(1.College of mechanics and aerospace, Hunan University, Changsha, 410082;2. Faculty of Architectural,Civil Engineering And Environment of Ningbo University, Ningbo,315211)
The dynamic behavior of the second class of non-trivial equilibrium points on 4D Qi system is analyzed,and a bifurcation diagram corresponding to the second class of equilibrium points is drawn. A parametric adaptive controller is presented utilizing the observations of the system variables. The controller can correct the perturbations of the parameter and ensure the stability of the controlled system. The Lyapunov function is used to prove that the parameter control system is asymptotically stable. The numerical simulation results are shown that the control method is of very quick convergent speed.