Flight Control System Design Of Laser Guided Bomb

As a precision strike weapon, the guided bomb more and more plays an important role in a modern war. The laser guided bomb with Proportional Navigation guidance law is a main kind of guided bomb, and has been developed in many countries. In this paper, the autopilot of this guided bomb is designed.Dynamic equations and kinematic equations are established for the design. Assuming that the body of the bomb is symmetrical and non-rolling, we decouple the motion equations into pitch, yaw and roll channels. Each channel is represented by a linearized model.A crucial technique in H-infinity mixed sensitivity design is how to properly choose the weighting functions that reflect both stability and performance requirements. This technique is carefully discussed. With the mixed sensitivity tool, the autopilots of pitch and yaw channels are designed, respectively. To test the control systems'robustness against the bomb system uncertainties and the command tracking performance of the designed systems, single channel simulation results are provided. The controller of the roll channel is designed with classical control tool.Comparing the mixed sensitivity design with a design based on the classical control tool, we conclude that the mixed sensitivity design achieves better robustness and command tracking performance. To verify the effectiveness of the H-infinity mixed sensitivity autopilot, we combine the three channels to simulate the six-degree of freedom motion of the guided bomb in a whole flight path. This simulation also proves that the H-infinity mixed sensitivity autopilot has better robustness against parameters'uncertainties, and it effectively attenuates disturbances and noises, and tracks an overload command rapidly.In order to intuitively show the variations of the guided bomb in a whole flight course, a three dimensional animation program is written in Matlab environment.