Human Machine Interaction and Gesture Recognition is a very challenging field. Scientists and researchers are trying to make communications with machines as easy, smooth and reliable as possible. With the help of learning techniques we present a vision based simulation of CHALK, BLACKBOARD, DUSTER game in which Robot plays this game with human identifying the moves generated by him in the form of gestures and also learns new gestures. Also with presented approach we are able to perform forearm deletion. We have verified our work using Webots simulation platform. View full abstract»

To solve the problems of difficultly making certain the control parameters and the unideal motion performance of snake robot, we develop a bionic autonomous strategy based on operant conditioning mechanism, which can realize autonomously optimize and adjust control parameters. The designed strategy is a 5-tupe and mainly contains: 1) state space; 2) action space; 3) state transfer function, meaning the consequence after action; 4) tendency function; 5) action selection strategy, adjusting the selected probability of each action. The designed bionic strategy is applied to motion control of snake robot. The experiment analysis is carried out combined with webots robot simulation software. The results of the simulation experiment indicate that the skill of autonomous optimization adjustment control parameters will gradually be enhanced with the learning proceeding. View full abstract»

The paper reviews a known robot control architecture using nonlinear analysis and control theory viewpoints. The architecture is based on a mesh of dynamic systems and feedthrough maps and is able to drive the robot under temporal constraints. The analysis points to an intuitive, though innovative, conclusion that control architectures can be constructed from a methodological perspective by mixing (i) dynamical systems with fixed points carefully selected to match mission requirements, and (ii) feedthrough maps that perform memoryless transformations on input data. Experiments using the Webots environment are presented to illustrate the ideas developed. View full abstract»

Collision Warning Systems (CWS) are safety systems designed to warn the driver about an imminent collision. A CWS monitors the dynamic state of the traffic in realtime by processing information from various proprioceptive and exteroceptive sensors. It assesses the potential threat level and decides whether a warning should be issued to the driver through auditory and/or visual signals. Several measures have already been defined for threat assessment and various CWS have been proposed in literature. In this paper, we will focus on two time-based measures that assess both front and rear collision threats. In particular, a new threat metric, the time-to-last-second-acceleration (T_lsa), for lead vehicles in rear-end collision is proposed and compared with its counterpart, the time-to-last-second-braking (T_lsb) [18]. The T_lsa is a novel time-based approach that focuses on the lead vehicle (as opposed to the following vehicle). It inherits the properties of the T_lsb and, as such, is coherent with the human judgement of urgency and severity of threats. It directly quantifies the threat level of the current dynamic situation before a required evasive action (i.e. maximum acceleration) needs to be applied. Furthermore, different warning thresholds are proposed by considering the average driver reaction time. Its effect on decreasing the severity of a rear-end collision is studied and its reliability is tested using a well-established physics-based robotics simulator, namely Webots [13]. View full abstract»

Given a multi-robot system, in order to preserve its geometric shape in a formation, the minimal persistence control addresses questions: (1) what pairwise communication connections have to be prescribed to minimize communication channels, and (2) which orientations of communication links are to be placed between robots. In this paper, we propose a minimal persistence control problem on multi-robot systems with underlying graphs being directed and dynamically switching. We develop distributed algorithms based on the rank of the rigidity matrix and the pebble game method. The feasibility of the proposed methods is validated by simulations on the robotic simulator Webots and experiments on e-puck robot platform. View full abstract»

From basic neuro-physiological evidences, it is now generally accepted that animals' walking control is subject to the combination function of central pattern generator(CPG) located at the spinal cords and reflexes from the peripheral stimulus. Since phase oscillators have the advantage of mathematical tractability, it's convenient to adjust the phase relationship between them. In this paper, coupled phase oscillators were designed to simulate CPG's behavior and establish vestibular reflex with feedbacks from accelerator sensors. Afterward, the synchronization condition of this proposed CPG model was studied. Forward and backward walking, gait transfers between trot and walk were realized as well. With feedbacks, AIBO detected uphill and downhill terrain and changed its posture automatically to fit for the new environment. Simulations were done in Webots to verify this method. View full abstract»

Mapping is the technique used by robots to build up a map within an unknown environment, or to update previously build map within a known environment. The problem is related to integrate the information obtained by multiple sensors on a consistent model and describing it by a given representation. The main aspects of mapping are the interpretation of sensor data and the representation of the environment. Topological approaches divide the environment into significant areas, being the aim to capture the connectivity of these areas rather than creating a geometrically accurate map. In this context, this paper proposes a method for mapping generic environments (structured or not) based on several semantic maps. In our implementation, each map can be described as a topological map, which is modeled using self-organizing neural networks. The approach was implemented and validated in a set of environments using Pioneer robots, equipped with an omni directional camera and a GPS. All the results were obtained using the robot simulator We bots, due its facility to test extreme conditions. Issues related to high dimensionality, perceptive correspondence and dynamicity have been evaluated. The results show the capabilities of the method to reduce data dimensionality and the generalization of the proposal. View full abstract»

Push recovery is an important technology needs to be developed for the effective use of bipedal humanoid robot in the household applications. In this paper, a three mass inverted pendulum model equivalent to Humanoid Open Architecture Platform (HOAP -2) has been developed and the effectiveness of the model has been demonstrated using a software framework known as WEBOTS. It has been developed as a test bed for the development of sophisticated Push recovery techniques for HOAP-2 humanoid robot. Functionality of this model is general and adaptable to any kind of three mass models. Ankle strategy technique has been implemented to verify the correctness of the model. The correctness of the model has been verified successfully by the simulation results. View full abstract»

In this paper, we describe a NAO H25 humanoid robot painter assisted by a human. The aim of this study is to reproduce the whole painting process by a humanoid robot with a vision system and fingers. The novelty of the study lies in using a human assistant in interaction with the robot and filling regions in the picture. The painting process is performed by the humanoid robot in three phases: obtaining the image of the environment which the objects are in, extracting the objects to paint and painting them in interaction with its assistant. (i.e. Robot says to human:”Could you give me the blue color”). In this paper, the process is simulated within Webots. This study will be used in disabled children's rehabilitation where children will be asked to assist the robot in painting. There is an on-going study which aims to implement this study on real NAO H25 humanoid robot. View full abstract»

In this work, we propose a system that has the ability to reproduce imitated motions of human during continuous and online observation with a humanoid robot. In order to achieve this goal, the problems for imitation have to be solved. In this paper, we treat two main issues. One is mapping between different kinematic structures and the other is computing humanoid body pose that satisfies the static stability generated from the human motion obtained by visual motion capture of the humanoid. The experimental results based on Webots simulation and subsequent execution by a Darwin-OP humanoid robot show the validity of the proposed system in this paper. View full abstract»

Ankle, momentum, and/or take-a-step strategies constitute different schemes that a humanoid robot may take to avoid falling, where each strategy has a different energy overhead associated to it. To minimize energy consumption it is important to know when each of these strategies can be applied and yet be effective at preventing a fall. This paper is a continuation of our previous work on the development of a hierarchical fall avoidance approach for humanoid robots. While ankle and hip strategies were previously developed, here we develop a decision surface for a stepping strategy that determines at the onset of a disturbance if by taking a step falling can be avoided. Experiments are conducted on the Webots simulator to validate the theory. View full abstract»

This paper provides a mobile robot navigation strategy using fuzzy logic is developed for a two wheeled mobile robot in a static environment. The information about the target and the low-range sensory information are used by the controller to produce the commands that gives a favorable direction in terms of reaching to the target within the collision detection. Furthermore, the mobile robot does not suffer from typical u-shape environment by a planned local minimum trapping algorithm and also designed controller is easy to understand, simple, and not sensitive to the system model parameters. The resulting path, connecting a start point to a target position where in this method there is no information about the environment. Due to its ability and effortlessness for real-time implementation, fuzzy controller has been used for the proposed navigation strategy. The resulting navigation system is implemented on the e-puck robot in Webots software, and tested in several environments. Simulation results are presented which show the effectiveness of the proposed fuzzy controller and local minimum algorithm to safely navigate the mobile robot in various dead end trap environment. View full abstract»

Multi-robot systems have emerged as a central research theme within robotics with applications in several domains that require automated robotic assistants such as unmanned search and rescue, automated surveillance and reconnaissance operations, automated civilian transportation, extra-terrestrial exploration, and even domestic applications such as agriculture, lawn mowing, vacuum cleaning, etc. One of the major computational challenges in multi-robot systems is to design appropriate coordination techniques between the robots that enable them to perform operations efficiently in terms of time, cost and energy expended while keeping the system robust to individual robot failures as well as scalable in the number of robots. Coordination technologies from the field of multi-agent systems offer a rich array of solutions that can be adapted to multi-robot sytems. In this talk, we will summarize our research on two operations that are frequently encountered in many multi-robot domains, namely, multi-robot area coverage [1] and multi-robot task allocation [2]. First, we will describe a coalition game theory based technique for dynamically reconfiguring multi-robot teams by splitting or merging them, when they encounter obstacles while covering an initially unknown environment. We will introduce two heuristics that, given the set of robots requiring reconfiguration, guarantee rapid convergence to the appropriate partition of the set of robots while taking into consideration the physical characteristics of the robots and the environment [3]. Secondly, I will describe a distributed, auction-based multirobot task allocation algorithm called DynamicBids [4] that improves the performance of tasks and significantly reduces the communication overhead between robots by allowing a bidder robot to selectively revise its bids on tasks if that improves the cost of the schedule of the tasks to the bidder robot. For both techniques, we will describe analytical results, and, experimental- results from simulations on the Webots simulator as well as on physical robots. Finally, we will demonstrate our ongoing work on autonomous, multi-robot landmine detection that uses the techniques mentioned above to coordinate a set of robots, fitted with different types of landmine detection sensors, to potentially improve the accuracy with which landmines can be detected [5]. View full abstract»

This paper proposes an optimal control method to generate a minimum-torque change trajectory of humanoid arm by using a differential dynamic programming (DDP). Since DDP is a locally optimal feedback controller, the convergence is not guaranteed unless DDP starts with a good reference trajectory for high-dimensional nonlinear dynamical systems. The reference trajectory is generated by using the minimum-jerk trajectory method, and then the corresponding torque profile is obtained by using the computed-torque method. This reference trajectory is not optimal because it is solely based on the kinematics of the system. In the proposed method, the rate of torque change is used as control input in DDP to generate the optimal trajectory, which concurrently minimizes the torque variations and considers the dynamics of the system. The effectiveness of the proposed method is verified by computer simulations for generating the optimal trajectory of a 7 degrees-of-freedom (DOF) MyBot humanoid arm in Webots simulator. View full abstract»

As the number of handicapped people increases worldwide, electric wheelchairs are becoming the solution to enable a higher degree of independence for wheelchair users. Many researchers pay attention to how to solve the problems in daily life for the wheelchair users, rarely care for their physical exercises. In Paralympics, nearly all the athletes participate in sport events with the usual wheelchairs or electric wheelchairs which it is not suitable for sports like tennis. In this paper, we present a new prototype of an intelligent tennis wheelchair which can help people move more flexibly in the tennis game. The novel intelligent tennis wheelchair with four omnidirectional wheels installed on the bottom can move in all directions. The centre of gravity can be computed by calculating the values of four pressure sensors under the wheelchair seat, thus the orientation and velocity of wheelchair can be controlled by using human body motion. A lot of simulations have been done on the Webots platform. This paper presents the architecture of the developed system and gives some simulation results. View full abstract»

Firstly, this paper introduces the OzTug mobile robot developed to autonomously manoeuvre large loads within a manufacturing environment. The mobile robot utilises differential drive and necessary design criteria includes low-cost, mechanical robustness, and the abPility to manoeuvre loads ranging up to 2000kg. The robot is configured to follow a predefined trajectory while maintaining the forward velocity of a user-specified velocity profile. A vision-based fuzzy logic line following controller enables the robot to track the paths on the floor of the manufacturing environment. Secondly, in order to tow large loads along predefined paths three different robot-load configurations are proposed. Simulation within the Webots environment was performed in order to empirically evaluate the three different robot-load configurations. The simulation results demonstrate the cost-performance trade-off of two of the approaches. View full abstract»

This paper investigates mobile robot navigation algorithms in unknown two-dimensional environments with the aim of improving performance using WSN technology. The algorithms which perform such navigation are called Bug Algorithms. Existing algorithms are implemented on a robot developing system called Boe-bot and their performances are measured and analyzed. The implementation part is done on Boe-bot equipped with Waspmote WSN module enabling the wireless control ability. This work uses Webots which is a popular commercial mobile robot simulation software developed by Cyberbotics Ltd. View full abstract»

Mobile robot navigation in an unknown environment has been studied. First, the current situation and the development of mobile robot development are given; Secondly, the major VHF and artificial potential field method are introduced; finally, the simulation of mobile robot is achieved on simulation software Webots combining grid method. And the results can be applied to practical applications. View full abstract»

In this paper a visual self-localization method for a humanoid robot is presented. This one is based on monocular information. The goal of this method is to obtain the position (x; y) and orientation θ of the humanoid robot inside the field of play. The methods proposed include some digital image processing algorithms and geometric interpretation to perform a 3D monocular reconstruction, that allows to measure the relative position between the robot and some known objects (goals and beacons), and to use them to obtain the robot's absolute position, by means of a triangulation method. Finally, the results obtained in Webots and in the real platform are presented. View full abstract»

In this paper the behavior control system developed for a humanoid soccer player is presented, according to the current rules established by the International RoboCup Federation. It is important to point out that this work deals only with field players, excluding the goalkeeper. The behavior control is modeled as a finite-state automaton, which comprises activities as: visual perception (self localization, ball localization, movement estimation), behavior control and game strategies. The developed system is implemented in Webots, which is the official simulation platform used in the RobotStadium league of RoboCup. The results obtained are shown and the path to improve the developed system in our humanoid soccer players is established as future work. View full abstract»

We propose two contrasting approaches to the scalable distributed control of a swarm of self-assembling miniaturized robots, specifically the formation of chains of a desired length: (1) a deterministic controller in which robots communicate with each other in order to directly limit the size of each chain, and (2) a probabilistic controller where the average chain size is controlled by the probability a robot will choose to leave its chain. We demonstrate the feasibility of both approaches by implementing them on a real swarm of Alice robots. Using Webots, a realistic simulator for mobile robotics, and macroscopic models based on the Chemical Reaction Network (CRN) framework, we investigate the limitations of the deterministic controller and demonstrate the existence of optimal parameters for the probabilistic controller where exploration and exploitation are well balanced, thus favoring the formation of larger chains. View full abstract»

In generating walking patterns for humanoid robots, a Center-of-Mass trajectory is usually derived from the desired Zero-Moment-Point (ZMP) trajectory. One way to accomplish this is the use of the preview-control method, which tracks the desired ZMP trajectory while minimizing the jerk. Another method, which is more computationally efficient, is based on the convolution-sum method. Although this method is simple to implement, the resulting motion could be jerky. In this paper, we utilize the convolution-sum method to generate walking patterns for slopes and stairs walking while minimizing jerky motions. Furthermore, we extend the method to generate walking patterns for non-uniform terrain walking. This is accomplished by defining certain coordinate frames and maintaining the right-foot posture necessary for achieving robust walking. Computer simulations utilizing Webots were performed to validate the proposed convolution-sum method for the generation of walking patterns for a HOAP-2 humanoid robot. View full abstract»

In this paper, kinematics and dynamics of traveling wave locomotion of a snake robot with two types of body shapes are developed. The body shape, also called body curve, is the actual geometrical shape in the plane in which the robot can assume during its progression. The snake can then travel along this curve. Two types of body curves, symmetrical and unsymmetrical, have been introduced for creeping locomotion, in horizontal plane. Kinematics and dynamic of traveling wave with symmetrical body curve has also been developed. These concepts are applied and kinematics and dynamics for traveling wave in vertical plane with unsymmetrical body shapes are obtained. In kinematics section, we first determine the joint relative angles using the body shape and curvature function. Next, position, velocity and acceleration of each link as well as center of gravity of the snake body are calculated. In Dynamic's section, force diagram of the i(exp th) link is shown. Using Newton principle, relative motion of the i(exp th) link with respect to the (i+1)(exp th) link is determined. Next, effects of friction coefficient, initial winding angle and the unsymmetrical factor on the joint torques are investigated. Results indicate that as the winding angle increases, joint torques decreases. Additionally, it is shown that the unsymmetrical factor, k, does not significantly affect torques. Finally, to validate our analysis, traveling wave locomotion is simulated in both Webots as well as MATLAB. It is shown that the traveling wave locomotion for both symmetrical and unsymmetrical body shapes is realized. View full abstract»

The number of vehicles hitting the road each day is rapidly increasing, and several problems, such as traffic congestion or driver safety, can no longer be solved in the same fashion as before. Intelligent transportation systems could potentially solve part of these problems, but prototyping, designing and testing cooperative smart vehicles is a cumbersome task. This paper presents a realistic simulator, capable of operating both at microscopic and sub-microscopic level, where intelligent vehicles can be designed and analyzed with a pragmatic approach. A number of advances in robotics have already been transferred to vehicular technology, with a potential increase of this trend into the future. Here, we develop a plugin for a well-established robotics simulator (Webots), in order to reinforce at the virtual level this cross-fertilization between the two areas and create a baseline for realistic studies of future solutions in real intelligent vehicles. View full abstract»

This paper describes a novel approach towards recognizing of Indian Sign Language (ISL) gestures for Humanoid Robot Interaction (HRI). An extensive approach is being introduced for classification of ISL gesture which imparts an elegant way of interaction between humanoid robot HOAP-2 and human being. ISL gestures are being considered as a communicating agent for humanoid robot which is being used in this context explicitly. It involves different image processing techniques followed by a generic algorithm for feature extraction process. The classification technique deals with the Euclidean distance metric. The concrete HRI system has been established for initiation based learning mechanism. The Real time robotics simulation software, WEBOTS has been adopted to simulate the classified ISL gestures on HOAP-2 robot. The JAVA based software has been developed to deal with the entire HRI process. View full abstract»