Pedro Lourenço

GMV · GNC Division - Flight Segment and Robotics BU

Fault tolerant control for clusters of engines in launchers has regained attention due to recent capabilities of new reusable launchers. The redundancy in clusters of engines can be exploited to be robust against potential propulsion or thrust vector control failures that jeopardize mission success. The project "Fault-Tolerant Control of Clusters o...

VV4RTOS is an activity supported by the European Space Agency aimed at the development and validation of a framework for the verification and validation of spacecraft guidance, navigation, and control (GNC) systems based on embedded optimisation, tailored to handle different layers of abstraction, from guidance and control (G&C) requirements down t...

This paper presents the design of attitude control systems for autonomous spacecraft subject to noisy measurements from sensors, external, and internal disturbances. The objective is to perform slew manoeuvres and maintain pointing stability while guaranteeing fast convergence and high performance. For slew manoeuvres, a Nonlinear Model Predictive...

This paper addresses two complementary problems of spacecraft formation flying, namely spacecraft platooning and on-orbit spacecraft servicing, using Model Predictive Control (MPC). With the proposed solutions, these space formation scenarios can be regarded as a cooperative system composed of several spacecraft with a common goal, which may have c...

This paper presents the design of attitude control systems for autonomous spacecraft subject to noisy measurements from sensors, external, and internal disturbances. The objective is to perform slew manoeuvres and maintain pointing stability while guaranteeing fast convergence and high performance. For slew manoeuvres, a Nonlinear Model Predictive...

This paper presents a Distributed Model Predictive Control (DMPC) algorithm for a scenario of spacecraft formation flying, namely spacecraft platooning in a leader-follower formation. This spacecraft formation application can be regarded as a cooperative system composed of several spacecraft with a common goal, for which a relative translational mo...

We introduce a closed-form method for identification of discrete-time linear time-variant systems from data, formulating the learning problem as a regularized least squares problem where the regularizer favors smooth solutions within a trajectory. We develop a closed-form algorithm with guarantees of optimality and with a complexity that increases...

Embedded on-board-optimization-based guidance is a set of guidance schemes that provide spacecraft the capability to plan and perform trajectories under several constraints autonomously. This autonomy will allow the space vehicle to more efficiently perform more challenging goals while dealing with rapidly changing environments, unmodelled/unforese...

In the past decade, GMV has been, both as a participant and a reviewer, at the forefront of ESA’s efforts in identifying and responding to criticalities in GNC technologies for future ADR and in-orbit servicing missions. This paper provides an anthology of the recent developments - the state of the art of ADR mission design from a GNC perspective,...

GUIBEAR is an on-going activity supported by the European Space Agency aimed at the demonstration of the feasibility of bearings-only (B-O) far-range rendezvous in near rectilinear Halo orbits (NROs). The studied scenario is the far-range rendezvous of the HERACLES Lunar Ascent Element (LAE) with the Lunar Orbital Platform – Gateway (LOP-G) that is...

This paper addresses the problem of obtaining an Earth-fixed trajectory and map (ETM), with the associated uncertainty, using the sensor-based map provided by a globally asymptotically/exponentially stable (GES) SLAM filter. The algorithm builds on an optimization problem with a closed-form solution, and its uncertainty description is derived resor...

This paper addresses the problem of minimizing the uncertainty through motion planning in a globally exponentially stable sensor-based simultaneous localization and mapping algorithm, with the objective of performing active exploitation. This is done by designing an optimization problem that weighs the final uncertainty, the overall uncertainty in...

This paper proposes a novel filter for sensor-based bearing-only simultaneous localization and mapping in three dimensions with globally exponentially stable (GES) error dynamics. A nonlinear system is designed, its output transformed, and its dynamics augmented so that the proposed formulation can be considered as linear time-varying for the purpo...

This chapter presents an overview of algorithms deeply rooted in a sensor-based approach to the SLAM problem that provide global convergence guarantees and allow for the use of partially observable landmarks. The presented algorithms address the more usual range-and-bearing SLAM problem, either in 2-D using a LiDAR or in 3-D using an RGB-D camera ,...

This paper addresses the weighted orthogonal Procrustes problem of matching stochastically perturbed point clouds, formulated as an optimization problem with a closed-form solution. A novel uncertainty characterization of the solution of this problem is proposed resorting to perturbation theory concepts, which admits arbitrary transformations betwe...

This paper presents the design, analysis, and experimental validation of a globally asymptotically stable (GAS) filter for simultaneous localization and mapping (SLAM) with application to unmanned aerial vehicles. The main contributions of this paper are the results of global convergence and stability for SLAM in tridimensional (3-D) environments....

This work proposes novel techniques that can be applied to simultaneous localization and mapping in order to bypass the inherent nonlinearity of the problem and, ultimately, to design novel globally convergent filters. Algorithms for range-bearing, range-only and bearing-only frameworks are analysed and implemented with success in experimental sett...

This paper proposes a novel filter for sensor-based bearing-only simultaneous localization and mapping in three dimensions with globally exponentially stable (GES) error dynamics. A nonlinear system is designed, its output transformed, and its dynamics augmented so that the proposed formulation can be considered as linear time-varying for the purpo...

This paper presents the design, analysis, and validation of a globally exponentially stable (GES) filter for tridimensional (3-D) range-only simultaneous localization and mapping in sensor networks with moving object tracking. For observability analysis purposes, two nonlinear sensor-based dynamic systems are formulated resorting only to exact line...

This paper proposes the design, analysis, and validation of a globally exponentially stable (GES) filter for tridimensional (3-D) range-only simultaneous localization and mapping. For observability analysis purposes, a nonlinear sensor-based dynamical system is formulated resorting only to exact linear and angular kinematics and a state augmentatio...

This paper addresses the problem of obtaining an inertial trajectory and map, with the associated uncertainty, using the sensor-based map provided by a globally asymptotically stable SLAM filter. An optimization problem with a closed-form solution is formulated, and its uncertainty description is derived resorting to perturbation theory. The combin...

This paper presents the design, analysis, performance evaluation, and preliminary experimental validation of a globally asymptotically stable (GAS) filter for simultaneous localization and mapping (SLAM) with application to unmanned aerial vehicles (UAVs). The SLAM problem is formulated in a sensor-based framework and modified in such a way that th...

Localization using the received signal strength indication (RSSI) of wireless local area networks with a priori knowledge of the coordinates of the routers/access points is addressed in this paper. The proposed algorithm employs a path loss model that allows for the inclusion of the logarithmic measurements of the signal strength directly in the st...