The altitude and yaw angle channel is decoupled, and
the change is so small that it is negligible.
The variation of speed in the forward and lateral
directions of four follower quadrotor and the leader
quadrotor in the formation is shown in Figure 11.
Figure 11: The speed in the forward and lateral
directions of five quadrotors
As can be seen from Figure 10 and Figure 11,
leader and followers form a stable formation at about
7 seconds. After that, formation configuration can be
maintained nice in the case of a variety of movements
in the leader quadrotor. Among them, under the
condition of unidirectional linear uniform motion and
uniformly variable motion of the leader, the speed in
the forward and lateral directions of any follower will
converge to the speed value of the leader. Under the
condition of curvilinear motion of the leader, the
speed of the follower in the outer circle will become
larger in order to keep the formation configuration,
the speed of the follower in the inner circle will
become smaller and even move in reverse in order to
keep the formation configuration. In this process,
although the speed of any follower will not converge
to the speed value of the leader, the formation
configuration has been kept very well. If the leader
quadrotor is allowed to continue to do circular motion,
the speed in the forward and lateral directions of any
follower will converge to a corresponding value.
5 CONCLUSIONS
This paper uses the combination of classical PI
control and feedforward control to design the
guidance law of autonomous formation of multiple
quadrotors. Simulation results of single quadrotor
trajectory tracking and formation of five quadrotors
are given. The accuracy and response speed of
trajectory tracking are verified. The formation control
law as a top layer controller commands the position
and controller of single quadrotor. Simulation results
show that the guidance instruction generated by the
presented formation control law can guide the
followers to form expected formation configuration
and keep the formation quite well.
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