Sharif Digital Repository

This book provides a comprehensive presentation of issues and challenges faced by researchers and practicing engineers in motion planning and hybrid control of dynamical legged locomotion. The major features range from offline and online motion planning algorithms to generate desired feasible periodic walking and running motions and tow-level control schemes, including within-stride feedback laws, continuous time update laws and event-based update laws, to asymptotically stabilize the generated desired periodic orbits. This book describes the current state of the art and future directions across all domains of dynamical legged locomotion so that readers can extend proposed motion planning... 

Autistic children are often impaired in initiating and responding to Joint Attention. In recent years, there has been an increase in the application of robots in diagnosis and treatment of autism. The purpose of the current research has been primarily to originate the proper therapeutic scenarios and to implement two interactive humanoid robots as therapy assistants in autism treatment in Iran. To this end, the humanoid robots were programmed and teleoperated via Microsoft Kinect Sensor and PhantomOmni Haptic Robot to elicit reactions consisting of imitation of humans by the humanoid robots and vice versa. In this paper, we elaborate on the therapeutic items that we have designed to improve... 

Optimal control frameworks are very important in optimization of multiple-arm robotic systems, although complexity, non-linearity and having large scales usually cause some computational problems in the capacity and time needed. In this paper, coordination of multiple-arm robotic systems in order to carry a rigid object is considered and the state space equations for the overall system are developed. Coordination of the robot arms is done through minimizing a related cost function based on the gradient method. This method is simple and easy to be used  

Robotic blimps have a wide range of applications, such as monitoring activities in their surroundings, advertising, and performing on stages. They also have remarkable capacities to be used as a social robot. In this research, a manually operated social robotic blimp has been developed intending to interact with children as a social agent and attract adults’ attention as an entertainer in indoor public environments. Since the appearance of a social robot has a significant impact on its acceptance, first, we acquired opinions of several participants on the shape of a desired floating robot. The results revealed that a simple spherical structure adequately draws people’s attention. After... 

In this paper, three pairs of children with autism include a pair of twins, two siblings, and two classmates were enrolled in a 12-session robot-assisted group-games program. As many environmental factors were for the most part the same for the siblings as well as genetic factors for the twins, we were able to observe/compare the effect of the designed games on the participants individually and in paired-groups. The results indicated that all participants’ autism severity decreased after the course of the program. Improvement in social skills, social participation/avoidance, and detrimental social behaviors were also observed in the participants with high-functioning autism with close to... 

This paper presents the design process and construction of a mobile social robot companion "Arash" for educational and therapeutic intervention for children with chronic diseases; one which is based on their interests and needs. This study concentrates on children with cancer who suffer from physical pain caused by both the disease and its treatment. Moreover, cancer treatment causes emotional distress, which can reduce the efficiency of medications. Using social robots to interact with ill children in a hospital environment could decrease their distress, thereby improving the efficiency of the treatment. Arash is a 15 degrees-of-freedom cost effective humanoid mobile robot companion,... 

In recent years, robotic rehabilitation has been utilized in treatment and recovery of patients with disabilities. In this paper, a novel design and kinematic analysis of a 4-DOF robot for upper-limb rehabilitation are proposed. The main novelty of this design is its mechanism for wrist and fingers motions which is added to the shoulder and elbow mechanism without any noticeable weight increase in the moving parts of the robot. For this purpose, a cable driven mechanism is implemented at the robot end-effector to move the wrist and fingers parts, and the corresponding actuators are placed at the base of the robot. © 2018 IEEE  

Controlling dynamic biped robots is a complex challenge. Almost all researches in this field assume that the internal structure and dynamics of the robot is known to the controller. But in real-world problems we don't have exact model of the robot or this model is very complicated and is not useful in real-time control. As a matter of fact, we use many devices without any knowledge about their internal structure or analytical models. Some researchers used learning algorithms to control bipeds, but their performance is not comparable to human's learning. Fuzzy controllers can control the bipeds with lower cost, but they need sufficient rules. In the previous works we proposed a linguistic... 

This study aims at examining the effect of Robot Assisted language learning (RALL) on the anxiety level and attitude in the English language learning classroom. Forty-six female students who were beginners at the age of 12 participated in this study and were randomly assigned into two groups of RALL (30 students) and non-RALL (16 students). The treatment was given by a teacher accompanied by a humanoid robot assistant for the RALL group. Two questionnaires of anxiety [15] and attitude [19] were utilized to measure the students' anxiety and attitude. The results of descriptive and t-tests indicated that there was lower anxiety and positive attitude towards English learning in the RALL group... 

This article proposes modelling, simulation and applied wrench workspace analysis of a 3D cable based robots which are consist of six cables are studies. After modelling, the kinds of workspace are defined then an available static combined workspace for different geometric structures of fixed and moving platform is obtained. This workspace is defined as the situations of reference point of the moving platform (center of mass) which under external forces such as weight and with ignorance of inertial effects, the end effector should be in static equilibrium under conditions that length of all cables must not be exceeded from the maximum value and all of cables must be at tension (they must... 

In this paper we present a novel planar structure of a snake-like robot. This structure enables passive locomotion in snake-like robots through an auxiliary link in joint and a torsional spring. Dynamic equations are derived, using Gibbs-Appell method. Kinematic model of the robot include numerous non-holonomic constraints, which can be omitted at the beginning by choosing proper coordinates to describe the model in Gibbs-Appell framework. In such a case, dynamic equations will be significantly simplified, resulting in significant reduction of simulation time. Simulation results show that, by proper selecting initial conditions, joint angles operate in a limit cycle and robot can locomote... 

One of the main requisites for multi agent researchers is a multi-purpose infrastructure that enables them to create, test and evaluate protocols, methods and algorithms. RoboCupRescue simulation environment is a flexible and configurable environment that can fill this gap. With changes in its configuration files, it will gain different features, so different methods can be designed, implemented, and tested. This environment is actually suitable for most multi-agent research issues such as cooperation, coordination, agent communication languages, and agent micro level issues. Sensible roles and tasks in the system motivate more research and make this environment a suitable infrastructure for... 

Treatment of cancer involves many invasive procedures that could be a source of distress in kids suffering from cancer. Distress itself can be an important obstacle in patients' acceptance of treatment and their adaptation to it, consequently reducing its efficiency. Distress symptoms, in a spectrum from mild to critical, are shown to be widespread in children struggling with cancer. In recent years to alleviate this psychological condition, researchers have proposed and examined several methods such as relaxation, hypnosis, desensitization, and distraction. This study presents a new approach to explore the impact of utilizing a humanoid robot as a therapy-assistant in dealing with patients'... 

Treating cancer encompasses many invasive procedures that can be a source of distress in oncology patients. Distress itself can be a major obstruction in the path of acceptance of treatment and the patient's adaptation to it, thereby reducing its efficiency. These distress symptoms have been found to be prevalent in children suffering from cancer, in a spectrum from mild to critical. In the past years in response to this psychological suffering, researchers have proposed and tested several methods such as relaxation, hypnosis, desensitization, and distraction. This paper propounds a new approach by exploring the effect of utilizing a humanoid robot as a therapy-assistive tool in dealing with... 

Many research and development projects are being performed worldwide to develop new products and applications for computer-assisted and medical robotic systems. In this paper, an overview of selected state-of-the-art applications of robotic technology in medicine is presented. Four key areas of image-guided surgery, virtual reality in medicine, surgical robots, and robotic rehabilitation systems, are studied. As well, current challenges in research and development are discussed. Copyright  

Morphological computation (MC) has revolutionized robotic systems employing morphological properties (MP). Thus far, morphology has been mostly used to analyze morphological functionalities qualitatively after design phase of robotic systems. Furthermore, morphology has verified qualitative requirements, not modeled quantitative specifications. To fill this gap, we present a distributed algorithm to monitor module reconfiguration for homogeneous self-reconfigurable robots (HSRs) considering the size of modules. In this method, neighboring modules of a particular module occupy a spatial region called adjacency configuration (AC), whose size depends on the module size; then, we monitor... 

time-optimal problem for redundantly actuated robots moving on a specified path is a challenging problem. Although the problem is well explored and there are proposed solutions based on phase plane analysis, there are still several unresolved issues regarding calculation of solution curves. In this paper, we explore the characteristics of the maximum velocity curve and propose an efficient algorithm to establish the solution curve. Then we propose a straightforward method to calculate the maximum or minimum possible acceleration on the path based on the pattern of saturated actuators, which substantially reduces the computational cost. Two numerical examples are provided to illustrate the... 

Exoskeleton robots are developed for human rehabilitation and power augmentation. Human and robot interaction is an important issue involved with these robots. In this paper, the interaction force reduction is considered leading to the transparency of a lower limb exoskeleton during swing phase of walking. Achieving this goal, a robust Lyapunov based motion control method has been developed. The desired reference signals for motion control are generated using a direct force control approach. Robot accelerations are estimated by an observer to be employed in the control loop. An adaptation procedure has been proposed for the bound estimation of uncertainties. As part of assumptions, the... 

In this paper a technique for autonomous navigation of mobile robots is presented. The most important advantage of this method is to ignore the physical model of the robot and that the robot model is considered as an unknown but predictable system. This approach can be executed in environments which robot navigation is done using global sensors e.g. a camera installed in the environment to sense and control the robot and also every feedback system which is able to measure the velocity of the robot can be used for this technique. In this approach, the well-known fuzzy method, Takagi-Sugeno, has been applied to estimate the dynamic model of robot. Our technique has been applied successfully in... 

Cable-driven parallel robots have several outstanding characteristics that make them unique in many robotic applications. Since cables can only pull, one of the most important issues associated with these robots is obtaining their workspace. In this paper a spatial translational cable-driven robot with active/passive cables is considered and its workspace is investigated from several points of views. First the moment resisting capability of the robot is discussed and the effects of some robot's parameters on the workspace are studied. Then, both force-feasibility and moment-resisting capability of the robot are considered to find the region where the end-effector may exert the required...