The Development of Neural Network Based System Identification ...

Chapter 7
FLIGHT CONTROL SYSTEM DESIGN: RESULTS
AND DISCUSSION
7.1 INTRODUCTION
This chapter presents the validation results of the proposed NN based predictive
controller discussed in Chapter 6. The flight tests were carried out in the experimental
test rig mentioned in Section 3.3, in order to validate the performance of the proposed
system identification and control methods in autonomous hovering flight. This chapter
describes the implementation of the experiments in Section 7.2, including the alteration
of the software program to reduce computation time in Subsection 7.2.1. Section 7.3
presents the experimental results of the proposed flight controller. In Subsection 7.3.1,
the tuning procedures are discussed and results on the effect of the tuning parameters are
given for the NNAPC with the recursive NN training. After the best tuning parameters
for each controller have been determined, the tracking performance for each controller is
compared under parameter variations and discussed in Subsection 7.3.3. The robustness
of controllers is also tested under input disturbance in this subsection. Finally, the
chapter summary is given in Section 7.4.
7.2 FLIGHT TESTS IMPLEMENTATION
The automatic flight controller can be designed incrementally where the experiments
are split in several development stages. The best tuning parameters obtained in these
development stages are then used as the basic tuning parameters in the design of the
hovering (4 DOF) flight controller. The pitch and roll dynamics can be tested together or