Modelling, control and development of GUI-based simulator for a quadcopter using nonlinear PID control

Quadcopters are a type of unmanned aerial vehicles (UAV) that are kept aloft by four rotors. They are gaining increasing popularity for a variety of applications. However, quadcopters can be difficult to control and are susceptible to disturbances such as wind gusts. In this paper, we present a method for modelling, controlling, and simulating a quadcopter. The complete mathematical dynamics of quadcopter motion is obtained using Newton-Euler formalism. Stabilisation and trajectory tracking of the quadcopter are achieved by designing a cascade control scheme with nonlinear PID controllers and linear PD controllers. The nonlinear PID controllers in the inner loop stabilise the attitude of the quadcopter, while the linear PD controllers in the outer loop produce the desired references of the inner loop. The nonlinear PID controllers use error scaling in the integral action to improve the stability and performance of the closed-loop system. Based on the nonlinear model and control laws derived in this work, a graphical user interface (GUI) simulator is developed in terms of combining visualisation with animation features. Then, the effectiveness of the proposed method is evaluated through a set of simulation works on the nonlinear mathematical model. The results show that the quadrotor reaches the desired position within 4 s and effectively stabilises at the appropriate time. The proposed simulator will help engineers and researchers to tune controller parameters or test the performance of the quadcopter. ©, Engineers Australia.