Abstract:A finite time backstepping control strategy is proposed for a class of uncertain nonlinear systems with asymmetric time-varying output constraints and input delay. Firstly， a new nonlinear transformation function that transforms the constrained system into an unconstrained system is proposed to solve the asymmetric time-varying output constraint. Secondly， To deal with the “explosion of complexity” problem of backstepping control， a new finite-time filter is constructed， where the filter error is eliminated by an error compensation mechanism. Then the Pade approximation method and intermediate variable are applied to compensate for the influence of input delay on the control system. According to the Lyapunov theory， the finite-time stability of the closed-loop system is proved， and the output does not violate the constraint. Finally， the effectiveness of the new filter and finite-time control strategy is verified by the comparative simulation of the filter and the simulation of a manipulator system.

Abstract:For the tedious parameter settings of sliding mode controller of bridge crane and insufficient global searching ability of Cuckoo Search（CS），an improved Cuckoo Search algorithm based on adaptive crossover operation point selection（ASCP-CS） was proposed and applied to the adjustment of parameters for the sliding mode controllor of bridge crane. The ASCP-CS algorithm improves the adaptive searching steps based on the CS algorithm, and introduces the adaptive selecting chromosome crossover points in the crossover operation. The test results of four typical optimization functions show that ASCP-CS algorithm has better optimization accuracy and search ability. The sliding mode controller of bridge crane is tuned by different optimization algorithms. It is showed in the simulation results that the controller based on ASCP-CS algorithm can locate the payload more quickly, suppress the swing of the payload more effectively and has strong robustness.

Abstract:A particle filter method based on fruit fly optimization algorithm is proposed to alleviate the sample impoverishment caused by resampling. When fruit flies forage, they usually fly from low concentration areas to high concentration areas efficiently and constantly. This optimum process is introduced into the particle filter to drive particles towards the high likelihood areas ceaselessly, and thus improves the overall quality of the particle swarm. Considering that the premature convergence is always associated with the fruit fly optimization algorithm, crossover and mutation operations of genetic algorithms are applied herein adaptively to keep the diversity of samples. Firstly, the particle distribution is improved by cross operation. When the algorithm falls into the local optimum, the Cauchy mutation perturbation is then used to help the fruit fly optimization algorithm jump out of the local optimal point effectively and continue searching for global extremum. The nonlinear simulations and target tracking experiments show that the proposed algorithm improves the estimation accuracy of the nolinear systems state, and it has better stability and reduces the number of particles required for state estimation at the same time.

Abstract:The relationships between the input energy of elastic multi-degree-offreedom systems and that of equivalent single-degree-of-freedom systems were derived.Based on the energy responses of 3 frame tube structures to 12 ground motion records,a simple calcula

Abstract:With in mind the inverse model identification problems in inverse system method,this paper studied the realization of inverse system identification and control using support vector machines(SVM),and proposed a compound control strategy combing SVM inverse

Abstract:An online adaptive fuzzy neural network identification and robust control approach were proposed for the adaptive control problem of SISO nonlinear system.First,the generalized fuzzy neural network(G-FNN) learning algorithm was used to model the unknown s

Abstract:By introducing a parameter transformation and based on a hypothesis, the strongly nonlinear conservative system was transformed into a weakly nonlinear conservative system, whose solution was expanded by Fourier series. Thus the approximate resonance cyc

Abstract:The robust stabilization problem of a class of uncertain nonlinear systems with mismatched uncertainties is investigated in this paper.Applying Lyapunov direct method,a design method of continuous robust controller is proposed based on the upper bounds of

Abstract:This paper presents a new design method of observers for the class of nonlinear systems with Lipschtz nonlinearity,our results show that the stability of the nonlinear observers for such systems is not determined purely by the Eigenvalues of the linear st

Abstract:The stroboscopic method presented by Li Li for the study of strongly nonlinear systems with single degree of freedom is extended to systems with many degrees of freedom.By using the method,the stroboscopic equations are set up and the approximate expressi