Guilherme V. Raffo

An integral predictive/nonlinear H∞ control structure for a quadrotor helicopter

This paper presents an integral predictive and nonlinear robust control strategy to solve the path following problem for a quadrotor helicopter. The dynamic motion equations are obtained by the Lagrange-Euler formalism. The proposed control structure is a hierarchical scheme consisting of a model predictive controller (mpc) to track the reference trajectory together with a nonlinear H~ controller to stabilize the rotational movements. In both controllers the integral of the position error is considered, allowing the achievement of a null steady-state error when sustained disturbances are acting on the system. Simulation results in the presence of aerodynamic disturbances, parametric and structural uncertainties are presented to corroborate the effectiveness and the robustness of the proposed strategy.

Backstepping/nonlinear H ∞ control for path tracking of a quadrotor unmanned aerial vehicle

This paper presents a nonlinear robust control strategy to solve the path tracking problem for a quadrotor unmanned aerial vehicle. The helicopter motion equations is obtained by the Lagrange- Euler formalism. The control structure is performed through a nonlinear Hinfin controller to stabilize the rotational movements and a control law based on backstepping approach to track the reference trajectory. Finally, simulations results in presence of aerodynamic moments disturbances and parametric uncertainty is carried out to corroborate the effectiveness and the robustness of the strategy proposed.

Nonlinear H∞ Controller for the Quad-Rotor Helicopter with Input Coupling

Abstract This paper presents a nonlinear H∞ control law for underactuated mechanical systems with input coupling. Apart from the controlled degrees of freedom (DOF), the proposed controller considers the dynamics of the remaining DOF in the cost variable, which allows to stabilize them. The underactuated mechanical system is normalized to obtain a diagonal inertia matrix allowing to weigh with various criteria different DOF. This controller is applied to the quadrotor helicopter to perform path tracking, whose mechanical structure has been modified in order to obtain coupling between longitudinal and lateral movements with roll and pitch motions. Simulation results in presence of aerodynamic disturbances, structural and parametric uncertainties are presented to corroborate the effectiveness and the robustness of the proposed controller. Copyright

Path Tracking of a UAV via an Underactuated Control Strategy

In this study, a nonlinear robust control strategy designed for underactuated mechanical systems is proposed in order to solve the path tracking problem for a quadrotor unmanned aerial vehicle. An underactuated nonlinear controller based on the six degrees of freedom dynamic model is designed to control the helicopter attitude and altitude in the inner-loop. The outer-loop control is performed using a model-based predictive controller ( MPC ) to track the reference trajectory. The robust performance achieved with the proposed control strategy is checked by simulation in the presence of aerodynamic disturbances, unmodelled dynamics and parametric uncertainties.

MPC with Nonlinear ℋ∞ Control for Path Tracking of a Quad-Rotor Helicopter

Abstract This paper presents a predictive and nonlinear robust control strategy to solve the path tracking problem for a quadrotor helicopter. The dynamic motion equations are obtained by the Lagrange-Euler formalism. The control structure is performed through a model-based predictive controller (MPC) to track the reference trajectory and a nonlinear ℋ ∞ controller to stabilize the rotational movements. Simulations results in presence of aerodynamic disturbances and parametric uncertainty are presented to corroborate the effectiveness and the robustness of the proposed strategy.

An application of the underactuated nonlinear ℋ ∞ controller to two-wheeled self-balanced vehicles

This paper presents an application of the nonlinear ℋ∞ controller to two-wheeled self-balanced vehicles. An underactuated mechanical control system representation under input coupling is used to design the control law. To achieve null steady-state error when persistent disturbances are acting on the system, the integral of the position error is considered in the state vector. Practical results obtained in experiments using a two-wheeled vehicle equipped with an embedded microcontroller system are presented. These results corroborate the good features of the proposed controller in presence of external disturbances, extreme initial conditions and unmodeled dynamics.