1 research outputs found
Nonlinear PID Controller Design for a 6-DOF UAV Quadrotor System
A Nonlinear PID (NLPID) controller is proposed to stabilize the translational
and rotational motion of a 6-DOF UAV quadrotor system and enforce it to track a
given trajectory with minimum energy and error. The complete nonlinear model of
the 6-DOF quadrotor system are obtained using Euler-Newton formalism and used
in the design process, taking into account the velocity and acceleration
vectors resulting in a more accurate 6-DOF quadrotor model and closer to the
actual system. Six NLPID controllers are designed, each for Roll, Pitch, Yaw,
Altitude, and the Position subsystems, where their parameters are tuned using
GA to minimize a multi-objective Output Performance Index (OPI). The stability
of the 6-DOF UAV subsystems has been analyzed in the sense of Hurwitz stability
theorem under certain conditions on the gains of the NLPID controllers. The
simulations have been accomplished under MATLAB/SIMULINK environment and
included three different trajectories, i.e., circular, helical, and square. The
proposed NLPID controller for each of the six subsystems of the 6-DOF UAV
quadrotor system has been compared with the Linear PID (LPID) one and the
simulations showed the effectiveness of the proposed NLPID controller in terms
of speed, control energy, and steady-state error