Magnetic Adhesion Mechanism Research Articles

Development of a wheeled wall‐climbing robot with an internal corner wall adaptive magnetic adhesion mechanism

AbstractThe wall‐climbing robot is a growing trend for robotized intelligent manufacturing of large and complex components in shipbuilding, petrochemical, and other industries, while several challenges remain to be solved, namely, low payload‐to‐weight ratio, poor surface adaptability, and ineffective traversal maneuverability, especially on noncontinuous surfaces with internal corners (non‐CSIC). This paper designs a high payload‐to‐weight ratio wheeled wall‐climbing robot which can travel non‐CSIC effectively with a payload capacity of up to 75 kg, and it can carry a maximum load of 141.5 kg on a vertical wall. By introducing a semi‐enclosed magnetic adhesion mechanism, the robot preserves a redundant magnetic adsorption ability despite the occurrence of significant gaps between localized body components and the wall surface. In addition, by ingeniously engineering a passive adaptive module into the robot, both the surface adaptability and crossability are enhanced without increasing the gap between the body and the wall, thereby ensuring the optimization of the adsorption force. Considering the payload capacity and diversity when climbing on vertical walls, inclined walls, ceilings, and internal corner transitions, control equations for internal corner transitions and comprehensive simulations of magnetic adsorption forces are performed using FEA tools. Finally, a functional prototype was developed for rigorous experimental testing, with the results confirming that the robot successfully meets the desired functionality and performance benchmarks.

Experimental investigations on permanent magnet based wheel mechanism for safe navigation of climbing robot

This paper presents excremental studies on permanent magnet based wheel mechanism for safe navigation of climbing robot on ferrous wall surface structures. Three types of wheel mechanism (Wheel 1, Wheel 2 and Wheel 3) are manufactured and compared for their working performance experimentally for climbing robot locomotion trials. The Wheel 1 mechanism with MS hub is very compact, simple in design with easy assemble/dissemble features, and having less manufacturing cost. However, the adhesion force of the prototype wheel is comparable with already reported permanent magnet based adhesion mechanism. Wheel 1 design is further improved by developing Wheel 2 and 3 versions by changing hub material from mild steel to Aluminum. These wheel mechanisms are light in weight and more powerful to achieve maximum adhesion force i.e., 210 N and 251 N with and without rubber grip, respectively, at only 200 gm wheel weight as compared to previously reported permanent magnetic adhesion mechanism. Thus, more payload carrying capacity climbing robot can be developed using these developed mechanisms for field trials of climbing robot. A comprehensive experimental study on the influence of rubber grip thickness, air gap, wheel tilt angle and test surface thickness variation on adhesion force of these developed wheel mechanisms have been reported. The influence of both static and kinetic coefficient of friction (COF) for vertical surface locomotion of climbing robot has also been investigated. These developed wheel mechanisms have been further demonstrated using a four-wheel differential drive prototype-climbing robot for safe navigation testing first on a 2-D framed plane wall structure and next on a 3-D framed wall structure. It is found from the laboratory trials that based on these wheel mechanisms, the climbing robot can safely navigate remotely on even surface for these chosen structures.

Experimental and Numerical Optimization of Magnetic Adhesion Force for Wall Climbing Robot Applications

Wall climbing robots require adhesion methods which are suited to the climbing surface material and roughness. In this paper, an optimum design of a magnetic adhesion mechanism has been developed for ferrous surfaces that maximises the magnetic adhesion force. This in turn maximises the payload that can be carried by the climbing robot. Experiments have been designed using the Response Surface Methodology (RSM) to study the effect of identified independent parameters (namely the distance between magnets, air gap and yoke thickness) that affect the response variable i.e. the magnetic adhesion force. A quadratic regression model has been developed to represent an empirical relationship between the response variable and the independent variables. Statistical analysis of the predicted model has been investigated using analysis of variance (ANOVA). To inspect the adequacy of the predicted quadratic model, validating experiments have been carried out at different conditions where the experimental results showed similar response values to the predicted model responses. Numerical optimisation has been applied to predict the optimum variable conditions for maximum adhesion force and air gap, resulting in an adhesion force of 240.3 N at 20 mm distance between magnets, 18.5 mm air gap and 8.3 mm yoke thickness. The optimum conditions have been numerically validated using a commercial finite element simulator. The numerically optimised design parameters have been used to design and construct a prototype wall climbing robot.

Finite Element Analysis based Optimization of Magnetic Adhesion Module for Concrete Wall Climbing Robot

Wall climbing robot can provide easier accessibility to tall structures for Non Destructive Testing (NDT) and improve working environments of human operators. However, existing adhesion mechanism for climbing robots such as vortex, electromagnet etc. are still at development stage and offer no feasible adhesion mechanism. As a result, few practical products have been developed for reinforced concrete surfaces, though wall-climbing robots have been researched for many years. This paper proposes a novel magnetic adhesion mechanism for wall-climbing robot for reinforced concrete surface. Mechanical design parameters such as distance between magnets, the yoke thickness, and magnet arrangements have been investigated by Finite Element Analysis (FEA). The adhesion module can be attached under the chassis of a prototype robot. The magnetic flux can penetrate maximum concrete cover of 30 mm and attain adhesion force of 121.26 N. The prototype provides high Force-to-Weight ratio compared to other reported permanent magnet based robotic systems. Both experiment and simulation results prove that the magnetic adhesion mechanism can generate efficient adhesion force for the climbing robot to operate on vertical reinforced concrete structures.

Analytical Optimization of a New Adjustable Magnetic Field Adhesion Mechanism

A novel adjustable magnetic field adhesion mechanism for use in wall-climbing robot is designed. The magnetic field in air gap can be switchable by rotating the center axis of adhesion mechanism so that the magnetic adhesion force is variable and it is conveniently for robot adhesion and detachment from the wall. The influence of structure parameters on adhesion performance and the optimal dimensions of mechanism are obtained by parameter variation method for best performing design. The novel optimal mechanism has been dimensioned and its magnetic force is measured. The results are compared to the simulation and it is shown that it is one of the best performing of magnet designs published for wall climbing robot adhesion mechanism.

Design and Optimal Research of a Non-Contact Adjustable Magnetic Adhesion Mechanism for a Wall-Climbing Welding Robot

Wall-climbing welding robots (WCWRs) can replace workers in manufacturing and maintaining large unstructured equipment, such as ships. The adhesion mechanism is the key component of WCWRs. As it is directly related to the robot's ability in relation to adsorbing, moving flexibly and obstacle-passing. In this paper, a novel non-contact adjustably magnetic adhesion mechanism is proposed. The magnet suckers are mounted under the robot's axils and the sucker and wall are in non-contact. In order to pass obstacles, the sucker and the wheel unit can be pulled up and pushed down by a lifting mechanism. The magnetic adhesion force can be adjusted by changing the height of the gap between the sucker and the wall by the lifting mechanism. In order to increase the adhesion force, the value of the sucker's magnetic energy density (MED) is maximized by optimizing the magnet sucker's structure parameters with a finite element method. Experiments prove that the magnetic adhesion mechanism has enough adhesion force and that the WCWR can complete wall-climbing work within a large unstructured environment.

Development of in-Pipe Robot with Controllable Magnetic Force

Pipes are everywhere; they are used in a variety of pipelines that should be inspected and maintained to ensure their safety and integrity. Currently, the in-pipe robot for such applications is considered as one of the most attractive solutions available. The most important thing, in-pipe robot must concerned adhesion mechanisms. Several adhesion mechanisms have been proposed and developed. We applied magnetic adhesion mechanism. Magnetic adhesion on in-pipe robots has some advantages such as fast locomotion, no additional energy for adhesion process, and one definite disadvantage like difficulty to control magnetic force. To solve this disadvantage, the permanent magnetic wheels that allow controllable magnetic force. This paper proposes a new in-pipe robot that applied controllable magnetic wheel. The idea is conceptualized, simulated, fabrication, and validated experimentally. The pulling force increases linearly form 8 newtons (N) to 26 newtons. It means that the proposed method is effective to control magnetic force between the wheel and interior surfaces of ferromagnetic pipes.

Permanent Magnetic System Design for the Wall-Climbing Robot

This paper presents the design and analysis of the permanent magnetic system for a wall-climbing robot with permanent magnetic tracks. Based on the behaviour of gecko lizards, the architecture of the robot was designed and built, including the structure of the adhesion mechanism, the mechanical architecture and the anti-toppling mechanism. The permanent magnetic adhesion mechanism and the tracked locomotion mechanism were employed in this kind of wall-climbing robot. Through static and dynamic force analysis of the robot under different situations, design requirements for the adhesion mechanism were derived. Two different types of structures were put forward for the permanent magnetic units and are further discussed in this paper. These two types of structures are also analysed in detail. In addition, a finite-element method was used to verify the results of magnetic units. Finally, two wall-climbing robots, equipped with different magnetic systems described previously, are explained and their applications are discussed in this paper.

Permanent Magnetic System Design for the Wall‐Climbing Robot

This paper presents the design and analysis of the permanent magnetic system for a wall‐climbing robot with permanent magnetic tracks. Based on the behaviour of gecko lizards, the architecture of the robot was designed and built, including the structure of the adhesion mechanism, the mechanical architecture and the anti‐toppling mechanism. The permanent magnetic adhesion mechanism and the tracked locomotion mechanism were employed in this kind of wall‐climbing robot. Through static and dynamic force analysis of the robot under different situations, design requirements for the adhesion mechanism were derived. Two different types of structures were put forward for the permanent magnetic units and are further discussed in this paper. These two types of structures are also analysed in detail. In addition, a finite‐element method was used to verify the results of magnetic units. Finally, two wall‐climbing robots, equipped with different magnetic systems described previously, are explained and their applications are discussed in this paper.