Attitude Tracking And Formation Control Algorithm Based On Uncertain Signal Estimator

With the increasing demands of task performance and battlefield survivability ofthe aircrafts, there are so many important application prospects for multi-aircraftformation flight collaborating to complete the tasks. However, the complex flightenvironment and the uncertainties of the model, seriously affect the performance of theflight control system. Therefore, we need to do lots of research for the attitude controland formation control technology, which is robust for the external disturbances and theuncertainties of the model.Robust flight control technology, based on the uncertain signal estimator, isproposed in this dissertation, whose research contents includes four parts: modelanalyses of the dynamics characteristics, pitch-channel’s robust attitude trackingcontrol technology, three-channel’s attitude robust tracking control technology basedon the quaternion model, multi-aircraft planar formation’s robust flight controltechnology based on the theory of the consistency of multi-agent. Specifically, thedissertation is completed as follows:At first, the aircraft’s model of the whole quantity equations is established inMatlab. On this basis, we analyze the coupling characteristics of the three-axis attitudedynamics, simply deduce the approximate decoupling form of the three-axis attitudedynamics model of Euler angles, and elaborate the relationship between the Eulerangles description and the quaternion description. All these are laying the foundationfor the pitch-channel robust attitude control technology and the three-axis attituderobust control technology based on the quaternion model.Next, for the pitch-channel attitude tracking problem with the model underuncertainties, considering the attitude angular rate signal measurable and immeasurableboth cases, two corresponding robust attitude control laws are designed with the helpof the uncertain signal and disturbance estimation, and compared with the conventionalPID control law, and the simulation results of all the control schemes are given.Then, for the three-axis attitude tracking problem with the model under uncertainties, considering the attitude angular rate signal can be measured andunmeasured both cases, two corresponding robust attitude tracking control laws aredesigned with the comprehensive utilization of sliding mode control technology andthe uncertain signal and disturbance estimation technique, and compared with anothersliding mode control law without estimator, which does not deal with the uncertainsignals and external disturbances, and all the simulation results are given afterwards.Finally, for the planar formation control problem of many small aircrafts, adistributed formation control law is designed by means of multi-agent consistencytheory. The ideal formation flight control, which means there are no externaldisturbances or model uncertainties, is considered first. Then taking the disturbancesand uncertainties into consideration, analyzes and compares the different planarformation control laws with estimator and without estimator. On this basis, thisdissertation shows different simulation results.