共查询到20条相似文献,搜索用时 250 毫秒
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坦克瞄准线稳定系统复杂的内部结构导致机理建模的准确性大大降低,提出了利用经典阶跃响应法与遗传算法相结合的方法对某型坦克瞄准线稳定系统伺服控制回路进行系统辨识;通过DSP系统与三次样条插值数据处理测得了某种工况下的瞄准线稳定系统阶跃响应曲线;以先验知识为基础确定待辨识系统模型阶次,并利用改进遗传算法辨识模型参数,从而获取被控对象的模型;用阶跃响应性能指标误差评价法对系统辨识方法的效果进行了验证,结果表明,该方法能准确地实现瞄准线稳定系统的模型辨识. 相似文献
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伺服系统又称为随动系统,是构成自动化体系的基本环节,是由若干元件和部件组成的具有功率放大作用的一种自动控制系统。系统辨识是指当用户无法从物理上得出所研究系统的数学模型,但可以通过适当的实验手段测试出系统的某种响应信息时,就可以根据它来获得系统的数学模型。本文完成了对直流伺服系统的建模以及辨识,尤其是利用系统的阶跃响应数据对直流伺服系统的模型进行了直接辨识,即由系统阶跃响应采样数据构造线性方程组,通过对方程组求解估计出系统参数。最后,对辨识出的系统进行仿真,通过将仿真结果与原阶跃响应数据比较表明,本文所采用的辨识方法取得了良好的辨识效果。 相似文献
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伺服系统又称为随动系统,是构成自动化体系的基本环节,是由若干元件和部件组成的具有功率放大作用的一种自动控制系统。系统辨识是指当用户无法从物理上得出所研究系统的数学模型,但可以通过适当的实验手段测试出系统的某种响应信息时,就可以根据它来获得系统的数学模型。本文完成了对直流伺服系统的建模以及辨识,尤其是利用系统的阶跃响应数据对直流伺服系统的模型进行了直接辨识,即由系统阶跃响应采样数据构造线性方程组,通过对方程组求解估计出系统参数。最后,对辨识出的系统进行仿真,通过将仿真结果与原阶跃响应数据比较表明,本文所采用的辨识方法取得了良好的辨识效果。 相似文献
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伺服系统又称为随动系统,是构成自动化体系的一种基本环节,是由若干元件和部件组成的具有功率放大作用的一种自动控制系统。系统辨识是指当用户无法从物理上得出所研究系统的数学模型,但可以通过适当的实验手段测试出系统的某种响应信息时,就可以根据它来获得系统的数学模型。本文完成了对直流伺服系统的建模以及辨识,尤其是利用系统的阶跃响应数据对直流伺服系统的模型进行了直接辨识,即由系统阶跃响应采样数据构造线性方程组,通过对方程组求解估计出系统参数。最后,对辨识出的系统进行了仿真,将仿真结果与原阶跃响应数据比较,表明所采用的辨识方法取得了良好的效果。 相似文献
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激光焊接系统的非线性辨识和自适应控制 总被引:1,自引:0,他引:1
激光焊接涉及到复杂的物理和化学变化,是一个典型的非线性系统,用机理建模法很难得到系统的数学模型,通常采用基于输入输出数据的系统辨识方法来建模;为了得到未知参数的无偏估计,采用相关最小二乘法进行辨识建立激光焊接系统的双线性模型,并通过比较实际焊接系统的阶跃响应和模型的阶跃响应验证了模型的准确性和有效性;在此基础上,采用反馈线性化方法,对激光焊接系统设计了最小方差自适应控制器;仿真结果表明了该非线性自适应控制方法的有效性. 相似文献
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提出一种均匀设计的神经网络来进行系统辨识,其训练数据来自实验,通过找出模型参数与阶跃响应曲线之间的对应关系,以获得模型的结构,研究结果表明该方法的有效性. 相似文献
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本文介绍通过系统辨识方法建立换热器的动态模型。首先用CMC-80单板机产生伪随机二位式序列(PRBS),作为辨识实验的测试信号,同时采集换热器在PRBS作用下的输出响应数据。然后利用估计准则方法及快速多步最小二乘法(FMLS)辨识换热器的动态模型。辨识模型给出的计算阶跃响应曲线与换热器的实际阶跃响应曲线比较表明:换热器动态模型辨识的结果是令人满意的。 相似文献
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对于火电厂热工控制系统,建立精确的热工过程模型是保证控制质量的基础.将传统的阶跃响应法用于热工过程模型辨识,由于现场数据的不规则性使得阶跃响应法的经验结果精度不高.针对火电厂热工过程对象的特点及传统模型辨识的缺陷,将粒子群算法用于火电厂热工过程模型的辨识,以1000MW超超临界机组的风煤比作为控制对象,对空预器进口氧量变化系统进行系统辨识,辨识曲线能够很好的反应实际输出曲线,证明了该方法的有效性和可靠性,相比传统的辨识方法,将粒子群算法用于模型辨识提高了辨识的精确性与快速性. 相似文献
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将广义预测控制算法的各环节整合在一起,提出了根据模型参数和过程输入输出值直接计算未来时间的闭环预测值和单位阶跃响应曲线的新算法.在新算法中无需显式求解Diophantine方程,仅需要使用矢量相加减、点乘和移位运算等基本算子,易于在PLC中实现.新算法只需要存储未来时刻的闭环预测值及单位阶跃响应曲线数据,存储数据较现有方法明显减少.利用GPC模型导出了与DMC相似的闭环预测式,可以利用GPC算法的在线模型辨识功能计算DMC算法的闭环观测值及阶跃响应曲线,将这两种方法融合起来,使DMC算法也具备在线修正过程模型的能力.通过例子对算法的正确性进行了验证. 相似文献
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介绍辅助变量法与粒子群优化算法在舰艇发电机励磁系统辨识中的应用,并在Labview软件中编写了相应的计算程序。以某舰艇发电机励磁系统为例,在Matlab/Simulink中搭建该励磁系统仿真模型,将采样获得的输入输出数据,输入Labview辨识软件中,估计各参数值。实验分别采用+10%、+50%阶跃响应,辨识系统线性模型和非线性模型,并比较不同噪声幅值情况下的PSO辨识结果。实验结果证明PSO算法在励磁系统参数估计中的有效性。 相似文献
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Kajal Kothari Utkal Mehta Vineet Prasad Jito Vanualailai 《IEEE/CAA Journal of Automatica Sinica》2020,7(3):882-891
The parameter identification of a nonlinear Hammerstein-type process is likely to be complex and challenging due to the existence of significant nonlinearity at the input side. In this paper, a new parameter identification strategy for a block-oriented Hammerstein process is proposed using the Haar wavelet operational matrix(HWOM). To determine all the parameters in the Hammerstein model, a special input excitation is utilized to separate the identification problem of the linear subsystem from the complete nonlinear process. During the first test period, a simple step response data is utilized to estimate the linear subsystem dynamics. Then, the overall system response to sinusoidal input is used to estimate nonlinearity in the process. A single-pole fractional order transfer function with time delay is used to model the linear subsystem. In order to reduce the mathematical complexity resulting from the fractional derivatives of signals, a HWOM based algebraic approach is developed. The proposed method is proven to be simple and robust in the presence of measurement noises. The numerical study illustrates the efficiency of the proposed modeling technique through four different nonlinear processes and results are compared with existing methods. 相似文献
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In this paper, a new identification method performed in the time domain based on the decentralized step‐test is proposed for two inputs and two outputs (TITO) processes with significant interactions. In terms of parameter identification, the coupled closed‐loop TITO system is decoupled to obtain four individual single open‐loop systems with the same input signal. As in the SISO case, new linear regression equations are derived, from which the parameters of a first‐ or second‐order plus dead‐time model can be obtained directly. The proposed method outperforms the existing estimation methods for multivariable control systems that use step‐test responses. Furthermore, the method is robust in the presence of high levels of measurement noise. Simulation examples are given to show both effectiveness and practicality of the identification method for a wide range of multivariable processes. The usefulness of the identified method in multivariable process modeling and controller design is demonstrated. 相似文献
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In this paper,an analysis for ill conditioning problem in subspace identifcation method is provided.The subspace identifcation technique presents a satisfactory robustness in the parameter estimation of process model which performs control.As a frst step,the main geometric and mathematical tools used in subspace identifcation are briefly presented.In the second step,the problem of analyzing ill-conditioning matrices in the subspace identifcation method is considered.To illustrate this situation,a simulation study of an example is introduced to show the ill-conditioning in subspace identifcation.Algorithms numerical subspace state space system identifcation(N4SID)and multivariable output error state space model identifcation(MOESP)are considered to study,the parameters estimation while using the induction motor model,in simulation(Matlab environment).Finally,we show the inadequacy of the oblique projection and validate the efectiveness of the orthogonal projection approach which is needed in ill-conditioning;a real application dealing with induction motor parameters estimation has been experimented.The obtained results proved that the algorithm based on orthogonal projection MOESP,overcomes the situation of ill-conditioning in the Hankel s block,and thereby improving the estimation of parameters. 相似文献
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为了提高凸轮轴的加工效率和加工精度,开发可用于凸轮轴磨削修整系统的动态优化模块。根据凸轮轴恒线速磨削原理,在Matlab中完成了数学模型的建模,采用三次样条曲线拟合插值法对加工过程曲线进行了优化,从而得到了波动更小的速度曲线并减少了恒线速度磨削所引起的联动轴响应问题。实验表明,该方法很好地实现了在二次磨削中对凸轮轴表面轮廓的修整,提高了凸轮轴的表面质量。 相似文献
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In this paper, a Wiener–Hammerstein system identification problem is formulated as a semidefinite programming (SDP) problem which provides a sub-optimal solution for a rank minimization problem. In the proposed identification method, the first linear dynamic system, the static nonlinear function, and the second linear dynamic system are parameterized as an FIR model, a polynomial function, and a rational transfer function respectively. Subsequently the optimization problem is formulated by using the over-parameterization technique and an iterative approach is proposed to update two unmeasurable intermediate signals. For the modeling of static nonlinearity, the monotonically non-deceasing condition was applied to limit the number of possible selections for intermediate signals. At each step of iteration, the over-parametrized parameters are estimated and then system parameters are separated by using a singular value decomposition (SVD). The proposed method is applied to the benchmark problem and the estimation result shows the effectiveness of the proposed algorithm. 相似文献