Fernando Gómez-Bravo

Parking maneuvers of industrial-like electrical vehicles with and without trailer

Maneuvering autonomous vehicles in constrained environments is not a trivial task. This paper concentrates in the practical maneuvering of electrical vehicles. The autonomous vehicles considered in the paper, ROMEO-3R and ROMEO-4R, have been developed at the University of Seville, Seville, Spain, as the result of the adaptation of a tricycle and a car-like conventional electrical vehicles for transportation of people, respectively. Moreover, maneuvering of ROMEO-4R backing up a trailer has also been considered. A particular maneuver, namely, autonomous parallel parking, has been used to illustrate the application of the presented methods to different electrical vehicles.

Continuous curvature path generation based on ß-spline curves for parking manoeuvres

This paper focuses attention on continuous curvature path generation for parallel parking manoeuvres of autonomous conventional vehicles. The method is based on @b-spline curves generation from a collision-free path previously calculated. Several constraints have been considered in order to ensure the existence of collision-free and admissible curves. The efficiency of the proposed method is demonstrated using the nonholonomic autonomous vehicles ROMEO-3R and ROMEO-4R designed and built at the University of Seville.

Application of multicriteria decision-making techniques to manoeuvre planning in nonholonomic robots

In the scientific literature, one can find different techniques for tackling the problem involved in generating manoeuvres in robots with nonholonomic restrictions. Among these, probabilistic generation methods have been widely used. This paper presents a new technique that enables the best paths to be selected from among a set provided by a probabilistic planning method (RRT). This selection involved the application of multicriteria decision-making techniques (MCDMT). The particularity of these MCDMT lies in the fact that they provide the same result as would arise if the decision had been taken by a human being. The application of these techniques (generation and ranking) has enabled the development of an automatic tool for finding the best manoeuvres for nonholonomic robots. Lastly, we present the application of these techniques to a real situation, obtaining excellent results.

Motion and Operation Planning of Robotic Systems

Monitoring and surveillance is a very relevant issue in recent years where the use of multiple Unmanned Aerial Vehicles (UAVs) offers interesting advantages. In this kind of mission, assuming that there is no “a priori” information about the location or time of the events or intruders to detect, a frequency-based criterion seems to be an interesting approach to solve the problem. This chapter describes a frequency-based approach applied to a cooperative area monitoring problem using a team of UAVs. Three different cooperative patrolling strategies (cyclic, path partitioning and area partitioning) are analyzed and compared with respect to refresh and latency times criteria. Finally, assuming communication constraints, a distributed implementation is required and convergence to the centralized cooperative patrolling strategy should be ensured. Two different distributed techniques are described: oneto-one coordination and a method based on coordination variables. Both techniques are compared from a convergence complexity criterion.

Manoeuvring in nonholonomic industrial-like electrical vehicles

Manoeuvring autonomous vehicles in constrained environments is not a trivial task. This paper concentrates in the practical maneuvering of electrical vehicles. The autonomous vehicles considered in the paper, ROMEO3R and ROMEO4R, have been developed at the University of Seville as the result of the adaptation of a tricycle and a car-like conventional electrical vehicles for transportation of people, respectively. Moreover maneuvering of ROMEO4R backing up a trailer has also been considered. A particular maneuver, namely, autonomous parallel parking, has been used to illustrate the application of the presented methods to different electrical vehicles.

A Wireless Sensor System for Real-Time Monitoring and Fault Detection of Motor Arrays

This paper presents a wireless fault detection system for industrial motors that combines vibration, motor current and temperature analysis, thus improving the detection of mechanical faults. The design also considers the time of detection and further possible actions, which are also important for the early detection of possible malfunctions, and thus for avoiding irreversible damage to the motor. The remote motor condition monitoring is implemented through a wireless sensor network (WSN) based on the IEEE 802.15.4 standard. The deployed network uses the beacon-enabled mode to synchronize several sensor nodes with the coordinator node, and the guaranteed time slot mechanism provides data monitoring with a predetermined latency. A graphic user interface offers remote access to motor conditions and real-time monitoring of several parameters. The developed wireless sensor node exhibits very low power consumption since it has been optimized both in terms of hardware and software. The result is a low cost, highly reliable and compact design, achieving a high degree of autonomy of more than two years with just one 3.3 V/2600 mAh battery. Laboratory and field tests confirm the feasibility of the wireless system.

An Efficient Wireless Sensor Network for Industrial Monitoring and Control

This paper presents the design of a wireless sensor network particularly designed for remote monitoring and control of industrial parameters. The article describes the network components, protocol and sensor deployment, aimed to accomplish industrial constraint and to assure reliability and low power consumption. A particular case of study is presented. The system consists of a base station, gas sensing nodes, a tree-based routing scheme for the wireless sensor nodes and a real-time monitoring application that operates from a remote computer and a mobile phone. The system assures that the industrial safety quality and the measurement and monitoring system achieves an efficient industrial monitoring operations. The robustness of the developed system and the security in the communications have been guaranteed both in hardware and software level. The system is flexible and can be adapted to different environments. The testing of the system confirms the feasibility of the proposed implementation and validates the functional requirements of the developed devices, the networking solution and the power consumption management.

A Smart Sensor for Defending against Clock Glitching Attacks on the I2C Protocol in Robotic Applications

This paper presents a study about hardware attacking and clock signal vulnerability. It considers a particular type of attack on the clock signal in the I2C protocol, and proposes the design of a new sensor for detecting and defending against this type of perturbation. The analysis of the attack and the defense is validated by means of a configurable experimental platform that emulates a differential drive robot. A set of experimental results confirm the interest of the studied vulnerabilities and the efficiency of the proposed sensor in defending against this type of situation.

Planning an Optimal Step Motion for a Hybrid Wheeled-Legged Hexapod

This paper addresses the path planning problem for an hybrid wheeled–legged hexapod. In particular, the proposed procedure is aiming to identify optimal trajectories for a leg when it has to step over an obstacle. The proposed procedure is a combination of a quick random search algorithm together with an optimisation method. This combination is used to achieve a good compromise between computational costs and path planning performance. The optimization method is efficiently solved by using a genetic algorithm to achieve properly smooth leg movements. A case of study is numerically solved by referring to a built prototype of Cassino Hexapod at LARM in Cassino.

Vodec: A fast voronoi algorithm for car-like robot path planning in dynamic scenarios

Traditionally, robot motion planners use Voronoi Diagrams for generating admissible paths that connect an initial with a final configuration. When dynamic scenarios are involved, these techniques imply a heavy computational cost. The novelty of the technique presented here is that it can provide fast and particularly suitable routes without considering the full scenario if environmental changes appear. The new method is designed to work with a post-process technique in order to provide admissible paths for car-like robots coping with kinematic constraints. This new approach is capable of supplying continuous paths and also elaborate maneuvers if cluttered environments are involved.