| المستخلص: |
In this thesis, two leader-follower formation control methods are proposed for a group of quadrotors that are stabilized by using the linear quadratic regulator (LQR) control technique. The quadrotor nonlinear model is first linearized at the hovering operating point. Comparison between the time response of the nonlinear model and the obtained linear one shows a good estimation with a certain range around the operating point. Then an LQR controller is designed to stabilize the linear model. Comparison the closed loop of both the linear and nonlinear models is presented. The leader-follower approach is used to achieve formation control where the position and the heading of the leader are used with offsets as references to be tracked by the follower. To obtain shape formation, the offsets are set to achieve the shape specifications. Two shape formation methods are used to achieve a prescribed formation flight. In the first method, the potential field technique is used to achieve a desired formation. The attractive potential field attracts the followers towards the leader while the repulsive potential field repulses each two neighboring followers in order to keep a distance between them. In the second method, the followers positions that achieve the required formation are obtained from the geometry of the desired formation shape. These followers positions are expressed in equations that relate them to the leader position and then given to the followers as references to be followed. An extensive simulation is presented to examine the validity of the results. In all simulations, a real quadrotor simulation is used as a leader which is given a desired path as a set reference while the followers are required to form a prescribed shape around that leader.
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