Six Degree-of-Freedom Nonlinear H Helicopter Control

Ciann Dong Yang, Chi Chung Luo, Chien Chung Kung, Yeong Hwa Chang

Research output: Contribution to journalArticlepeer-review


The purpose of this paper is to develop a nonlinear H controller for helicopter to improve its flight performance and stability under large-range exogenous disturbances or perturbations. The nonlinear H helicopter control is a very new topic to be developed in the international researches. In this issue, the nonlinear H helicopter controller will directly merge into the nonlinear helicopter mathematical model with six degree-of-freedom (DOF6) to perform nonlinear control. It is quite different to the procedure in linear control, which has to linearize the DOF6 equations of motion with respect to some trim condition. Hence, linear control theory is not valid for large flight envelope. Nonlinear H control can cover large flight envelope without using gain-scheduling mechanism, and can effectively conquer the difficulties encountered in linear control. The Hamilton-Jacobi Partial Differential Inequality (HJPDI) related to the nonlinear H helicopter control is solved analytically in this paper, and its implementation by helicopter aerodynamic pitch control is also investigated in details. We will show the differences in responses of the control system established by nonlinear DOF6 simulations between the nonlinear H controller and linear one. At last we will discuss the influence on the system response when the shaping parameters in the nonlinear H controller are changed.

Original languageEnglish
Pages (from-to)215-227
Number of pages13
JournalZhongguo Hangkong Taikong Xuehui Huikan/Transactions of the Aeronautical and Astronautical Society of the Republic of China
Issue number3
Publication statusPublished - 2002 Sep 1

All Science Journal Classification (ASJC) codes

  • Aerospace Engineering


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