Georgios Andrikopoulos

• Ph.D., Electrical and Computer Engineer
• Assistant Professor at KTH Royal Institute of Technology

The presented work investigates the potential of utilizing commercially available Electric Ducted Fans (EDFs) as adhesion actuators, while providing a novel insight on the analysis of the adhesion nature related to negative pressure and thrust force generation against a target surface. To this goal, a novel EDF-based Vortex Actuation Setup (VAS) is...

Using soft actuators as legs, soft quadruped robots have shown great potential in traversing unstructured and complex terrains and environments. However, unlike rigid robots whose gaits can be generated using foot pattern design and kinematic model of the rigid legs, the gait generation of soft quadruped robots remains challenging due to the high D...

Quadruped robots have the advantages of traversing complex terrains that are difficult for wheeled robots. Most of the reported quadruped robots are built by rigid parts. This paper proposes a new design of quadruped robots using soft actuators driven by tendons as the four legs. Compared to the rigid robots, the proposed soft quadruped robot has i...

In this study, we propose a novel family of onset and offset detection algorithms for electromyographic (EMG) signals, based on the Teager-Kaiser Energy Operator (TKEO). These algorithms are derived from an existing double-threshold statistical detector, which is modified to use Shifted Skew Log Laplace Distribution (SSLLD) probabilities and likeli...

Sensors play a vital role in the industry transformation. Commercial sensors such as force sensors have limited options in shapes, stiffness, measuring ranges, etc. Customized force sensors optimized for the production environment can greatly increase the integration workflow and avoid the trade-off in design freedom of using commercial sensors. 3D...

Essential tremor (ET) is one of the most common movement disorders and can occur unexpectedly and develop indefinitely to any population unit. According to the recorded statistics of people suffering from ET, the disorder affects 5% of people worldwide, thus creating an ever-increasing need to investigate ways for its suppression and treatment. In...

This article tackles the challenge of negative pressure adhesion control of a Vortex Robotic (VR) platform, which utilizes a modified Electric Ducted Fan (EDF)-based design for successfully adhering to surfaces of variable curvature. The resulting Vortex Actuation (VA) system is estimated through a switching Autoregressive-Moving-Average with eXter...

In this article, the challenge of discriminating between essential and Parkinson’s tremor is addressed. Although a variety of methods have been proposed for diagnosing the severity of these highly occurring tremor types, their rapid and effective identification, especially in their early stages, proves particularly difficult and complicated due to...

In this article, the challenge of identifying between Essential and Parkinson's tremor is addressed. To this goal, a clinical analysis was performed, where a number of volunteers including Essential and Parkinson's tremor-diagnosed patients underwent a series of pre-defined motion patterns, during which a wearable sensing setup was used to measure...

In this article, a soft exoskeletal glove is proposed for investigating the potential of utilizing Pneumatic Artificial Muscles (PAMs) for suppressing hand tremor of Essential Tremor (ET) patients. The glove setup is first presented from a conceptual point, which is focused on the dual investigation of applying local kinesthetic forces exerted via...

The area of service robots has steadily gained interest over the years as an attempt for deploying robots to tackle problems faced in our everyday lives. In this article, a survey on the application areas of home service robots is presented. A collection of robotic appliances is selected to be introduced based on their application objective of bein...

The paper presents the results obtained in the first two years of the H2020 CompInnova project which deals with the development of an innovative approach for inspection and repair of damage in aeronautical composites. The development of a newly designed robotic platform for autonomous inspection using combined infrared thermography (IRT) and phased...

In this article, the potential of utilizing a commercially available Electric Ducted Fan (EDF) as a negative pressure actuator for adhesion purposes is experimentally tested. To this purpose, a novel EDF-based Vortex Actuation System (VAS) is proposed and presented from a design, development and experimental evaluation perspective. The effect of di...

This paper deals with the development of an innovative approach for inspection and repair of damage in aeronautical composites that took place in the first two years of the H2020 CompInnova project which. The aim is a newly designed robotic platform for autonomous inspection using combined infrared thermography (IRT) and phased array (PA) non-destr...

In this article, a HUmanoid Robotic Leg (HURL) via the utilization of pneumatic muscle actuators (PMAs) is presented. PMAs are a pneumatic form of actuation possessing crucial attributes for the implementation of a design that mimics the motion characteristics of a human ankle. HURL acts as a feasibility study in the conceptual goal of developing a...

Musculoskeletal modeling based on Electromyography (EMG) has many applications in physiotherapy and biologically-inspired robotics. In this article, a novel methodology for the modeling of the dynamics of an antagonistic muscle pair that actuates the human ankle joint movements will be established. As it will be presented, the musculoskeletal model...

In this paper, a modified static force modeling approach, which is based on fundamental pneumatic muscle actuator (PMA) modeling techniques, is proposed. In addition, the thermal expansion effect is considered as the main cause of the gradual shift in the PMA's force-displacement relationship and the geometric properties, which are being affected b...

The aim of this article is to present a survey on inspection applications of Pneumatic Wall-Climbing Robots (PWCR). In general, a PWCR utilizes negative pressure as its adhesion method, through mainly suction cups or negative pressure thrust-based mechanisms. Their main advantage being their ability to climb non-ferromagnetic surfaces, such as glas...

In this article, a novel Vertical Take-Off and Landing (VTOL) Single Rotor Unmanned Aerial Vehicle (SR-UAV) will be presented. The SRUAV's design properties will be analysed in detail, with respect to technical novelties outlining the merits of such a conceptual approach. The system's model will be mathematically formulated, while a cascaded P-PI a...

In this article a Tilt-Wing Unmanned Aerial Vehicle (TW-UAV) and the preliminary evaluation of its hovering characteristics in extended simulation studies are presented. In the beginning, an overview of the TW-UAV's design properties are established, highlighting the novelties of the proposed structure and the overall merits. The TW-UAV's design an...

The aim of this article is to present a novel four-degree-of-freedom aerial manipulator allowing a multirotor Unmanned Aerial Vehicle (UAV) to physically interact with the environment. The proposed design, named CARMA (Compact AeRial MAnipulator), is characterized by low disturbances on the UAV flight dynamics, extended workspace (with regard to it...

In this article, the thermal expansion effect is considered as the main cause of the gradual shift in the forcedisplacement relationship, which describes the operation of Pneumatic Artificial Muscles (PAMs). A modified static force modeling approach is proposed, based on fundamental PAM modeling techniques, while incorporating the geometrical prope...

Full or partial loss of function in the shoulder, elbow or wrist is an increasingly common ailment caused by various medical conditions like stroke, occupational and sport injuries, as well as a number of neurological conditions, which increases the need for the development and improvement of upper limb rehabilitation devices. In this article, the...

In this article, a 6 Degree-of-Freedom (DOF) parallel manipulator, actuated by Pneumatic Artificial Muscles (PAMs), is being presented. Incorporated in a two Stewart Platform-based design, the novel manipulator's motion capabilities are being examined through kinematic analysis, while the open-loop operation characteristics and performance of the m...

In this paper, the modeling and control problem of a pneumatic artificial muscle (PAM) is being considered. The PAM is an actuator characterized by a decrease in the actuating length when pressurized. Its nonlinear nature and time-varying parameters cause difficulties in modeling their characteristics, as well as in designing controllers for high-p...

In this article, a switching Model Predictive Controller (sMPC) for a pneumatic artificial muscle (PAM) is presented. The control scheme is based on a switching PieceWise Affine (PWA) system model approximation that is able to capture the high nonlinearities of the PAM, while improving the overall model accuracy, and is composed of: (a) a feed-forw...

In this article, the model identification and control problem of a Pneumatic Artificial Muscle (PAM) is being considered. The identification of the PAM's model parameters is being carried out by a Recursive Least Square (RLS) based algorithm, while an Internal Model Control (IMC) structure is being synthesized. Experimental studies are being utiliz...

In this article, a non-linear PID structure is being synthesized, providing ameliorated compensation of the Pneumatic Artificial Muscle's (PAM) non-linear hysteretic phenomena and advanced robustness. Experimental studies are being utilized to prove the overall efficiency of the non-linear control scheme regarding: a) set-point tracking performance...

The aim of this article is to provide a survey on the most popular modeling approaches for Pneumatic Muscle Actuators (PMAs). PMAs are highly non-linear pneumatic actuators where their elongation is proportional to the interval pressure. During the last decade, there has been an increase in the industrial and scientific utilization of PMAs, due to...

In the past fifty years, several attempts have been made to model the characteristics of Pneumatic Artificial Muscles (PAMs). PAM models based on their geometrical properties are the most commonly found ones in the scientific literature. In the process of deriving those models a lot of assumptions and simplifications are made due to the fact that P...

The aim of this article is to present a dynamic analysis and a cascade movement simulation of a Pneumatic Muscle Actuator (PMA). PMAs are highly non--linear pneumatic actuators where their elongation is proportional to the interval pressure. Their non--linear characteristics and the property of the hysteresis are posing several difficulties in simu...

This article presents the development and control of a novel hybrid controlled vertical climbing robot based on Pneumatic Muscle Actuators (PMAs). PMAs are highly non– linear pneumatic actuators where their elongation is proportional to the internal pressure. The vertical sliding of the robot is based on four PMAs and through the combined and seque...

The aim of this article is to provide a survey on the most popular modeling approaches for Pneumatic Muscle Actuators (PMAs). PMAs are highly non-linear pneumatic actuators where their elongation is proportional to the interval pressure. During the last decade, there has been an increase in the industrial and scientific utilization of PMAs, due to...