Nonlinear Formation Control of Small Fixed-Wing UAVs with Velocity and Heading Rate Constraints

To achieve a desired formation of multiple unmanned aerial vehicles (UAVs), especially small and identical fixed-wing UAVs with limited computational capability, a practical leader-follower formation control method based on nonlinear control with positive velocity and saturated heading rate constraints is proposed in this paper, in which a heading angle controller is developed with least turn logic and a velocity controller based on a geometric method is designed with acceleration constraint to guarantee the formation keeping performance. In addition, a proportional derivative (PD) controller for acceleration is applied to smooth the velocity response of each vehicle. Finally, simulations of 5 UAVs in different situations are carried out to verify the effectiveness of the proposed method, both the trajectory tracking and formation keeping performance is as expected.