Evangelos Papadopoulos

Evangelos Papadopoulos
National Technical University of Athens | NTUA · School of Mechanical Engineering

PhD MIT

About

320
Publications
105,698
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
5,782
Citations
Additional affiliations
October 1996 - present
National Technical University of Athens
September 1991 - December 2002
Position
  • McGill University
September 1991 - May 1997
McGill University
Position
  • Professor

Publications

Publications (320)
Chapter
Quadrupedal locomotion skills are challenging to develop. In recent years, Deep Reinforcement Learning (DRL) promises to automate the development of locomotion controllers and map sensory observations to low-level actions. However, legged locomotion still is a challenging task for DRL algorithms, especially when energy efficiency is taken into cons...
Article
Full-text available
Most holonomic Unmanned Aerial Vehicles (HUAVs) (usually small-scale), employ at least four high-power thrusting actuators, resulting in increased mass, inertia, and energy consumption. In this work, a novel design for a HUAV using only three high-power thrusting actuators is developed. The pointing dynamics of the high rpm motor-propeller assembli...
Article
This article reintroduces the concept of Extended Physiological Proprioception (EPP) for below the elbow amputations, eliminating the use of a harness, cineplasty, or Bowden cables, and proposing instead a contemporary scheme inspired by teleoperation theory and its applications. A biomechatronics-based master/slave topology is developed to provide...
Conference Paper
Piezoelectric energy harvesting from vibrating structures under nonlinear oscillations has been proved quite promising, with a large amount of scientific works focusing on the maximum energy harvested. However, the detailed dynamic response of an electromechanical coupled nonlinear vibrating system and the interaction between the piezoelectric stru...
Article
Full-text available
Piezoelectric energy harvesting (PEH) is studied in the case of a low-velocity impact of a rigid mass on a composite beam. A methodology is outlined, encompassing modelling of the open-circuit impact response in a finite element (FE) package, formulation of a lumped parameter (LP) model for the piezoelectric transducer connected with the harvesting...
Article
Full-text available
A finite element-based methodology is introduced for studying composite beams with piezoelectric transducers connected to energy harvesting circuits. Continuous and lumped-parameter models are developed based on finite element approximations and verified by means of experiments performed on a cantilever beam subjected to sinusoidal excitation at lo...
Conference Paper
Full-text available
This paper presents a high-precision docking system enabling controlled motion of mobile robots and automatic guided vehicles in micrometer range. The developed system employs a low-cost, vehicle installed camera and a docking base with Quick Response (QR) codes in the form of a two-dimensional matrix. The docking base is free of active components,...
Article
Full-text available
Space exploration and exploitation depend on the development of on-orbit robotic capabilities for tasks such as servicing of satellites, removing of orbital debris, or construction and maintenance of orbital assets. Manipulation and capture of objects on-orbit are key enablers for these capabilities. This survey addresses fundamental aspects of man...
Article
The passive behavior of a compliant biped walking model, subject to variations in its design is investigated. A biped gait model is developed that allows for studying the effects of leg impedance, geometry, foot curvature and inertial properties on the stable gait performed passively. A set of non-dimensional parameters has been produced that fully...
Article
This paper presents a unified framework for the design and development of a passive biped robot and of its digital twin. A serial procedure is followed starting from the system's physical description, continuing to the dynamic analysis of independent models, and concluding with an experimental validation. The biped's mechanical model is tailored to...
Data
In free-floating mode, space manipulator systems have their actuators turned off, and exhibit nonholonomic behavior due to angular momentum conservation. The system is underactuated and a challenging problem is to control both the location of the end effector and the attitude of the base, using manipulator actuators only. Here a path planning metho...
Conference Paper
Full-text available
In this paper, Maera, a low-cost open-source hybrid legged-wheeled robot, is presented. The robot is designed to be used as a teaching platform and a hands-on introductory example in the field of robotics. To this end, the paper describes in detail the design and manufacturing methods used, along with the main specifications and capabilities of the...
Article
A complex motion encountered in a number of robotic, industrial and defense applications is the motion of a rigid body when one of its body-fixed axes tracks a desired Pointing Direction while it rotates at high Angular Velocity around the pointing direction (PDAV); during this motion high frequency precession/nutation oscillations arise. This work...
Conference Paper
Modeling and experimental verification of energy harvesting for a composite cantilever beam with a piezoelectric patch are presented. Finite element and lumped-parameter models are developed for open- and closed resistive circuit. A basic in-house circuit is compared to a commercial one in terms of power output. Results indicate good performance of...
Conference Paper
Full-text available
Space manipulator systems in orbit are subject to link flexibilities since they are designed to be lightweight and long reaching. Often, their joints are driven by harmonic gear- motor units, which introduce joint flexibility. Both of these types of flexibility may cause structural vibrations. To improve endpoint tracking, advanced control strategi...
Conference Paper
Full-text available
A novel identification method is developed which identifies the accumulated angular momentum (AAM) of spinning reaction wheels (RWs) of an uncooperative satellite captured by a robotic servicer. In contrast to other methods that treat captured satellite’s RWs as non-spinning, the developed method provides simultaneously accurate estimates of the AA...
Poster
Full-text available
Modeling and experimental verification of energy harvesting for a composite cantilever beam with a piezoelectric patch are presented. Finite element and lumped-parameter models are developed for open- and closed resistive circuit. A basic in-house circuit is compared to a commercial one in terms of power output. Results indicate good performance of...
Conference Paper
Full-text available
To enhance current robotic OOS capabilities, autonomous operations must be considered, that will rely on advanced controllers. The design and adaptation of such controllers requires reliable system identification methods and algorithms, especially regarding the system inertial parameters and flexibilities. The main objective of the OBSIdian project...
Article
Upper-limb prosthetic technology has significantly changed in recent years. The devices available and those under development, have progressed the state of the art considerably. However, most are based on velocity control and fail to activate the proprioception of the amputee, as they do not provide their user with adequate feedback. A novel contro...
Preprint
Upper-limb prosthetic technology has significantly changed in recent years. The devices available and those under development, have progressed the state of the art considerably. However, most are based on velocity control and fail to activate the proprioception of the amputee, as they do not provide their user with adequate feedback. A novel contro...
Preprint
Despite the undeniable progress in the field of upper-limb prosthetics in terms of robotic design and control methodologies, the goal of subconscious manipulation has yet to be fulfilled. Feedback information in most prostheses control strategies is not adequately provided to the amputee, leading to lack of proprioceptive stimuli, and consequently,...
Conference Paper
Full-text available
The design of a model-based Fault Tolerant Control (FTC) strategy based on Virtual Actuators (VA) in a built-in Guidance, Navigation and Control (GNC) setup is addressed for the e.Deorbit space mission. This mission, initiated by the European Space Agency (ESA), aims at removing a large defunct satellite from Earth orbit: ENVISAT. The goal of this...
Conference Paper
Full-text available
In this paper, an outline of NTUA’s work in the framework of project INTELLICONT is presented. We describe the current state of the air-cargo handling procedures and how the autonomous system that is under development is going to simplify these and increase the overall efficiency. Important issues and challenges regarding the system's development a...
Conference Paper
The ESA (European Space Agency) is currently pursuing the development of the e.Deorbit mission that will remove a large defunct satellite from Earth orbit: ENVISAT. To fulfil the mission autonomy requirements, ESA has decided to embed in the GNC (Guidance, Navigation, Control) software, fault tolerance capacities against actuator faults. The aim of...
Conference Paper
Full-text available
Extending life or repairing damaged on-orbit assets is not only a very attractive economic option for satellite operators as it could potentially increase margins for commercial services or increasing delivered value of scientific missions, but it would also help reducing the number of debris objects in space. These types of servicing missions pose...
Preprint
Full-text available
This paper presents contributions on nonlinear tracking control systems for a quadrotor unmanned micro aerial vehicle. New controllers are proposed based on nonlinear surfaces composed by tracking errors that evolve directly on the nonlinear configuration manifold thus inherently including in the control design the nonlinear characteristics of the...
Conference Paper
Historically, Classic Extended Physiological Proprioception (EPP) as an upper-limb prosthesis control topology has been outperforming functionally all other topologies of the past. A novel Biomechatronic EPP controller has been designed to overcome shortcomings of the classic EPP control topology, and has been hypothesized to be functionally equiva...
Conference Paper
Full-text available
In this paper a real time, stand-alone wireless Biomechatronic Extended Physiological Proprioception (EPP) teleoperation system was implemented using two Bluetooth Low Energy (BLE) wireless Systems on Chip (SoCs). This system is designed to achieve kinesthetic coupling between the amputee and prosthetic arm without the use of the classic EPP mechan...
Conference Paper
Full-text available
A method for identifying the full set of inertial parameters of a space object on orbit is presented, which is applicable at the pre-capture phase. The method’s objective is to reduce the risk during the capture phase, the most critical of a mission. Using data from visual and force sensors, the object’s center of mass, mass and moments of inertia...
Conference Paper
Full-text available
The quadrotor task of negotiating aggressive attitude maneuvers while adhering to motor constraints is addressed here. The majority of high level quadrotor Nonlinear Control System (NCS) solutions ignore motor control authority limitations , especially important during aggressive attitude maneuvers, generating unrealizable thrusts and negating the...
Article
In this paper, the design, the development, and the control for an 18 degree-of-freedom electrohydraulic hexapod robot for subsea operations are presented. The hexapod, called HexaTerra, can be equipped with a trenching machine, and move over obstacles and on sloped terrain. Optimization techniques are employed to size the robot legs. Rigid body eq...
Preprint
Full-text available
The quadrotor task of negotiating aggressive attitude maneuvers while adhering to motor constraints is addressed here. The majority of high level quadrotor Nonlinear Control System (NCS) solutions ignore motor control authority limitations, especially important during aggressive attitude maneuvers, generating unrealizable thrusts and negating the v...
Article
Full-text available
One of the most intriguing research challenges in legged locomotion is robot performance on compliant terrains. The foot-terrain interaction is usually tackled by disregarding some of the effects of ground deformation, like permanent deformation and compaction; however this approach restricts their application to stiff environments. In this work, t...
Conference Paper
Full-text available
New quadrotor UAV control algorithms are developed, based on nonlinear surfaces composed of tracking errors that evolve directly on the nonlinear configuration manifold, thus inherently including in the control design the nonlinear characteristics of the SE(3) configuration space. In particular, geometric surface-based controllers are developed and...
Article
Full-text available
Tracking a desired Pointing Direction and simultaneously obtaining a reference Angular Velocity (PDAV) around the pointing direction constitutes a very involved and complicated motion encountered in a variaty of robotic, industrial and military applications. In this paper through the utilization of global analysis and simulation techniques, the smo...
Conference Paper
Full-text available
An important phase in On-Orbit servicing missions is robotic docking. Successful docking is subject to a number of parameters and conditions. In this work, the robotic impact docking between two space systems is considered. The docking of a robotic Chaser to a Target spacecraft is modeled using a multibody approach. The impedance properties require...
Article
Full-text available
In this paper, the control of free-floating space manipulator systems with non-zero angular momentum (NZAM), for both motions in the joint and Cartesian space, is studied. Considering NZAM, dynamic models in the joint and Cartesian space are derived. It is shown that the NZAM has a similar result to the effect of gravity in terrestrial fixed base m...
Conference Paper
Full-text available
Recent successes of missions, such as the Rosetta, have increased the interest in the robotic exploration of other planets and asteroids. Although, in most landers passive landing systems are used, bouncing due to inappropriate descent speed and hardware malfunction have been observed in cases such as that of the Philae. In this paper, an impedance...
Article
In this paper, a method is developed that results in guidelines for selecting the best Ordinary Differential Equation (ODE) solver and its parameters, for a class of nonlinear hybrid system were impacts are present. A monopod interacting compliantly with the ground is introduced as a new benchmark problem, and is used to compare the various solvers...
Conference Paper
Full-text available
In this paper, the development of an Orbital Robotics educational prototype platform is presented, consisting of a hardware-developed physical system and an accompanying set of curriculum-based lessons (IB Physics curriculum) that target upper secondary students (16–18 years old target group). The platform was the outcome of a joint project between...
Article
Full-text available
Exploitation of space must benefit from the latest advances in robotics. On-orbit servicing is a clear candidate for the application of autonomous rendezvous and docking mechanisms. However, during the last three decades most of the trials took place combining extravehicular activities (EVAs) with telemanipulated robotic arms. The European Space Ag...
Article
A novel concept of a nonlinear oscillator is proposed, based on a bistable element, which operates around an unstable equilibrium point. Contrary to the Quasi-Zero Stiffness oscillators, a totally different redistribution of the stiffness elements is followed, so that any level required static stiffness for the entire system can be maintained. This...
Chapter
In this paper, the development of an Orbital Robotics edu- cational prototype platform is presented, consisting of a hardware- developed physical system and an accompanying set of curriculum-based lessons (IB Physics curriculum) that target upper secondary students (16–18 years old target group). The platform was the outcome of a joint project betw...
Chapter
Full-text available
Development and prototyping of robotic systems requires the involvement of many people and many hours of design, development and cooperation; significant time and effort overhead is required for evaluating conceptual ideas in design, control and technology, and for bringing them fast into reality for testing. Based on the important advances of the...
Conference Paper
Full-text available
On-orbit servicing missions will rely on space robots; however their complexity requires prior careful studies. Among these, robotic docking is especially challenging. In this work, the robotic impact docking between two space systems is considered. The impedance properties required to design an impedance controller are studied. These properties in...
Conference Paper
We present a novel algorithm for estimating a quadruped robot's pitch and roll angles. Assuming even terrain and an ideal bounding gait, we compute the roll and pitch angles to be fused with on-board Inertial Measurement Unit (IMU) measurements in an unscented Kalman filter (UKF). Simulation results illustrate the validity of the methodology develo...
Conference Paper
In this paper, we present the idea that very simple control schemes can lead to complex running gaits. To show this, a novel control framework is proposed for dynamic quadruped trotting, consisting of a toe trajectory planning part and an active compliance part driving each leg. While keeping the controller's structure simple, the notion of the sys...