Miguel Hernando

An improved bit parallel exact maximum clique algorithm

This paper describes new improvements for BB-MaxClique (San Segundo etxa0al. in Comput Oper Resour 38(2):571–581, 2011), a leading maximum clique algorithm which uses bit strings to efficiently compute basic operations during search by bit masking. Improvements include a recently described recoloring strategy in Tomita etxa0al. (Proceedings of the 4th International Workshop on Algorithms and Computation. Lecture Notes in Computer Science, vol 5942. Springer, Berlin, pp 191–203, 2010), which is now integrated in the bit string framework, as well as different optimization strategies for fast bit scanning. Reported results over DIMACS and random graphs show that the new variants improve over previous BB-MaxClique for a vast majority of cases. It is also established that recoloring is mainly useful for graphs with high densities.

Telerobotic system for live-power line maintenance: ROBTET

Abstract This paper is focused on a telerobotic application for the maintenance of electrical live-power lines, called “ROBTET”. Maintenance-related tasks are of great relevance for utilities companies, as their goal of achieving a good service quality depends to a great extent on maintenance and inspection issues. On live lines up to 69 kV , the tasks are carried out by teleoperated robots. These manipulators are teleoperated by a human operator sitting in a vehicle required to place the telerobotic system over the desired line. In this paper, the main developments in live-line teleoperated systems are mentioned, followed by a detailed description of the ROBTET. This telerobotic system has been developed by the Universidad Politecnica de Madrid, in collaboration with Iberdrola and Cobra, a Spanish utility company and contractor, respectively. The ROBTET system has been in operation in the Spanish electricity network for over a year, which attests to the success of the prototype and also allows for the incorporation of improvements.

Telerobotic system for live power lines maintenance: ROBTET

Outage-free maintenance of electrical power lines has been conducted throughout the years in order to fulfil the increasing demand of uninterrupted power supply. In these techniques care regarding electric shock and falls must be exercised while the work is performed on or near energized elements. In order to increase the safety and comfort of the workers as well as the overall efficiency, a teleoperated system for live-line maintenance, called ROBTET, has been developed for the electrical utility IBERDROLA. ROBTET is described in detail in the paper. It has two hydraulic-driven master-slave teleoperated manipulators on top of an insulated boom over a truck. The operator commands the manipulators from a cabin on the truck via a pair of master arms, while he receives visual feedback through a vision system. Multimedia display, voice commands, stereo vision and force-feedback are some of the new features implemented in order to achieve the required telepresence of the operator and hence increase the performance of the system.

Ten Years of Cybertech: The Educational Benefits of Bullfighting Robotics

After 10 years of organizing the Cybertech robotics competition, this paper presents this unique and innovative educational experience of teaching engineering at Universidad Politécnica de Madrid (UPM), Spain. Cybertech is not only a well-known robotic contest in Spain due to the Robotaurus bullfighting, but is also a whole academic activity spanning theory, laboratory practical lessons, seminars, tutoring, and a spectacular contest in which robots, developed by the students, compete. It is an open activity, for all students and grades, requiring knowledge of various subjects such as mechanics, microcontrollers, control, and electronics. The experience acquired has shown how this novel educational approach can boost the motivation of students, who in a real applied project effectively learn not only the particular subject matter, but also skills in teamwork, oral presentations, budget management, and so on. This is considered the flagship of innovation in education at UPM. This paper describes the evolution of Cybertech over the past 10 years, summarizes the educational experience, and provides some statistics and results as well as a perspective for future editions of the competition.

Modular Multiconfigurable Architecture for Low Diameter Pipe Inspection Microrobots

The inspection of low diameter pipes is a subject of great complexity due to the small operation environment in which the tasks must be developed. Besides, the construction of microrobots for specific pipe inspection is too expensive. In this article, a modular multiconfigurable architecture is presented. The fact of being modular and multiconfigurable makes it capable of performing different tasks and to adjust to different pipes and environments. Different types of modules that can be combined to form a whole microrobot and a control and communication system are also presented.

Urbano, an Interactive Mobile Tour-Guide Robot

Autonomous service robot applications can be divided in two main groups: outdoor and field robots, and indoor robots. Autonomous lawnmowers, de-mining and search and rescue robots, mars rovers, automated cargo, unmanned aerial and underwater vehicles, are some applications of field robotics. The term indoor robotics usually applies to autonomous mobile robots that move in a typical populated indoor environment. Robotic vacuum cleaners, entertainment and companion robots or security and surveillance applications are also some examples of successful indoor robot applications. Probably, one of the first real world applications of indoor service robots has been that of mobile robots serving as tour guides in museums or exhibitions. Such one is an extremely interesting application for researchers because allows them to advance in knowledge fields as autonomous navigation in dynamic environments, human robot interaction, indoor environment modelling with simultaneous localization and map building, etc., while also serving as a showcase for attracting the general public as well as possible investors. We have developed our own interactive mobile robot called Urbano, especially designed to be a tour guide in exhibitions. This chapter describes the Urbano robot system, its hardware, software and the experiences we have obtained through its development and use until its actual mature stage. This chapter doesn’t pretend to be an exhaustive technical description of algorithms, mathematical or implementation details, but just an overview of the system. The interested reader will be referred to more specific bibliography for these details. The rest of the chapter is structured as follows: This section presents the related work, other existing systems, as well as our motivation to develop our own robot. Section 2 presents an overview of Urbano, the description of its hardware and also the software components in which the robot control is structured. These components are afterwards described in subsequent sections: Section 3 describes the feature based mapping and navigation subsystem, while the interaction capabilities including our own proprietary voice recognition and synthesis engine will be described in section 4. Section 5 briefly describes the web based remote visit that Urbano is also able to perform. The integration of all these components is managed through a programmable kernel that allows a high level management of all modules, described in section 6. The chapter ends with the presentation of some successful real deployments of Urbano in section 7, and our conclusions in section 8.

A 2 DoF Servomotor-based Module for Pipe Inspection Modular Micro-robots

A 2 degrees of freedom module for pipe inspection modular micro-robots based on servomotors is presented in this article. A mechanical and electrical description of the module is also given, including the kinematics and the close control loop design to detect obstacles (walls). The main configurations in which it can be used are described as well: snake-like robots and chain multi-configurable modular robots. The different pipes and elbows it can move on are also shown

Hammer: An Android based application for end-user industrial robot programming

This paper presents a novel tablet based end-user interface for industrial robot programming (called Hammer). This application makes easier to program tasks for industrial robots like polishing, milling or grinding. It is based on the Scratch programming language, but specifically design and created for Android OS. It is a visual programming concept that allows non-skilled programmer operators to create programs. The application also allows to monitor the tasks while it is being executed by overlapping real time information through augmented reality. The application includes a teach pendant screen that can be customized according to the operator needs at every moment.

A behaviour-based control architecture for heterogeneous modular, multi-configurable, chained micro-robots

This article presents a new control architecture designed for heterogeneous modular, multi-configurable, chained micro-robots. This architecture attempts to fill the gap that exists in heterogeneous modular robotics research, in which little work has been conducted compared to that in homogeneous modular robotics studies. The architecture proposes a three-layer structure with a behaviour-based, low-level embedded layer, a half-deliberative half-behaviour-based high layer for the central control, and a heterogeneous middle layer acting as a bridge between these two layers. This middle layer is very important because it allows the central control to treat all modules in the same manner, facilitating the control of the robot. A communication protocol and a module description language were also developed for the control architecture to facilitate communication and information flow between the heterogeneous modules and the central control. Owing to the heterogeneous behaviour of the architecture, the system can automatically reconfigure its actions to adapt to unpredicted events (such as actuator failure). Several behaviours (at low and high levels) are also presented here.

Operator Performance in Exploration Robotics

Mobile robots can accomplish high-risk tasks without exposing humans to danger: robots go where humans fear to tread. Until the time in which completely autonomous robots are fully deployed, remote operators will be required in order to fulfill desired missions. Remotely controlling a robot requires that the operator receives the information about the robot’s surroundings, as well as its location in the scenario. Based on a set of experiments conducted with users, we evaluate the performance of operators when they are provided with a hand-held-based interface or a desktop-based interface. Results show how performance depends on the task asked of the operator and the scenario in which the robot is moving. The conclusions prove that the operator’s intra-scenario mobility when carrying a hand-held device can counterbalance the limitations of the device. By contrast, the experiments show that if the operator cannot move inside of the scenario, his performance is significantly better when using a desktop-based interface. These results set the basis for a transfer of control policy in missions involving a team of operators, some equipped with hand-held devices and others working remotely with desktop-based computers.