External control of the neuromuscular system.
Explore the source record for details and available documents.
Animals↗
SEARCH · Search PubMed
Results for “CYBERNETICS”
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Noninvasive brain-actuated control of a mobile robot by human EEG.
Brain activity recorded noninvasively is sufficient to control a mobile robot if advanced robotics is used in combination with asynchronous electroencephalogram (EEG) analysis and machine learning techniques. Until now brain-actuated control has mainly relied on implanted electrodes, since EEG-based systems have been considered too slow for controlling rapid and complex sequences of movements. We show that two human subjects successfully moved a robot between several rooms by mental control only, using an EEG-based brain-machine interface that recognized three mental states. Mental control was comparable to manual control on the same task with a performance ratio of 0.74.
Algorithms↗
Real-time myoprocessors for a neural controlled powered exoskeleton arm.
Exoskeleton robots are promising assistive/rehabilitative devices that can help people with force deficits or allow the recovery of patients who have suffered from pathologies such as stroke. The key component that allows the user to control the exoskeleton is the human machine interface (HMI). Setting the HMI at the neuro-muscular level may lead to seamless integration and intuitive control of the exoskeleton arm as a natural extension of the human body. At the core of the exoskeleton HMI there is a model of the human muscle, the "myoprocessor," running in real-time and in parallel to the physiological muscle, that predicts joint torques as a function of the joint kinematics and neural activation levels. This paper presents the development of myoprocessors for the upper limb based on the Hill phenomenological muscle model. Genetic algorithms are used to optimize the internal parameters of the myoprocessors utilizing an experimental database that provides inputs to the model and allows for performance assessment. The results indicate high correlation between joint moment predictions of the model and the measured data. Consequently, the myoprocessor seems an adequate model, sufficiently robust for further integration into the exoskeleton control system.
Arm↗
Adaptive tracking for pneumatic muscle actuators in bicep and tricep configurations.
Adaptive tracking techniques are applied to pneumatic muscle actuators arranged in bicep and tricep configurations. The control objective is to force the joint angle to track a specified reference path. Mathematical models are derived for the bicep and tricep configurations. The models are nonlinear and in general time-varying, making adaptive control desirable. Stability results are derived, and the results of simulation studies are presented, contrasting the nonlinear adaptive control to a nonadaptive PID control approach.
Biomimetics↗
The hyper-cube framework for ant colony optimization.
Ant colony optimization is a metaheuristic approach belonging to the class of model-based search algorithms. In this paper, we propose a new framework for implementing ant colony optimization algorithms called the hyper-cube framework for ant colony optimization. In contrast to the usual way of implementing ant colony optimization algorithms, this framework limits the pheromone values to the interval [0,1]. This is obtained by introducing changes in the pheromone value update rule. These changes can in general be applied to any pheromone value update rule used in ant colony optimization. We discuss the benefits coming with this new framework. The benefits are twofold. On the theoretical side, the new framework allows us to prove that in Ant System, the ancestor of all ant colony optimization algorithms, the average quality of the solutions produced increases in expectation over time when applied to unconstrained problems. On the practical side, the new framework automatically handles the scaling of the objective function values. We experimentally show that this leads on average to a more robust behavior of ant colony optimization algorithms.
Algorithms↗
Intelligent robust control for uncertain nonlinear time-varying systems and its application to robotic systems.
This paper addresses the problem of designing adaptive fuzzy-based (or neural network-based) robust controls for a large class of uncertain nonlinear time-varying systems. This class of systems can be perturbed by plant uncertainties, unmodeled perturbations, and external disturbances. Nonlinear H(infinity) control technique incorporated with adaptive control technique and VSC technique is employed to construct the intelligent robust stabilization controller such that an H(infinity) control is achieved. The problem of the robust tracking control design for uncertain robotic systems is employed to demonstrate the effectiveness of the developed robust stabilization control scheme. Therefore, an intelligent robust tracking controller for uncertain robotic systems in the presence of high-degree uncertainties can easily be implemented. Its solution requires only to solve a linear algebraic matrix inequality and a satisfactorily transient and asymptotical tracking performance is guaranteed. A simulation example is made to confirm the performance of the developed control algorithms.
Algorithms↗
From fuzzy logic toward plurimonism: the science of active and empathic observation.
Plurimonism is a new philosophy and method of science. It holds that the revolution in computer science and artificial intelligence has reached the point that all the sciences in general can now account for the complex relations of an irreducible plurality of unique observers engaged in describing the same event. Plurimonism seeks to describe the conscious and unconscious relations of the scientific observer during the act of observation of a given event while preserving the historical uniqueness and indivisible identity of each such observer. Using the framework of plurimonism, we mathematically formulate the problem of empathy. This self-reflective mathematical model entails four components of the empathic process involving two observers. They are: 1) the self; 2) the self's-other; 3) the other; and 4) the other's-self. It measures the degree of accuracy of the therapist-observer's empathy, as well as conscious and unconscious processes involved in the patient-observer's idealization and the therapist-observer's confidence in clinical psychotherapy. Ratings are obtained from both patient and therapist from four different points of view. The plural views of the patient's global assessment of functioning (GAF) are from: 1) the therapist's view (TGAF); 2) the patient's view (PGAF); 3) the therapist empathic view (TEGAF), which represents the therapist's estimate of PGAF; and 4) the patient's empathic estimate of the TGAF. The GAF scale is the standard dimensional 100-point-scale measure used in psychiatry for recording a patient's functioning. The patient's estimate of the therapist's degree of accuracy as well as the therapist's confidence in his or her empathic accuracy is also represented. Three formulae are presented that describe the degree of the therapist's empathic accuracy, the patient's over-idealization/under-idealization, and the therapist's over-confidence/under-confidence. The concept of empathy is here restricted to mean the degree to which one observer can take the point of view of another observer when both are observing the same thing.
Cybernetics↗
Training of a leaning agent for navigation--inspired by brain-machine interface.
The design clue for the remote control of a mobile robot is inspired by the Talwar's brain-machine interface technology for remotely training and controlling rats. Our biologically inspired autonomous robot control consciousness-based architecture (CBA) is used for the remote control of a robot as a substitute for a rat. CBA is a developmental hierarchy model of the relationship between consciousness and behavior, including a training algorithm. This training algorithm computes a shortcut path to a goal using a cognitive map created based on behavior obstructions during a single successful trial. However, failures in reaching the goal due to errors of the vision and dead reckoning sensors require human intervention to improve autonomous navigation. A human operator remotely intervenes in autonomous behaviors in two ways: low-level intervention in reflexive actions and high-level ones in the cognitive map. Experiments are conducted to test CBA functions for intervention with a joystick for a Khepera robot navigating from the center of a square obstacle with an open side toward a goal. Their statistical results show that both human interventions, especially high-level ones, are effective in drastically improving the success rate of autonomous detours.
Algorithms↗
The balance between initial training and lifelong adaptation in evolving robot controllers.
A central aim of robotics research is to design robots that can perform in the real world; a real world that is often highly changeable in nature. An important challenge for researchers is therefore to produce robots that can improve their performance when the environment is stable, and adapt when the environment changes. This paper reports on experiments which show how evolutionary methods can provide lifelong adaptation for robots, and how this evolutionary process was embodied on the robot itself. A unique combination of training and lifelong adaptation are used, and this paper highlights the importance of training to this approach.
Adaptation, Physiological↗
Balancing search and target response in cooperative unmanned aerial vehicle (UAV) teams.
This paper considers a heterogeneous team of cooperating unmanned aerial vehicles (UAVs) drawn from several distinct classes and engaged in a search and action mission over a spatially extended battlefield with targets of several types. During the mission, the UAVs seek to confirm and verifiably destroy suspected targets and discover, confirm, and verifiably destroy unknown targets. The locations of some (or all) targets are unknown a priori, requiring them to be located using cooperative search. In addition, the tasks to be performed at each target location by the team of cooperative UAVs need to be coordinated. The tasks must, therefore, be allocated to UAVs in real time as they arise, while ensuring that appropriate vehicles are assigned to each task. Each class of UAVs has its own sensing and attack capabilities, so the need for appropriate assignment is paramount. In this paper, an extensive dynamic model that captures the stochastic nature of the cooperative search and task assignment problems is developed, and algorithms for achieving a high level of performance are designed. The paper focuses on investigating the value of predictive task assignment as a function of the number of unknown targets and number of UAVs. In particular, it is shown that there is a tradeoff between search and task response in the context of prediction. Based on the results, a hybrid algorithm for switching the use of prediction is proposed, which balances the search and task response. The performance of the proposed algorithms is evaluated through Monte Carlo simulations.
Aircraft↗
Dynamic interactions in physically realistic collaborative virtual environments.
This work describes our efforts in creating a general object interaction framework for dynamic collaborative virtual environments. Furthermore, we increase the realism of the interactive world by using a rigid body simulator to calculate all actor and object movements. The main idea behind our interactive platform is to construct a virtual world using only objects that contain their own interaction information. As a result, the object interactions are application independent and only a single scheme is required to handle all interactions in the virtual world. In order to have more dynamic interactions, we also created a new and efficient way for human users to dynamically interact within virtual worlds through their avatar. In particular, we show how inverse kinematics can be used to increase the interaction possibilities and realism in collaborative virtual environments. This results in a higher feeling of presence for connected users and allows for easy, on-the-fly creation of new interactions. For the distribution of both the interactive objects and the dynamic avatar interactions, we keep the network load as low as possible. To demonstrate the effectiveness of our techniques, we incorporate them into an existing CVE framework.
Computer Simulation↗
Six degree-of-freedom haptic rendering using spatialized normal cone search.
This paper describes a haptic rendering algorithm for arbitrary polygonal models using a six degree-of-freedom haptic interface. The algorithm supports activities such as virtual prototyping of complex polygonal models and adding haptic interaction to virtual environments. The underlying collision system computes local extrema in distance between the model controlled by the haptic device and the rest of the scene. The haptic rendering computes forces and torques on the moving model based on these local extrema. The system is demonstrated on models with tens of thousands of triangles and developed in an accessibility application for finding collision-free paths.
Computer Simulation↗
An infrastructure for realizing custom-tailored augmented reality user interfaces.
Augmented Reality (AR) technologies are rapidly expanding into new application areas. However, the development of AR user interfaces and appropriate interaction techniques remains a complex and time-consuming task. Starting from scratch is more common than building upon existing solutions. Furthermore, adaptation is difficult, often resulting in poor quality and limited flexibility with regard to user requirements. In order to overcome these problems, we introduce an infrastructure for supporting the development of specific AR interaction techniques and their adaptation to individual user needs. Our approach is threefold: a flexible AR framework providing independence from particular input devices and rendering platforms, an interaction prototyping mechanism allowing for fast prototyping of new interaction techniques, and a high-level user interface description, extending user interface descriptions into the domain of AR. The general usability and applicability of the approach is demonstrated by means of three example AR projects.
Algorithms↗
Cutting on triangle mesh: local model-based haptic display for dental preparation surgery simulation.
A new method to realize stable and realistic cutting simulation using an impedance display haptic device and microcomputer is presented in this paper. Material removal or cutting simulation is a critical task in dental preparation surgery simulation. In this paper, a piecewise contact force model is proposed to approximately describe the cutting process. Challenging issues of minimizing the difference between the cutting simulation and haptic contact simulation are analyzed. The proposed contact-based simulation method is developed for a one-dimensional cutting task and can be expanded to three-dimensional cases. Local model-based multirate simulation cutting architecture is proposed and force control of the haptic device is decoupled from the cutting simulation loop, which can both ensure high fidelity of dynamical simulation as well as maintain stability of the haptic device. The cutting operation is realized using spherical and cylindrical shaped tools. An experiment based on the Phantom desktop proves that fidelity in one-dimensional cutting can be realized and stability in three-dimensional cutting can be ensured using the force-filtering method.
Computer Simulation↗
Development of anthropomorphic multi-D.O.F. master-slave arm for mutual telexistence.
We developed a robotic arm for a master-slave system to support "mutual telexistence," which realizes remote dexterous manipulation tasks and close physical communication with other people using gestures. In this paper, we describe the specifications of the experimental setup of the master-slave arm to demonstrate the feasibility of the mutual telexistence concept. We developed the master arm of a telexistence robot for interpersonal communication. The last degree of the 7-degree-of-freedom slave arm is resolved by placing a small orientation sensor on the operators arm. This master arm is made light and impedance control is applied in order to grant the operator as much freedom of movement as possible. For this development stage, we compared three control methods and confirmed that the impedance control method is the most appropriate to this system.
Arm↗
Educational science and education for medicine.
Explore the source record for details and available documents.
Cybernetics↗
The study of medical education.
Explore the source record for details and available documents.
Cybernetics↗