Search

Durante uma das mais graves crises hídricas no Brasil, em 2015, uma reportagem da Folha de São Paulo mostrou que 37% de toda a água tratada no Brasil não chega até o consumidor final, sendo as falhas nas tubulações a principal causa. Este trabalho de mestrado aborda esse problema de desperdício e falhas em tubulações, tanto de água como de esgoto. Dessa forma são apresentadas as características desses tipos de tubulações bem como os tipos mais comuns de falhas. Os métodos de inspeção de tubulações existentes também estão apresentados. E na tentativa de auxiliar na redução do desperdício em tubulações foi desenvolvido um método de detecção de falhas de tubulações, objetivando alcançar uma solução de baixo custo para que ela possa ser amplamente utilizada. A solução criada envolveu o desenvolvimento de um método de controle de posição utilizando um método de aprendizagem por reforço, o Q-Learning, que permite o robô percorrer a tubulação sem tombar, apenas utilizando um giroscópio. Foi desenvolvido, utilizando sensores de distância infravermelho e um acelerômetro, um método de detecção de falhas em que se conseguiu detectar falhas com apenas 2 mm de espessura, em todas as vezes em que o robô passou por ela. O método desenvolvido é capaz de superar a instabilidade e imprecisão do sensor infravermelho, permitindo, durante os testes, a detecção de todas as falhas em que o robô atravessou, tendo apenas 1 acusação de falsa falha a cada 25 m de percurso a uma velocidade mais de 60% maior que a velocidade máxima de uma vídeo inspeção. Os resultados foram satisfatórios, porém mais trabalho no aumento da área da superfície inspecionada e na redundância da detecção de falhas ainda se faz necessário. During one of the most critical water crises in Brazil, in 2015, a Folha de São Paulo Journal report showed that 37 % of all water treated in Brazil does not reach the final consumer, being the failures in pipes the main cause. This master’s work addresses this problem of waste and failure in piping, for both water and sewage. In this way the characteristics of these types of pipes as well as the most common types of faults are presented. Existing inspection piping methods are also presented. And in an attempt to help reduce this pipeline waste, a pipe failure detection method was developed to achieve a low cost solution so that it can be widely used. The developed solution involved the development of a position control method using a reinforcement learning method, Q-Learning, which allows the robot to run through the pipe without tumbling, using only a gyroscope. It was also developed, using infrared distance sensors and an accelerometer, a method of detecting failures in which it was possible to detect faults with only 2 mm of thickness, in all the times in which the robot passed through it. The developed method is able to overcome the instability and imprecision of the infrared sensor, allowing, during the tests, the detection of all the faults in which the robot crossed, having only 1 false failure accusation in 25 m of course at a speed 60 % greater than the maximum speed of a video inspection. The results were satisfactory, but more work on increasing the inspected surface area and redundancy of fault detection is still required. Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG

This paper designs and develops an automatic detection system in the substation environment where complex and multi-inspecting objects exist. The inspection robot is able to fix and identify the objects quickly using a visual servo control system. This paper focuses on the analysis of fast lockup and recognition method of the substation instruments based on an improved Adaboost algorithm. The robot adjusts its position to the best view point and best resolution for the instrument in real-time. The dial and pointer of the instruments are detected with an improved Hough algorithm, and the angle of the pointer is converted to the corresponding readings. The experimental results indicate that the inspection robot can fix and identify the substation instruments quickly, and has a wide range of practical applications.

Offline boiler header inspection is a tedious process if done manually since the opening is very small to insert big instruments and tools while the length can range up to 20 m. The geometry can also be complex since boiler tubes are connected to these headers from different directions. Designing of robots to assist in offline boiler header inspections can be made easier if a simulator is available for deciding the parameters of the robot. This paper describes the development of a 3D boiler header pipe environment template for boiler header inspection robot (BHIR) using Webots. The purpose is to use it as a simulator for the development of BHIR prototypes. Firstly, 3D boiler header pipe environment is constructed by using Pro Engineer (Pro\E). Next, Virtual Reality Modeling Language or VRML97 is used to convert file from Pro\E world file to Webots world file. Finally, simulations are carried out to verify the effectiveness of the developed 3D boiler header environment template. Results show the advantages of having the simulator for modeling and designing of BHIR prototypes.

Special current transformer (CT) is designed to induct power from the power transmission lines for an inspection robot. Equivalent circuit is used for calculating and modelling the parameters of the current transformer. Air gap analysis is given aiming at adapting dynamic range of bar current, and calculation of the effect of air gap is provided in detail. Ratio change of current transformer is introduced by which the secondary current could be adaptive to the bus current. Simulation results show that dynamic control of length of air gap and turns of the coils could make the current transformer be adaptive to the variable bus current and be more convenient for inducing power for the power transmission lines inspection robot.

The high-voltage transmission line had been used primarily for power distribution from power plant or power station to the end users. However, the transmission line is highly prone to damage due to exposure to various thermal–mechanical loadings and material degradation. Therefore, periodical inspection on transmission line after prolonged service is needed to prevent any failure before it happens. In this paper, we present a new design of three arms inspection robot for transmission lines. The robot is able to transverse along the line and bypass the in-line obstacles namely the anti-vibration hammers, spacer, strain clamps and others. The design of the inspection robot in term of the robot design and configuration with slotted cam at each arm is presented. The detailed analysis via simulation with respect to the robot stability; kinematic and movement analysis; and power consumption during operation is executed to make sure the proposed design able to do the inspection without any unexpected difficulties. Later, the lab testing on the developed prototype is done for feasibility study and validation

The national energy supplier (Eskom in South Africa) supplies electricity through thousands-of-kilometers of overhead power lines. The current methods of inspection of these overhead power lines are infrequent and expensive. In this paper, the authors present the development of a prototype monitoring system for power line inspection in South Africa. The developed prototype monitoring system collects data (information) from the overhead power lines, is remotely accessible and fits into a power line robot. The prototype monitoring system makes use of a PandaBoard ® (SBC) with GPS receiver and 5 MP camera to collect data. Hardware fatigue is the biggest problem faced on the overhead power lines and is captured by means of the 5 MP camera and is displayed on a website hosted by the PandaBoard ® via Wi-Fi. The monitoring system has low power consumption, is light weight, compact and easily collects data. The data obtained from the prototype monitoring system was satisfactory and provides an improved solution for monitoring power lines for Eskom in South Africa.

The purpose of this paper is to provide the design of a prototype power line inspection robot for the monitoring of Eskom transmission lines. It should also determine if an inspection robot would be a feasible solution to aid Eskom in monitoring their lines for potential problems and should also determine if it would be a viable financial choice to implement an inspection robot as to their current inspection methods. The designed prototype robot must be capable of balancing on a transmission line wire, should be capable of driving on it and to manoeuvre past certain obstacles that are found on a transmission line. Tests were done to ensure that the robot is capable of performing these tasks and other relevant tasks. The main reason for the prototype is to ensure a future development platform for an inspection robot. In return it would result in a cost effective, easy to maintain and a safer environment for the inspection staff

In South Africa, electricity is supplied through thousands-of-kilometers of overhead power cables, which is owned by Eskom the national energy supplier. Currently monitoring of these overhead power cables are done by means of helicopter inspection flights and foot patrols, which are infrequent and expensive. In this paper, the authors present the design of a prototype power line crawler (inspection robot) for the monitoring of these overhead power lines in South Africa. The designed prototype power line crawler is capable of driving on the wire, balancing on the wire and is capable of maneuvering past certain obstacles found on the overhead power cables. The prototype power line crawler is designed to host a monitoring system that monitors the power line as the inspection robot drives on it. Various experimental tests were performed and are presented in this paper, showing the capability of performing these tasks. This prototype inspection robot ensures a platform for future development in this area

Eskom has thousands-of-kilometres of transmission lines running across South Africa. The current methods of overhead power line inspection (foot patrols and air inspections) have been implemented for a long time now and are expensive and infrequent. The aim was to develop a prototype monitoring system, which had to fit into a transmission line robot to collect information from the power line and will allow a person to remotely (wirelessly) inspect the power line. The hardware consists of a PandaBoard® (SBC) together with a 5 MP camera and GPS receiver to collect information. High detail (resolution) photos of the power line covered the biggest problem faced on the lines, namely: hardware fatigue. The evidence was then accessible on a website hosted by the PandaBoard® via Wi-Fi. The solution is light weight, compact and has a low power consumption. The monitoring system makes collecting evidence easy and fast. The results obtained by this prototype are satisfactory as a concept for further development and can provide a feasible and improved solution for monitoring of transmission lines for Eskom

One of the major challenges in robotics is the improvement of inspections operations in confined and hazardous area using unmanned remote handling systems. Articulated arm are used in this case to carry some diagnostic tools for the inspection tasks. These long reach multi-link carriers should be characterized by a large workspace and reduced mass. Today, with about ten degrees of freedom and ten meters long they have reached their performance limit. Indeed, for long reach ,the arm should have enough torque to carry its own weight plus the payload in cantilever mode and enough stiffness to minimize the deflection caused by the gravity. Despite the use of best materials and components, this kind of robot has reach its performance limit. Overcoming this limit needs a change in paradigms. Therefore a problem-solving, analysis and forecasting tool TRIZ (theory of inventive problem solving) is used. It leads naturally to identify the origin of the dilemma: the proper weight of the arm and so its mass under gravity. In particular, it proposes to postulate that a no-mass robot exists. An analysis of the properties of such a robot leads to the patented concept of an ultra light inflatable robot with unique and constant volume and constant diameter joints. This new object would benefit from advantages such as easy implementation, harmlessness toward its environment and so the ability to lean on it without damage. Therefore it could easily increase its range and its foreseen low-cost building would open a wide field of new applications. This thesis work, elaborates appropriate technical concepts and dimensioning methods for ultra light inflatable robots. The payload and length performances of an inflatable robot are analytically validated. Experimentations and a finite-element modeling are used for a pre-dimensioning of the joints and different modes of construction are prototyped in partnership with, specialized company in thigh-tech textile. The joints are also modeled with a simple mass-spring system for time efficient simulations of deflections under load of a DOF inflatable robot. Actuators and sensors are pre-designed and an original cable transmission is developed. Finally, the geometric and kinematic models are built and we set the control problem of such a robot for future works.; Les robots dits à fort élancement, utilisés pour des opérations d'inspection et de maintenance en environnement hostile à l'homme, encombré, et accessible uniquement par des orifices de très faible diamètre, sont caractérisés par leur très grand ratio longueur sur diamètre. Aujourd'hui, malgré l'emploi de composants et de matériaux sophistiqués, ces robots ont atteint leur limite de performances. Franchir significativement cette limite nécessite un changement de paradigme. La TRIZ (théorie de résolution des problèmes inventifs), qui construit un processus systématique de résolution de problème technique, conduit naturellement à identifier l'origine de la contradiction : le poids propre des robots, et par conséquent leur masse en présence de gravité. Elle propose notamment de postuler l'existence d'un robot sans masse. L'analyse des propriétés d'un tel robot conduit à l'élaboration du concept breveté de robot ultraléger gonflé, ayant un volume constant unique et des articulations préservant le diamètre de la section. Ce nouvel objet aurait de nombreux autres avantages tels que la facilité de mise en œuvre, l'innocuité par rapport à l'environnement et donc des contacts sans dommages avec celui-ci. Son grand son rayon d'action et son coût prévisionnel très réduit peuvent lui donner accès à de nombreuses applications nouvelles. L'objet de ce travail de thèse est donc l'élaboration des concepts techniques et des méthodes de dimensionnement adaptés à ce robot ultraléger gonflé. Ainsi, les performances du robot gonflable en termes de capacité de charge et de portée sont validées analytiquement. Des expérimentations et une modélisation par éléments finis permettent d'effectuer un pré-dimensionnement des articulations. Différents modes de réalisation ont été prototypé en partenariat avec une entreprise spécialiste du textile technique. Ces articulations font aussi l'objet d'un modèle simplifié de type masse-ressort pour la simulation rapide des déformations d'un robot à degrés de liberté. Les actionneurs et capteurs font l'objet d'une préconception et une transmission originale à base de câble et adaptée à la cinématique particulière des articulations est développée. Enfin des modèles géométriques et cinématiques sont définis et le problème de la commande d'un tel robot est posé en vue des travaux à venir.

Power plants require periodical inspections to control their state. To ensure a safe operation, parts that could fail before the next inspection are repaired or replaced, since a forced outage due to a failure can cost up to millions of dollars per day. Non-Destructive Testing (NDT) methods are used to detect different defects that could occur, such as cracks, thinning, corrosion or pitting. Some parts are inspected directly in situ, but may be difficult to access; these can require opening access holes or building scaffoldings. Other parts are disassembled and inspected in workshops, when the required inspection tools cannot be moved. In this thesis, we developed innovative miniature mobile systems able to move within these small and complex installations and inspect them. Bringing sensors to difficult-to-access places using climbing robots can reduce the inspection time and costs, because some dismantling or scaffolding can be eliminated. New miniature sensors can help to inspect complex parts without disassembling them, and reduce the inspection costs, as well. To perform such inspections, miniature mobile systems require a high mobility and keen sensing capabilities. The following approach was used to develop these systems. First, different innovative climbing robots are developed. They use magnetic adhesion, as most structures are made of ferromagnetic steel. Then, vision is embedded in some of the robots. Performing visual inspections becomes thus possible, as well as controlling the robots remotely, without viewing them. Finally, non-visual NDT sensors are developed and embedded in some of the robots, allowing them to detect defects that simple vision cannot detect. Achieving the miniaturization of the developed systems requires strong system integration during these three steps. A set of examples for the different steps has been designed, implemented and tested to illustrate this approach. The Tripillars robots, for instance, use caterpillars, and are able to climb on surfaces of any inclination and to pass inner angles. The Cy-mag3Ds robots use an innovative magnetic wheel concept, and are able to climb on surfaces of any inclination and to pass inner angles, outer angles and surface flips. The Tubulos robots move in tubes of 25 mm diameter at any inclination. All robots embed the required electronics, actuators, sensors and energy to be controlled remotely by the user. Wireless transmission of the commands signals allows the systems to maintain their full mobility without disturbing cables. Integrating Hall sensors near the magnetic systems allows them to measure the adhesion force. This information improves the security of the robots, since when the adhesion force becomes low, the robots can be stopped before they fall. The Tubulo II uses Magnetic Switchable Devices (MSDs) for adhesion. An MSD is composed of a ferromagnetic stator and one or more moving magnets; it has the advantage of requiring only a low force to switch on or off a high adhesion force. MSDs have the advantage of being easy to clean of the magnetic dust that is present in most real environments and that sticks strongly to magnetic systems. As an additional step toward inspection, a camera is embedded on the Cy-mag3D II and the Tubulos. It allows these robots to inspect visually the structures the robots move in, and to control them remotely. The perspective of a climbing robot in an unknown environment is often not enough to give the user a sense of its scale, and to move efficiently in it. A distance sensor is designed and embedded on the Cy-mag3D II, which increases the user's perception of the environment substantially; Finally, an innovative miniature Magnetic Particle Inspection (MPI) system was developed to inspect turbine blades without disassembling them. An MSD is used to perform the required magnetization. The system can automatically inspect a flat surface, performing all the required steps of MPI: magnetize, spray magnetic particles, record images under UV light and demagnetize. Thanks to the strong integration and miniaturization, the system can potentially inspect complex parts such as steam turbines.

In this paper, we describe a miniature climbing robot, 96 x 46 x 64 [mm3], able to climb ferromagnetic surfaces and to make inner plane to plane transition using only two degrees of freedom. Our robot, named TRIPILLAR, combines magnetic caterpillars and magnets to climb planar ferromagnetic surfaces. Two triangular tracks are mounted in a differential drive mode, which allows squid steering and on spot turning. Exploiting the particular geometry and magnetic properties of this arrangement, TRIPILLAR is able to transit between intersecting surfaces. The intersection angle ranges from -10° to 90° on the pitch angle of the coordinate system of the robot regardless of the orientation of gravity. A possible path is to move from ground to ceiling and back. This achievement opens new avenues for mobile robotics inspection of ferromagnetic industrial structure with stringent size restriction, like the one encountered in power plants.

Ce projet consiste au développement mécatronique d’un robot magnétique d’inspection devant être en mesure de naviguer dans un tube ferromagnétique de 25 [mm] de diamètre intérieur. Ce tube peut être recourbé selon un rayon de courbure de 150 [mm], peut être orienté dans tous les sens de l’espace et possède des cordons de soudure réduisant localement le diamètre à 21mm.