Books by George Moustris
In this chapter we analyse a SoC implementation for the non-holonomic robot path tracking task us... more In this chapter we analyse a SoC implementation for the non-holonomic robot path tracking task using a fuzzy logic controller, along with a non-linear feedback-equivalence transformation which reduces path tracking to straight line tracking. The major components of the SoC are a parametrized Digital Fuzzy Logic Controller (DFLC) soft IP core Deliparaschos et al. (2006) Deliparaschos & Tzafestas (2006), implementing the fuzzy tracking
algorithm, and Xilinx’s Microblaze soft processor core as the top level flow controller. The system was tied to a differential drive robot and experiments were performed in order to asses the efficacy and performance of the overall control scheme. This was facilitated using an image analysis algorithm, presented in the following sections, which calculated the robot’s
position from a video stream captured using an overhead camera. The analysis was made off-line.
Papers by George Moustris
Frontiers in Manufacturing Technology
This paper presents an innovative approach, based on industry 4.0 concepts, for monitoring the li... more This paper presents an innovative approach, based on industry 4.0 concepts, for monitoring the life cycle of optoelectronical devices, by adopting image processing and deep learning techniques regarding defect detection. The proposed system comprises defect detection and categorization during the front-end part of the optoelectronic device production process, providing a two-stage approach; the first is the actual defect identification on individual components at the wafer level, while the second is the pre-classification of these components based on the recognized defects. The system provides two image-based defect detection pipelines. One using low resolution grating images of the wafer, and the other using high resolution surface scan images acquired with a microscope. To automate the entire process, a communication middleware called Higher Level Communication Middleware (HLCM) is used for orchestrating the information between the processing steps. At the last step of the process...
Mathematics and Computers in Simulation, Nov 1, 2008
In this paper a piecewise linear homeomorphism is presented that maps a strictly monotone polygon... more In this paper a piecewise linear homeomorphism is presented that maps a strictly monotone polygonal chain to a straight line. This mapping enables one to reduce the path tracking task for mobile robots to straight line tracking. Due to the simplicity of the transformation, closed form solutions for the direct and inverse mapping are presented. Furthermore, the transformation also defines a feedback equivalence relation between the original and the transformed system equations of the mobile robot. It is shown that the form of the system equations is preserved and that the transformation essentially maps a car-like robot in the original domain, to a car-like robot in the transformed domain. This enables one to use straight line trackers developed solely for this system, for the tracking of arbitrary strictly monotone polygonal curves. Finally, it is shown that the use of this mapping can also simplify the application of existing path tracking controllers since they only need to track straight line paths. In general, one can eliminate from the existing path controllers all parameters that are needed for non-straight paths, thus obtaining respective simplified controllers. For example, it is shown that a fuzzy path controller with 135 rules can be reduced to an equivalent fuzzy straight line tracking controller with 45 rules.
International Journal on Artificial Intelligence Tools, Dec 1, 2005
In this paper the path tracking problem for non-holonomic mobile robots is dealt with. The model ... more In this paper the path tracking problem for non-holonomic mobile robots is dealt with. The model used is known as the Dubins Car model. A robust fuzzy logic controller that steers the car to the appropriate direction is proposed. A technique called "spatial window technique" which greatly increases the overall performance of the control scheme is also introduced. The simulations of this scheme show that the path following problem is treated very adequately and the noise tolerance of the overall system is high.
Control Engineering Practice, 2011
In this paper a switching fuzzy logic controller for mobile robots with a bounded curvature const... more In this paper a switching fuzzy logic controller for mobile robots with a bounded curvature constraint is presented. The controller tracks piece-wise linear paths, which are an approximation of the feasible smooth reference path. The controller is constructed through the use of a map, which transforms the problem to a simpler one; namely the tracking of straight lines. This allows the use of an existing fuzzy tracker deployed in a previous work, and its simplification leading to a 70% rule reduction. Simulation results and a comparison analysis with existing trackers are also presented along with some stability considerations on the impulsive error dynamics which emerge.
International Conference on Robotics and Automation, 2016
Mobility assistance robots (MARs) provide support to elderly or patients during walking. The desi... more Mobility assistance robots (MARs) provide support to elderly or patients during walking. The design of a safe and intuitive assistance behavior is one of the major challenges in this context. Here we present work on two modes of physical Human-Robot interaction; one where the human in is direct contact with the MAR, e.g. by holding some handles, and the other where the human releases the handles whilst the MAR has to follow him/her from the front, i.e. contactless. For the first mode, we present an integrated approach for the context-specific, on-line adaptation of the assistance level of a rollator-type MAR by gain-scheduling of low-level robot control parameters. A human-inspired decision-making model, the Drift-Diffusion Model, is introduced as the key principle to gain-schedule parameters and with this to adapt the provided robot assistance in order to achieve a human-like assistive behavior. The MAR is designed to provide a) cognitive assistance to help the user follow a desired path as well as b) sensorial assistance to avoid collisions with obstacles while allowing for an intentional approach of them. For the second mode, an intention-based assistive controller for allowing the robot to follow a human while moving in the front is analysed. This task is particularly challenging in indoor environments, as there are situations that are undecidable, namely in junctions. We describe a novel local kinodynamic planner which concurrently detects discrete routes and continuous motion paths. An intention recognition algorithm is also detailed, along with tests in a T-Junction.
2022 30th Mediterranean Conference on Control and Automation (MED)
International Journal of Computer Assisted Radiology and Surgery, Apr 24, 2023
Purpose Using robotic technology and communications infrastructure to remotely perform surgery ha... more Purpose Using robotic technology and communications infrastructure to remotely perform surgery has been a persistent goal in medical research in the past three decades. The recent deployment of the Fifth-Generation Wireless Networks has revitalized the research efforts in the telesurgery paradigm. Offering low latency and high bandwidth communication, they are well suited for applications that require real-time data transmission and can allow smoother communication between surgeon and patient, making it possible to remotely perform complex surgeries. In this paper, we investigate the effects of the 5 G network on surgical performance during a telesurgical demonstration where the surgeon and the robot are separated by nearly 300 km. Methods The surgeon performed surgical exercises on a robotic surgery training phantom using a novel telesurgical platform. The master controllers were connected to the local site on a 5 G network, teleoperating the robot remotely in a hospital. A video feed of the remote site was also streamed. The surgeon performed various tasks on the phantom such as cutting, dissection, pick-and-place and ring tower transfer. To assess the usefulness, usability and image quality of the system, the surgeon was subsequently interviewed using three structured questionnaires. Results All tasks were completed successfully. The low latency and high bandwidth of the network resulted into a latency of 18 ms for the motion commands while the video delay was about 350 ms. This enabled the surgeon to operate smoothly with a high-definition video from about 300 km away. The surgeon viewed the system's usability in a neutral to positive way while the video image was rated as of good quality. Conclusion 5 G networks provide significant advancement in the field of telecommunications, offering faster speeds and lower latency than previous generations of wireless technology. They can serve as an enabling technology for telesurgery and further advance its application and adoption.
International Journal of Computer Assisted Radiology and Surgery
Purpose Using robotic technology and communications infrastructure to remotely perform surgery ha... more Purpose Using robotic technology and communications infrastructure to remotely perform surgery has been a persistent goal in medical research in the past three decades. The recent deployment of the Fifth-Generation Wireless Networks has revitalized the research efforts in the telesurgery paradigm. Offering low latency and high bandwidth communication, they are well suited for applications that require real-time data transmission and can allow smoother communication between surgeon and patient, making it possible to remotely perform complex surgeries. In this paper, we investigate the effects of the 5 G network on surgical performance during a telesurgical demonstration where the surgeon and the robot are separated by nearly 300 km. Methods The surgeon performed surgical exercises on a robotic surgery training phantom using a novel telesurgical platform. The master controllers were connected to the local site on a 5 G network, teleoperating the robot remotely in a hospital. A video f...
Invited talk which presents the technological research efforts of various academic and reasearch ... more Invited talk which presents the technological research efforts of various academic and reasearch institution in Greece, regarding Mininally Invasive Surgery, either "regular" of robotic.
Surgical robots are becoming mainstream in medical practice and present many advantages over clas... more Surgical robots are becoming mainstream in medical practice and present many advantages over classical methods. However, there is a golden standard that applies: it is the human who performs the surgery. Allowing the robot to act on its own has raised concerns and expectations. Who is really operating? The surgeon, the robot or the programmer? This talk will present the problems faced with inserting various levels of autonomy in surgical robots and the interaction between surgeon and robot. Current research results will be discussed along with emerging trends in surgical robotics.
Abstract. Mobility disabilities are prevalent in our ageing society and impede activities importa... more Abstract. Mobility disabilities are prevalent in our ageing society and impede activities important for the independent living of elderly people and their quality of life. The goal of this work is to support human mobility and thus enforce fitness and vitality by developing intelligent robotic platforms designed to provide user-centred and natural support for ambulating in indoor environments. We envision the design of cognitive mobile robotic systems that can monitor and understand specific forms of human activity, in order to deduce what the human needs are, in terms of mobility. The goal is to provide user and context adaptive active sup-port and ambulation assistance to elderly users, and generally to individuals with specific forms of moderate to mild walking impairment. To achieve such targets, a reliable multimodal action recognition system needs to be developed, that can monitor, analyse and predict the user actions with a high level of accuracy and detail. Different modalit...
2013 European Control Conference (ECC), 2013
ABSTRACT Motion compensation is a prominent application in robotic beating heart surgery, with si... more ABSTRACT Motion compensation is a prominent application in robotic beating heart surgery, with significant potential benefits for both surgeons and patients. In this paper we investigate an activate assistance control scheme on a simple tracking task, which helps the surgeon guide the robot on a predefined reference. The control is implemented on top of a shared control system, which serves as a basis for implementing higher level controllers. Experiments with a trained surgeon are also presented, which show the positive effect of the approach.
2009 European Control Conference (ECC), 2009
In this paper a System-on-a-Chip (SoC) for the path following task of autonomous non-holonomic mo... more In this paper a System-on-a-Chip (SoC) for the path following task of autonomous non-holonomic mobile robots is presented. The SoC consists of a digital fuzzy logic processor and a flow control program that runs under the Xilinx Microblaze™ soft processor core. The fuzzy processor implements a fuzzy path tracking algorithm introduced by the authors. The system was tied to an actual P3-DX8 robot and field experiments have been performed in order to assess the overall performance. Quantization problems and limitations imposed by the system configuration are also discussed.
Recent Advances in Mobile Robotics, 2011
2013 IEEE International Conference on Robotics and Automation, 2013
This paper presents a shared control approach for motion compensation in robotic beating heart su... more This paper presents a shared control approach for motion compensation in robotic beating heart surgery. Motion compensation consists of three main tasks; motion synchronization, image stabilization and shared control. The paper discusses a unifying framework under which the three tasks combine seamlessly. In this work, the planar 1-manifold case is considered, where a strip-wise affine map is performed to achieve image stabilization onto a canonical space, where shared control emerges naturally. A prototype teleoperation system is also described, implementing the algorithms. Experiments were performed with medically trained users, and the positive effect of motion compensation is analyzed.
Universal Access in Human-Computer Interaction. Aging and Assistive Environments, 2014
The International Journal of Medical Robotics and Computer Assisted Surgery, 2011
21st Mediterranean Conference on Control and Automation, 2013
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Books by George Moustris
algorithm, and Xilinx’s Microblaze soft processor core as the top level flow controller. The system was tied to a differential drive robot and experiments were performed in order to asses the efficacy and performance of the overall control scheme. This was facilitated using an image analysis algorithm, presented in the following sections, which calculated the robot’s
position from a video stream captured using an overhead camera. The analysis was made off-line.
Papers by George Moustris
algorithm, and Xilinx’s Microblaze soft processor core as the top level flow controller. The system was tied to a differential drive robot and experiments were performed in order to asses the efficacy and performance of the overall control scheme. This was facilitated using an image analysis algorithm, presented in the following sections, which calculated the robot’s
position from a video stream captured using an overhead camera. The analysis was made off-line.