Journal of Systems Engineering and Electronics ›› 2014, Vol. 25 ›› Issue (1): 129-137.doi: 10.1109/JSEE.2014.00015

• CONTROL THEORY AND APPLICATION • Previous Articles     Next Articles

Direct adaptive control for a class of MIMO nonlinear discrete-time systems

Lei Li1,2,* and Zhizhong Mao1   

  1. 1. Automation Institute, College of Information Science and Engineering, Northeastern University, Shenyang 110004, China;
    2. College of Electricity Information and Automation, Qufu Normal University, Rizhao 276826, China
  • Online:2014-02-25 Published:2010-01-03


This paper considers the problem of adaptive control for a class of multiple input multiple output (MIMO) nonlinear discrete-time systems based on input-output model with unknown interconnections between subsystems. Based on the Taylor expand technology, an equivalent model in affine-like form is derived for the original nonaffine nonlinear system. Then a direct adaptive neural network (NN) controller is implemented based on the affine-like model. By finding an orthogonal matrix to tune the NN weights, the closed-loop system is proven to be semiglobally uniformly ultimately bounded. The σ-modification technique is used to remove the requirement of persistence excitation during the adaptation. The control performance of the closed-loop system is guaranteed by suitably choosing the design parameters.