Sensors in modular robotics for pipeline inspection : design and test of erekobot- σ module

Pipelines still are the most efficient, safe, ecological and economical environmental to transport crude oil over long distances. However, the transported oil and the environment in which the pipeline is located may corrode the metal to the point of failure, affecting not only production but also the environment. In addition, activities such as inspection and maintenance are more complex due to difficult access – exposure to toxins, a wide variety of terrains and the special cloths are just some of the challenges. Therefore, pipelines require processes recurrent and autonomous, which motivates the development of new technologies: the machinery of inspection should be cheap, robust and versatile for maintenance, cleaning, removal of fluids, product separation and inspection. The reconfigurable modular robots are autonomous machines with variable morphology and, with the reorganization of the connectivity of parts (called modules), this architecture offers a greater degree of flexibility and fault tolerance at a lower cost. Because of its low cost, robustness and versatility reconfigurable modular robots can perform inspection tasks and reduce production costs in the Oil and Oil Industry. The objective of this work is to design, build and test a module of a reconfigurable modular robot with sensors for inspection in pipelines, called ErekoBot. Each module must have the ability to estimate its own pose, detect an obstacle and align yourself with a plan (simulating a pipe). In this work, the most suitable sensors for ErekoBot were chosen: four infrared sensors and an inertial measurement unit. After the definition of the sensors, the complete module was designed and its prototype was built, considering shape, size, weight, electronic circuit, position of components and material. Tests with the prototype has shown that the module is capable of (1) to estimate its own orientation, (2) detecting the presence of obstacles and (3) align with a plane. These abilities are sufficient to allow a situation where the robot must move moved through a pipeline, avoid obstacles and stop at a specific position to perform an inspection inside the tube.