In this paper, an adaptive sliding mode neural network(NN) control method is investigated for input delay tractor-trailer system with two degrees of freedom. An uncertain camera-object kinematic tracking error model of a tractor car with n trailers with input delay is proposed. Radial basis function neural networks(RBFNNs) are applied to approximate the unknown functions in the error model. A sliding mode surface with variable structure control is designed by using backstepping method. Then, an adaptive NN sliding mode control method is thus obtained by combining Lyapunov-Krasovskii functionals. The controller realizes the global asymptotic trajectories tracking of the kinematics system. The stability of the closed-loop system is strictly proved by the Lyapunov theory. Matlab simulation results demonstrate the feasibility of the proposed method.
宏观经济和证券市场的关系一直受到人们的关注,由于数据的选取和研究方法上的不同,导致宏观经济与证券市场的关系存在不同的结论或解释。从名义 GDP 和上证指数发展速度的视角,运用 HP 滤波以及 SVAR 等方法实证研究了宏观经济和证券市场的关系。研究发现:宏观经济和证券市场存在显著的因果关系;短期证券市场的波动是经济偶然性波动的预期,两者之间的滞后期效应与当期效应相互影响;方差分解表明宏观经济对于证券市场的长期贡献度很大。 相似文献