Spherical Inverted Pendulum on a Quadrotor UAV: A Flatness and Discontinuous Extended State Observer Approach

This article addresses the problem of balancing an inverted spherical pendulum on a quadrotor. The full dynamic model is obtained via Euler-Lagrange formalism, where dynamics coupled to quadrotor, taking as control inputs torques associated with yaw, roll, and pitch dynamics, input for vertical displacement in height. A trajectory tracking scheme proposed by means active disturbance rejection based discontinuous extended state observer (ADRC-DESO) that allows controlling system translational quadrotor including rotational dynamics. To address this problem, linearized around equilibrium point, into consideration operates close vicinity points, thus considerably simplifying model. Proving linear controllable therefore differentiable flat, flat outputs are displacements three cartesian axes Euclidean space, yaw allowing parameterize system. Simulation results well convergence analysis validate performance strategy.