Real Time Parameter Estimation For Reconfigurable Control Of Unstable Aircraft

The real time open loop parameter estimation of unstable/augmented aircraft is very essential for reconfigurable/adaptive control. This report describes two parameter estimation algorithms that are based on the equation error minimization principle. One is the recently developed, well-established recursive DFT technique in frequency domain. The other is a novel application of RLS in equation error minimization concept, applied, perhaps, for the first time to unstable/augmented aircraft parameter estimation. This technique is implemented by a methodology that is analogous to the recursive DFT technique. Hence, in time domain, this can be viewed as a counter part of recursive DFT. The algorithms are implemented and tested for robustness against measurement noise. For the implementation, data was generated under realistic conditions from simulation software that captures the dynamics of an unstable high performance aircraft, which is stabilized by full authority control laws. The results bring out the pros and cons of the algorithms and show their suitability for modeling of unstable aircraft, for subsequent adaptive/reconfigurable control or fault diagnosis