Abstract: The rapid development of telerobotic systems led to novel applications beyond the nuclear and industrial domains. Medical telerobotics enabled surgeons to perform medical operations from remote places, far from their patient. Telesurgery systems allow great flexibility, improved performance in general, and support the creation of ideal surgical conditions. The first attempts to develop telesurgical systems borrowed the idea from space research, where the need of novel robots emerged for invasive treatment, even under extreme situations, such as weightlessness. Telesurgical instruments on Earth appeared following the same concept, aiming first for military, then onward for civilian applications. Today, more than 1.5 million patients are receiving telerobotic treatment annually, worldwide. As the surgical robotics domain grew from the initial concepts, it developed along three major concepts: telesurgery, cooperatively controlled robots and automated (image-guided) applications. These domains continue to develop into application specific systems with the goal of reaching the specificity and versatility of conventional surgical instruments.
Keywords: surgical robotics; space robotics; teleoperation
Abstract: Medical Robotics is an interdisciplinary field that focuses on developing electromechanical devices for diagnosis and therapy. The long-term goal of this application area is to enable new medical techniques by providing new capabilities to the physician or by providing assistance during surgical procedures. The field has tremendous potential for improving the precision and capabilities of physicians when performing surgical procedures, and thus it is believed that the field will continue to grow. On the other hand – and unlike the area of factory robotics, which grew rapidly during the 1970s and 1980s – Medical Robotics has not yet gained widespread acceptance. There are still many technological challenges and research topics – including both the development of system components and the development of systems as a whole. The paper aims to give a short overview on the state-of-the-art of Medical Robotics in selected application areas, to highlight some open problems e.g., system architecture, user interfaces and safety issues, and finally to show some examples for medical robotic developments from Austria.
Keywords: Medical Robotics; Computer-Aided Surgery; Surgical Mechatronic Assistance
Abstract: Professor Dr. Antal K. Bejczy, the Hungarian-born scientist innovator worked for the NASA Jet Propulsion Laboratory (JPL) in California from 1969, where he developed, with his colleagues, the first dynamic model of robotic manipulators based on the Lagrangian formulation. In the field of teleoperation, he developed, and sponsored through NASA Telerobotics program, a number of prototypes aimed at achieving full Telepresence in space and undersea. He pioneered robot dynamics development and published one of the first papers in this field, describing “smart hands” with multi-fingered, effector equipped sensors. One of his research papers named “The Robot Arm Dynamics and Control” was published by JPL in 1974. This was one of the most important papers in the history of robotics.
Keywords: Antal K. Bejczy; smart hands;exoskeleton; Antal Bejczy Center for Intelligent Robotics; dynamic model of robotic manipulators; teleoperation
Abstract: This paper aims to highlight the relationship of Artificial Intelligence, the first Chessautomaton (The Turk), Computer Chess (Deep Blue), Mars Mission (Pathfinder Sojourner), Intelligent Robotics and Industrial Robots Biographical and technical data is presented in order to evaluate and laudate the extraordinary achievements of extreme talents, starting with two Hungarian world class innovators: Farkas Kempelen and Antal Bejczy. This paper gives an overview of their lives and contributions, pointing out some interesting connections. A novel evaluation and classification method of robots is suggested.
Keywords: Mars Rover; Pathfinder; Chess automaton
Abstract: This paper proposes a new tuning approach, by which, all parameters of a datadriven Model-Free Adaptive Control (MFAC) algorithm are automatically determined using a nonlinear Virtual Reference Feedback Tuning (VRFT) algorithm. The approach is referred to as mixed MFAC-VFRT control and it leads to mixed MFAC-VFRT algorithms. An advantage of mixed MFAC-VFRT control, is that it combines systematically, the features of VRFT (it computes the controller parameters using only the input/output data) with those of MFAC. This is especially illustrated by comparison with the classical MFAC algorithms, the initial values of the parameters, which are obtained through a process that involves solving an optimization problem. The application that validates the mixed MFACVFRT algorithms, by experiment, is a nonlinear twin rotor aerodynamic system laboratory equipment position control system, that represents a tribute, to Prof. Antal (Tony) K. Bejczy for his excellent results in space robotics, robot dynamics and control, haptics and force perception/control.
Keywords: Model-Free Adaptive Control; twin rotor aerodynamic system; optimal control; state-space model; Virtual Reference Feedback Tuning
Abstract: In the practice, precise and efficient control is needed for certain state variables of multiple variable physical systems in which the number of the independent control variables is less than that of the independent state variables. In such cases, either the propagation of certain state variables is completely abandoned or the concept of the Model Predictive Control (MPC) is applied in which the model of the controlled system is embedded into the mathematical framework of the Optimal Controllers. This approach uses a cost function that summarizes the contributions of the frequently contradictory requirements. By minimizing this cost a kind of “compromise” is achieved. Whenever approximate and/or incomplete system models are available, the use of this controller is justified only for short time-intervals. The only way to reduce the accumulation of the effects of the modeling errors is the frequent re-design of the time horizon from the actual state as initial state that is done by the Receding Horizon Controllers. The more sophisticated Adaptive Controllers are designed by the use of Lyapunov’s “Direct Method” that has a complicated mathematical framework that cannot easily be combined with that of the optimal controllers. As a potential competitor of the Lyapunov function-based adaptive controllers a Fixed Point Transformation-based approach was invented that in the first step transforms the the problem of computing the control signal into the task of finding an appropriate fixed point of a contractive map. The fixed point can be found by iteration in which the iterative sequence is generated by this contracting map. This method can be used for contradiction resolution without the minimization of any cost function by tracking the observable state components with time-sharing on a rotary basis. In the present paper a novel fixed point transformation is introduced. It is shown that this construction for monotonic response function of bounded derivative can guarantee global stability. Furthermore, the time-sharing-based method is demonstrated by the control of an underactuated 3 DoF Classical Mechanical system via numerical simulations.
Keywords: adaptive control; underactuated mechanical systems; fixed point transformations; optimal control; contradiction resolution; time-sharing;
Abstract: The paper presents numerical verification and experimental results for the setpoint control of the nonholonomic mobile robot. The task is to move to the goal and reach it with desired orientation avoiding collisions with static obstacles. The obstacles in the task space are modelled using analytic functions. The algorithm is investigated for both convex and non-convex star-shape obstacles
Keywords: nonholonomic mobile robot; collision avoidance; navigation function; set-point control
Abstract: The paper deals with the formation control of Unmanned Ground Vehicles (UGVs) moving in horizontal plane. The control system consists of the high level centralized formation control of the UGVs and the low level decentralized PID type suspension, speed and steering control of the different vehicles. Both problems are discussed in multi-body assumptions. The paper presents the generalization of the multi-body method for underactuated car-like vehicles, developed originally for fully-actuated surface ships. In order to simplify the design and implementation on the formation level, an approximate single track dynamic model was assumed for each vehicle. At low level a more realistic two track dynamic model is used in the form of a multibody system in tree structure. This realistic nonlinear model is obtained by using Appell’s method, Pacejka’s magic formula for tyre-road connections and kinematic constraints expressing the nullity of vertical accelerations of the contact points. The interface between the higher and lower control levels is presented in the form of acceleration and steering angle prescriptions (output of high level). The decentralized control system of each vehicle converts the specifications in smooth reference signals and performs the desired motion. Simulation results of the high level control of UGV formations are presented for sine-shaped and circular paths.
Keywords: Formation Control, Unmanned Ground Vehicles, Multi-Body Approach, Tree Structured Vehicle, Pacejka’s Magic Formula, Contact Point Constraints, Robust PID Control
Abstract: Autonomous Underwater Vehicle (AUV) response robots are special multipurpose devices, capable of moving and performing various tasks in water, autonomously, or with human teleoperation. Capability assessment of such devices is hard and complex work. This paper describes our work in AUV Response Robot testing from two aspects: First, additional testing methods are proposed for AUV capability assessment and second, we describe, in detail, how an AUV can be enhanced to pass the existing underwater response robot tests, defined by National Institute of Standards and Technology (NIST). In the first part of the paper, a short overview of the existing AUV testing methods is given, followed by our proposed, new test scenarios. The second part covers a general overview about our system design and development, which enabled the custom, enhanced AUV to pass the test scenarios.
Keywords: autonomous underwater vehicles (AUV); response robotics; AUV testing; underwater manipulation; underwater teleoperation
Abstract: In this study we introduce different novel interpretations in the case of Linear Parameter Varying (LPV) methodology, which are directly usable in modeling and control design in diabetes research. These novel interpretations are based on the parameter vectors of the LPV parameter space. The theoretical solutions are demonstrated on a simple, known Type 1 Diabetes Model used in intensive care.
Keywords: Diabetes, LPV model, Affine LPV, qLPV
Abstract: Bilateral Teleoperation is a key technology to allow humans to interact with remote environments by providing the operator with haptic feedback. Haptic feedback from the one hand improves human perception and therefore the quality of the human-robot interaction, on the other hand it can tamper with the stability of the system when the communication between the master side (where the operator is) and the slave side (where the remote robot interacts with the environment) is not instantaneous but affected by delay and packet drops. In the last 40 years many algorithms have been developed to guarantee the stability of haptic teleoperation in the presence of time delay, many of them based on passivity theory. In this paper we review and compare a few algorithms that are representative of the tools in the frequency or in the time domains that have been used to develop a safe and transparent physical human-robot interaction with unknown environments.
Keywords: Bilateral teleoperation, Passivity, Communication delay, Haptics, Force reflection.