Cooperative Exploration by Multi-robots without Global Localization
Shi Chao-xia; Hong Bing-rong and Wang Yan-qing

Abstract: Efficient exploration of unknown environments is a fundamental problem in mobile robotics. We propose a novel topological map whose nodes are represented with the range finder's free beams together with the visual scale-invariant features. The topological map enables teams of robots to efficiently explore environments from different, unknown locations without knowing their initial poses, relative poses and global poses in a certain world reference frame. The experiments of map merging and coordinated exploration demonstrate the proposed map is not only easy for merging, but also convenient for robust and efficient explorations in unknown environments.
Keywords: Cooperative exploration, Topological map, Map merging, Scale-invariant features

Multi-Robot Motion Planning Using Swarm Intelligence
Gerasimos G. Rigatos

Abstract: Swarm intelligence theory is proposed for motion planning of multi-robot systems. Multiple particles start from different points in the solutions space and interact to each other while moving towards the goal position. Swarm intelligence theory is a derivative-free approach to the problem of multi-robotcooperation which works by searching iteratively in regions defined by each robot's best previous move and the best previous move of its neighbors. The method's performance is evaluated through simulation tests.
Keywords: Swarm intelligence, Multi-robot system, Motion planning, Stochastic search algorithms, Lyapunov stability

Study on State Transition Method Applied to Motion Planning for a Humanoid Robot
Xuyang Wang; Tiansheng Lu and Peiyan Zhang

Abstract: This paper presents an approach of motion planning for a humanoid robot using a state transition method. In this method, motion planning is simplified by introducing a state-space to describe the whole motion series. And each state in the state-space corresponds to a contact state specified during the motion. The continuous motion is represented by a sequence of discrete states. The concept of the transition between two neighboring states, that is the state transition, can be realized by using some traditional path planning methods. Considering the dynamical stability of the robot, a state transition method based on search strategy is proposed. Different sets of trajectories are generated by using a variable 5th-order polynomial interpolation method. After quantifying the stabilities of these trajectories, the trajectories with the largest stability margin are selected as the final state transition trajectories. Rising motion process is exemplified to validate the method and the simulation results show the proposed method to be feasible and effective.
Keywords: State-space, State transition, Motion planning, Humanoid robots

Navigation Strategy by Contact Sensing Interaction for a Biped Humanoid Robot
Hanafiah Yussof; Masahiro Ohka; Mitsuhiro Yamano and Yasuo Nasu

Abstract: This report presents a basic contact interaction-based navigation strategy for a biped humanoid robot to support current visual-based navigation. The robot's arms were equipped with force sensors to detect physical contact with objects. We proposed a motion algorithm consisting of searching tasks, self-localization tasks, correction of locomotion direction tasks and obstacle avoidance tasks. Priority was given to right-side direction to navigate the robot locomotion. Analysis of trajectory generation, biped gait pattern, and biped walking characteristics was performed to define an efficient navigation strategy in a biped walking humanoid robot. The proposed algorithm is evaluated in an experiment with a 21-dofs humanoid robot operating in a room with walls and obstacles. The experimental results reveal good robot performance when recognizing objects by touching, grasping, and continuously generating suitable trajectories to correct direction and avoid collisions.
Keywords: Navigation strategy, Humanoid robot, Contact sensing, Biped locomotion, Trajectory generation

A Low-Cost Easy-Operation Hexapod Walking Machine
Giuseppe Carbone and Marco Ceccarelli

Abstract: This paper presents the mechanical design of an hybrid hexapod walking machine that has been designed and built at LARM: Laboratory of Robotics and Mechatronics in Cassino. Basic characteristics are investigated in order to design a leg system with suitable low-cost modular components. Moreover, special care has been addressed in proposing an architecture that can be easily operated by a PLC with on-off logic. Experimental tests are reported in order to show feasibility and operational capability of proposed design.
Keywords: Walking machines; Wheeled leg, Low-cost design

An Implementation of Seamless Human-Robot Interaction for Telerobotics
Kai Wei Ong; Gerald Seet and Siang Kok Sim

Abstract: Achieving human-robot cooperation in a telerobotics system is the focus of this paper. The implementation of human-robot systems can be extremely challenging when the robot is not directly controlled by the human. The interaction mode, depending on the task context, can be continuous manual, semi-autonomous or autonomous. To address the Human-Robot Interaction (HRI) issues in such a system, a concept of seamless HRI is introduced. Seamless HRI implies flexibility in human control in interacting with a robot in different situations, and the adaptability of the robot autonomy in response to the human control. The main idea is to design a telerobotics system that allows a shift from manual to autonomous operation, dynamically, via different human-robot roles and relationships. These roles are Master-Slave, Supervisor-Subordinate, Partner-Partner, Teacher-Learner and Full Autonomous mode by the robot. This paper presents the theoretical foundations and the requirements for seamless HRI. An implementation of the concept and an experimental evaluation is presented.
Keywords: Seamless, Human-robot interaction (HRI), Telerobotics, Cooperation

A Methodology for the Design of Robotic Hands with Multiple Fingers
Jorge Eduardo Parada Puig; Nestor Eduardo Nava Rodriguez and Marco Ceccarelli

Abstract: This paper presents a methodology that has been applied for a design process of anthropomorphic hands with multiple fingers. Biomechanical characteristics of human hand have been analysed so that ergonomic and anthropometric aspects have been used as fundamental references for obtaining grasping mechanisms. A kinematic analysis has been proposed to define the requirements for designing grasping functions. Selection of materials and actuators has been discussed too. This topic has been based on previous experiences with prototypes that have been developed at the Laboratory of Robotics and Mechatronics (LARM) of the University of Cassino. An example of the application of the proposed method has been presented for the design of a first prototype of LARM Hand.
Keywords: Methodology, Design, Robotic hands, Anthropomorphic

The Design and Implementation of a Biomimetic Robot Fish
Chao Zhou; Min Tan; Nong Gu; Zhiqiang Cao; Shuo Wang and Long Wang

Abstract: In this paper, a novel design of a biomimetic robot fish is presented. Based on the propulsion and maneuvering mechanisms of real fishes, a tail mechanical structure with cams and connecting rods for fitting carangiform fish body wave is designed, which provides the main propulsion. Two pectoral fins are mounted, and each pectoral fin can flap separately and rotate freely. Coordinating the movements of the tail and pectoral fins, the robot fish can simulate the movements of fishes in water. In order to obtain the necessary environmental information, several kinds of sensors (video, infrared, temperature, pressure and PH value sensors) were mounted. Finally, the realization of the robot fish is presented.
Keywords: Biomimetic robot fish, Carangiform fish body wave, Pectoral fins, Sensors

Wheels Optimization and Vision Control of Omni-directional Mobile Microrobot
Jianghao Li; Zhenbo Li and Jiapin Chen

Abstract: This paper presents a millimeters scale omni-directional mobile microrobot with special dual-wheel structure. The microrobot was actuated by three electromagnetic micromotors of 2mm diameter. Dynamic analysis of translational and steering movements presented the relationship between the sizes of the dual-wheel structure and the output torque of the micromotor. Genetic algorithm (GA) was employed to optimize the dualwheel's sizes for reducing the unnecessary torque consumption and improving the driving ability of the microrobot. A computer vision system contained two sets of feedback control is devised for the microrobot. Torque self-balance and current-limiting control approach are presented to ensure the accuracy of step movement. Experiment results demonstrate the feasibility of these concepts.
Keywords: Microrobot, Dual-wheel, Genetic algorithm, Optimization

A Virtual Simulation Environment for Lunar Rover: Framework and Key Technologies
Yan-chun Yang; Jin-song Bao; Ye Jin and Yun-long Cheng

Abstract: Lunar rover development involves a large amount of validation works in realistic operational conditions, including its mechanical subsystem and on-board software. Real tests require equipped rover platform and a realistic terrain. It is very time consuming and high cost. To improve the development efficiency, a rover simulation environment called RSVE that affords real time capabilities with high fidelity has been developed. It uses fractional Brown motion (fBm) technique and statistical properties to generate lunar surface. Thus, various terrain models for simulation can be generated through changing several parameters. To simulate lunar rover evolving on natural and unstructured surface with high realism, the whole dynamics of the multi-body systems and complex interactions with soft ground is integrated in this environment. An example for path planning algorithm and controlling algorithm testing in this environment is tested. This simulation environment runs on PC or Silicon Graphics.
Keywords: Virtual reality, Planetary rover, Robot dynamics, Real-time systems, fBm

Mechanical Implementation and Simulation of MoboLab, A Mobile Robot for Inspection of Power Transmission Lines
Mostafa Nayyerloo; Seyyed Mohammad Mehdi Yeganehparast; Alireza Barati and Mahmud Saadat Foumani

Abstract: This paper describes the first phase in development of a mobile robot that can navigate aerial power transmission lines completely unattended by human operator. Its ultimate purpose is to automate inspection of power transmission lines and their equipments. Authors have developed a scaled functional model of such a mobile robot with a preliminary simple computer based on-off controller. MoboLab (Mobile Laboratory) navigates a power transmission line between two strain towers. It can maneuver over obstructions created by line equipments such as insulators, warning spheres, dampers, and spacer dampers. It can also easily negotiate the towers by its three flexible arms. MoboLab has an internal main screw which enables the robot to move itself or its two front and rear arms independently through changing gripped points. When the front arm gets close to an obstacle, the arm detaches from the line and goes down, the robot moves forward, the arm passes the obstacle and grippes the line again. In a same way another arms pass the obstacle.
Keywords: Aerial power transmission lines, Inspection, Mobile robot, Automated operation

Workspace Topologies of Industrial 3R Manipulators
Erika Ottaviano; Marco Ceccarelli and Manfred Husty

Abstract: A mathematical analysis is used to characterize workspace topologies of industrial 3R manipulators. A level-set reconstruction of the workspace is formulated to identify characteristic points with fairly simple algebraic expressions. Thus, industrial 3R manipulators are classified as functions of workspace kinematic properties. Examples are illustrated to show practical usefulness of the proposed workspace characterization.
Keywords: Manipulators, Workspace analysis, Classification