Journal of Systems Engineering and Electronics ›› 2010, Vol. 21 ›› Issue (6): 1063-1071.doi: 10.3969/j.issn.1004-4132.2010.06.020

• CONTROL THEORY AND APPLICATION • Previous Articles     Next Articles

Control of static unstable airframes

Junfang Fan1,*, Defu Lin2, Zhong Su1, and Qing Li1   

  1. 1. School of Automation, Beijing Information Science and Technology University, Beijing 100101, P. R. China;
    2. School of Aerospace Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
  • Online:2010-12-20 Published:2010-01-03


The challenge and control problems of static unstable missiles are presented. The steady-state benefits of static instability are illustrated, while the corresponding control challenge is described both by the characteristic lag of airframe and the increment of necessary control usage. Control limitation led by unstable zero-pole pair is analyzed for preliminary design and evaluation. Linear control strategy is examined wherein two and three loop acceleration autopilots with different control usages are developed using an optimal control approach combined with frequency domain constraint. The weights selection and relation with system performance are detailed. Then the nonlinear backstepping recursive method is detailed to determine how well it is able to follow command and its engineering feasibility. The results show that a static unstable missile is controllable, while the actuator bandwidth is the crucial limited factor. There should be a compromise between overall performance and actuator payment.

Key words: missile control, static instability, optimal control, backstepping, weight matrix, unstable zero-pole pair