基于准零刚度隔振理论与神经网络PID滑模控制的光栅刻划机隔振研究

发布时间：2018-04-17 21:34

本文选题：非线性隔振 + 准零刚度　；参考：《合肥工业大学》2017年硕士论文

【摘要】：当前,线性振动和线性隔振理论已经被研究地比较透彻,并且在工程实际问题中得到了广泛的应用,很好地解决了许多实际工程问题。然而,实际问题中产生的振动绝大部分都带有非线性因素。但非线性隔振理论及应用当前仍处于不断探索研究阶段,低频振动的隔振仍然在工程领域中面临挑战。从振动传递率曲线可知,如果激励频率不小于隔振系统固有频率的2~(1/2)倍时,那么系统才会达到隔振效果。众所共知,弹性元件刚度越小,隔振系统的固有频率也相应减小,却会使被隔振物体产生的静位移量变大以及系统稳定性变差。因此,为了克服这个不利影响,研究人员采用不同的准零刚度隔振系统达到目的。本文在经过借鉴和吸收前人的研究成果后,分析、讨论并设计了一种准零刚度隔振系统。该系统是由一根具有正刚度特性的垂直线性弹性元件和具有负刚度特性的四个磁力弹簧连杆结构组成,具有良好的隔振效果。本文的主要内容如下:(1)首先,设计了一种准零刚度隔振系统模型,并且对该模型进行了理论上的研究分析,包括无垂直弹性元件和有垂直弹性元件时隔振系统的静力学分析。(2)其次,对准零刚度隔振系统进行了动力学建模分析,运用了谐波平衡法求解了简谐激励作用下隔振系统的响应,获得了系统的幅频特性方程,讨论了系统参数对幅频特性的影响。然后,对准零刚度隔振系统的力传递特性和位移传递特性进行了讨论分析,比较详尽系统地讨论了准零刚度隔振系统的传递特性。(3)最后,基于准零刚度隔振系统的基础上,建立起了准零刚度主动隔振系统的数学模型,同时基于滑模变结构控制理论的基础上,由于滑模控制会不可避免地出现抖振现象,因此采用RBF神经网络来降低抖振,设计了一种RBF神经网络PID滑模控制器。
[Abstract]:At present, the theory of linear vibration and linear vibration isolation has been studied thoroughly, and has been widely used in practical engineering problems, and has solved many practical engineering problems.However, most of the vibration produced in practical problems have nonlinear factors.However, the theory and application of nonlinear vibration isolation are still in the research stage, and the low frequency vibration isolation is still facing the challenge in the engineering field.From the vibration transfer rate curve, if the excitation frequency is not less than 2 / 2 times of the natural frequency of the vibration isolation system, then the vibration isolation effect of the system will be achieved.It is well known that the smaller the stiffness of the elastic element, the smaller the natural frequency of the isolation system, but the larger the static displacement of the isolated object and the worse the stability of the system.Therefore, in order to overcome this adverse effect, the researchers adopted different quasi-zero stiffness vibration isolation system to achieve the goal.In this paper, a quasi zero stiffness vibration isolation system is discussed and designed after reference and absorption of previous research results.The system is composed of a vertical linear elastic element with positive stiffness and four magnetic spring connecting rod structures with negative stiffness. The system has a good vibration isolation effect.The main contents of this paper are as follows: (1) first of all, a quasi-zero stiffness vibration isolation system model is designed, and the model is theoretically studied and analyzed.The static analysis of the vibration isolation system with no vertical elastic element and the vibration isolation system with vertical elastic element. Secondly, the dynamic modeling analysis of the zero stiffness vibration isolation system is carried out.The harmonic balance method is used to solve the response of the vibration isolation system under simple harmonic excitation. The amplitude-frequency characteristic equation of the system is obtained, and the influence of system parameters on the amplitude-frequency characteristic is discussed.Then, the force transfer characteristics and displacement transfer characteristics of the zero stiffness isolation system are discussed and analyzed, and the transfer characteristics of the quasi zero stiffness isolation system are discussed in detail. Finally, based on the quasi-zero stiffness isolation system,The mathematical model of quasi zero stiffness active vibration isolation system is established. On the basis of sliding mode variable structure control theory, the chattering phenomenon will inevitably occur in sliding mode control, so RBF neural network is used to reduce buffeting.A RBF neural network PID sliding mode controller is designed.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH74;TP273

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