基于非线性变速积分算法的电动汽车充电电源

对传统的PID控制算法进行了深入的分析,结合电动汽车充电电源项目,对原PID算法中的积分部分进行了改进,先后采用了分段积分,变速积分,非线性变速积分等方法.经过实验验证,相比传统的PID算法,上述改进方法的效果十分显著.     

变速积分PID在AUV航向姿态控制中的应用

AVU在航行过程中容易受慢变干扰,传统PID通过加大积分项来抑制干扰,但易引起超调.积分分离PID可以抑制干扰和减小超调,但当慢变干扰大于积分分离的门限时,退化为PD控制器.对此,将变速积分PID引入AUV的航向控制中.在航向运动线性模型基础上设计了控制器,并利用劳斯判据证明了系统稳定性,在典型干扰下进行了仿真验证.结果表明,变速积分PID相对于传统的PID和积分分离PID有更好的性能.     

基于变速积分PID的恒温控制系统的应用研究

在多个领域都会用到恒温控制系统,设计一种基于变速积分PID的恒温控制系统,系统以STM32为核心处理器。该文讲述了系统的构成,分析了变速积分PID算法,并在恒温控制系统中得到运用。经过长时间的调试,得到合适的PID系数,使得系统的控制精度达到±0.01℃/30min。系统具有性能稳定,可靠性高的优点。     

基于变速积分PID的恒温控制系统的应用研究

在多个领域都会用到恒温控制系统,设计一种基于变速积分PID的恒温控制系统,系统以STM32为核心处理器。该文讲述了系统的构成,分析了变速积分PID算法,并在恒温控制系统中得到运用。经过长时间的调试,得到合适的PID系数,使得系统的控制精度达到＆#177;0.01℃/30min。系统具有性能稳定,可靠性高的优点。     

变速积分PID控制在二容水箱系统的实验研究

针对大滞后、非线性的二容水箱实验系统,进行了变速积分PID控制研究。在该方法中,分析了变速积分PID控制,推导其控制算法,整定了相关参数。在MATLAB语言环境下编写三种PID控制程序,并将程序应用于二容水箱实验系统,从实验运行结果可见,变速积分PID控制比普通PID控制和积分分离PID控制效果都好,表明使用该控制方法的正确性和优越性。     

一种改进的数字PID控制方法

本文在分析了两种常用数字PID控制方法的基础上提出了一种改进方案，该方案具有变速积分的特点，采用了分别固定参数的方法，比前两种方法更好地解决了积分项引入的动态性下降问题，仿真结果表明其输出响应较为优良。     

电阻炉温度的微机双模控制

论述了微机双模控制在电阻炉温度控制上的应用,描述了对象的数学模型,设计了变速积分PID控制器,以及采用Bang-Bang控制和变速积分PID控制的双模控制方式,并取得了较好的效果。     

变速积分PID算法在空气压缩机压力控制系统中的应用

介绍了以单片机AT89C51为核心的变速积分PID控制的压力控制系统,给出了系统的硬件与软件设计的实现方法。实验结果表明该系统的优越性。     

微生物发酵过程的温度控制

微生物发酵过程的温度控制精度非常重要,发酵罐罐体温度是通过夹套中的水温来调节的,使用加热器和冷却水调节夹套温度进而控制发酵罐温度。由于温度对象是滞后积分对象,使用传统的PID控制,控制效果差,因此对传统PID控制进行了改造。研究了积分分离PID,指数积分PID和FuzzyPID控制算法在发酵过程温度控制中的应用。实践证明,经过改进的PID算法的控制效果明显提高。     

基于PID控制的积分改进算法在呼吸机中的应用

呼吸机在启动或者是大幅度增减作用时中会出现较大的偏差,会造成PID(Proportion Integration Differentiation)运算过程中的积分累积,使得波形产生较大的超调,进而影响呼吸质量。针对呼吸机的气路特性,通过对普通PID算法的深入研究,在分析普通PID算法不足后,提出了相应的改进算法。通过对PID控制中积分算法的分析并进行改进,在一定程度上明显减弱了系统超调引起的精度问题。仿真结果表明,此算法在快速性、稳定性、精确性性上均优于传统PID算法。     

多普勒频率补偿算法在GPS信号捕获中的应用

在GPS卫星高速运动和地面GPS接收机的移动中,由于卫星和接收机之间的径向速度引起了载波多普勒频移、C/A码的多普勒频移和数据码的多普勒频移,多普勒频移会对GPS接收机的信号捕获产生影响,使其准确度下降。针对上述情况,在常用的相干积分结合非相干积分的GPS信号捕获方案中引入一种多普勒频率补偿算法,并对此算法进行相应的仿真。结果表明该设计方案是可行的,引入的补偿算法能够有效消除多普勒频移对GPS信号捕获的影响,能够实现对GPS卫星信号的多普勒和码相的准确捕获。     

Nonlinear control of planar multibody systems in shape space

Modeling, reduction, and nonlinear control of planar multibody systems motivated by the classicalcat-fall problem and the practical problem of reorientation of free-floating multibody satellites with rotational joints using angular-momentum-preserving controls is studied. The system model considered is reduced by the first integral (the system angular momentum) resulting in a Hamiltonian system with a configuration space of relative joint angles (shape space). Reconstruction of dynamics is applied to modify the shape-space model and track the phase shift of the absolute angles. An important reachability result is then proved in the unreduced configuration space. Control synthesis can then be found in a feedback form, solving the reorientation problem completely. Surprisingly, the reachability result breaks down in the case of the planar coupled two-body system with zero angular momentum, proving that the cat-fall phenomenon is definitely nonplanar.     

Solution of problem of identification of time shift of pseudorandom sequences on the basis of nonlinear probabilistic criteria

A solution of the problem of identification of the time shift of pseudorandom sequences received against a background of interference is proposed. The solution is based on a nonlinear probabilistic criterion—the criterion of minimum a posteriori integral estimation error. An algorithm of nonlinear parametric identification that yields a solution of the problem is synthesized. A numerical example of the identification of the time shift of a concrete sequence that confirms the effectiveness and adequate degree of efficiency of the algorithm proposed in the study is presented.     

Pulse compensation for PD-type iterative learning control against initial state shift

The rectangular pulse function is adopted to incorporate feed-forward compensation for various proportional-derivative-type iterative learning control updating laws applied to a class of linear time-invariant systems with initial state shift. The objective of pulse compensation is to suppress the tracking discrepancy incurred by initial state shift. By means of the generalised Young inequality of the convolution integral, the tracking performance of the pulse-based learning updating laws is analysed and the suppressive effect of the pulse compensation is evaluated by measuring the tracking error in the sense of Lebesgue-p norm. The derivation clarifies that the upper bound of the asymptotical tracking error can be improved by tuning the compensation gain properly though it is determined not only by the proportional and derivative learning gains but also by the system state, input and output matrices as well. Numerical simulations show that pulse compensation can effectively suppress the tracking error caused by initial state shift.     

A new backward shift algorithm for system identification by a good choice of frequencies

In this study, we propose a novel backward shift algorithm for pole estimation of linear time-invariant (LTI) systems. By making adjustments, we address the question: How should the frequencies of input signals be chosen? We select the frequencies based on algebraic accuracy in the numerical integral and use the Gaussian–Legendre formula in this process. After poles are located, the discrete Fourier transform (DFT) and the new backward shift algorithm (new BSA) along with the least squares (LS) method are used to identify the systems. Two examples show that the proposed method for pole estimation performs better and the corresponding identification algorithm is practical.     

Approximate solution of dual integral equations using Chebyshev polynomials

The aim of the present work is to introduce solution of special dual integral equations by the orthogonal polynomials. We consider a system of dual integral equations with trigonometric kernels which appear in formulation of the potential distribution of an electrified plate with mixed boundary conditions and convert them to Cauchy-type singular integral equations. We use the Chebyshev orthogonal polynomials to construct approximate solution for Cauchy-type singular integral equations which will solve the main dual integral equations. Numerical results demonstrate effectiveness of this method.     

一种模糊分类器集成的方法

提出了一种基于模糊积分的模糊分类器集成的方法，该方法能在模糊分类器生成过程中，进一步减少主观因素的参与成份，使分类模器具有更好的稳定性和更高的分类识别率。给出了基于隶属度矩阵的模糊积分密度确定方法，介绍了基于模糊积分的分类器集成算法。用权威的数据集作为实验数据集，将提出方法与已有的分类器集成方法进行实验比较，评测了所提出方法的有效性。     

基于遗传算法和模糊积分的多分类器集成

多分类器联合是解决复杂模式识别问题的有效办法。模糊积分是其中一种多分类器联合方法。但是对于模糊积分。如何计算模糊积分密度是一个尚未解决的问题。本文提出了一种基于模糊积分和遗传算法的分类器集成方法，该方法利用遗传算法计算模糊积分密度函数，再利用模糊积分把分类器输出信息联合起来。实验结果表明，该方法比其他方法能够得到更好的识别性能。     

Upper integral network with extreme learning mechanism

The upper integral is a type of non-linear integral with respect to non-additive measures, which represents the maximum potential of efficiency for a group of features with interaction. The value of upper integrals can be evaluated through solving a linear programming problem. Considering the upper integral as a classifier, this paper first investigates its implementation and performance. Fusing multiple upper integral classifiers together by using a single layer neural network, this paper considers a upper integral network as a classification system. The learning mechanism of ELM is used to train this single layer neural network. A comparison of performance between a single upper integral classifier and the upper integral network is given on a number of benchmark databases.     

Rigid body mode and spurious mode in the dual boundary element formulation for the Laplace problems

In this paper, the general formulation for the static stiffness is analytically derived using the dual integral formulations. It is found that the same stiffness matrix is derived by using the integral equation no matter what the rigid body mode and the complementary solutions are superimposed in the fundamental solution. For the Laplace problem with a circular domain, the circulant was employed to derive the stiffness analytically in the discrete system. In deriving the static stiffness, the degenerate scale problem occurs when the singular influence matrix can not be inverted. The Fredholm alternative theorem and the SVD updating technique are employed to study the degenerate scale problem mathematically and numerically. The direct treatment in the matrix level is achieved to deal with the degenerate scale problems instead of using a modified fundamental solution. The addition of a rigid body term in the fundamental solution is found to shift the zero singular value for the singular matrix without disturbing the stiffness.