Manuel Soler

University Carlos III de Madrid | UC3M · Department of Bioengineering and Aeroespace Engineering

Numerical optimal control techniques play an increasingly relevant role in trajectory planning for aerial vehicles. In the last decade, pseudospectral methods have been identified as a powerful alternative to other direct methods in numerical optimal control. We study the applicability and performance of pseudospectral methods when applied to probl...

Aviation's non-CO$_2$ effects, especially the impact of aviation-induced contrails, drive atmospheric changes and can influence climate dynamics. Although contrails are believed to contribute to global warming through their net warming effect, uncertainties persist due to the challenges in accurately measuring their radiative impacts. This study ai...

This paper aims to explore machine learning techniques for post‐processing high‐resolution Numerical Weather Prediction (NWP) products for the early detection of convection. Data from the Arome Ensemble Prediction System and satellite observations from the Rapidly Developing Thunderstorm (RDT) product by Météo‐France are used to train a recurrent n...

This paper presents a comprehensive analysis exploring the potential of climate-friendly flight planning as an operational measure to mitigate the aviation sector’s climate impact. The analysis considers the effects induced by CO2 emissions and the most relevant non-CO2 forcing agents, including NOx emissions and contrail-cirrus. We demonstrate tha...

The optimization of aircraft trajectories involves balancing operating costs and climate impact, which are often conflicting objectives. To achieve compromised optimal solutions, higher-level information such as preferences of decision-makers must be taken into account. This paper introduces the SolFinder 1.0 module, a decision-making tool designed...

Thunderstorms can be a large source of disruption for European air-traffic management causing a chaotic state of operation within the airspace system. In current practice, air-traffic managers are provided with imprecise forecasts which limit their ability to plan strategically. As a result, weather mitigation is performed using tactical measures w...

Hydrogen fuel has emerged as a promising solution for addressing the challenges associated with traditional fossil fuel-based propulsion systems in aviation. This disruptive technology has the potential to revolutionize the industry, but it is crucial to quantify and maximize the benefits of hydrogen aviation from both economical and climatic persp...

Aviation aims to reduce its climate effect by adopting trajectories that avoid regions of the atmosphere where aviation emissions have a large impact. To that end, prototype algorithmic climate change functions (aCCFs) can be used, which provide spatially and temporally resolved information on aviation's climate effect in terms of future near-surfa...

The optimization of aircraft trajectories involves balancing operating costs and climate impact, which are often conflicting objectives. To achieve compromise optimal solutions, higher-level information such as preferences of decision-makers must be taken into account. This paper introduces the SolFinder 1.0 module, a decision-making tool designed...

The climate impact of non-CO2 emissions, which are responsible for two-thirds of aviation radiative forcing, highly depends on the atmospheric chemistry and weather conditions. Hence, by planning aircraft trajectories to reroute areas where the non-CO2 climate impacts are strongly enhanced, called climate-sensitive regions, there is a potential to...

Climate impact models of the non-CO2 emissions of aviation are still subject to significant uncertainties. Condensation trails, or contrails, are one of these non-CO2 effects. In order to validate the contrail simulation models, a dataset of observations covering the entire lifetime of the contrails will be required, as well as the characteristics...

Society has a pressing need to reduce pollutants and noise in air transport to achieve the COP26 goal of global net-zero emissions by 2050. Hydrogen has emerged as a promising long-term sustainable solution for aviation without excessive performance and energy efficiency penalties. However, integration of the hydrogen-based powertrain into the airc...

Integration of trajectory optimization into sequence optimization is required for next-generation Arrival Managers (AMANs) to support Collaborative Decision-Making (CDM) and implementation of user-preferred 4D trajectories. In addition, considering uncertainty in the optimization is also necessary for making more robust decisions. To achieve these...

In this research, we consider the commercial aircraft trajectory optimization problem for a general cruise model with arbitrary spatial wind fields to be solved using the Pontryagin maximum principle. The model features two fundamental controls, namely, throttle setting (which appears as a singular control) and heading angle (appearing as a regular...

This paper addresses a non-fragile robust model predictive control design for a class of continuous-time uncertain systems with multiple state-delay and constrained control signals. The parameters of the system and the control gain are assumed to have perturbation in the additive form. The Lyapunov–Krasovskii functional approach is employed to deri...

Aviation contributes to anthropogenic climate change through carbon dioxide (CO2) and non-CO2 emissions. Due to dependency on atmospheric conditions, the non-CO2 climate impacts can be mitigated using aircraft trajectory optimization. However, adopting independently optimized trajectories may not be operationally feasible for the air traffic manage...

The herein coined PADOC (perturbed‐analytic direct transcription for optimal control) stands for a new transcription method for direct trajectory optimization. We construct PADOC on a novel segmented decomposition method that provides series solutions for nonlinear problems. To transcribe the infinite dimensional problem into a finite one, PADOC co...

In this research, we consider the commercial aircraft trajectory optimization problem for a general cruise model with arbitrary spatial wind fields to be solved using the Pontryagin’s maximum principle. The model features two fundamental controls, namely “throttle setting” (appearing as a singular control) and “heading angle” (appearing as a regula...

Convective weather poses a major threat that compromises the safe operation of flights while inducing delay and cost. The aircraft trajectory optimization problem under thunderstorms is addressed, proposing a novel heuristic approach that incorporates uncertainties in the evolution of convective cells. Namely, the Augmented Random Search (ARS) algo...

The climate impact of the non-CO2 emissions, being responsible for two-thirds of aviation radiative forcing, highly depends on the atmospheric chemistry and weather conditions. Hence, by planning aircraft trajectories to reroute areas where the non-CO2 climate impacts are strongly enhanced, called climate-sensitive regions, there is a potential to...

The development, implementation and validation of optimisation algorithms for robust airline operations that result in stable and resilient Air Traffic Management (ATM) performance even in disturbed scenarios are the overall goals of START. This presentation focusses on the validation part. The validation of the START robust airline operations is p...

Network-wide robust and resilient trajectory planning is realized after the uncertainty propagations at trajectory and ATM levels. The inputs are the 4D trajectories with uncertainty and the delays applied to trajectories for network resiliency. The delays only shift the trajectories in time. The output is a set of algorithmic solutions for optimal...

One of the main objectives of Trajectory-Based Operations (TBO) is to increase the predictability of the aircraft behavior within the Air Traffic Management (ATM) system. However, most systems involved in TBO (such as flight planning systems) focus on proposing deterministic trajectories in the strategic phase, not taking into account the uncertain...

In this work, as a part of START, we have developed an ATM network macro-model, allowing us to model the propagation of flight trajectory uncertainties and further assess the impact of disruptive events, i.e., thunderstorms. We utilized data-driven analytics models mimicking the dynamics of epidemic spreading, which is analogous to delay or uncerta...

Aviation aims to reduce its climate impact by adopting trajectories, that avoid those regions of the atmosphere where aviation emissions have a large impact. To that end, prototype algorithmic climate change functions can be used, which provide spatially and temporally resolved information on aviation’s climate impact in terms of future near-surfac...

Aircraft trajectories are currently flown and optimized to reduce operating costs, keeping engine CO2-emissions from burnt fuel at a minimum by following fuel optimized routes under consideration of wind. However, research has shown that the location and time of non-CO2 emissions such as NOx, water vapor or the formation of contrail cirrus contribu...

The presence of convective cells makes sector demand irregular and not easy to predict, increasing traffic complexity and reducing sector's capacity. In this paper we present a novel, integrated trajectory predictor, which considers multiple sources of meteorological uncertainty at different temporal and geographical scales together with takeoff un...

This paper presents a new air traffic complexity metric based on linear dynamical systems, of which the goal is to quantify the intrinsic complexity of a set of aircraft trajectories. Previous works have demonstrated that the structure and organization of air traffic are essential factors in the perception of the complexity of an air traffic situat...

The herein coined Optimal Decomposition Method (ODM) is presented; an analytic decomposition approach to solve nonlinear problems that circumvents the well-known convergence barrier within nonlinear decomposition methods, e.g., Adomian Decomposition Method (ADM) and Duan –Rach ADM. ODM initially concerns removing the unknown coefficients from the r...

The strong growth rate of the aviation industry in recent years has created significant challenges in terms of environmental impact. Air traffic contributes to climate change through the emission of carbon dioxide (CO2) and other non-CO2 effects, and the associated climate impact is expected to soar further. The mitigation of CO2 contributions to t...

Aircraft trajectory planning is affected by various uncertainties. Among them, those in weather prediction have a large impact on the aircraft dynamics. Trajectory planning that assumes a deterministic weather scenario can cause significant performance degradation and constraint violation if the actual weather conditions are significantly different...

Darstellung des Projekts FlyATM4E

Trajectory-based operations (TBO) is one of the cornerstones of a modernised air traffic-management (ATM) system. The TBO operation concept takes into account the trajectory of every aircraft during all phases of the flight and manages their interactions to achieve the optimum system outcome, with minimal deviation from the user requested flight tr...

One of the main objectives of the so-called trajectory-based operations (TBO) concept is to increase the predictability of the aircraft behavior within the air traffic management (ATM) system, thus reducing inefficiencies and increasing the robustness and resiliency of operations. Most systems involved in TBO, such as flight planning systems or on-...

Uncertainties are inherent in aircraft trajectory planning. Trajectories designed under deterministic hypotheses can cause significant performance degradation or constraint violation if the actual situation significantly differs from the assumed conditions. This study proposes computational strategies to plan a robust trajectory in terms of weather...

In recent years, convective weather has been the cause of significant delays in the European airspace. With climate experts anticipating the frequency and intensity of convective weather to increase in the future, it is necessary to find solutions that mitigate the impact of convective weather events on the airspace system. Analysis of historical a...

Thunderstorms represent a major hazard for flights, as they compromise the safety of both the airframe and the passengers. To address trajectory planning under thunderstorms, three variants of the scenario-based rapidly exploring random trees (SB-RRTs) are proposed. During an iterative process, the so-called SB-RRT, the SB-RRT∗ and the Informed SB-...

Convective weather is a large source of disruption for air traffic management operations. Being able to predict thunderstorms the day before operations can help traffic managers plan around weather and improve air traffic flow management operations. In this paper, machine learning is applied on data from satellite storm observations and ensemble nu...

In the pursuit of increasing autonomy in descent and landing missions onto small bodies, a robust, autonomous method for powered soft landing has been proposed and validated on the asteroid Eros. With a Quadratic Model Predictive Control as a baseline, robustness has been guaranteed through the use of robust invariant tubes. Seeking on-board and re...

Convective weather and its inherent uncertainty constitute one of the major challenges in the air traffic management (ATM) system, entailing both safety hazards and economic losses. In the present work, we propose a stochastic algorithm for trajectory planning that ensures feasibility and safety of the path between two points while avoiding unsafe...

In this paper, we provide a survey on available numerical approaches for solving low-thrust trajectory optimization problems. First, a general mathematical framework based on hybrid optimal control will be presented. This formulation and their elements, namely objective function, continuous and discrete state and controls, and discrete and continuo...

Thunderstorms are one of the leading causes of Air Traffic Management delays. In this paper, we assess how incorporating convective information into flight planning algorithms can lead to reductions in reroutings due to storm encounters during the execution of the flight. We use robust open-loop optimal control methodology at the flight planning le...

The existence of significant uncertainties in the models and systems required for trajectory prediction represents a major challenge for the Air traffic Management (ATM) system. Weather can be considered as one of the most relevant sources of uncertainty. Understanding and managing the impact of these uncertainties is necessary to increase the pred...

A main objective of Air Traffic Flow Management is matching airspace and airport capacity with demand. Being able to accurately predict unexpected disruptions to the air traffic network, such as convective weather is essential in order to make better informed decisions and improve performance of the system. In this paper we demonstrate how machine...

The optimal design of orbit raising trajectories is formulated within a multi-objective hybrid optimal control framework. The spacecraft can be equipped with chemical, electric or combined chemical-electric propulsion systems. The model incorporates realistic effects of the space environment and complex operational constraints. An automated solutio...

In recent years, convective weather has been the cause of significant delays in the European airspace. With climate experts anticipating the frequency and intensity of convective weather to increase in the future, it is necessary to find solutions to mitigate the impact of convective weather events on the airspace system. Analysis of historical air...

Convective weather and its inherent uncertainty constitute one of the major challenges in the Air Traffic Management (ATM) system, entailing both safety hazards and economic losses. In the present work we propose a stochastic algorithm for trajectory planning that ensures feasibility and safety of the path between two points while avoiding unsafe s...

The future Air Traffic Management (ATM) system will feature trajectory-centric procedures that give airspace users greater flexibility in trajectory planning. However, uncertainty generates major challenges for the successful implementation of the future ATM paradigm, with meteorological uncertainty representing one of the most impactful sources. I...

The existence of significant uncertainties in the models and systems required for trajectory prediction represents a major challenge for the Trajectory-Based Operations concept. Weather can be considered as one of the most relevant sources of uncertainty. Understanding and managing the impact of these uncertainties are necessary in order to increas...

A novel study is presented aiming at characterizing and illustrating potential enhancements in flight planning predictability due to the effects of wind uncertainty. A robust optimal control methodology is employed to calculate robust flight plans. Wind uncertainty is retrieved out of Ensemble Probabilistic Forecasts. Different wind approximation f...

We tackle the problem of minimizing the number of aircraft potential conflicts via speed regulations and taking into account uncertainties on aircraft position due to wind and temperature. The resolution is done at a strategic level, before any of the aircraft has departed. Owing to the complexity of this kind of optimisation problem, a simulated a...

Convective weather, and thunderstorm development in particular, represents a major source of disruption, delays and safety hazards in the Air Traffic Management system. Thunderstorms are challenging to forecast and evolve on relatively rapid timescales; therefore, aircraft trajectory planning tools need to consider the uncertainty in the forecasted...

The multi-objective optimal design of low-thrust multigravity-assist trajectories is formulated within the hybrid optimal control framework. A new automated solution strategy for this problem is proposed in this Paper based on a two-step algorithm. In the first step, the trajectory is assumed to be a generalized logarithmic spiral. A heuristic glob...

Please cite this article in press as: D. Hentzen et al., On maximizing safety in stochastic aircraft trajectory planning with uncertain thunderstorm development, Aerosp. Sci. Technol. (2018), https://doi. Abstract Dealing with meteorological uncertainty poses a major challenge in air traffic management (ATM). Convective weather (commonly referred t...

The future air traffic management system is to be built around the notion of trajectory-based operations. It will rely on automated tools related to trajectory prediction in order to define, share, revise, negotiate and update the trajectory of the aircraft before and during the flight, in some case, in near real time. This paper illustrates how ex...

In this paper, a first step to analyse the effects of reducing the uncertainty of aircraft trajectories on sector demand is presented. The source of uncertainty is wind, forecasted by Ensemble Prediction Systems, which are composed of different possible atmosphere realizations. A trajectory predictor determines the routes to be followed by the diff...

The existence of significant uncertainties in the models and systems required for trajectory prediction represent a major challenge for Trajectory-Based Operations concept. Weather can be considered as one of the most relevant sources of uncertainty. Understanding and managing the impact of these uncertainties is necessary in order to increase the...

Global warming represents a major problem for human being life as it is known today. Nations are more aware of that issue and are settled contingency measurements to reduce the called greenhouse gas emission, known as the source of global warming. Initially, CO2 was considered as the key agent, later also N Ox, but recent studies shows that persist...

Uncertainty in aircraft trajectory planning and prediction generates major challenges for the future Air Traffic Management system. Therefore, understanding and managing uncertainty will be necessary to realize improvements in air traffic capacity, safety, efficiency and environmental impact. Meteorology (and, in particular, winds) represents one o...

High levels of uncertainty are associated to the characterization of the environment around small bodies in the Solar System. In an effort to develop efficient methods to consider uncertainty in the analysis of missions to irregular-shaped bodies, the problem of robust and efficient optimization of descent trajectories in the presence of uncertaint...