首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
ZHOU Ping 《保鲜与加工》2003,(10):104-107
According to the theory of parameters adaptive control and variable driving, for a kind of discrete nonlinear chaotic systems, a method of chaotic synchronization is presented for different system parameters. In the equation of parameters adaptive control, control coefficients are chaotic signal. Because control coefficients are constant usually for the former parameters adaptive control, so the parameters adaptive control method is very universal, namely the former parameters adaptive control methods are special examples in our control method. Simulation results show that this method is available.  相似文献   

2.
A fuzzy adaptive tracking control scheme is proposed for MIMO nonlinear time-varying delay systems. A fuzzy T-S model-based adaptive time-varying delay fuzzy logic systems is developed to approximate the unknown nonlinear time-varying delay functions.Thus, the modeling to nonlinear systems is implemented. The update laws for parameters of the fuzzy logic systems are derived by the tracking error. A Hcompensator is designed to eliminate fuzzy approximation errors and external disturbances. Based on Lyapunov stability theorem, the proposed control scheme can guarantee the stability of the closed loop systems and obtain anticipant Htracking performance as well. Simulation results of the manipulator demonstrate the effectiveness of the control scheme.  相似文献   

3.
Because parameter disturbed exist every practical system,so chaos synchronization for different system parameters is availabe. Chaos synchronization of continuous system for different system parameters is studied with the relation between chaotic synchronization and asymptotic stability, parameter adaptive and driving feedback. Lorenz system is used to verify the effectivenss of the proposed method,and the simulation results confirm it.  相似文献   

4.
Based on the good chaotic properties of tangent delay ellipse reflecting cavity mapping system (TD ERCS), a kind of novel substitution boxes were constructed. The cryptographic properties, such as bijection, nonlinearity, strict avalanche, independence of output bits, the differential approximation probability and the nonlinear approximation probability of the S box are analyzed. The investigation method for the strength of the S box with the discrete chaotic system proposed by Kocarev is discussed. Theoretical analysis and backtesting results show that the method is efficient and easy to put into practice, while the constructed S boxes show better cryptographic properties than the S boxes based on other chaotic system, which can be used to improve the existing encryption scheme.  相似文献   

5.
The two-level handstand pendulum system based on fuzzy control is designed. It is impossible to adopt classical control theory, for the mathematical modeling of the system is nonlinear, the fuzzy control is proposed to improve the former linear control algorithms. For the key to fuzzy control is control rule, it becomes most important to design suitable fuzzy rules. Two methods, one based on experience and the other based on system simulation, are presented to set u Pan effective rule base. The practice proves that the control result is of well stability. A control example for two-level handstand pendulum system shows that the control law is efficient and more robust than the classical state feedback optimal control law with respect to errors produced by the external disturbances.  相似文献   

6.
In system controlled,Sampling these parameters and with parameters for controller in time, it is an object to adaptive control. The article presents a scheme that the structure parameters on it's model and model parameters is robust identified by on line, while to optimal of algorithm on adaptive control is fulfilled. In control scheme, method of intelligent identifying to the structure parameters(levels of model) and algorithm of robust pole placement are introduced also It is advancer for already mentioned scheme. Whole scheme presents new model on adaptive control.  相似文献   

7.
An adaptive robust L2design method with dead -zone modification is proposed for a class of nonlinear systems with external disturbances and uncertain parameters. With priori knowledge of the bounds of the parametric uncertainties, the smooth projection method and the dead zone modification technology are incorporated into the adaptive laws to prevent parameter drifting and reduce the computation burden. The number of parameter estimates is minimal for the adaptive system. The algorithm can guarantee the tracking errors asymptotically converge to the desired dead zone if the external disturbances are zero. The system satisfies L2 disturbance rejection criterion when the external disturbances are considered.  相似文献   

8.
This paper presents a new method of self tuning adaptive control which adopts a neural network to identify the characteristics of a second order nonlinear system, which is in turn applied to adaptive control. The simulations show that the method has good capability of sduty and adaptation.  相似文献   

9.
An improved predictive control method is presented to compensate the random time delay in the networked control system. The feedback time delay is compensated by predictive controller based on softened increment input strategy. The forward time delay is unknown for controller, so an extra feedback loop is added to compensate the delay by estimating the error between the actual control signal effected on plant and the output of controller in historical moment. For the controlled system with unknown or slowly varying parameters, the networked feedback correction algorithm is discussed based on a modified recursive least-squares identi cation algorithm. The system stability is analyzed and the simulation results show that the time delay in the networked control system can be accurately compensated. The excellent network performance is ensured with this strategy.  相似文献   

10.
With the development and complication of power system, the problem of low frequency oscillation in electric network becomes obvious. Unified Power Flow Controller is one of the most powerful facilities in Flexible AC Transmission Systems, which can improve the transient stability and damp the low oscillation in power system with suitable control. Considering the characteristics of inverter's output voltage magnitude, adjustment of phase and process of charge and discharge of dc capacitance, the dynamic model of UPFC is proposed by a series of nonlinear differential coefficient equations. Based on UPFC's dynamic model, the linear optimal controller of UPFC with state feedback is proposed. In this way, the low frequency oscillation is damped effectively. A simulation is processed basing the theory.  相似文献   

11.
A method of detecting the signal frequency which is disturbed by the noise based on the autonomous chaotic system is proposed. A signal with noise was added to an autonomous chaotic system, and then a negative feedback was imposed to it. The feedback gain was appropriately adjusted, so as to let the noisy system orbit be a limit cycle. The number of times that the orbit went directly through a plane was calculated by loop phase technology, and the vibration frequency was found according to it. The frequency of system is determined by the frequency of the test signal, yet free from noise, so the frequency of the test signal is the vibration frequency of the system. Simulation results further demonstrate the effectiveness of the method.  相似文献   

12.
Based on the fuzzy control technology,the feedback control method of synthesized yaw rate and side slip angle is presented for the ESP system.The influence of nonlinear characteristics of tires on cornering characteristics and driving stability of vehicle is considered.The nonlinear tire model(Magic Formula) is adopted,and the four-wheel vehicle model with two degrees of freedom and a vehicle reference model are set up on this basis.Then the fuzzy controller of yaw rate and the fuzzy controller of side slip angle are designed and a simulation model generated by Simulink software is used.Simulation results show that the lateral stability of vehicle can be enhanced by controlling yaw rate and side slip angle with the synthesized feedback control method.  相似文献   

13.
An adaptive robust control based on synthetical algorithm was presented in this paper. The main character is to put the expert knowledge into parameter identification to realize the robust estimation, and combine the generalised minimum variance control with the pole assignment control for improving the robustness of the controller. Numerical simulation has proved that the control scheme suggested by authors quite prevailed over the general adaptive controller in control effects.  相似文献   

14.
Some control schemes for complex nonlinear systems have been developed recently and the robotic adaptive control is one of the typical examples. Due to the inevitable presence of unmodeled dynamics,if the adaptive control technique combined with nonlinear model-based control takes full advantages over any known parametric model while dealing with the remaining unknown parameters by using adaptive control,it may be an efficient control strategy, therefore.an algorithm of computed torque-self tuning control for robot is presented, whose simulation results have proved its effectiveness.  相似文献   

15.
In order to improve the long-playing frequency tracking ability in the signal processing for coriolis mass flowmeter (CMF) , a new IIR adaptive notch filter (ANF) is developed via steiglitz-mcBride method (SMM) and applied to filter the sensor output signal whose frequency, amplitude and phase are time-varying following the random walk model. The proposed method can detect the signal frequency fleetly and track the frequency variations continuously. The tracking performances of the proposed method and the adaptive lattice notch filter (LANF) method are investigated with computer simulations. Simulations demonstrate the superiority of the proposed method and show it has advantages of fast convergence rate, insensitivity to initial phase variations, and higher long-playing tracking stability and accuracy than LANF method.  相似文献   

16.
A method based on radial basis function networks for forecasting chaotic time series is proposed.The nonlinear time series identification problem is formulated with a nonlinear autoregressive moving average(NARMAX)model then a new identification algorithm based on dynamic radial basis function networks is proposed.Then this method is applied to the estimation of embedding dimension for chaotic time series of Henon mapping and the confirmation of the chaotic phenomena in stock markets of China,from which one can get the desired results.Further research directions are also pointed out.  相似文献   

17.
The authors introduce the applied issue of optics navigation in systems new traffic method,Bus Rapid Transit-BRT.They apply Hough switch to dispose sampling image,through the road tracking system navigation emulate educed instantaneous road curve function,and provides vehicles instantaneous road information.By using error feedback control to control vehicles' orient, they put forward the concretely application method of the optics navigation technique in BRT.  相似文献   

18.
A mathematic model for filtering reducer transmission robots which have the characteristics of parameter uncertaintiesexternal disturbancestrong couplingnonlinearities and multi-variable is establishedand then an adaptive RBF networks backstepping method is proposed to control the robot.RBF is employed to approach the nonlinear item of the filtering reducer transmission robot on lineand an adaptive RBF network controller is developed based on backstepping method which effectively suppresses the effect of parameter uncertainties and external disturbance etc.It is combined with Lyapunov stabilization analytical method to demonstrate the close loop system convergence.Simulation results verify that the proposed controller not only satisfies high performance position trackingbut also has good accuracy and robustness.  相似文献   

19.
A 3-degrees of freedom multi-axle vehicle dynamic model is established.Taking account of the practical difficulties for measuring the sideslip,rolling angles and rolling angle speed,a Luenberger observer is designed,and the simulation and analysis of the Luenberger observer are performed.The results show that the Luenberger observer has excellent characteristics in the considered speed range in tracking path.Then,a state feedback controller is designed on the basis of the Luenberger observer,and simulation of a multi-axle vehicle is also carried out.The results show that the performances of a multi-axle vehicle with the proposed control strategy is better than a multi-axle vehicle with front wheel steering strategy,and its control system has fine dynamic characteristic and strong robustness,so multi-axle vehicle with the proposed control strategy can improve vehicle handling stability and security.  相似文献   

20.
The relative motion model of UAVs formation flight is constructed with tensor analysis, and the system energy function is constructed with the estimations of the external disturbances during flight. According to Lyapunov stability criterion, an adaptive robust control law is presented to keep the UAVs formation flight. The research results show that the proposed UAVs formation flight tensor model has broad applicability, and provides new ways to the further research of the UAVs formation flight as well as new ways to overcome the computing problem resulting from the singular point of the body frame, while the proposed control law is simple and effective.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号