共查询到20条相似文献,搜索用时 15 毫秒
1.
An iterative learning control algorithm based on shifted Legendre orthogonal polynomials is proposed to address the terminal control problem of linear time-varying systems. First, the method parameterizes a linear time-varying system by using shifted Legendre polynomials approximation. Then, an approximated model for the linear time-varying system is deduced by employing the orthogonality relations and boundary values of shifted Legendre polynomials. Based on the model, the shifted Legendre polynomials coefficients of control function are iteratively adjusted by an optimal iterative learning law derived. The algorithm presented can avoid solving the state transfer matrix of linear time-varying systems. Simulation results illustrate the effectiveness of the proposed method. 相似文献
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针对存在不确定扰动的线性时变系统的轨迹跟踪控制问题,提出了基于泰勒级数的迭代学习算法.该算法利用泰勒级数将系统参数化,导出一种基于泰勒级数的线性时变系统的近似模型.在此模型的基础上,利用迭代学习方式修正输入量的泰勒展开系数,并用LMI方法求解学习增益矩阵.所提出算法在系统不满足正则性或无源性时,仍可用输出误差信号来构造学习律.仿真结果表明了该算法的有效性. 相似文献
3.
Linear time-varying systems and bilinear systems are analysed via shifted Chebyshev polynomials of the second kind. Using the operational matrix for integration and the product operational matrix, the dynamical equation of a linear time-varying system (or bilinear system) is reduced to a set of simultaneous linear algebraic equations. The coefficient vectors of shifted Chebyshev polynomials of the second kind can be determined by using the least-squares method. Illustrative examples show that shifted Chebyshev polynomials of the second kind having a finite number of terms are more accurate than either the Legendre or Laguerre methods. 相似文献
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This paper extends the application of shifted Legendre polynomial expansion to time-varying systems. The extension is achieved through representing the product of two shifted Legendre series in a new shifted Legendre series. With this treatment of the product of two time functions, the operational properties of the shifted Legendre polynomials are fully applied to the analysis and optimal control of time-varying linear systems with quadratic performance index. 相似文献
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A direct method based on using shifted Legendre polynomials is developed to obtain suboptimal control for linear time-varying systems with multiple state and control delays and quadratic performance index. In this method, both the control and state variables are first expanded into finite shifted Legendre series. The governing delay-differential equation is then converted to a set of linear algebraic equations through use of the operational matrices of integration and delay. The problem finally becomes the simple one of finding the unknown coefficients of the control variables alone, which minimizes the quadratic form of performance index. 相似文献
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针对非线性网络控制系统中测量数据的量化及随机丢包问题,给出一种基于数据驱动的自适应迭代学习控制算法.该算法能够保证系统在数据量化、随机丢包以及不确定迭代学习长度等因素的影响下,经过有限次迭代后输出轨迹跟踪误差收敛到零;借助伪偏导线性化方法,将非线性系统转换为线形时变系统形式;在线性系统框架下利用前一批次的系统输出信息更新自适应学习增益.与传统迭代学习控制算法不同的是,该算法无需预知迭代长度的先验信息和控制系统模型信息.最后通过Matlab仿真实验验证所提出算法的有效性. 相似文献
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本文提出了利用移位勒让德(Shifted Legendrc)多项式辨识时变双线性系统的一个方法。首先,利用移位勒让德多项式展开和积分运算矩阵,把微分方程化为便于计算机计算的矩阵代数方程形式;然后解代数方程从而得到双线性系统未知时变参数的估计;最后给出了仿真例子。本文的方法不仅简化了计算,而且给出了相当精确的辨识结果。 相似文献
8.
带控制时滞广义系统的PID型迭代学习算法 总被引:1,自引:0,他引:1
研究了一类线性时滞广义系统的迭代学习控制问题.针对广义系统的特点,引入选代学习控制方法,给出了线性时滞广义系统的PID型选代学习算法.结合矩阵广义逆理论,利用λ范数和Bellman引理,并从理论上给出了算法收敛性的完整证明.研究结果表明,只要充分利用广义系统的特点,寻找合适的收敛性分析方法,便可解决控制时滞广义系统的收敛性问题,对时滞广义系统速代学习控制问题的研究具有重要的理论意义与应用价值. 相似文献
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针对P型迭代学习算法对初始偏差和输出误差扰动敏感,以及PD型迭代学习算法容易放大系统噪声,降低系统鲁棒性的问题,研究了具有任意有界扰动及期望输出的重复运行非线性时变系统的PD型迭代学习跟踪控制算法.利用迭代学习过程记忆的期望轨迹、期望控制以及跟踪误差,给出基于变批次遗忘因子的学习控制器设计,并借助λ范数理论和Bellman-Gronwall不等式,讨论保证闭环跟踪系统批次误差有界的学习增益存在的充分必要条件,及分析控制算法的一致收敛性.本算法改善了系统的鲁棒性和动态特性,单关节机械臂的跟踪控制仿真验证了方法的有效性. 相似文献
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本文针对具有迭代初始误差的高相对度线性多变量离散系统,提出了一种P型的迭代学习控制算法.通过将迭代学习控制系统的二维运动过程描述为一维的线性离散系统,证明了该迭代学习控制算法的收敛性及其收敛的充要条件.该迭代学习控制算法通过对系统前次重复运动过程中的输入和跟踪误差信号进行学习,来不断地调整输入量,使得系统在经过一定次数的学习以后,在初始时间点以外的实际输出趋于期望输出.数值仿真结果表明了所提出算法的有效性. 相似文献
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Zhen Shao 《International journal of systems science》2019,50(5):1028-1038
In this paper, an adaptive iterative learning control (ILC) method is proposed for switched nonlinear continuous-time systems with time-varying parametric uncertainties. First, an iterative learning controller is constructed with a state feedback term in the time domain and an adaptive learning term in the iteration domain. Then a switched nonlinear continuous-discrete two-dimensional (2D) system is built to describe the adaptive ILC system. Multiple 2D Lyapunov functions-based analysis ensures that the 2D system is exponentially stable, and the tracking error will converge to zero in the iteration domain. The design method of the iterative learning controller is obtained by solving a linear matrix inequality. Finally, the efficacy of the proposed controller is demonstrated by the simulation results. 相似文献
13.
殷春武 《计算机工程与应用》2019,55(3):266-270
对存在执行器故障的连续线性时变系统,给出了PID型迭代学习容错控制律的收敛条件。对连续时变故障系统设计了一种PID迭代学习容错控制律,在[λ]范数意义下给出了故障系统PID型迭代容错控制器收敛的充要条件;基于Schur补原理和不等式变换,将容错控制器收敛条件转换成线性矩阵不等式,当迭代学习收敛速度设定时,基于线性矩阵不等式能快速确定最优迭代控制增益,避免了迭代控制增益设置的盲目性。旋转控制系统的数值仿真,验证了PID迭代容错控制器优良的容错性能和跟踪性能。 相似文献
14.
在同一迭代学习控制(Iterative learning control, ILC)系统中,选取一个合适的初次迭代控制信号相对于从零开始学习达到目标跟踪精度的迭代次数更少.本文针对线性系统研究从历次轨迹跟踪控制信息中通过期望轨迹匹配提取初次迭代控制信号的方法.首先提出了一种轨迹基元优化匹配算法,在满足一定相似度的情况下,通过轨迹分割、平移与旋转变换,在轨迹基元库中寻找与当前期望轨迹叠合的轨迹基元组合轨迹;进而,依据线性叠加原理和轨迹叠合的平移矢量与旋转变换矩阵,获取与期望轨迹叠合的轨迹基元控制信号;在此基础上,通过轨迹基元控制信号串联组合和时间尺度变换,提取出当前期望轨迹的初次迭代控制信号.对于初次迭代控制信号在拼接处由边界条件差异引起的干扰,给出了一种H∞反馈辅助ILC方法.最后,在XYZ三轴运动平台实现所提算法,实验结果表明本文所提方法的有效性. 相似文献
15.
Repetitive learning control is presented for finite-time-trajectory tracking of uncertain time-varying robotic systems. A hybrid learning scheme is given to cope with the constant and time-varying unknowns in system dynamics, where the time functions are learned in an iterative learning way, without the aid of Taylor expression, while the conventional differential learning method is suggested for estimating the constant ones. It is distinct that the presented repetitive learning control avoids the requirement for initial repositioning at the beginning of each cycle, and the time-varying unknowns are not necessary to be periodic. It is shown that with the adoption of hybrid learning, the boundedness of state variables of the closed-loop system is guaranteed and the tracking error is ensured to converge to zero as iteration increases. The effectiveness of the proposed scheme is demonstrated through numerical simulation. 相似文献
16.
This article proposes three novel time-varying policy iteration algorithms for finite-horizon optimal control problem of continuous-time affine nonlinear systems. We first propose a model-based time-varying policy iteration algorithm. The method considers time-varying solutions to the Hamiltonian–Jacobi–Bellman equation for finite-horizon optimal control. Based on this algorithm, value function approximation is applied to the Bellman equation by establishing neural networks with time-varying weights. A novel update law for time-varying weights is put forward based on the idea of iterative learning control, which obtains optimal solutions more efficiently compared to previous works. Considering that system models may be unknown in real applications, we propose a partially model-free time-varying policy iteration algorithm that applies integral reinforcement learning to acquiring the time-varying value function. Moreover, analysis of convergence, stability, and optimality is provided for every algorithm. Finally, simulations for different cases are given to verify the convenience and effectiveness of the proposed algorithms. 相似文献
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管海娃 《计算机工程与应用》2020,56(14):231-239
研究任意初态下,机器人系统的有限时间自适应迭代学习控制方法。引入初始修正吸引子的概念,构造一个含有初始修正项的误差变量。针对定常机器人系统和时变机器人系统,采用Lyapunov-like方法,分别设计迭代学习控制器处理系统中不确定性。并且,采用未含/含限幅学习机制,保证闭环系统各变量的一致有界性和误差变量在整个作业区间一致收敛性。藉以实现跟踪误差在预先指定区间的完全跟踪。仿真结果验证所设计控制方法的有效性。 相似文献
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In this paper, both output-feedback iterative learning control (ILC) and repetitive learning control (RLC) schemes are proposed for trajectory tracking of nonlinear systems with state-dependent time-varying uncertainties. An iterative learning controller, together with a state observer and a fully-saturated learning mechanism, through Lyapunov-like synthesis, is designed to deal with time-varying parametric uncertainties. The estimations for outputs, instead of system outputs themselves, are applied to form the error equation, which helps to establish convergence of the system outputs to the desired ones. This method is then extended to repetitive learning controller design. The boundedness of all the signals in the closed-loop is guaranteed and asymptotic convergence of both the state estimation error and the tracking error is established in both cases of ILC and RLC. Numerical results are presented to verify the effectiveness of the proposed methods. 相似文献