Sharif Digital Repository

Facial expression imitation with applications in the design of human robot interaction (HRI) systems is an active area of research. In this study, we propose an approach for real-time imitation of human facial expression by a humanoid social robot 'Alice'. Artificial neural network (ANN) and Kinect sensor are used for recognition and classifying of the facial expressions like happiness, sadness, fear, anger and surprise; with the Alice humanoid robot imitating the comprehended expressions. Results and experiments demonstrate the effectiveness of the approach. © 2016 IEEE  

In this paper, two online path planning methods are presented for SURENA III humanoid robot by using model predictive control scheme. The methods are general control schemes which can generate the online motions for walking of a humanoid robot. For lowering computational costs a three dimensional linear inverted pendulum model is used instead of the full dynamical model of the robot. The generated trajectories are then used for computing the zero-moment point (ZMP) of the robot and the joint torques. The resulted joint torques of the two methods are compared to torques obtained from Genetic Algorithm (GA) path planning method presented for SURENA III humanoid robot in previous studies. The... 

In this paper we aimed to explore young Iranian EFL learners’ attitude towards Robot Assisted Language Learning (RALL) in an English language classroom. To this end, 19 preschool children ranging from 3 to 6 years old were randomly assigned to a RALL group which had a robot as an assistant to the teacher. Their attitude towards the robot was video recorded for one month, during ten sessions of their English classroom course. Their overall attitude was examined focusing on the three factors of anxiety, motivation and interaction based on human-robot interaction (HRI) theory. The result of this study showed that children’s motivation increased as a result of interacting with the robot and... 

This paper introduces a novel robotic platform, called RASA (Robot Assistant for Social Aims). This educational social robot is designed and constructed to facilitate teaching Persian Sign Language (PSL) to children with hearing disabilities. There are three predominant characteristics from which design guidelines of the robot are generated. First, the robot is designed as a fully functional interactive social robot with children as its social service recipients. Second, it comes with the ability to perform PSL, which demands a dexterous upper-body of 29 actuated degrees of freedom. Third, it has a relatively low development cost for a robot in its category. This funded project, addresses... 

In this paper obtaining the optimal configuration of the dual-arm cam-lock (DACL) robot at a specific point is addressed. The objective is to optimize the applicable task-space force in a desired direction. The DACL robot is a reconfigurable manipulator formed by two parallel cooperative arms. The arms normally operate redundantly but when needed, they can lock into each other in certain joints in order to achieve a higher stiffness, while losing some degrees of freedom. Furthermore, the dynamics of the DACL robot is discussed and parametrically formulated. Considering the geometrical constraints at a given point in the robot's workspace, the optimum configuration for maximizing the... 

This paper introduces a novel robotic platform, called RASA (Robot Assistant for Social Aims). This educational social robot is designed and constructed to facilitate teaching Persian Sign Language (PSL) to children with hearing disabilities. There are three predominant characteristics from which design guidelines of the robot are generated. First, the robot is designed as a fully functional interactive social robot with children as its social service recipients. Second, it comes with the ability to perform PSL, which demands a dexterous upper-body of 29 actuated degrees of freedom. Third, it has a relatively low development cost for a robot in its category. This funded project, addresses... 

Purpose: Robot localization in dynamic, cluttered environments is a challenging problem because it is impractical to have enough knowledge to be able to accurately model the robot’s environment in such a manner. This study aims to develop a novel probabilistic method equipped with function approximation techniques which is able to appropriately model the data distribution in Markov localization by using the maximum statistical power, thereby making a sensibly accurate estimation of robot’s pose in extremely dynamic, cluttered indoors environments. Design/methodology/approach: The parameter vector of the statistical model is in the form of positions of easily detectable artificial landmarks... 

In a multi-robot system, a number of autonomous robots would sense, communicate, and decide to move within a given domain to achieve a common goal. In the pursuit-evasion problem, a polygonal region is given and a robot called a pursuer tries to find some mobile targets called evaders. The goal of this problem is to design a motion strategy for the pursuer such that it can detect all the evaders. In this paper, we consider a new variant of the pursuit-evasion problem in which the robots (pursuers) each moves back and forth along an orthogonal line segment inside a simple orthogonal polygon P. We assume that P includes unpredictable, moving evaders that have bounded speed. We propose the... 

Social robots may soon be able to play an important role in expanding communication with the deaf. Based on the literature, adaptive user interfaces lead to greater user acceptance and increased teaching efficiency compared to non-adaptive ones. In this paper, we build a robotic architecture able to simultaneously adjust a robot’s teaching parameters according to both the user’s past and present performance, adapt the content of the training, and then implement it on the RASA robot to teach sign language based on these parameters in a manner similar to a human teacher. To do this, a word to teach in sign language, repetition, speed, and emotional valence were chosen to be adaptive using a... 

Sign language is a non-verbal communication tool used by the deaf. A robust sign language recognition framework is needed to develop Human–Robot Interaction (HRI) platforms that are able to interact with humans via sign language. Iranian sign language (ISL) is composed of both static postures and dynamic gestures of the hand and fingers. In this paper, we present a robust framework using a Deep Neural Network (DNN) to recognize dynamic ISL gestures captured by motion capture gloves in Real-Time. To this end, first, a dataset of fifteen ISL classes was collected in time series; then, this dataset was virtually augmented and pre-processed using the “state-image” method to produce a unique... 

Deficit in imitation skills is one of the core symptoms of children with Autism Spectrum Disorder (ASD). In this study, we have tried to look closer at the body gesture imitation performance of 20 participants with autism, i.e. ASD group, and 20 typically developing subjects, i.e. TD group, in a set of robot-child and human-child gross imitation tasks. The results of manual scoring by two specialists indicated that while the TD group showed a significantly better imitation performance than the ASD group during the tasks, both ASD and TD groups performed better in the human-child mode than the robot-child mode in our experimental setup. Next, to introduce an automated imitation assessment... 

Rehabilitation is the best approach for patients who suffer physical disability of their upper-limbs. Maintaining the intensity of exercise during treatment is the main factor that makes the robots suitable for rehabilitation since robots do not get tired and do the exercises with constant intensity under supervision of the doctor. Two main categories of rehabilitation robots are End-Effector based robots and wearable robots. According to the fact that most problems occur in need of rehabilitation for hand wrist area, in this paper a wearable rehabilitation robot has been developed for the wrist. Nowadays, wearable robots attract more attention than the other group. Wearable robots are... 

One of the main issues in the field of social and cognitive robotics is the robot’s ability to recognize emotional states and emotional interaction between robots and humans. Through effective emotional interaction, robots will be able to perform many tasks in human society. In this research, we have developed a robotic platform and a vision system to recognize the emotional state of the user through its facial expressions, which leads to a more realistic humanrobot interaction (HRI). First, a number of features are extracted according to points detected by a vision system from the face of the user. Then, the emotional state of the user is analyzed with the help of these features. For the... 

A novel impedance-controlled teleoperation system is developed for robot-assisted tele-echography of moving organs such as heart, chest and breast during their natural motions (beating and/or breathing). The procedure of devising the two impedance models for the master and slave robots is developed such that (a) the slave robot holding the ultrasound (US) probe follows the master trajectory but complies with the oscillatory interaction force of the moving organ, and (b) the sonographer receives feedback from the non-oscillatory portion of the slave-organ interaction force via the master robot similar to the haptic feedback received in echography of a stationary organ. These goals are... 

Self-reconfigurable modular robots (SRMRs) have recently attracted considerable attention because of their numerous potential applications in the real world. In this paper, we draw a comprehensive comparison among five different algorithms in path planning of a novel SRMR system called ACMoD through an environment comprised of various terrains in a static condition. The contribution of this work is that the reconfiguration ability of ACMoD has been taken into account. This consideration, though raises new algorithmic challenges, equips the robot with new capability to pass difficult terrains rather than bypassing them, and consequently the robot can achieve better performance in terms of... 

Single wheel robots are typically those kinds of robots which contain all the necessary mechanizations, namely the stabilization and driving mechanizations, within a shell-liked housing appearing analogous to a wheel. These robots have proved to be useful in various fields of industry due to their advantages of giving high instant acceleration and maintaining high cruise speeds for considerable amount of time in addition to being compact and small. It is a sharp-edged wheel actuated by a spinning flywheel for steering and a drive motor for propulsion. The spinning flywheel acts as a gyroscope to stabilize the robot and it can be tilted to achieve steering. In this paper first the kinematics...