Modeling and analysis of colored petri net based on the semi-tensor product of matrices

This paper applies the model petri net method based on the semi-tensor product of matrices to colored petri net. Firstly, we establish the marking evolution equation for colored petri net by using the semitensor product of matrices. Then we define the concept of controllability and the control-marking adjacency matrix for colored petri net. Based on the marking evolution equation and control-marking adjacency matrix, we give the necessary and sufficient condition of reachability and controllability for colored petri net. The algorithm to verify the reachability of colored petri net is given, and we analyze the computational complexity of the algorithm. Finally, an example is given to illustrate the effectiveness of the proposed theory. The significance of the paper lies in the application of the model petri net method based on the semitensor product of matrices to colored petri net. This is a convenient way of verifying whether one marking is reachable from another one as well as finding all firing sequences between any two reachable markings. Additionally, the method lays the foundations for the analysis of other properties of colored petri net.     

基于扰动补偿的无微分模型参考自适应控制系统设计

针对一类含有参数不确定性和未知非线性扰动的系统,本文提出一种基于扰动补偿的无微分模型参考自适应控制方法,实现系统输出对参考模型输出信号的高精度跟踪.首先,利用被控对象模型信息设计扰动估计器,对系统非线性扰动进行在线估计;其次,基于非线性扰动估计值设计参考模型和无微分参数更新律,构建无微分模型参考自适应控制器,建立基于扰动补偿和状态反馈的自适应控制律,以消除参数不确定性和非线性扰动对系统输出的影响,保证系统输出对参考模型输出的准确跟踪;然后,给出闭环系统误差信号收敛条件和控制器参数整定方法;最后,通过数值仿真验证所提方法的有效性和优越性.     

Robust adaptive control of nonlinearly parametrized multivariable systems with unmatched disturbances

A new robust adaptive control scheme is developed for nonlinearly parametrized multivariable systems in the presence of parameter uncertainties and unmatched disturbances. The developed control scheme employs a new integrated framework of a functional bounding technique for handling nonlinearly parametrized system dynamics, an adaptive parameter estimation algorithm for dealing with parameter uncertainties, a nonlinear feedback controller structure for stabilization of interconnected system states, and a robust adaptive control design for accommodating unmatched disturbances. It is proved that such a new robust adaptive control scheme is capable of ensuring the global boundedness and mean convergence of all closed‐loop system signals. A complete simulation study on an air vehicle system with nonlinear parametrization in the presence of an unmatched wind disturbance is conducted, and its results verify the effectiveness of the proposed robust adaptive control scheme.     

基于DRFNN的共振频率自适应反推控制

针对共振破碎机频率控制系统的不确定性问题,提出基于动态递归模糊神经网络的自适应反推控制策略。建立了破碎机频率控制系统的数学模型,在忽略不确定性项的前提下,设计了基于自适应Back-stepping方法控制律。其次将电液系统中影响频率控制性能的不确定性因素定义为待估计项,采用动态递归模糊神经网络对其进行实时估计,给出了基于动态递归模糊神经网络的参数自适应律,并通过了Lyapunov的稳定性分析。仿真实验和车载测试结果表明,对于系统参数的不确定性,该方法具有较好地频率控制性能。     

Robust adaptive controller with disturbance observer for vehicular radar servo system

In vehicular radar servo system, parameter variations of the executive motor and external disturbance uncertainties have great effects on the position tracking precision of the system. In this paper, a robust adaptive controller with disturbance observer is designed for vehicular radar servo system, which combines the merits of disturbance observer, adaptive backstepping method and sliding mode control. The system is modeled, and a disturbance observer is employed to observe and compensate for the unknown uncertainties. Adaptive backstepping method is used to design the sliding model controller to guarantee the global stability of the overall system. Simulation results show that the proposed robust adaptive controller has good performance in position tracking and enhances the robustness of vehicular radar servo system while observing the uncertainties precisely and quickly.     

Matrix expression and reachability analysis of finite automata

In this paper,we propose a matrix-based approach for finite automata and then study the reachability conditions.Both the deterministic and nordeterministic automata are expressed in matrix forms,and th...     

单元机组的非线性自适应反演综合控制

针对同时考虑参数不确定性和外界干扰的单元机组整体模型(锅炉–汽轮机–发电机模型),提出了一种基于自适应反演法和协调无源性理论的非线性综合控制策略.首先,针对预处理后的被控对象各子系统,采用反演法得到汽门控制输入,然后以高压侧电压为控制目标对励磁部分进行优化设计,最后逐步递推设计燃料控制器.在控制律设计过程中,为克服模型参数的不确定性,避免可能出现的参数漂移,通过引入充分光滑投影算子设计了参数自适应律.同时,借助在控制律中添加阻尼项,以有效抑制外界干扰对控制品质的影响.仿真分析和变负荷实验的结果表明,本文所设计的综合控制策略同时优化了单元机组的有功和无功响应特性,使其具有良好的负荷跟踪性能、抗干扰能力和对模型不确定参数的鲁棒性.     

控制力矩陀螺框架伺服系统期望补偿自适应鲁棒控制

本文针对控制力矩陀螺框架伺服系统中存在的参数不确定性、摩擦非线性及外部干扰问题,提出了一种考虑LuGre摩擦的自适应鲁棒控制方法.针对陀螺框架伺服系统未知惯量和阻尼系数、LuGre摩擦参数不确定性及未知外部干扰上界,设计参数更新律对其进行估计.在此基础上,为提高系统对不确定参数及未知干扰的鲁棒性,设计带有期望补偿的自适应鲁棒控制器,可实现对LuGre摩擦非线性的精确补偿,同时减小测量信号噪声及外部干扰对系统的不利影响.应用Lyapunov稳定性理论分析了闭环系统的稳定性.对挠性航天器姿态机动控制的仿真结果,验证了所提方法的有效性.     

Distributed fault-tolerant parallel formation control of underactuated marine surface vehicles with limited control input

In this paper, an adaptive distributed parallel formation control approach is proposed for a group of underactuated marine surface vehicles with actuator fault and limited control input. Firstly, the algebraic topology is employed to model the intervehicle communication network of the multiple vehicles. Both the model uncertainties and environmental disturbance satisfying norm-bounded conditions are discussed. Secondly, a concise bounded-feedback adaptive law is developed to compensate the supremum of the neural network weight matrix, rather than each element of the matrix. That could dramatically reduce the computation burden of the algorithm and facilitate its application in practical engineering. Furthermore, a new adaptive parameter is introduced to analyze the input saturation and compensate the energy fading of actuator fault simultaneously. Finally, it is proved that all the signals of the closed-loop system are semiglobal uniformly ultimately bounded. Numerical examples are presented to demonstrate the performance and superiority of the proposed control strategy in different cases.     

Robust fuzzy tracking control for robotic manipulators

In this paper, a stable adaptive fuzzy-based tracking control is developed for robot systems with parameter uncertainties and external disturbance. First, a fuzzy logic system is introduced to approximate the unknown robotic dynamics by using adaptive algorithm. Next, the effect of system uncertainties and external disturbance is removed by employing an integral sliding mode control algorithm. Consequently, a hybrid fuzzy adaptive robust controller is developed such that the resulting closed-loop robot system is stable and the trajectory tracking performance is guaranteed. The proposed controller is appropriate for the robust tracking of robotic systems with system uncertainties. The validity of the control scheme is shown by computer simulation of a two-link robotic manipulator.     

An adaptive disturbance rejection control scheme for multivariable nonlinear systems

An adaptive disturbance rejection control scheme is developed for uncertain multi-input multi-output nonlinear systems in the presence of unmatched input disturbances. The nominal output rejection scheme is first developed, for which the relative degree characterisation of the control and disturbance system models from multivariable nonlinear systems is specified as a key design condition for this disturbance output rejection design. The adaptive disturbance rejection control design is then completed by deriving an error model in terms of parameter errors and tracking error, and constructing adaptive parameter-updated laws and adaptive parameter projection algorithms. All closed-loop signals are guaranteed to be bounded and the plant output tracks a given reference output asymptotically despite the uncertainties of system and disturbance parameters. The developed adaptive disturbance rejection scheme is applied to turbulence compensation for aircraft fight control. Simulation results from a benchmark aircraft model verify the desired system performance.     

一类非线性切换系统鲁棒H∞可靠控制

为了克服扰动与执行器故障对控制系统的影响，使系统具有抗干扰性和可靠性，针对一类不确定非线性切换系统，研究了在任意切换规则下鲁棒H∞可靠控制问题．首先，系统所有矩阵同时含有参数不确定性，并且系统也存在未知非线性扰动．当执行器存在故障时，基于线性矩阵不等式技术以及公共李亚普诺夫函数方法得到鲁棒H∞可靠控制器，使切换系统在任意切换律下全局二次稳定并且满足H∞性能指标．最后，通过求解凸优化问题得到了鲁棒H∞最优可靠控制器．仿真结果表明控制器在任意切换规则下是可行和有效的．     

带有控制受限的卫星编队飞行六自由度自适应协同控制

针对存在参数不确定性以及干扰的卫星编队飞行六自由度协同控制问题,提出了一种满足控制输入有界的自适应L2增益干扰抑制控制方法.该方法首先在不考虑干扰的条件下,针对卫星编队六自由度协同运动模型存在参数不确定性提出了一种自适应协同控制器;接着,考虑到系统存在干扰,进一步设计了具有L2增益干扰抑制能力且满足输入有界条件的自适应...     

一类不确定广义系统的非脆弱保性能控制

研究了一类时变时滞不确定广义系统的非脆弱保性能控制问题。在系统矩阵、滞后状态矩阵、输入矩阵和滞后输入矩阵都具有不确定性时,带有反馈增益扰动的控制器能够保证闭环系统是正则、无脉冲、指数稳定的;且性能函数存在上界。对于出现的两个不确定项乘积的问题,采用两个线性矩阵不等式,两次运用Schur补引理的方法得以解决。控制器的增益可通过求解一系列严格线性矩阵不等式得到。数值仿真实例证明了所提方法的有效性。     

线性参数不确定系统的H-鲁棒控制器设计

本文主要讨论了带有未知不确定参数的线性系统的H_∞鲁棒控制问题,这里假定其中的不确定性是时变有界的,并同时存在于系统的状态矩阵和输入矩阵中,文中提出了一种同时使受控对象保持二次稳定并满足干扰约束的状态反馈设计方法。结果表明,该类反馈控制律可以通过求解一个含有参数的代数Riccati方程得到。     

Robust tracking enhancement of robot systems including motordynamics: a fuzzy-based dynamic game approach

A robust tracking control design of robot systems including motor dynamics with parameter perturbation and external disturbance is proposed in this study via adaptive fuzzy cancellation technique. A minimax controller equipped with a fuzzy-based scheme is used to enhance the tracking performance in spite of system uncertainties and external disturbance. The design procedure is divided into three steps. At first, a linear nominal robotic control design is obtained via model reference tracking with desired eigenvalue assignment. Next, a fuzzy logic system is constructed and then tuned to eliminate the nonlinear uncertainties as possibly as it can to enhance the tracking robustness. Finally, a minimax control scheme is specified to optimally attenuate the worst-case effect of both the residue due to fuzzy cancellation and external disturbance to achieve a minimax tracking performance. In addition, an adaptive fuzzy-based dynamic game theory is introduced to solve the minimax tracking problem. The proposed method is appropriate for the robust tracking design of robotic systems with large parameter perturbation and external disturbance. A simulation example of a two-link robotic manipulator driven by DC motors is also given to demonstrate the effectiveness of proposed design method's tracking performance     

高超声速飞行器再入姿态鲁棒控制

本文针对气动参数和惯性参数不确定性,同时考虑反作用控制系统(RCS)参与控制,设计高超声速再入飞行器的鲁棒自适应控制器.根据奇异摄动理论将整个控制系统分为快、慢两个回路分别进行设计,将各回路的不确定参数写成矢量的形式,并用自适应估计器进行在线估计,从而使得控制器实现在线自适应调整.利用非线性干扰观测器来处理控制系数矩阵的不确定性部分.提出一种改进的控制分配权重函数,并将总控制力矩分配到气动舵面偏角指令和RCS所需提供的控制力矩指令.利用Lyapunov稳定性理论来分析整个闭环系统的稳定性.最后,通过仿真验证该控制方案能够有效抑制不确定参数引起的干扰.     

Semi-tensor product of matrices approach to reachability of finite automata with application to language recognition

This paper investigates the transition function and the reachability conditions of finite automata by using a semitensor product of matrices, which is a new powerful matrix analysis tool. The states and input symbols are first expressed in vector forms, then the transition function is described in an algebraic form. Using this algebraic representation, a sufficient and necessary condition of the reachability of any two states is proposed, based on which an algorithm is developed for discovering all the paths from one state to another. Furthermore, a mechanism is established to recognize the language acceptable by a finite automaton. Finally, illustrative examples show that the results/algorithms presented in this paper are suitable for both deterministic finite automata (DFA) and nondeterministic finite automata (NFA).     

不确定多通道奇异大系统分散鲁棒H∞控制

研究不确定多通道奇异系统的鲁棒分散H_∞控制问题,假定不确定性是时不变、范数有界,且存在于系统和控制输入矩阵中．主要考虑分散H_∞输出反馈控制问题．推导出了使不确定多通道奇异系统能鲁棒稳定且满足一定的性能指标的充分必要条件,没有等式约束的非线性矩阵不等式条件,采用两步同伦法迭代来求解非线性矩阵不等式(NMI),首先,通过逐步对控制器的系数矩阵加上结构限制,计算出当确定性不存在时的标称系统的分散H_∞控制器．然后,逐步改变标称系统分散控制器的系数,计算出不确定性参数存在时的分散鲁棒控制器．在每一阶段,每一次迭代过程中,通过交替固定NMI的一个变量,使NMI转变为线性矩阵不等式(LMI)．数值例子说明了本文提出的方法的有效性．     

Identification Recurrent Type 2 Fuzzy Wavelet Neural Network and L2‐Gain Adaptive Variable Sliding Mode Robust Control of Electro‐Hydraulic Servo System (EHSS)

An electro‐hydraulic servo system (EHSS) is a kind of system with the characteristics of time‐variant, serious nonlinearity, parameter and structural uncertainty, and uncertain load disturbance in most cases. These characteristics make it very difficult to realize highly accurate control by conventional methods. In order to solve the above problems, this paper introduces a recurrent type 2 fuzzy wavelet neural network to approximate the unknown nonlinear functions of the dynamic systems through tuning by the desired adaptive law. Based on the identification by recurrent type 2 fuzzy wavelet neural network, a L2 gain design method, combining gain adaptive variable sliding mode control with H infinity control, is proposed for load disturbance, thereby accommodating uncertainties that are the main factors affecting system stability and accuracy in EHSS. In this algorithm, a recurrent type 2 fuzzy wavelet neural network is employed to evaluate the unknown dynamic characteristics of the system and gain adaptive variable sliding mode control to compensate for evaluating errors, and H infinity control to suppress the effect on system by load disturbance. The experiment results show that the proposed system L2 gain design method can make the system exhibit strong robustness to parameter variation and load disturbance.