Natasa Koceska

Evaluation of an Assistive Telepresence Robot for Elderly Healthcare

In this paper we described the telepresence robot system designed to improve the well-being of elderly by supporting them to do daily activities independently, to facilitate social interaction in order to overcome a sense of social isolation and loneliness as well as to support the professional caregivers in everyday care. In order to investigate the acceptance of the developed robot system, evaluation study involved elderly people and professional caregivers, as two potential user groups was conducted. The results of this study are also presented and discussed.

Design and Evaluation of Cell Phone Pointing Interface for Robot Control

In this work a pointing interface based on human gestures using a mobile phone accelerometer for interaction with robots is proposed. Through this interface the user can sketch stroke gestures on a computer screen using the cell phone accelerometer to make a selection and instruct a robot to perform a task. Selection, cancelation and movement, as well as some additional commands such as stop, pause and resume are supported. All the projected gestures are processed using known image analysis algorithms providing instantaneous position and path information. The proposed interface is experimentally evaluated and the results show that it is efficient, natural, robust and easy to use. It also provides asynchronous robot control with minimum operator effort and engagement.

Control Architecture of a 10 DOF Lower Limbs Exoskeleton for Gait Rehabilitation

This paper describes the control architecture of a 10 DOF (Degrees of Freedom) lower limbs exoskeleton for the gait rehabilitation of patients with gait dysfunction. The system has 4 double-acting rod pneumatic actuators (two for each leg) that control the hip and knee joints. The motion of each cylinders piston is controlled by two proportional pressure valves, connected to both cylinder chambers. The control strategy has been specifically designed in order to ensure a proper trajectory control for guiding patients legs along a fixed reference gait pattern. An adaptive fuzzy controller which is capable of compensating for the influence of the dry friction was successfully designed, implemented and tested on an embedded real-time PC/104. In order to verify the proposed control architecture, laboratory experiments without a patient were carried out and the results are reported here and discussed.

A Novel Quad Harmony Search Algorithm for Grid-based Path Finding

A novel approach to the problem of grid-based path finding has been introduced. The method is a block-based search algorithm, founded on the bases of two algorithms, namely the quad-tree algorithm, which offered a great opportunity for decreasing the time needed to compute the solution, and the harmony search (HS) algorithm, a meta-heuristic algorithm used to obtain the optimal solution. This quad HS algorithm uses the quad-tree decomposition of free space in the grid to mark the free areas and treat them as a single node, which greatly improves the execution. The results of the quad HS algorithm have been compared to other meta-heuristic algorithms, i.e., ant colony, genetic algorithm, particle swarm optimization and simulated annealing, and it was proved to obtain the best results in terms of time and giving the optimal path.

Review: Robot Devices for Gait Rehabilitation

The main motivation of gait rehabilitation is to help a patient recovering from injury, illness or disease, to recover some locomotor abilities in order to promote as much independence as possible in activities of daily living tasks, and to assist the patient in compensating for deficits that cannot be treated medically. However, the amount of hands-on therapy that patients can receive is limited, as economic pressures are inherent in the health care system. Therefore, worldwide efforts are being made to automate locomotor training. Robotic devices has the potential to make therapy more affordable and thus more available for more patients and for more time. This article reviews the most important characteristics and features of the current robot devices for gait rehabilitation, both in clinical use and in the phase of research.

Gait Training using Pneumatically Actuated Robot System

Powered exoskeleton device for gait rehabilitation has been designed and realized, together with proper control architecture. Its DOFs allow free leg motion, while the patient walks on a treadmill with its weight, completely or partially supported by the suspension system. The use of pneumatic actuators for actuation of this rehabilitation system is reasonable, because they offer high force output, good backdrivability, and good position and force control, at a relatively low cost. The effectiveness of the developed rehabilitation system and proposed control architecture was experimentally tested. During the experiments, the movement was natural and smooth while the limb moves along the target trajectory.

Control architecture for a lower limbs rehabilitation robot system

This paper describes the control architecture for lower limbs rehabilitation robot system and its implementation. The system has exoskeleton structure with 10 DOF (Degrees Of Freedom) and is pneumatically actuated.

Characterization and modeling of a 3D scanner for mobile robot navigation

In this paper an accurate physics-based simulation model of the 3D laser scanner, based on 2D range sensor (SICK LD-OEM1000) is presented. The model of the 2D sensor derives from the characteristics of the physical one and includes the uncertainty of the measurement, the dependency of the beam incidence angle and the target surface properties. Some experiments aimed to characterize the effects of the operation time, time autocorrection, different object surface properties and orrientations are also presented in this paper. 3D scanner virtual model, developed in rigid body dynamics environment, was verified experimentally and the resultss are reported.

Global Path Planning in Grid-Based Environments Using Novel Metaheuristic Algorithm

The global path planning problem is very challenging NP-complete problem in the domain of robotics. Many metaheuristic approaches have been developed up to date, to provide an optimal solution to this problem. In this work we present a novel Quad-Harmony Search (QHS) algorithm based on Quad-tree free space decomposition methodology and Harmony Search optimization. The developed algorithm has been evaluated on various grid based environments with different percentage of obstacle coverage. The results have demonstrated that it is superior in terms of time and optimality of the solution compared to other known metaheuristic algorithms.

Design and Evaluation of a Cell Phone Pointing Interface for Interaction with Large Projector based Displays

The availability of mobile phones enhanced with different sensors increased the possibility of using the mobile devices in various applications in ubiquitous computing. Mobile phones can be used as interaction device with other devices such as large projected displays. In this paper we propose a design of a cell phone pointing interface based on its embedded accelerometer sensor for interaction with large projector based displays. The main idea is to use a simple hand gestures for pointing to a certain point, for object selection, for object movement or for drawing various forms on large display screen. Rigorous and systematic evaluation of the proposed interface has been conducted and its efficiency has been experimentally evaluated on various tasks. The results have shown that embedded accelerometer sensor in mobile phones in combination with a simple hand gestures are a promising approach for interaction with large display screen and that potential users see ease of use, intuitiveness and enjoyment as advantages of this interaction technique.