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1.
The article deals with the design and implementation of a flat filter tracking digital controller for a boost dc-dc power converter. A highly perturbed switched boost converter circuit is shown to be efficiently controlled, in a trajectory tracking task for its non-minimum phase output, by means of a suitable linear filter, here addressed as a flat filter. Flat filtering is a natural robust version of generalized proportional integral control (GPIC) by which the effects of arbitrary time varying exogenous disturbances, unknown endogenous nonlinearities and un-modeled dynamics can be jointly attenuated in a conceptually similar fashion to observer-based active disturbance rejection control (ADRC) and algebraic identification based model free control (MFC) but: a) without using extended state observers and b) respecting the original system order in a time-varying simplified model while avoiding algebraic estimation techniques. The proposed control technique based on the TMS320F28335 digital signal processor chip is tested by means of realistic simulations and experimental setup.  相似文献   

2.
Electromechanical actuators are widely used in many industrial applications. There are usually some constraints existing in a designed system. This paper proposes a simple method to design constrained controllers for electromechanical actuators. The controllers merge the ideas exploited in internal model control and model predictive control. They are designed using the standard control system structure with unity negative feedback. The structure of the controllers is relatively simple as well as the design process. The output constraint handling mechanism is based on prediction of the control plant behavior many time steps ahead. The mechanism increases control performance and safety of the control plant. The benefits offered by the proposed controllers have been demonstrated in real-life experiments carried out in control systems of two electromechanical actuators: a DC motor and an electrohydraulic actuator.  相似文献   

3.
This paper proposes a discrete-time nonsmooth internal model control (NSIMC) approach for mechanical transmission systems described by so-called sandwich system with backlash. In this method, a dynamic compensator is introduced to compensate for the effect of the input linear subsystem. Thus, the sandwich systems with backlash can be simplified as a pseudo-Hammerstein system with backlash. The corresponding NSIMC strategy is designed to control this system. The design procedure of the controller is presented based on the analysis on the robust stability by considering the model errors involved with the effect of backlash as well as the compensated error of the input linear subsystem. Moreover, as the model is switched among the different operating zones, the robust filters are proposed to guarantee the robust stability and satisfactory control performance of the system.  相似文献   

4.
The global stabilization of asymptotically null controllable linear systems by bounded control is considered. A nested type saturation control law is proposed which is a generalization of the existing results reported in the literature. The primary characteristic of this modified control law is that more design parameters, which are the closed-loop eigenvalues when the system is operating in linear form, are introduced and which can be well designed to achieve better system performance. Using this law, the pole locations of the closed-loop systems depending on a linear trans- formation can be placed arbitrarily within certain areas. Numerical example shows that the performance of the closed-loop system under this control law can be significantly improved if the free parameters are properly chosen.  相似文献   

5.
This paper investigates a fault detection problem for a class of discrete-time Markovian jump systems with norm-bounded uncertainties and mode-dependent time-delays. Attention is focused on constructing the residual generator based on the filter of which its parameters matrices are dependent on the system mode, that is, the fault detection filter is a Markovian jump system as well. The design of fault detection filter is reduced to H-infinity filtering problem by using H-infinity control theory, which can guarantee the difference between the residual and the fault (or, more generally weighted fault) as small as possible in the context of enhancing the robustness of residual to modeling errors, control inputs and unknown inputs. Sufficient condition for the existence of the above filters is established by means of linear matrix inequalities, which can be readily solved by using standard numerical software. A numerical example is given to illustrate the feasibility of the proposed method.  相似文献   

6.
The paper analyzes and compares the phase margins of four active disturbance rejection control (ADRC) designs, which are based on different common-used extended state observers (ESOs) of various orders, for second-order systems. The quantitative results indicate that, besides good dynamic response, ADRC can guarantee enough phase margin. It is also proved that by decreasing the order of ESO, the phase margin can be increased. Furthermore, it is demonstrated that the phase margins of the ADRC-based systems can be almost uninfluenced by the uncertainties of the system parameters. Finally, the theoretical results are verified by both simulations and experiments on a motion control platform.  相似文献   

7.
A robust adaptive control scheme is proposed for a class of uncertain nonlinear systems in strict feedback form with both unknown control directions and non-symmetric dead-zone nonlinearity based on backstepping design.The conditions that the dead-zone slopes and the boundaries are equal and symmetric are removed by simplifying nonlinear dead-zone input model,the assumption that the priori knowledge of the control directions to be known is eliminated by utilizing Nussbaum-type gain technique and neural networks(NN) approximation capability.The possible controller singularity problem and the effect of dead-zone input nonlinearity are avoided perfectly by combining integral Lyapunov design with sliding mode control strategy.All the signals in the closed-loop system are guaranteed to be semi-globally uniformly ultimately bounded and the tracking error of the system is proven to be converged to a small neighborhood of the origin.Simulation results demonstrate the effectiveness of the proposed control scheme.  相似文献   

8.
In this paper, the stabilization problem is considered for the class of wireless networked control systems (WNCS). An indicator is introduced in the WNCS model. The packet drop sequences in the indicator are represented as states of a Markov chain. A new discrete Markov switching system model integrating 802.11 protocol and new scheduling approach for wireless networks with control systems are constructed. The variable controller can be obtained easily by solving the linear matrix inequality (LMI) with the use of the Matlab toolbox. Both the known and unknown dropout probabilities are considered. Finally, a simulation is given to show the feasibility of the proposed method.  相似文献   

9.
Design of secure operating systems with high security levels   总被引:2,自引:0,他引:2  
Numerous Internet security incidents have shown that support from secure operating systems is paramount to fighting threats posed by modern computing environments. Based on the requirements of the relevant national and international standards and criteria, in combination with our experience in the design and development of the ANSHENG v4.0 secure operating system with high security level (hereafter simply referred to as ANSHENG OS), this paper addresses the following key issues in the design of secure operating systems with high security levels: se- curity architecture, security policy models, and covert channel analysis. The design principles of security architecture and three basic security models: confidentiality, integrity, and privilege control models are discussed, respectively. Three novel security models and new security architecture are proposed. The prominent features of these proposals, as well as their applications to the ANSHENG OS, are elaborated. Cover channel analysis (CCA) is a well-known hard problem in the design of secure operating systems with high security levels since to date it lacks a sound theoretical basis and systematic analysis approach. In order to resolve the fundamental difficulties of CCA, we have set up a sound theoretical basis for completeness of covert channel identification and have proposed a unified framework for covert channel identification and an efficient backward tracking search method. The successful application of our new proposals to the ANSHENG OS has shown that it can help ease and speedup the entire CCA process.  相似文献   

10.
In this paper, the problem of output tracking for a class of uncertain nonlinear systems is considered. First, neural networks are employed to cope with uncertain nonlinear functions, based on which state estimation is constructed. Then, an output feedback control system is designed by using dynamic surface control (DSC). To guarantee the L-infinity tracking performance, an initialization technique is presented. The main feature of the scheme is that explosion of complex- ity problem in backstepping control is avoided, and there is no need to update the unknown parameters including control gains as well as neural networks weights, the adaptive law with one update parameter is necessary only at the first design step. It is proved that all signals of the closed-loop system are semiglobally uniformly ultimately bounded and the L-infinity performance of system tracking error can be guaranteed. Simulation results demonstrate the effectiveness of the proposed scheme.  相似文献   

11.
~~Feedback diagonal canonical form and its application to stabilization of nonlinear systems1. Aeyels, D., Stabilization of a class of non-linear systems by a smooth feedback control, Sys. Contr. Lett., 1985, 5: 289-294. 2. Behtash, S., Dastry, D., Stabilization of non-linear systems with uncontrollable linearization, IEEE Trans. Aut. Contr., 1988, 33(6): 585-590. 3. Byrnes, C. I., Isidori, A., Willems, J. C., Passivity, feedback equivalence, and the global stabilization of …  相似文献   

12.
For first-order nonlinear uncertain systems with delay, the analytical design of active disturbance rejection control (ADRC) with matched time delay is rigorously studied. The conditions of stabilizing the closed-loop system are studied in the form of parameters’ explicit sets such that the tuning laws of ADRC can be directly obtained and intuitively demonstrated in engineering practice. The necessary and sufficient condition of the asymptotical stability for the closed-loop system in the case of linear time-invariant is explicitly given. The condition of stabilizing the closed-loop system with nonlinear uncertain dynamics is quantitatively presented. Moreover, the water tank experiment illustrates the proposed tuning laws.  相似文献   

13.
针对具有非最小相位时滞的过程,基于Smith预估控制思想,提出一种改进控制方案,对右半平面零点和纯滞后同时进行补偿,使闭环特征方程中不含右半平面零点,从而简化控制器设计。根据期望闭环传函,解析得出PID控制器形式,综合负调、响应时间、ISE以及鲁棒性要求整定控制器参数,针对Smith控制抗扰性较差提出了抗扰性设计。仿真结果表明,该方案对于具有非最小相位时滞的对象有较好的控制效果,并且在模型失配和有干扰输入的情况下,有较好的鲁棒性和抗扰性。  相似文献   

14.
This paper deals with the problem of active disturbance rejection control (ADRC) design for a class of uncertain nonlinear systems with sporadic measurements. A novel extended state observer (ESO) is designed in a cascade form consisting of a continuous time estimator, a continuous observation error predictor, and a reset compensator. The proposed ESO estimates not only the system state but also the total uncertainty, which may include the effects of the external perturbation, the parametric uncertainty, and the unknown nonlinear dynamics. Such a reset compensator, whose state is reset to zero whenever a new measurement arrives, is used to calibrate the predictor. Due to the cascade structure, the resulting error dynamics system is presented in a non-hybrid form, and accordingly, analyzed in a general sampled-data system framework. Based on the output of the ESO, a continuous ADRC law is then developed. The convergence of the resulting closed-loop system is proved under given conditions. Two numerical simulations demonstrate the effectiveness of the proposed control method.   相似文献   

15.
16.
针对高阶次、多变量、强耦合的倒立摆系统,提出了基于自抗扰解耦控制方法对其进行控制。该方法采用双通道复合控制的方式,突破摆角和小台车相耦合作用的定位控制难点,完成摆角和小台车精确定位控制。采用该方法无需进行精确的输入变量与输出变量配对,只需要对控制作用的耦合矩阵进行静态解耦,分别构建控制通道。对于模型摄动造成的影响和各子对象间的动态耦合作用可由状态观测器(ESO,extended state observer)来估计并反馈到控制器以进行补偿。最终通过调节控制系统的相关参数,达到摆角和小台车位移相耦合作用的定位控制。仿真结果表明:该方法能够完成摆角和小台车位移相耦合作用的定位控制,瞬态性能和稳态性能好,超调量小,具有良好的控制效果。  相似文献   

17.
飞机俯仰运动自抗扰控制器设计   总被引:2,自引:1,他引:2  
提出了利用自抗扰控制器在大包线范围内设计飞机俯仰运动控制器的新方法.利用二阶自抗扰控制器补偿系统模型扰动和外扰,实现了纵向运动俯仰角变量的跟踪控制.自抗扰控制器直接依据飞机的非线性模型,符合飞机动力学模型摄动大的特点,在很大的包线范围内不需要改变控制器的结构和参数,简化了飞行控制律的设计过程.大包线范围内的仿真结果表明,系统具有良好的动态和稳态性能,控制器具有很强的鲁棒性,为解决大包线范围内的飞行控制问题提供了一种有效的新途径.  相似文献   

18.
This paper investigates iterative learning control of nonlinear discrete time non-minimum phase systems in tracking problems. The main objective of this paper is to find an input-to-output mapping in order to stabilize the non-minimum phase systems and to obtain an input update law for handling uncertain systems. In conventional approaches on the tracking of non-minimum phase systems, zero dynamics is stabilized from the system equations and the input is calculated from the state information. For the learning of uncertain systems, conventional approaches depend on the output-to-state and state-to-input mappings. In the proposed method, the inverse system is stabilized using the input-to-output mapping for nonlinear non-minimum phase systems. A new input update law is proposed based on the relative degree and the number of non-minimum phase zeros. This makes the overall proposed learning system have a simple structure as in the classical ILC.  相似文献   

19.
离散型自抗扰控制器在四旋翼飞行姿态控制中的应用   总被引:1,自引:0,他引:1  
本文首先介绍了自抗扰控制器的结构组成,包括跟踪微分器、扩张状态观测器以及非线性状态误差反馈律,及各部分的典型算法.针对四旋翼盘旋系统的姿态控制问题,设计了3种离散型自抗扰控制器,搭建了仿真结构图,并进行了参数整定,得到了优良的仿真结果.进而在实际装置上进行试验,调试出了令人满意的姿态实时控制结果.实时控制结果表明,文中所设计的自抗扰控制器可以满足控制精度及快速性的要求,并且具有抗干扰性能、稳定控制能力以及对非线性强耦合系统的解耦能力.最后,总结并分析了3种自抗扰控制器的优缺点及适用范围.  相似文献   

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