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Gianluca Pepe

Università degli Studi "La Sapienza" di Roma, Department of Mechanical and Aerospace Engineering, Post-Doc

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Papers by Gianluca Pepe

Auto-Sapiens, an Experimental Autonomous Driving System

XI International Conference on Structural Dynamics, 2020

The author has investigated the learning style of the students and behavioral change in the learn... more The author has investigated the learning style of the students and behavioral change in the learner and also when they note the persistence of this change. Learning happens in stages, and at each stage, students learn in different ways. Difficulties that arise at home, schooling are often due to differences in learning styles. It has been proposed that teachers should assess the learning styles of their students and adapt their classroom methods to best fit each student's learning style. These possessed learning styles play a vital role in deciding their level of achievement. This achieved test score determines their future career. The ambitions and aspirations of our students are largely governed by their learning skills adopted by the students. There is no significant difference between XI and XII standard higher secondary school students in their learning styles in the dimensions. This study will be more fruitful when suggestions given by the investigator are applied for further study and it will be of great help for those who want to study further in this field.

Mine Clearance through an Artificial Intelligence Flying Drone

NODYCON Conference Proceedings Series, 2022

This work presents an algorithm which combines a convolutional neural network (CNN) and a symboli... more This work presents an algorithm which combines a convolutional neural network (CNN) and a symbolic data analysis (SDA) process to detect antipersonnel mines from GPR data acquisitions. The CNN is aimed at automatically detecting buried objects; the SDA reduces the probability of objects identified as mines, even though they are not.

Optimal control with memory effects: theory and application to wings

2019 18th European Control Conference (ECC), 2019

A novel indirect variational optimal control theory is proposed for integral-differential equatio... more A novel indirect variational optimal control theory is proposed for integral-differential equations of motion. This algorithm is applied to an engineering application: the control of a an underawater autonomous vehicle's 2-Dof lifting surface. The variational approach proposed is an extension of the classical Potryagin optimal control theory which normally refers to differential equations. The control has been extended by developing a novel integral MPC technique. Numerical results show good performace of the optimal control proposed compared with the standard LQR method.

A New Approach for Structural Health Monitoring: Damage Detection on Large Structures through a Swarm of Moving Sensors

NODYCON Conference Proceedings Series, 2022

The present paper takes place in the context of identification problems: the aim is to propose a ... more The present paper takes place in the context of identification problems: the aim is to propose a new approach for the detection of damages within large structures via the deployment of a set of moving sensors. The goal of the method is to optimally control the motion of the swarm driving the sensors in the optimal measurement regions, in order to perceive the field as clean as possible and to enhance the identification of any possible irregularity along the structure. The optimal control of the sensors motion and the consequent damage identification are achieved through a two-step strategy. The first one is based on: i) models for the dynamics of the structure, for the dynamics of the sensors; ii) LQR control logic to define the optimal trajectory of the swarm. The second step includes the identification of the damage module: the process of data analysis is investigated through a revision of the technique based on Empirical Mode Decomposition, combined with the Hilbert-Huang Transform.

A new optimal control of obstacle avoidance for safer autonomous driving

2019 AEIT International Conference of Electrical and Electronic Technologies for Automotive (AEIT AUTOMOTIVE), 2019

The autonomous vehicle is one of the greatest challenges in modern vehicle design. This paper pro... more The autonomous vehicle is one of the greatest challenges in modern vehicle design. This paper proposes a new method of control named FLOP, Feedback Local Optimality Principle, recently proposed by the authors. The method, starting from the Pontryagin's theory, introduces a new optimality principle that minimizes a sequence of individual functionals with the chance of a direct feedback control. The theory is applied to the steering and traction control of a two-wheeled vehicle, showing the ability of tracking a given trajectory, obstacles avoidance in a complex environment and measuring the benefits for driving safety.

Car collision avoidance with velocity obstacle approach: Evaluation of the reliability and performace of the collision avoidance maneuver

2019 IEEE 5th International forum on Research and Technology for Society and Industry (RTSI), 2019

The obstacle avoidance maneuver is required for an autonomous vehicle. It is essential to define ... more The obstacle avoidance maneuver is required for an autonomous vehicle. It is essential to define the system's performance by evaluating the minimum reaction times of the vehicle and analyzing the probability of success of the avoiding operation. This paper presents a collision avoidance algorithm based on the velocity obstacle approach that guarantees collision-free maneuvers. The vehicle is controlled by an optimal feedback control named FLOP, designed to produce the best performance in terms of safety and minimum kinetic collision energy. Dimensionless accident evaluation parameters are proposed to compare different crash scenarios.

Variational Control Approach to Energy Extraction from a Fluid Flow

Energies, 2020

Energy harvesting from the environment is an important aspect of many technologies. The scale of ... more Energy harvesting from the environment is an important aspect of many technologies. The scale of energy capturing and storage can involve the power range from mWatt up to MWatt, depending on the used devices and the considered environments (from ambient acoustic and vibration to ocean wave motion, or wind). In this paper, the wind turbine energy harvesting problem is approached as an optimal control problem, where the objective function is the absorption of an amount of energy in a given time interval by a fluid-flow environment, that should be maximized. The interest relies on outlining general control models of fluid-flow-based extraction plants and identifying an optimum strategy for the regulation of an electrical machine to obtain a maximum-efficiency process for the related energy storage. The mathematical tools are found in the light of optimal control theory, where solutions to the fundamental equations are in the frame of Variational Control (the basis of the Pontryagin opt...

Quadrupedal Robots’ Gaits Identification via Contact Forces Optimization

Applied Sciences, 2021

The purpose of the present paper is the identification of optimal trajectories of quadruped robot... more The purpose of the present paper is the identification of optimal trajectories of quadruped robots through genetic algorithms. The method is based on the identification of the optimal time history of forces and torques exchanged between the ground and the body, without any constraints on leg kinematics. The solutions show how it is possible to obtain similar trajectories to those of a horse’s walk but obtaining better performance in terms of energy cost. Finally, a map of the optimal gaits found according to the different speeds is presented, identifying the transition threshold between the walk and the trot as a function of the total energy spent.

Demining War Scenarios: A Project Based on New Technologies

XI International Conference on Structural Dynamics, 2020

Článek pojednává o Znalostním managementu jako nástroji pro podporu znalostí-přináší definici poj... more Článek pojednává o Znalostním managementu jako nástroji pro podporu znalostí-přináší definici pojmu, vysvětlení konceptu a jeho stručnou historii spolu s uvedením jednotlivých druhů znalostí. Dále se zaobírá koncepty znalostního managementu, jeho oblastech a syntézou znalostí. Závěrem popisuje problematiku rozpočtu aktivit znalostního managementu spolu s definicí cílů a problematiku tvorby týmu.

Auto-Sapiens Autonomous Driving Vehicle

Proceedings of the 6th International Conference on Vehicle Technology and Intelligent Transport Systems, 2020

This paper presents the Auto-Sapiens project, an autonomous driving car developed by the Mechatro... more This paper presents the Auto-Sapiens project, an autonomous driving car developed by the Mechatronics and Vehicle Dynamics Lab, at Sapienza University of Rome. Auto-Sapiens is a technological platform to test and improve innovative control algorithms. The car platform is a standard car (Smart ForTwo) equipped with throttle, brake, steering actuators and different sensors for attitude identification and environment reconstruction. The first experiments of the Auto-Sapiens car test a new obstacle avoidance. The vehicle, controlled by an optimal variational feedback control, recently developed by the authors, includes the nonlinearities inherent in the car dynamics for better performances. Results show the effectiveness of the system in terms of safety and robustness of the avoidance maneuvers.

Semi-active damping by variational control algorithms

Semi-active damping control of oscillating devices and structures is a challenging field that con... more Semi-active damping control of oscillating devices and structures is a challenging field that conjugates a relative actuators simplicity together with the chance of studying new algorithms and system architectures. This paper proposes an overview of the investigation recently developed by the authors in the field of semi-active damping using the variational optimal control. The method produces a general class of controllers that can be applied to linear as well as nonlinear suspension systems and vibrating structures. Their performances are systematically investigated and compared with the sky-hook benchmark.

Extraction of the Beam Elastic Shape from Uncertain FBG Strain Measurement Points

Mechanisms and Machine Science, 2018

Aim of the present paper is the analysis of the strain along the beam that is equipped with Glass... more

Architecture of a new semi-active suspension system and associated control logic

Energy exchange between nonlinear oscillators: An entropy foundation

In the field of vibrations of complex structures, energy methods like SEA and a series of mid-fre... more In the field of vibrations of complex structures, energy methods like SEA and a series of mid-frequency methods, represent an important resource for computational analysis. All these methods are based in general on a linear formulation of the elastic problem. However, when nonlinearities are present, for example related to clearance or stiffening of joints, these methods, in principle, cannot be applied. This paper, on the basis of a theory presented recently by one of the authors, proposes a foundation of a new energy method able to deal with nonlinearities when studying the energy exchange between subsystems. The idea relies on the concept of a thermodynamic vibroacoustic temperature, that can be directly defined when introducing the entropy of a vibrating structure. The theory is introduced in general, and examples of calculation of the power flow between nonlinear resonators are presented introducing stiffening and clearences for systems with many degrees of freedom.

Prototyping a new car semi-active suspension by variational feedback controller

New suspension systems electronically controlled are presented and mounted on board of a real car... more New suspension systems electronically controlled are presented and mounted on board of a real car. The system consists of variable semi-active magneto-rheological dampers that are controlled through an electronic unit that is designed on the basis of a new optimal theoretical control, named VFC-Variational Feedback Controller. The system has been mounted on board of a BMW Series 1 car, and a set of experimental tests have been conducted in real driving conditions. The VFC reveals, because of its design strategy, to be able to enhance simultaneously both the comfort performance as well as the handling capability of the car. Preliminary comparisons with several industrially control methods adopted in the automotive field, among them skyhook and groundhook, show excellent results. 1 Introduction: key-performance-indexes of suspension systems A first application to semi-active control of VFC-Variational Feedback Control has been considered to enhance suspension performance of a motor vehicle and presented in [1-6]. There, the control logic was applied in a context of numerical simulations, optimizing comfort and handling, minimizing the car body acceleration and maximizing the road-tire contact force. This paper proceed ahead in this direction, describing the prototyping activities to install a complete integrated device based on VFC on a real vehicle. Namely, this research is motivated by the fact that the VFC control logic is capable of reaching excellent compromise performances between handling and comfort, not usual in others control systems. In fact, when designing a new suspension concept, many physical parameters contribute to the final performances of the system. For example, the comfort ability is frequently related to the chance of mitigating the vertical accelerations on the car seats, while the handling ability of the car is indeed related to the tire grip the suspension system can assure by preventing sudden decreasing of the load on the road. Beside this, for example, also the stroke of the suspension is an important physical response to limit. It is clear, in fact, that it is easy to reduce the car body acceleration if one can accept large deflections of the elastic elements of the suspension system. The acceleration reduction is indeed much more difficult to achieve if a severe constraint is demanded on the maximum admissible stroke. At the same time, the settling time is an important parameter in the suspension performance, but not specifically related to the comfort or handling, and it deserves its own emphasis at the suspension design stage. In this paper, a set of key-performance-indexes are defined and systematically considered to provide a general optimal control of the suspension system. In particular these parameters, considered as pair to be associated to the x and y axes, can in turn define special performance-planes. In these planes can be identified regions of performances that can be associated to the different existing suspension control logics. In this sense, the ability of a new method of control can be measured by its capability of reaching zones that are indeed prohibited to the conventional strategies.

Fast Moving of a Population of Robots Through a Complex Scenario

Nonlinear Dynamics and Control, 2020

Swarm robotics consists in using a large number of coordinated autonomous robots, or agents, to a... more Swarm robotics consists in using a large number of coordinated autonomous robots, or agents, to accomplish one or more tasks, using local and/or global rules. Individual and collective objectives can be designed for each robot of the swarm. Generally, the agents' interactions exhibit a high degree of complexity that makes it impossible to skip nonlinearities in the model. In this paper, is implemented both a collective interaction using a modified Vicsek model where each agent follows a local group velocity and the individual interaction concerning internal and external obstacle avoidance. The proposed strategies are tested for the migration of a unicycle robot swarm in an unknown environment, where the effectiveness and the migration time are analyzed. To this aim, a new optimal control method for nonlinear dynamical systems and cost functions, named Feedback Local Optimality Principle-FLOP, is applied.

Safe and Secure Control of Swarms of Vehicles by Small-World Theory

Energies, 2020

The present paper investigates a new paradigm to control a swarm of moving individual vehicles, b... more The present paper investigates a new paradigm to control a swarm of moving individual vehicles, based on the introduction of a few random long-range communications in a queue dominated by short-range car-following dynamics. The theoretical approach adapts the small-world theory, originally proposed in social sciences, to the investigation of these networks. It is shown that the controlled system exhibits properties of higher synchronization and robustness with respect to communication failures. The considered application to a vehicle swarm shows how safety and security of the related traffic dynamics are strongly increased, diminishing the collision probability even in the presence of a hacker attack to some connectivity channels.

A new tow maneuver of a damaged boat through a swarm of autonomous sea drones

IFAC-PapersOnLine, 2019

Given the huge rising interest in autonomous drone swarms to be employed in actual marine applica... more Given the huge rising interest in autonomous drone swarms to be employed in actual marine applications, the present paper explores the possibility to recover a distressed vessel by means of the other agents belonging to the swarm itself. Suitable approaches and control strategies are developed and tested to find the highest performance algorithms. Different rules are exploited to obtain a correct behaviour in terms of swarm interaction, namely collective and coordinated, and individual. An innovative feedback control strategy is adopted and demonstrated its effectiveness. Extensive simulation runs have been conducted, whose results validate the approach.

OPTYRE—Real Time Estimation of Rolling Resistance for Intelligent Tyres

Sensors, 2019

The study of the rolling tyre is a problem framed in the general context of nonlinear elasticity.... more The study of the rolling tyre is a problem framed in the general context of nonlinear elasticity. The dynamics of the related phenomena is still an open topic, even though few examples and models of tyres can be found in the technical literature. The interest in the dissipation effects associated with the rolling motion is justified by their importance in fuel-saving and in the context of an eco-friendly design. However, a general lack of knowledge characterizes the phenomenon, since not even direct experience on the rolling tyre can reveal the insights of the correlated different dissipation effects, as the friction between the rubber and the road, the contact kinematics and dynamics, the tyre hysteretic behaviour and the grip. A new technology, based on fibre Bragg grating strain sensors and conceived within the OPTYRE project, is illustrated for the specific investigation of the tyre dissipation related phenomena. The remarkable power of this wireless optical system stands in the...

Experimenting Sensors Network for Innovative Optimal Control of Car Suspensions

Sensors, 2019

This paper presents an innovative electronically controlled suspension system installed on a real... more This paper presents an innovative electronically controlled suspension system installed on a real car and used as a test bench. The proposed setup relies on a sensor network that acquires a large real-time dataset collecting the car vibrations and the car trim and, through a new controller based on a recently proposed theory developed by the authors, makes use of adjustable semi-active magneto-rheological dampers. A BMW series 1 is equipped with such an integrated sensors-controller-actuators device and an extensive test campaign, in real driving conditions, is carried out to evaluate its performance. Thanks to its strategy, the new plant enhances, at once, both comfort and drivability of the car, as field experiments show. A benchmark analysis is performed, comparing the performance of the new control system with the ones of traditional semi-active suspensions, such as skyhook devices: the comparison shows very good results for the proposed solution.