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Modelling and Realization of Pneumatics based Wall Climbing Robot for Inspection Applications

2016; Engg Journals Publications; Volume: 8; Issue: 5 Linguagem: Inglês

10.21817/ijet/2016/v8i5/160805418

2319-8613

G. Muthukumaran, Uppu Ramachandraiah,

Robotics and Sensor-Based Localization

Climbing robots are highly in need for catering the inspection of the high rise buildings.Climbing Robots has to work in challenging environments and has to maneuver vertically against gravity and orient towards the specified target by adapting to various surfaces.The proposed Wall Climbing Robot weighs 1 Kg , works with four active suction cups and driven with pneumatic supply cylinder drive assembly.The robot moves by absolute holding of two suction cups at any instance and remaining two cups are allowed free to enable forward movement of the robot.The robot consists of vacuum generator, suction cup, pneumatic driven traverse assembly, controller and wireless high resolution camera.The designed robot is highly suitable for the continuous monitoring and inspection of high rise buildings.The vacuum generator is externally positioned and suction is derived through pneumatic supply hose.The developed robot climbs on the vertical wall at a velocity of 1.5 cm/s.Keyword -Wall climbing robot, suction cup, smooth surface, pneumatic operation, programmable logic controller I. INTRODUCTIONThe design of a wall climbing robot (WCR) requires appropriate/good adhesion mechanism so that the robot latches on to the wall without compromising with mobility.In this context many climbing robot designs are attempted by researchers by using suction cups.The required negative pressure to hold the robot is derived through either external vacuum generators or on board vacuum pumps.To check the defects in concrete walls, SaekoTokuomi et.al.developedsuction cup based climbing robots.Two major problems faced are inadequate ring-seal decompression in suction cups and suction cup slippage [1].To increase the reliability of the holding of the robot is attempted with multiple cups by providing multi-legged wall-climbing robot which latches to a wall with negative pressure adsorption [2].Wall climbing robots for inspecting industry pipe network is developed with bio-mechanical suction cups actuated by shape memory alloy (SMA) actuators [3].These robots can move either straight or can turn with a fixed angle on an inclined glass wall.Wall-climbing robots employing single suction cup are used in ultrasonic inspection of steel storage tanks and cleaning high-rise buildings.The robots have three major parts.A vacuum pump, a sealing mechanism and a driving mechanism [4].The researchers developed adaptive trajectory tracking approach for WCR.The major challenge faced is to ensure complete contact of the drive wheels with the wall surface which affects robot movement.[5].The adhering capability is one of the most important performance indices of WCRs.Another approach to achieve this is the sliding suction cup (SSCs) using fluid network theory [6].H. Zhang et.al.developedSky cleaner 3, which is used for wall cleaning, maintenance of high-rise buildings and glass-wall cleaning [7].Critical suction, based on the negative suction and thrust force is analyzed for understanding the smart movement of the wall climbing robot reliably on the wall [8].A miniature smart robotic foot, consisting of integrated vacuum pump, suction cup, pressure sensor, micro-valve, micro-controller, a video micro-camera, wireless interface and thin film battery was designed, fabricated and tested [9].Tohru Miyake et.al.attempteda vacuum-based wet adhesion system for WCRs with adherability and low friction performance when a suction cup clings on rough surface (say, concrete wall) [10].T. C. Apostolescuet.al.used electro-pneumatic vacuum cups to address several factors which effect the robot in holding, moving on horizontal and vertical surfaces [11].Z. Wang et.al presented Walkman-I (a new kind of flexible pneumatic wall-climbing robot) composed of a flexible pneumatic actuator, a flexible pneumatic spherical joint and six suction cups [12].The alternative techniques by using low-frequency vibrating passive attachment principle to hold the robot is also suggested [13].J. Zhu et.al.developed a service climbing robot (with visual sensing mechanism) so as to clean the glass wall of high-rise buildings [14].Though few climbing robots are realized with on board vacuum generator and dc motor driven drive assembly, the robot cannot be continuously operated due to high power requirements and limitations in payload capacity.This proposed robot is developed for vertical wall climbing applications, highly suitable for continuous monitoring and inspection.Hence vacuum is generated using an external Vacuum generator and robot movement is effected through pneumatic drive assembly.