制网络层，从而达到提高悬架工作性能，改善汽车行驶舒适性的目的。将三种非线性控制方法的仿真结果进行分析比较表明：经模糊控制或神经网络控制后的悬架承受的冲击响应小、振动强度低，比微分几何控制能获得更优异的性能。

A dynamic impedance-based structural health monitoring technique is introduced. According to the direct and the converse piezoelectric property of piezoelectric materials, the piezoceramic ( PZT ) can be used as an actuator and a sensor synchronously. If damage like cracks, holes, debonding, or loose connections are presented in the structure, the physical variations of the structure will cause the mechanical impedance modified. On the basis of introducing the principle and the theory, the experiment and the analysis on some damages of the structure are studied by means of the dynamic impedance technique. On the view of experiment, kinds of structural damages are evaluated by the information of dynamic impedance in order to validate the feasibility of the method.

This paper describes a new approach for non-destructive evaluation and the structural health monitoring with a high frequency impedance-based technique and wave propagation measurement. This new technique utilizes the direct and the converse electromechanical properties of piezoceramic (PZT) patches which are used as actuator-sensors to provided a low-power driven constant voltage dynamic excitation, and to record the modulated current flow through the structure. Elastic wave can be generated in structure by using PZT transducers. Therefore, it relies on tracking the electrical point impedance to identify incipient level damage. The wave may be used to obtain fundamental properties of the structural or to locate flaws. The advantage of this new approach compared with other NDE techniques are discussed. The most advantage of this technique over other NDE techniques is that it can perform continuous monitoring of the structure using non-intrusive small transducer that could be remotely interrogated in an automated mode. In addition, the experimental example is used to show the measurement method and the results.

建立了在高频情况下，一维构件的波传播模型，针对工程中常见的螺栓连接梁结构，讨论了波在这种情况中传播的特性及能量耗散问题，提出了一种简化的非线性接头模型。分析与实践结果表明这种非线性模型更能接近实际，波通过梁的螺栓接部时，存在着能量耗散。螺栓松紧程度对能量耗散有较大的影响。在共振频率处，连接部分发生较大的折射。

The vibration system with slow-changing parameters is a typical nonlinear system in which the masses, stiffness, damping and exciting force vary slowly with respect to time comparing with an ordinary parameter system. It often occurs in the working and controlled process of some intelligent structures, when vibration and deformation exist at the same time. In this paper, the system with slow-changing stiffness, damping and mass is analyzed, the relationship between the amplitude and the frequency of the system studied, meanwhile, its dynamic characteristic is also described. In addition, on the basis of the asymptotic method, the piecewise linear method is developed.