Soft-Tentacle Gripper for Pipe Crawling to Inspect Industrial Facilities Using UAVs

This paper presents a crawling mechanism using a soft-tentacle gripper integrated into an unmanned aerial vehicle for pipe inspection in industrial environments. The objective was to allow the aerial robot to perch and crawl along the pipe, minimizing the energy consumption, and allowing to perform contact inspection. This paper introduces the design of the soft limbs of the gripper and also the internal mechanism that allows movement along pipes. Several tests have been carried out to ensure the grasping capability on the pipe and the performance and reliability of the developed system. This paper shows the complete development of the system using additive manufacturing techniques and includes the results of experiments performed in realistic environments.Unión Europea SI-1762/23/201

Conceção, produção e validação experimental de um dispositivo trepador para inspeção não destrutiva de cabos

Os robôs trepadores têm sido alvo de desenvolvimento nos últimos anos devido às várias vantagens que apresentam. Estes permitem aumentar a eficiência de várias operações, reduzir os custos das mesmas e ainda salvaguardar os operadores de locais potencialmente perigosos. Estes podem ser caracterizados pelo seu método de movimentação e pela técnica de fixação. O objetivo deste trabalho consistiu em conceber, produzir e testar um robô trepador para ser utilizado como uma ferramenta de inspeção para cabos e tubos, com recurso a correntes induzidas (CI), em locais altos e de difícil acesso. O dispositivo foi concebido com recurso à manufatura aditiva. Este encontra-se dividido em 3 partes e engloba todo o perímetro da superfície. Para a inspeção de defeitos, acoplou-se ao dispositivo uma sonda de correntes induzidas, produzido em PCB flexível. Para validar o desempenho do dispositivo, foi utilizado um varão de latão com 25 mm de diâmetro, onde foram realizados 3 defeitos artificiais para serem detetados pela sonda. O dispositivo, com uma massa aproximada de 1,5 kg, conseguiu trepar o varão de forma fiável com velocidades até 4100 mm/min. Com diferentes velocidades, a sonda foi também capaz de detetar os diferentes defeitos impostos sobre o varão.Climbing robots have been a development subject in recent years due to the several advantages they present. These allow the efficiency increase of various works, lower operations costs and even safeguard workers from potentially dangerous scenarios. These can be characterized by their locomotion method and by their attachment technique. The goal of this work was to develop a climbing robot to be used as an inspection tool for cables and pipes, using eddy currents (EC), at great heights and difficult to access spots. The device was designed using additive manufacturing. The device is divided in 3 parts and involves the entire surface perimeter. For the defect inspection, an eddy currents probe, produced with flexible PCB, was coupled to the device. To validate the device performance, a 25 mm diameter brass rod was used, where 3 artificial defects were made to be detected by the probe. The device, with an approximate mass of 1,5 kg, was able to reliably climb the rod up to speeds of 4100 mm/min. With different frequencies, the probe was also able to detect the different defects imposed on the rod

A Compact and Compliant External Pipe-Crawling Robot

The focus of this paper is on the practical aspects of design, prototyping, and testing of a compact, compliant external pipe-crawling robot that can inspect a closely spaced bundle of pipes in hazardous environments and areas that are inaccessible to humans. The robot consists of two radially deployable compliant ring actuators that are attached to each other along the longitudinal axis of the pipe by a bidirectional linear actuator. The robot imitates the motion of an inchworm. The novel aspect of the compliant ring actuator is a spring-steel compliant mechanism that converts circumferential motion to radial motion of its multiple gripping pads. Circumferential motion to ring actuators is provided by two shape memory alloy (SMA) wires that are guided by insulating rollers. The design of the compliant mechanism is derived from a radially deployable mechanism. A unique feature of the design is that the compliant mechanism provides the necessary kinematic function within the limited annular space around the pipe and serves as the bias spring for the SMA wires. The robot has a control circuit that sequentially activates the SMA wires and the linear actuator; it also controls the crawling speed. The robot has been fabricated, tested, and automated. Its crawling speed is about 45 mm/min, and the weight is about 150 g. It fits within an annular space of a radial span of 15 mm to crawl on a pipe of 60-mm outer diameter