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针对一类特定结构的含有未知参数的混沌系统,给出了一种基于状态观测器的自适应同步控制方法。通过一个带有控制器的非线性状态观测器实现混沌系统的渐进同步并对未知参数进行估计。该控制方法简单易行,且能通过自适应律自动调整以跟随参数的变化,具有较强的鲁棒性。理论分析和仿真实验都证明了该方法的有效性。 相似文献
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基于自适应同步的混沌系统参数辨识方法的研究 总被引:1,自引:1,他引:0
利用混沌系统的动力学特性对参数极其敏感的特点,以驱动响应同步结构为框架,设计了与同步误差有关的二次型指标函数,采用优化方法对参数进行自适应调节,直到同步误差最小,即实现混沌同步.该方法实现了参数未知混沌系统的参数辨识和自适应同步.为了研究参数收敛速度,对准高斯牛顿法、Hook-Jeeves方法(又名模式搜索法)和共轭梯度法等三种优化方法进行了对比研究.对具有两个未知参数的离散Hénon系统和连续Lorenz系统的仿真研究表明,基于共轭梯度的参数调节方法参数收敛速度最快,可以应用于混沌保密通信的解密. 相似文献
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Parameters Estimation of Chaotic Telemetry System between Two Different Time-delayed Chaotic Systems
WEI Heng-dong 《电讯技术》2013,53(5)
针对混沌遥测系统的参数估计问题,研究了基于混沌同步的不同混沌时延系统的
参数估计方法。构造了利用不同混沌系统进行参数估计的自适应方案,利用Krasovskii
-Lyapunov理论推导出两个不同混沌时延系统同步和参数估计的充分条件。所提方案应用到
混沌遥测系统参数估计可以有效估计系统参数。非合作者可用所构造方法利用不同混沌
系统获取混沌遥测系统的有用信息。仿真分析验证了方案的有效性。 相似文献
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针对混沌遥测系统的参数估计问题,研究了基于混沌同步的不同混沌时延系统的参数估计方法。构造了利用不同混沌系统进行参数估计的自适应方案,利用Krasovski-i Lyapunov理论推导出两个不同混沌时延系统同步和参数估计的充分条件。所提方案应用到混沌遥测系统参数估计可以有效估计系统参数。非合作者可用所构造方法利用不同混沌系统获取混沌遥测系统的有用信息。仿真分析验证了方案的有效性。 相似文献
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该文针对含未知参数的异结构超混沌复系统,基于自适应控制及Lyapunov稳定性理论,提出一种新的自适应广义组合复同步方法 (GCCS)。首先给出广义组合复同步的定义,将驱动-响应系统的同步问题转化为误差系统零解的稳定性问题;然后从理论上设计了非线性反馈同步控制器及参数辨识更新律,并引入误差反馈增益,以控制同步的收敛速度;最后以超混沌复Lorenz系统、超混沌复Chen系统、超混沌复L系统的广义组合复同步与参数估计为例,从数值仿真角度验证了所提方法的正确性和有效性。 相似文献
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基于自适应模糊理论的某型无人机起飞控制方法 总被引:1,自引:0,他引:1
基于合理简化的无人机纵向模型,设计了一种自适应模糊控制器,该控制器将Takagi-Sugeno模糊系统与等效控制器相结合,以增强系统的鲁棒性.只要求预先知道系统的相对阶以及未知函数的上下界即可,不需要精确的数学模型.Lyapunov合成方法证明了跟踪误差能趋近于零且其余的控制信号均有界.最后,结合优先级按比例分配的控制分配器,给出了存在扰动情况下飞行控制系统的仿真结果,表明即使在模型部分未知的情况下,该系统仍然能够达到飞行控制的指标性能和品质要求,验证了该方法的有效性. 相似文献
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This paper presents a new adaptive controller for visual tracking control of a robot manipulator in 3D general motion with a fixed camera whose intrinsic and extrinsic parameters are uncalibrated. In addition to camera parameters, the feature positions are also assumed unknown. Based on the fact that the unknown parameters appears linearly in the closed-loop dynamics of the system if the depth-independent interaction matrix is adopted to map the image errors onto the joint space of the manipulator, a new adaptive algorithm was developed to estimated the unknown parameters on-line. With a full consideration of dynamic responses of the robot manipulator, the Lyapunov method is employed to prove asymptotic convergence of the image errors. Simulation and experiment results are used to demonstrate the performance of the proposed approach. 相似文献
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《Mechatronics》2020
Wheel-legged robots operating on the ground experience real-time interactions with the complex unknown terrain, which may lead to tilting of the whole body and instability if no regulated effort is made. Maintaining a horizontal posture of the whole body with changes in the terrain geometry via impedance control (IC) that is widely used in many fields is desirable to be realized. However, because the stiffness and location of the terrain relative to the robot are not known in advance, the force-tracking error occur when using IC, which is the main cause of robot tilting. In this paper, an adaptive variable impedance control (AVIC) method is proposed to minimize the force-tracking error for the forces of each leg that are exerted on the body, thereby maintaining a horizontal posture of the whole body and improving the stability. This control method is applied by adjusting the target stiffness to compensate for terrain uncertainties. In terms of the existence of the dynamic force tracking error, the proposed control method also allows the robot to adapt to changes to track the desired force. The theoretical analysis of the stability of the AVIC was demonstrated through a stable force-tracking application. The numerical and experimental results were compared to those obtained using IC, and the proposed control method was validated on complex, unknown terrain. 相似文献
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Shaojie Zhang Xiangwei Qiu Chunsheng Liu 《Circuits, Systems, and Signal Processing》2014,33(6):1971-1984
A neural adaptive compensation control scheme for a class of multi-input multi-ouput (MIMO) uncertain nonlinear systems with actuator failures is proposed based on prescribed performance bound (PPB) transient performance which characterizes the convergence rate and maximum overshoot of the tracking error. RBF neural networks are used to approximate the error of plant model, the control law proposed can guarantee the asymptotic output tracking and closed-loop signal bounds. The control scheme is applied to a twin otter aircraft longitudinal nonlinear dynamics model in the presence of unknown failures. Simulation results demonstrate the effectiveness of the proposed method. 相似文献
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Predictive control with enhanced robustness for precision positioning in frictional environment 总被引:2,自引:0,他引:2
Chi-Cheng Cheng Cheng-Yi Chen Chiu G.T.-C. 《Mechatronics, IEEE/ASME Transactions on》2002,7(3):385-392
A modified predictive control strategy is developed to overcome positioning and tracking difficulties for a transmission mechanism with friction. Enhanced robustness with respect to unknown dynamics is achieved by incorporating a zero phase error tracking controller (ZPETC) and a time-delay disturbance estimation scheme. Time delay control is used to cancel disturbances and potential nonlinearities. ZPETC is included to improve the overall system bandwidth. Both realistic numerical simulations, which consider the effect of sampling, quantization, and friction, and practical experiments are performed to investigate the effectiveness of the proposed control method. Encouraging transient response and steady-state control performance were observed in the results of positioning control of a one-dimensional transmission mechanism. 相似文献
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空天飞行器模糊自适应轨迹线性化控制器设计 总被引:1,自引:1,他引:0
针对一类单输入单输出非线性不确定系统,提出了模糊自适应轨迹线性化控制(TLC)方法并应用于空天飞行器(ASV)飞行控制系统设计.利用模糊系统具有以任意精度逼近非线性系统的能力对未知干扰和不确定进行估计,以减小其对系统性能的影响,并通过鲁棒控制项来克服模糊系统的逼近误差.采用Lyapunov方法,证明了闭环系统所有信号一致最终有界.最后利用提出的控制方案设计了空天飞行器飞行控制系统,并在高超声速条件下进行了仿真验证,仿真结果表明了该方法的有效性和鲁棒性. 相似文献