This manuscript presents a fully detailed methodology in order to identify the hydrodynamic parameters of a mini autonomous underwater vehicle (mini-AUV) and evaluate its performance using different controllers. The methodology consists of close-to-reality simulation using a Computed Fluid Dynamics (CFD) module of the ANSYS™ Workbench software, the processing of the data, obtained by simulation, with a set of Savistky–Golay filters; and, the application of the Least Square Method in order to estimate the hydrodynamic parameters of the mini-AUV. Finally, these parameters are considered to design the three different controllers that are based on the robot manipulators theory. Numerical simulations are carried out to evaluate the performance of the controllers.

The current work exploits the effects of time-delays on the stability of unmanned aerial vehicles s). In this regard, the main contribution is a symbolic/numeric application of the multiplicity-induced-dominancy property in the control of unmanned aerial vehicles rotorcrafts featuring time-delays. The multiplicity-induced-dominancy property is considered to address two of the most representative aerial robotic platforms: a classical quadrotor vehicle and a quadrotor vehicle endowed with tilting rotors. The aforementioned property leads to an effective delayed feedback control design (multiplicity-induced-dominancy tuning criteria), allowing the system to meet prescribed behavior conditions based on the placement of the rightmost root of the corresponding closed-loop characteristic function/quasipolynomial. Lastly, the results of detailed numerical simulations, including the linear and non-linear dynamics of the vehicle, are presented and discussed to validate the proposal.

The actual paper presents the modeling and control of a multi-link unmanned aerial system (ML-UAS) whose dynamics is computed by means of the Euler-Lagrange approach. The aforementioned system is subjected to lumped disturbances which comprise external disturbances and parametric uncertainties. An Augmented-State Extended Kalman Filter intended to estimate endogenous and exogenous uncertainties is conceived and a trajectory-tracking controller fulfilling Lyapunov asymptotic stability is synthesized. A simulation stage is conducted to validate the effectiveness of the proposal.

The paper addresses a robust navigation strategy of a rotorcraft class having a simple robotic arm to perform rapid in-flight retrieving operations in presence of wind gusts and aerodynamic effects. The target-acquiring trajectory planner is based on a cosinusoidal dynamic pattern. The mathematical model is extended to account not only the dynamics of the robotic arm but also the aerodynamics. The navigation control scheme is based on a soft integral sliding-mode control (ISC) to stabilize both inner-and outer-loop dynamics regarding the rejection of not only the dynamic couplings but also aerodynamic disturbances. Detailed simulations including realistic aerodynamic effects results show the validity of the proposed navigation strategy while tracking the object-to-retrieve trajectory.

In this letter, we describe a new light-flashing shield to be used at flash-based imaging or event-based vision tasks performed in environments with poor light conditions. The shield incorporates a multiplexer that permits to set the operation mode, the nominal current, the pulse-width and the trigger sensitivity of up-to 2 high-brightness LEDs by means of a single I2C bus. A trigger conditioning circuit permits to synchronize the LEDs light and an Intel RealSense d455 camera to obtain a set of clear images while the LEDs are illuminated, being this feature the main novelty and contribution of this work in order to provide light on-demand in visual-based tasks performed in environments with poor light conditions. Images obtained during real tests prove the correct synchronization between the light-flashing shield and the camera.