M. XIN, Member, IEEE
S. N. BALAKRISHNAN
University of Missouri–Rolla
In this paper, a new nonlinear He control technique, called q–D He method, is employed to design a missile longitudinal autopilot. The q–D He design has the same structure as that of linear He, except that the two Riccati equations that are part of the solution process are state dependent. The q–D technique yields suboptimal solutions to nonlinear optimal control problems in the sense that it provides an approximate solution to the Hamilton-Jacobi-Bellman (HJB) equation. It is also shown that this method can be used to provide an approximate closed-form solution to the state dependent Riccati equation (SDRE) and consequently reduce the on-line computations associated with the nonlinear He implementation. A missile longitudinal autopilot design demonstrates the capabilities of q–D method. This new nonlinear He design also shows favorable results as compared with the linear He design based on the linearized model.
Manuscript received May 10, 2004; revised May 28, 2005; released
for publication January 16, 2007.
IEEE Log No. T-AES/44/1/920387
Refereeing of this contribution was handled by Y. Oshman.
This work was supported by grants from the Naval Surface Warfare
Center through Anteon Corporation.
Authors' addresses: S. N. Balakrishnan, Dept. of Mechanical and
Aerospace Engineering, University of Missouri–Rolla, 1870 Miner
Circle, Rolla, MO 65401, E-mail: (bala@umr.edu); M. Xin, Dept. of
Aerospace Engineering, Mississippi State University, Jackson, MS
39762, E-mail: (xin@ae.msstate.edu).
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