Kalman-based velocity-free trajectory tracking control of an underactuated aerial vehicle with unknown system dynamics, Joel Reis, Gan Yu, and Carlos Silvestre, Automatica, 2023

A Kalman filter for the linear motion subsystem is designed. The filter attenuates the noise of position measurements, and simultaneously estimates the linear velocity of the vehicle as well as an unknown term of lumped dynamics. The output and residual of the filter are then fed to a nonlinear controller.

Quadrotor Neural Network Adaptive Control: Design and Experimental Validation, Gan Yu, Joel Reis, and Carlos Silvestre, IEEE Robotics and Automation Letters, 2023

We employ an adaptive neural network, used to approximate the partially unknown system, in tandem with a simple controller designed for trajectory tracking, not of the center of mass, but of a point located along the UAV’s vertical body axis.

Nonlinear backstepping control of a quadrotor-slung load system, Gan Yu, David Cabecinhas, Rita Cunha, and Carlos Silvestre, IEEE/ASME Transactions on Mechatronics, 2019

Reduced-Complexity Active Disturbance Rejection Controller for Quadrotor-Slung-Load Transportation, Gan Yu, Joel Reis, David Cabecinhas, Rita Cunha, and Carlos Silvestre, IEEE Transactions on Systems, Man, and Cybernetics: Systems, 2023

The problem of trajectory tracking control of a quadrotor-slung-load system is addressed.

Aggressive maneuvers for a quadrotor-slung-load system through fast trajectory generation and tracking, Gan Yu, David Cabecinhas, Rita Cunha, and Carlos Silvestre, Autonomous Robots, 2022

We propose a framework to efficiently generate aggressive load-swing trajectories. Trajectory generation for the load aims to minimize the fifth order time derivative of the load position which, indirectly, minimizes the quadrotor angular velocity actuation. Aggressive load-swing trajectories are obtained by having the constraints for load cable direction embedded into the trajectory generation via constraints on the load acceleration.

Robust Cooperative Transportation of a Cable-Suspended Payload by Multiple Quadrotors Featuring Cable-Reconfiguration Capabilities, Yanhu Wang, Gan Yu, Wei Xie, Weidong Zhang, and Carlos Silvestre, IEEE Transactions on Intelligent Transportation Systems, 2024

We investigate the tracking control of a multi-quadrotor slung-load system (MQSLS) and introduce a novel force distribution algorithm, which bifurcates the cooperative control to two distinct components: slung-load position control; and cable configuration control along with quadrotor attitude control. Employing this strategy results in a cooperative controller that: (i) relaxes the constraints on cable configuration; and (ii) requires only up to the third time derivative of the reference trajectory.

Robust Nonlinear 3D Control of an Inverted Pendulum Balanced on a Quadrotor, Weiming Yang, Gan Yu, Joel Reis, and Carlos Silvestre, Automatica, 2024

This paper addresses the nonlinear control problem of balancing an inverted pendulum on an underactuated unmanned aerial vehicle.