Hugo Rodríguez-Cortés

Nonlinear motion control of a rotary wing vehicle powered by four rotors

In this paper a nonlinear controller for motion control of a rotary wing vehicle powered by four rotors is presented. The proposed controller is based on the well known backstepping control design technique. The control system design proposed is validated through numerical simulations

Basic Small Fixed Wing Aircraft Sizing Optimizing Endurance

In this paper we address the endurance optimization problem for an electric powered fixed wing aircraft. An endurance equation in terms of aircraft aerodynamics and electric power plant characteristics is obtained. The endurance equation is optimized as a nonlinear problem and handled using optimization constrained techniques. This gives an optimal basic aircraft sizing with maximum endurance.

Robust trajectory tracking control of a quadrotor helicopter

In this paper, a nonlinear controller endowed with a disturbances estimator, based on the Immersion and Invariance control technique, is proposed. This nonlinear controller is applied to the six degrees of freedom dynamics of the quadrotor helicopter to achieve regulation and trajectory tracking. The proposed estimator can reconstruct constant disturbances entering additively to the dynamic model. An experimental evaluation was carried out in order to show the performance of the proposed controller.

Experimental Implementation of a Leader-Follower Strategy for Quadrotors Using a Distributed Architecture

This paper deals with a distributed experimental implementation of a leader-follower coordination scheme using quadrotors. A set of inter-agent distances defines the position of the followers about the leader. The desired position of each agent is kept using a robust local nonlinear controller in combination with a distributed trajectory generator. The distributed implementation comes from the fact that each quadrotor has an onboard digital processor to compute its control algorithm, and there is a wireless communication channel between the leader and the followers. Real-time experiments show the performance of the distributed leader-follower strategy.

An output maneuvering approach to control the Cartesian position of the quadrotor helicopter

This paper proposes an output maneuvering control scheme for the Cartesian position of the quadrotor helicopter. The output maneuvering controller is used in conjunction with previously proposed altitude and attitude nonlinear controllers. It is shown that the closed-loop system enters to an invariant manifold where the path following error is equal zero while all other signals are bounded. The performance of the proposed controller is verified by means of numerical simulations.

Quadrotor control based on an estimator of external forces and moments

This paper presents a trajectory tracking non-linear controller for the quadrotor that compensates external forces and moments. The external forces, their first and second time derivatives, as well as the external moments, are reconstructed using an estimator based on the immersion and invariance technique. The evaluation of the proposed controller is performed with the aid of a series of experimental flights.

Attitude observer and trajectory tracking for a group of unicycle-type robots

This paper presents three trajectory tracking control strategies for groups unicycle-type robots based on the leader-followers scheme using an observer to estimate the orientation angle of each robot. The leader robot converges asymptotically to a smooth trajectory while the follower robots are formed in an undirected open-chain configuration at the same time. The control laws are based on a dynamical extension of the kinematic model of each robot. The output functions to be controlled are the midpoint of the wheels axis of each robot. This choice leads to an ill defined control law when the robot is at rest. To avoid such singularities, a complementary control law is enabled momentarily when the linear velocity of the unicycles is close to zero. Numerical simulations complete the paper.

Nonlinear control for trajectory tracking of a quadrotor unmanned vehicle

This paper presents a new solution to the motion control problem for a rotary wing vehicle powered by four rotors. The proposed control structure is a parallel scheme consisting of a partial state saturated feedback to control the vehicle altitude and a partial feedback linearizing feedback to control the planar vehicles position. It is shown that the resulting closed-loop dynamics has a local asymptotic stability property. Numerical simulations show the performance of the proposed controller.

Path following through reference points for a car-like mobile robot

In this paper a solution for the problem of following paths defined by reference points for a car-like mobile robot is addressed. The proposed control law is a linearizing state feedback for the rotational kinematics of the mobile robot. The orientation error is defined in such a way that it remains in the interval greater than or equal minus one hundred eighty degrees and smaller than one hundred eighty degrees in order to avoid the unwinding phenomena. The efficiency of the proposed control strategy is verified through numerical simulations.

A coordinated turn controller for a fixed-wing aircraft

This paper describes the design of a controller for a fixed-wing aircraft to make it perform coordinated turns. First, a state feedback partial linearization controller drives the airplane to carry out an ideal coordinated turn. A second control loop, inspired by the total heading control system technique, mixes the ailerons and rudder inputs to perform a coordinated turn considering the sideslip dynamics. The control design development gives new insights to establish the fundamental basis for the total heading control system. Simulations in an advanced flight simulator (X-Plane 10) are presented to show the closed-loop system behavior.