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Research on the deployment of various cognitive tasks in the experimental paradigm of a human brain-computer interface (BCI) is on-going in particular upper-limb tasks. Less has been investigated on the lower-limbs, due to its somatotopic arrangement in the sensorimotor cortex compared to that of upper limbs. Hip, knee, foot and toes share spatial proximity with each other. We therefore investigated the possibility to deploy the left vs. right knee extension kinaesthetic motor imagery (KMI) as a cognitive task in a BCI for the control of lower-limbs, primarily for people with neurodegenerative disorders, spinal cord injury or lower-limb amputation. The method involved feature extraction using common spatial pattern (CSP), and filter bank common spatial pattern (FBCSP) algorithm for the optimization of individual spatial patterns. This was followed by supervised machine learning using logistic regression (Logreg) and linear discriminant analysis (LDA) for classification of tasks. The paradigms resulted in four combinations/methods for discriminating between left and right knee tasks. The FBCSP-Logreg outperformed remaining paradigms with a maximum accuracy of 70.00% ± 2.85 and kappa=0.40. The results elicit the possibility to deploy left vs. right knee extension KMI in a 2-class BCI for controlling robotic/prosthetic knee. [ABSTRACT FROM AUTHOR]

Over recent years, electroencephalography’s (EEG) use in the state-of-the-art brain-computer interface (BCI) technology has broadened to augment the quality of life, both with medical and non-medical applications. For medical applications, the availability of real-time data for processing, which could be used as command signals to control robotic devices, is limited to specific platforms. This paper focuses on the possibility to analyse and visualize EEG signal features using OpenViBE acquisition platform in offline mode apart from its default real-time processing capability, and the options available for processing of data in offline mode. We employed OpenViBE platform to acquire EEG signals, pre-process it and extract features for a BCI system. For testing purposes, we analysed and tried to visualize EEG data offline, by developing scenarios, using method for quantification of event-related (de)synchronization ERD/ERS patterns, as well as, built in signal processing algorithms available in OpenViBE-designer toolbox. Acquired data was based on deployment of standard Graz BCI experimental protocol, used for foot kinaesthetic motor imagery (KMI). Results clearly reflect that the platform OpenViBE is a streaming tool that encourages processing and analysis of EEG data online, contrary to analysis, or visualization of data in offline, or global mode. For offline analysis and visualization of data, other relevant platforms are discussed. In online execution of BCI, OpenViBE is a potential tool for the control of wearable lower-limb devices, robotic vehicles and rehabilitation equipment. Other applications include remote control of mechatronic devices, or driving of passenger cars by human thoughts. [ABSTRACT FROM AUTHOR]

The article discusses a study which investigated delayed feedback control (DFC) for libration of tethered satellite system. The study examined the effect of gravity on the motion of the tethered satellite system by assuming the elasticity of the tether and the aerodynamic drag force affecting the system negligible. The motion of the tethered system is classified into librational and rotational motion. Details of the experimental setup are discussed.

This paper proposes a new configuration for a tethered satellite system, named the "clustered electrodynamic tether system." This configuration consists of multi-electrodynamic tethered satellite systems located in a record disk orbit, which is a useful orbit for formation flight of multisatellite. The main difference of the clustered electrodynamic tether system from usual constellation flight configurations is that the clustered electrodynamic tether system uses tethers. This new configuration, thus, can be interpreted as constellation flight both toward out-of-plane direction using a record disk orbit, and in-plane direction using tethers. If librational motion of the clustered electrodynamic tether system is synchronized, the clustered electrodynamic tether system can serve as a platform system to periodically capture launched payloads and to move them to higher altitude, or a system to periodically observe the atmosphere at different altitudes at the same time. To synchronize the librational motion of the clustered electrodynamic tether system, control methods based on the Kuramoto model are proposed. The Kuramoto model is a mathematical model that can be used to describe synchronized behavior of a large set of coupled oscillators. In this paper, the proposed control methods are validated by numerical simulations. [ABSTRACT FROM AUTHOR]

The article presents a study on a proposed ground-based experimental setup for verifying periodic libration of tethered satellite systems in elliptic orbit. Researchers designed the setup in order to emulate pitch moptions of a tethered satellite system in elliptic orbits. An overview of the effect of gravity on the motion of the satellite system is provided, along with an examination of the elasticity of the tether and the aerodynamic drag force influencing the system. They found that the setup was effective for emulating the motion of a satellite.