Design and parametric investigations of permanent magnet adhesion mechanism for robots climbing on reinforced concrete walls

Wall Climbing Robots (WCRs) have found extensive applications in the past decade in numerous engineering fields, however, the design of efficient adhesion mechanism for robots climbing on concrete surfaces remains a challenge and attracts research attention. This paper proposes various designs of magnetic adhesion mechanism for concrete surfaces and investigates the adhesion force and payload capacities each design would accommodate for wall climbing robot applications. Permanent magnet is used as the magnetic adhesion mechanism and a yoke structure helps in holding the magnets and influences the adhesion characteristics of the mechanism. The effect of various structural designs of adhesion mechanisms on the adhesion force and payload capacity on the concrete surface is studied in this work. The adhesion forces against the different standoff distances which comprise the gap between the magnet and the concrete surface are also investigated therein. The results show that the developed adhesion mechanism can be applied for concrete walls generating the required adhesion forces and providing a better insight in choosing the best configuration, number of magnets and standoff distances for the design of adhesion mechanism against the required payload of WCR

Safeguarding Safety Critical Infrastructure with Mobile Robot Inspectors , Opportunities and Challenges

Safeguarding Critical Infrastructure with Robotic Inspection, Opportunities and Challenges Reliable Non Destructive Testing (NDT) is vital to the integrity, performance management and sustainability of capital assets in safety critical industries such as oil and gas, aerospace, transportation, power generation and off-shore and subsea operations. The talk will explore opportunities to improve the NDT of industrial structures and decrease the cost of inspection by automating the NDT with mobile robots. The challenges of developing mobile wall climbing and submersible robots will be presented that can provide access to test sites on very large vertical structures or structures located in hazardous environments thereby eliminating the large expense of erecting scaffolding or lengthy preparation for rope and platform access before inspection can start. Some of these developments provide the possibility of saving costs by reducing outage times or carrying out the NDT in-service thus preventing expensive outages. The presentation will show climbing and swimming robots developed to detect weld and corrosion defects on ship hulls, floating platforms, mooring chains, petrochemical storage tanks, pressure vessels, concrete structures, wind blades and aircraft wings and fuselage

Robotics for Inspection and Decommissioning of Nuclear Power Plant

Describes robots developed by the London South Bank Innovation Centre to: 1.Inspect Pressure Vessel shell and nozzle welds 2.Inspect nozzle welds in the primary circuit of nuclear power plant 3.Inspect radiation cells, stacks, buildings 4.Cut steel objects for nuclear decommissionin

Chapter 3.4: Wall Climbing Crawlers for Nondestructive Testing

There is a strong international trend that uses robots as a strategic technology for automated inspection and maintenance work in hazardous environments such as in chemical plants and the nuclear power industry [Fukuda, 1990, Roman, 1993, Takehara, 1989]. The main plant components that benefit from automated inspection are long pipelines and the walls of storage or buffer tanks that are inspected either from the outside or the inside. Large benefits in performance and cost savings are possible. For example, an electric utility has reported a saving of five million dollars within eight years on two plants with a capital spend on robotic hardware of two million dollars [Proc. Int. Conf. on Intelligent Robots and Systems, 1993]

Non-destructive testing and condition monitoring with mobile wall climbing and swimming robots

Reliable Non Destructive Testing (NDT) is vital to the integrity, performance management and sustainability of capital assets in safety critical industries such as oil and gas, aerospace, transportation, power generation and off-shore and subsea operations. The talk will explore opportunities to improve the NDT of industrial structures and decrease the cost of inspection by automating the NDT with mobile robots. The challenges of developing mobile wall climbing and submersible robots will be presented that can provide access to test sites on very large vertical structures or structures located in hazardous environments thereby eliminating the large expense of erecting scaffolding or lengthy preparation for rope and platform access before inspection can start. Some of these developments provide the possibility of saving costs by reducing outage times or carrying out the NDT in-service thus preventing expensive outages. The presentation will show climbing and swimming robots developed to detect weld and corrosion defects on ship hulls, floating platforms, mooring chains, petrochemical storage tanks, pressure vessels, concrete structures, wind blades and aircraft wings and fuselage

Climbing ring robot for inspection of offshore wind turbines

A rapid expansion of wind turbine farms for sustainable electric power production is planned in Europe by 2020. At least in the UK, these will largely be located offshore to meet growing concerns about the visual intrusiveness and noise generation producedby onshore based farms. The necessary structural integrity inspection of offshore wind turbine blades poses tremendous problems of access, danger to human operatives and costs in the event of blades having to be taken out of service and transported on shore forschedules inspections. For these reasons robotic in-situ blade inspection of offshore wind turbines has been proposed and micro/nano focus computed axial X ray tomography (MNCAT) has been identified as the optimal if not the only solution for identification of safety critical defects in the thickest blade sections. The weight of such an inspection system is very high, typically 200kg and typical cross sectional scanner dimensions of 1 m × 2 m to encircle as blade, clearly involve very high destabilizing moments to be countered by the deployment robot. The solution is a climbing ring robot completely encircling a turbine tower, typically 3 meter in diameter, to provide the necessary adhesion forces and anti-destabilizing force moments. Because of the size and thus development costs of such a huge robot the optimal design path is to prototype a small scale model. First results on such a model are described and from its performance the load carrying capabilities of a full scale version can be computed and the scale model can then berefined by 'reverse engineering' to guarantee that a full scale construction is able tomeet requirements. The key design innovation is that the adhesive forces between the robot and climbing surface a provided entirely by mechanical means rather than by usingthe usual methods of vacuum suction or magnetic force, making the system much cheaper andeasier to manipulate. Furthermore the design is entirely modular. Copyright © 2008 by World Scientific Publishing Co. Pte. Ltd

Amphibious NDT Robots

Oil, petrochemical, and food processing industries worldwide store their raw materials and product in tens of thousands of storage tanks. The tanks are mostly constructed using welded steel plates and therefore subject to corrosion and weld cracking. Testing the structural integrity of these storage tanks with non-destructive testing (NDT) techniques is an expensive and time consuming activity. The walls of a large tank can usually be tested manually (for corrosion thinning and weld defects using ultrasonic techniques) from outside the tank. Access to most areas of a wall is obtained by constructing scaffolding or abseiling down from the top. However, erecting scaffolding is expensive and the inspection is tedious and slow. These costs can be reduced and the inspection speeded up by using climbing robots that deploy ultrasonic probes with scanning arms

Total Integrated Robotic Structural Inspection for Enhanced Aircraft Life and Safety

Aircraft life can be extended, safety standards and passenger confidence enhanced, and structural inspection costs dramatically reduced, by establishing at major airports specialised ‘Total Inspection Centres’ that would be open 24 hours a day. Aircraft would be flown to these centres. Here every relevant type of Non Destructive Testing (NDT) sensor would be deployed by multi-axis robots moving on Cartesian gantries to cover the wing, fuselage, tail and rudder. Each inspection would produce a defect map of 100% of the aircraft surface. This is very unreliable if done manually because of operator fatigue. A gantry robotic system has the advantage that very heavy NDT sensors such as X-ray tubes and SQUID magnetometers can be deployed in addition to all the more common sensors such as ultrasonic and Eddy current probe arrays. Acoustic emission monitoring of an entire airframe can be achieved with robotic scanning without the need for a vast and expensive array of sensors. This would be most useful for fuselage pressure testing. At present NDT of aircraft is carried out in many relatively small units attached to individual airports that cannot possibly afford the whole range of NDT equipment and robotic deployment facilities. A specialised centre can do so and in addition achieve complete data fusion of the results from different sensors

Robotic system for inspection of test objects with unknown geometry using NDT methods

The aim of this work is to develop a portable Non-Destructive Testing (NDT) robotic system that can be carried by CLA WAR to evaluate defects in geometrically complex surfaces and industrial products. In this paper, the difference in quality of defect dataduring manual inspection and automated inspection will be compared. Tests have been performed amongst others on complex shaped turbine blades using eddy currents. The challenge is to be able to follow the surface by keeping the NDT probe normal to the surface while maintaining a constant contact force with it. The approach to maintaining a constant contact force and angle to the object was to use a secure contact using permanent magnets and a force adapting control of the manipulator which resulted in improvements inthe quality of inspection compared to manual inspection. Furthermore, a novel application of the position-force-moment (PFM) control was developed. Here, the robotic arm scans unknown contoured surfaces by keeping the sensor probe normal to the test surface, maintaining at the same time constant contact force, thereby ensuring good data acquisition. Copyright © 2008 by World Scientific Publishing Co. Pte. Ltd