ABSTRACT
Traditionally, a missile autopilot is designed using linear control approaches. The plant model is linearized around a given trim point and then used for the resultant controller design [4, 15]. The initial design is then carried out by assuming that no coupling exists between the roll, pitch, and yaw axes. Thus, the controllers are designed individually for each axis. The pitch, yaw, and roll channel control system parameters are selected based on relative stability margins (Bode methods) and missile response time requirements. The guidance loop provides the required pitch and roll axis acceleration commands, whereas the yaw axis control loop operates in a regulator mode. In order to obtain consistent performance throughout the operational envelope of the missile, gain scheduling is used. Generally, control system parameters are scheduled with respect to slowly varying parameters like Mach number, dynamic pressure, altitude, and weight. Interpolation techniques are used to
CONTENTS
4.1 Introduction ................................................................................................ 129 4.2 Nonlinear Air-Air Missile Model ........................................................... 133 4.3 Missile Autopilot Control Loop Design ................................................. 135
4.3.1 Outer Loop Control Design .......................................................... 136 4.3.1.1 Upper Bound on Estimation Error ............................... 138 4.3.1.2 Upper Bound of Neural Network Weights ................. 139 4.3.1.3 Outer Loop Controller Design ...................................... 140
4.3.2 Inner Loop Control Design .......................................................... 140 4.3.3 BTT/STT Command Logic............................................................ 142
4.4 Simulation Studies ..................................................................................... 143 4.4.1 Performance at Various Altitude Conditions............................. 149
4.5 Conclusions ................................................................................................. 154 Acknowledgment ................................................................................................ 154 References ............................................................................................................. 155
obtain the controller gains at intermediate points. The nal control system parameters are chosen based on a six-degrees-of-freedom nonlinear simulation analysis.
