Ricardo Castro

Ricardo Castro
University of California, Merced | UCM · Department of Mechanical Engineering

PhD

About

86
Publications
22,132
Reads
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1,064
Citations
Introduction
Ricardo de Castro received the Licenciatura and Ph.D. degrees in electrical and computers engineering from University of Porto, Faculty of Engineering, Portugal, in 2006 and 2013, respectively. From 2013 to 2020, he was with the German Aerospace Center (DLR), Institute of System Dynamics and Control (SR), where he developed enabling technologies for electric mobility and automated driving. In 2021, he joined University of California, Merced as an assistant professor.
Additional affiliations
January 2006 - March 2013
University of Porto
Position
  • Researcher and PhD student

Publications

Publications (86)
Cover Page
Full-text available
Vehicle controls systems are control commands directed to vehicle actuators that control steering, throttle, and braking, as well as other related commands to support a safe transition between manual and automatic vehicle control. Additionally, the various parts of sensing, positioning, or motion control and energy optimization are crucial for its...
Article
Full-text available
Batteries have been the predominant energy storage system used in electric vehicles. Battery packs have a large number of cells that develop charge, thermal, and capacity imbalances over time, limiting the power, range, and lifetime. Electronic battery management and state of charge (SoC) equalization methods are necessary to mitigate such imbalanc...
Article
Full-text available
Traffic congestion and the occurrence of traffic accidents are problems that can be mitigated by applying cooperative adaptive cruise control (CACC). In this work, we used deep reinforcement learning for CACC and assessed its potential to outperform model-based methods. The trade-off between distance-error minimization and energy consumption minimi...
Article
Full-text available
This work addresses the design of an active fault-tolerant motion controller for over-actuated road vehicles. Our concept revolves around a control allocation framework, extended with Lyapunov-based stability constraints and costs. Besides the ability to cope with actuator constraints and optimal actuator reconfiguration, the proposed Lyapunov-base...
Article
This work deals with the design and validation of a control strategy for hybrid balancing systems (HBSs), an emerging concept that joins battery equalization and hybridization with supercapacitors (SCs) in the same system. To control this system, we propose a two-layer model predictive control (MPC) framework. The first layer determines the optimal...
Article
Full-text available
Batteries stacks are made of cells in certain series-parallel arrangements. Unfortunately, cell performance degrades over time in terms of capacity, internal resistance, or self-discharge rate. In addition, degradation rates are heterogeneous, leading to cell-to-cell variations. Balancing systems can be used to equalize those differences. Dissipati...
Article
This paper focuses on the control of nonlinear systems with redundant actuation, where the number of actuators is higher than the controllable degrees of freedom. To effectively handle actuation redundancy, we propose a control allocation (CA) approach that combines numerical optimization methods with control Lyapunov and control barrier functions....
Preprint
Full-text available
This works deals with the design and validation of a control strategy for hybrid balancing systems, an emerging concept that joins battery equalization and hybridization with supercapacitors in the same system. To control this system, we propose a two-layer model predictive control (MPC) framework. The first layer determines the optimal state-of-ch...
Article
Battery packs of electric vehicles are prone to capacity, thermal, and aging imbalances in their cells, which limit power delivery to the vehicle. In this chapter, a hybrid battery management system (HBMS), capable of simultaneously equalizing battery capacity and temperature while enabling hybridization with supercapacitors, is investigated. We us...
Conference Paper
Safety, comfort, and responsible use of natural resources are motivating the work regarding road vehicles in the automotive research group at the DLR (German Aerospace Center) Institute of System Dynamics and Control. The present article presents an overview of the research activities of this group, including recent results on energy management, ve...
Chapter
The availability of the most relevant vehicle states is crucial for the development of advanced vehicle control systems and driver assistance systems. Specifically the vehicle sideslip angle plays a key role, yet this state is unpractical to measure and still not straightforward to estimate. This paper investigates a particle filter approach to est...
Article
Full-text available
Performance of series connected batteries is limited by the ‘weakest link’ effect, i.e. the cell or group of cells with the poorest performance in terms of temperature, power, or energy characteristics. To mitigate the ‘weakest link’ effect, this study deals with the design, modeling and experimental demonstration of a smart and hybrid balancing sy...
Conference Paper
Motion control, in particular path following control (PFC), is an important function of autonomous vehicles. PFC controls the propulsion, steering and braking such that the vehicle follows a parametric path and reference velocity. For the design of traditional model-based PFC approaches a sufficiently accurate synthesis model of the vehicle has to...
Chapter
Dieser VDI-Bericht ist ausschließlich als PDF-Dokument erschienen! Sie möchten erfahren, was alles an spannenden Themen auf der Tagung in Mannheim präsentiert wurde? Inhalt Jahrmarkt der Innovationen Modellbasierte Folgeregelung für nichtlineare Regelstrecken am Beispiel der Ladedruckregelung – Ein applikationsnaher Entwurf 1 K. Wulff, J. Willkomm,...
Preprint
Full-text available
This work deals with the design of a supervisory module for the motion control of autonomous vehicles. The su-pervisor's goal is to monitor the behavior of a trajectory tracking controller (TTC), introducing corrective control actions to prevent violations of safety and input constraints. It relies on the combination of control barrier functions an...
Article
Full-text available
This article presents a predictive braking control algorithm for electric vehicles with redundant braking actuators, composed of friction brake actuator(s) and electric motor(s). The proposed algorithm is based on a model predictive control framework and is able to optimally tackle several control goals, such as maximization of energy recuperation...
Conference Paper
An approach for fault tolerant control of an electrohydraulic brake (EHB) in case of a pressure sensor failure is presented. Automotive Brake-by-Wire actuators are safety critical components, and an EHB under closed-loop pressure control is critically affected by faults in the pressure sensor. Timely fault detection and reconfiguration to use a bra...
Article
This paper presents a study of the combined influence of battery models and sizing strategy for hybrid and battery-based electric vehicles. In particular, the aim is to find the number of battery (and supercapacitor) cells to propel a light vehicle to run two different standard driving cycles. Three equivalent circuit models are considered to simul...
Article
This paper proposes a robust model predictive controller for linear parameter varying (LPV) systems subject to additive disturbances. The proposed controller relies on the constraint tightening method to guarantee that the MPC's optimization problem remains feasible in the presence of additive disturbances. In order to decrease the conservativeness...
Conference Paper
This work describes the optimization of velocity profiles for the usage in (semi-) autonomous driving. The focus of the optimization lies on the trade-off between time and energy optimal velocity profiles. This trade-off can be directly chosen by the driver. With help of a dynamic programming framework the global optimum of the complex optimization...
Conference Paper
This paper proposes a robust model predictive controller for linear parameter varying (LPV) systems subject to additive disturbances. The proposed controller relies on the constraint tightening method to guarantee that the MPC's optimization problem remains feasible in the presence of additive disturbances. In order to decrease the conservativeness...
Conference Paper
Full-text available
This work is concerned with the design of a vehicle following controller (VFC). The goal of the VFC is to determine appropriate control actions for a highly actuated electric vehicle such that the longitudinal and lateral motion of a target vehicle is followed. To achieve this goal, a combination of a non-linear guidance law, based on pure pursuit...
Article
In this paper a novel battery electric vehicle (BEV) concept based on a small fixed and a big swappable Li-ion battery pack is proposed in order to achieve: longer range, lower initial purchase price and lower energy consumption at short ranges. For short ranges the BEV is only powered by the relatively small fixed battery pack, without the large s...
Conference Paper
This article presents a braking control algorithm for electric vehicles endowed with redundant actuators, i.e. friction brakes and wheel-individual electric motors. This algorithm relies on a model predictive control framework and is able to optimally split the wheel braking torque among the redundant actuators, while providing anti-lock braking fe...
Conference Paper
This paper introduces a vision-based Controller for automatic vehicle following, also known as 2-vehicle platooning. A direct homography controller is applied to calculate the motion demand for an autonomous vehicle from only the data of a monocular camera. The direct control without an intermediate step to a Cartesian representation increases the...
Conference Paper
The paper presents a simulative investigation of the performance provided by different powertrain configurations of road vehicles. This comparison involves factors such as energy consumption of the vehicle, energy losses in the powertrain’s components, vehicle handling and vehicle’s robustness against lateral disturbances. As reference vehicle for...
Article
Bremsregelverfahren für ein Fahrzeug (116) mit wenigstens einem Fahrzeugrad (118, 207) und einem ersten Bremsaktuator (102, 208, 218, 220, 228, 236, 238) sowie wenigstens einem weiteren Bremsaktuator (102, 212, 214, 216, 224, 226, 232, 234) zum Bremsen des wenigstens einen Fahrzeugrads (118, 207), wobei an dem wenigstens einen Fahrzeugrad (118, 207...
Conference Paper
Full-text available
During many years, battery models have been proposed with different levels of accuracy and complexity. In some cases, simple low-order aggregated battery pack models may be more appropriate and feasible than complex physic-chemical or high-order multi-cell battery pack models. For example: in early stages of the system design process, in non-focuse...
Article
Autonomous vehicles are becoming a reality that in the next future will most probably start populating everyday roads. Such vehicles can, on the one hand, increase safety through automated driving, and, on the other, be a means of transportation also for people with disabilities who cannot move alone on commercial cars. Within this class of vehicle...
Conference Paper
Full-text available
In this paper a novel battery electric vehicle (BEV) concept based on a small fixed and a big swappable li-ion battery pack is proposed in order to achieve: longer range, lower initial purchase price and lower energy consumption at short ranges. For short ranges the BEV is only powered by the relatively small fixed battery pack, without the large s...
Conference Paper
In an effort to reduce aircraft fuel consumption and emissions in airports, electric driving systems are being studied by several stakeholders. When assessing the overall benefit at mission level in the design of those systems, it is necessary to determine the optimal control strategy of the system on ground for a given architecture in order to com...
Conference Paper
This article is concerned with the design of braking control systems for electric vehicles endowed with redundant braking actuators, i.e., with friction brakes and wheel-individual electric motors. Facing the challenge to optimally split the braking torque between these two actuators, a unified model predictive control (MPC) algorithm is presented...
Conference Paper
Full-text available
While a great number of battery balancing circuit topologies have been proposed, the unique control objective typically pursued is equalization of single cell charge. However, a balancing circuit could offer potentially more control features, especially with topologies able to provide bidirectional power flow control. This has not been explored yet...
Conference Paper
Full-text available
This paper presents a comparative study of the influence of different aggregated electrical circuit battery models in the sizing process of a hybrid energy storage system (ESS), composed by Li-ion batteries and supercapacitors (SCs). The aim is to find the number of cells required to propel a certain vehicle over a predefined driving cycle. During...
Article
Full-text available
This paper is concerned with the study of combined sizing and energy management algorithms for electric vehicles (EVs) endowed with batteries and supercapacitors (SCs). The main goal is to find the number of cells of each source that minimizes the installation and running costs of the EV, taking into account the performance requirements specified f...
Article
Full-text available
The new vehicle platforms for electric vehicles (EVs) that are becoming available are characterised by actuator redundancy, which makes it possible to jointly optimise different aspects of the vehicle motion. To do this, high-level control objectives are first specified and solved with appropriate control strategies. Then, the resulting virtual con...
Conference Paper
With the recent emergence of electric drivetrains, a faster and energy efficient braking actuator - the electric motor - has become available to complement the operation of the traditional friction brakes. The decision on how to split the braking torque among the friction brake and the electric motor is one of the main issues of such hybrid braking...
Article
Full-text available
The coordinated control of vehicle actuators is gaining more and more importance as new platforms are becoming available, with chassis endowed with many different actuators that may help controlling the vehicle motion. Furthermore, wheel individual motors allow using a single system to apply both positive and negative torques at the wheels, which c...
Conference Paper
This paper presents a comparative study between two non-causal algorithms for the energy management problem of electric vehicles, endowed with batteries and supercapacitors(SCs). Toward that goal, an optimization-based energy problem is formulated, which targets the minimization of the source's energy losses throughout a given driving cycle. This p...
Conference Paper
The coordinated control of vehicle actuators is gaining more importance as new platforms are becoming available, with chassis endowed with many different actuators that may help controlling the vehicle motion. Further, in-wheel motors (IWMs) allow using a single system to apply both positive and negative torques at the wheels, which can be actuated...
Article
Full-text available
This work focuses on the development of a pressure-loop controller for a hybrid brake-by-wire system, composed of a hydraulic link and an electro-mechanical actuator. Towards this goal, we will start by constructing a reduced model that is capable of capturing the fundamental dynamics of the actuator, which is particularly useful for control design...
Article
Full-text available
This paper presents a new control system, based on field programmable gate array technology, targeting the powertrain control of multi-motor electric vehicles (EVs). The control chip builds around a reusable intellectual property core named propulsion control unit, which features motor control functions with field-orientation methods, and energy lo...
Chapter
Full-text available
This work addresses the problem of optimal selection of the flux level in induction motors used in electric vehicles (EVs). The basic function of a fully electric powertrain controller is to generate electric torque (force) which is required at any time by the driver. But, it is wellknown that the flux level used in a controller for induction motor...
Article
Full-text available
The energy storage system (ESS), as well as its efficient management, represents a key factor for the success of electric vehicles. Due to well-known technological constraints in ESSs, there has been a growing interest in combining various types of energy sources with complementary features. Among the many possible combinations, our interest here l...
Conference Paper
This paper targets the development of hybrid energy storage systems (ESS), based on the batteries-supercapacitors blending. In particular, we will develop two methodologies for the combined sizing/energy management of hybrid ESS. The first method assumes that the division of power between the sources is performed through low/high pass filters, whic...
Article
Full-text available
Spurred by the problem of identifying, in real-time, the adhesion levels between the tyre and the road, a practical, linear parameterisation (LP) model is proposed to represent the tyre friction. Towards that aim, results from the theory of function approximation, together with optimisation techniques, are explored to approximate the non-linear Bur...
Conference Paper
This paper presents FIEEV - Fault Injection Environment for Electric Vehicles, a Matlab/Simulink-based simulator environment for evaluating the fault impacts on vehicle stability in electrical vehicles. FIEEV makes it possible to simulate the temporal behavior of the faults and to study its effects on loss of vehicle's performance. Simulation resul...
Conference Paper
Full-text available
In spite of several technical advances made in recent years by the automotive industry, the driver's behaviour still influences significantly the overall fuel consumption. With the rise of smartphones adoption, there are also new opportunities to increase the awareness to this issue. The main aim of this paper is to present a new smartphone applica...
Article
Full-text available
Among the many opportunities offered by electric vehicles (EVs), the design of power trains based on in-wheel electric motors represents, from the vehicle dynamics point of view, a very attractive prospect, mainly due to the torque-vectoring capabilities. However, this distributed propulsion also poses some practical challenges, owing to the constr...
Article
This article is concerned with the design of an energy management system (EMS) for the hybridization of multiple energy sources (ES's) in electric vehicles, focusing in a particular configuration composed by batteries and supercapacitors (SCs). As a first design step, we investigated an (non-causal) optimal power allocation, targeting the minimizat...
Conference Paper
Full-text available
In this paper, a detailed description of a control architecture for managing the DC link control of EVs with multiple energy sources is presented. The proposed topology allows the control of the power flow among supercapacitors and batteries, while ensuring the regulation of the DC link voltage, thanks to a cascade of voltage and current linear con...
Conference Paper
In the last years we have witnessed a growing interest, by the academic community and the automotive industry, in the multi-motor electric vehicles. The electrical nature of the propulsion is going to stress even more an increasing insertion of electronic devices in the vehicles. Furthermore, carmakers are performing research and already presented...