共查询到18条相似文献,搜索用时 109 毫秒
1.
电动振动台作为振动环境试验的主设备,开展电动振动台建模和模型辨识研究,将有助于深入了解电动振动台系统的内部结构和工作原理,准确掌握其特性与性能;并将有利于更好地设计振动环境试验,维护设备;也是开展振动控制技术研究和振动试验仿真研究所必须的。我们首先分析了电动振动台的电力学模型,然后在建立电动振动台数学模型的基础上,采用了时域和频域两种辨识方式,通过试验和算法设计,针对振动台空台面及带滑台和带简单试件的3种情形下开展了辨识工作,结果表明辨识效果良好。 相似文献
2.
3.
4.
本文用电声类比方法分析了三种电动振动台的力学特性,给出了计算电动振动台的输入阻抗,位移频率特性,推力频率特性和加速度频率特性的公式.对振动台动圈电感补偿方法进行了分析.最后讨论了与它配套用功率放大器和电动振动台的三种不同运用方式对振动台力学特性的影响. 相似文献
5.
针对蓄电池荷电状态在线监测中对准确度和测量速度的要求,本文提出采用模糊辨识算法对蓄电池进行系统辨识。并通过对蓄电池的荷电状态与内阻、端电压数据的分析,建立了蓄电池荷电状态的模糊规则模型,并以此进行蓄电池荷电状态的测量,得到均方误差为0.0052。测量结果表明基于模糊辨识算法的蓄电池荷电状态测量能够满足蓄电池在线监测的要求,且易于硬件实现。文章还使用DSP Builder设计了蓄电池荷电状态测量模块,其中内阻测量采用了特征分解谱估计的信号提取方法,荷电状态测量则实现了模糊辨识算法所得出的模糊规则模型的运用。 相似文献
6.
7.
当前电动振动台自动控制器利用PID作为控制核心,其抗干扰能力较弱,启动时间过长,导致控制器的使用寿命较短。提出旋转机械电动振动台的PLC自动控制器设计。将PLC作为主控单元对PLC自动控制器进行设计,制定PLC自动控制器的总体结构,采用RS-485串行通讯口和EEPROM数据存储器对电源模块、LED显示模块、报警模块、通讯模块、信号采集模块及存储器模块等硬件设备进行细节改进;对控制器软件部分的自动控制功能主程序和中断、LED显示功能子程序进行重新编程,实现控制器自动控制效果的优化,完成旋转机械电动振动台PLC自动控制器的设计。实验结果表明,改进设计的控制器有效提高了旋转机械电动振动台的抗干扰能力,缩短了电动振动台的启动时间,延长了电动振动台的使用寿命。 相似文献
8.
为了能实时而有效地辨识参数不确定的超混沌lü系统,以便于对该系统进行控制或跟踪,本文提出了一种基于Wiener模型自适应分段线性(PWL)滤波器的超混沌系统辨识方法.Wiener模型的线性部分采用了线性横向滤波器,非线性部分用分段线性滤波器近似表示.根据最小均方误差准则导出了滤波器参数更新算法,并进一步推导出算法的收敛性条件.计算机仿真证实了该自适应滤波器辨识超混沌系统的有效性.该方法不仅克服了自适应线性滤波器难以辨识出这类强非线性系统,而且比其他非线性自适应滤波器的计算复杂性低得多. 相似文献
9.
10.
采用一种基于鲁棒模糊聚类算法的模糊辨识方法,通过引入局部划分关联度因子,增强了系统辨识的抗干扰能力,提高了系统辨识的鲁棒性.首先用最近邻模糊聚类法划分初始输入空间,得到模糊规则数及初始聚类中心;然后用鲁棒模糊聚类算法求解并优化模糊隶属度和聚类中心,建立高精度的T-S模糊模型;最后利用最小二乘法辨识模型的初始结论参数,进一步利用带遗忘因子的递推最小二乘法优化结论参数.采用该方法对Mackey-Glass混沌时间序列进行建模和预测,仿真结果表明利用本方法可以进行准确建模和预测,验证了本方法的鲁棒性、有效性和实
关键词:
最近邻模糊聚类
鲁棒模糊聚类
混沌时间序列
最小二乘法 相似文献
11.
12.
This paper presents an experimental way of characterizing the nonlinearities of electrodynamic microphones used as acoustical sources. This functioning occurs for reciprocal calibration techniques. For this purpose, its electrical impedance is measured with a Wayne Kerr wedge which has an excellent precision. Moreover, it can be noted that the Thiele and Small model is used to characterize its electrical impedance. Furthermore, an experimental method based on Simplex algorithm allows us to construct polynomial laws which describe the dependence of the Thiele and Small parameters with the input voltage. The nonlinear variations obtained allow us to determine the nonlinear differential equation of the electrodynamic microphone. Then, this equation is solved numerically in order to confirm the accuracy of the polynomial laws obtained by the Simplex algorithm. The distortions are measured with a laser Doppler velocimeter and compared with the ones obtained by the numerical solving of the nonlinear differential equation. The experimental displacement spectrum is consistent with the theoretical one. 相似文献
13.
Pierre Marcotte Jérôme Boutin Juliana Jasinski 《Journal of sound and vibration》2010,329(10):1968-1980
This paper reports on the development and validation of a mechanical system designed to simulate the hand-arm dynamic response when coupled with a chipping hammer. The design is based on a two-degree-of-freedom lumped parameters model, in which the parameters are optimized such that the apparent mass of the mechanical analogue provides a close fit with the measured apparent mass of the hand-arm mechanical system. The apparent mass of the mechanical analogue has been validated on an electrodynamic shaker, than it was used to evaluate the vibration emission values of two different chipping hammers. Preliminary results show variations of <15 percent of the vibration emission values between human subjects and the hand-arm simulator for two different types of chipping hammers, while the variability in the results is found to be considerably reduced when using the mechanical analogue. The implementation of the mechanical analogue as part of a test set-up for the determination of the vibration emission values of chipping hammers is thus seen as an attractive alternative to the use of human subjects. 相似文献
14.
Knowledge of the acoustical impedances is required to understand the fluid oscillations in the manifolds of positive displacement machinery. This paper presents an impedance measurement method which puts emphasis on the lower frequencies. The technique is based on providing a known volume velocity excitation to the manifold through an electrodynamic, shaker driven, oscillating piston. Harmonic, random and transient excitations have been utilized. Digital data acquisition and processing techniques are used to acquire piston displacement and acoustic pressure signals for input and transfer impedances. The proposed method is direct and efficient. It is applied to the measurement of the acoustical impedances of a two-cylinder refrigeration compressor discharge system. Various aspects of the measurement procedures are discussed along with the recommendations. 相似文献
15.
16.
This paper describes the dynamic behaviour of a coupled system which includes a nonlinear hardening system driven harmonically by a shaker. The shaker is modelled as a linear single degree-of-freedom system and the nonlinear system under test is modelled as a hardening Duffing oscillator. The mass of the nonlinear system is much less than the moving mass of the shaker and thus the nonlinear system has little effect on the shaker dynamics. The nonlinearity is due to the geometric configuration consisting of a mass suspended on four springs, which incline as they are extended. Following experimental validation, the model is used to explore the dynamic behaviour of the system under a range of different conditions. Of particular interest is the situation when the linear natural frequency of the nonlinear system is less than the natural frequency of the shaker such that the frequency response curve of the nonlinear system bends to higher frequencies and thus interacts with the resonance frequency of the shaker. It is found that for some values of the system parameters a complicated frequency response curve for the nonlinear system can occur; closed detached curves can appear as a part of the overall amplitude-frequency response. These detached curves can lie outside or inside the main resonance curve, and a physical explanation for their occurrence is given. 相似文献
17.
A. L. Sushchikh 《Radiophysics and Quantum Electronics》1995,38(9):631-639
An algorithm and a program for the calculation of the natural frequencies and fields of irregular waveguides are presented. The algorithm permits calculation of the fields of waveguides with complex cross-sections (L-, H, and E-profiles) and waveguides partially filled with dielectrics having constant electromagnetic characteristics. The method involves replacement of the 2-D electrodynamic problem by a discrete mathematical model, which can be interpreted as a system of electrically coupled circuits. Analyzing the behavior of the currents in a discrete model by electrical engineering methods, we obtain an approximate solution of the reference electrodynamic problem. Numerical calculation results and errors are given.State Technical University, Novosibirsk. Translated from izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 38, No. 9, pp. 969–981, September, 1995. 相似文献
18.
针对环境模拟试验温度控制系统中被控对象存在的非线性、时滞等特点,本文采用区间限幅PID控制算法和模糊PID控制算法对传统控制方法进行了改进。首先为了解决模拟量三通粗调阀调节缓慢的缺点,建立了区间限幅PID控制算法的控制规则表,并将其在PLC中实现。其次提出用模糊PID控制算法来解决电加热器的非线性、大时滞性问题,并结合实际控制经验建立了模糊控制规则表,然后将模糊PID控制算法在PLC中进行实现。最后将限幅PID和模糊PID控制算法应用于某大型环境模拟试验控制系统,实验结果表明利用改进算法对温度控制具有良好的稳定性及精确度。 相似文献