Ncmmi2014007

Proceedings of The National Conference on Man Machine Interaction 2014 [NCMMI 2014]

Remotely Piloted Unmanned Underwater Vehicle Design and Control for Pipeline Maintenance R. Vasantharaj, Vaidehi Paravastu, M. Shobana, S. Loganayaki

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Assistant Professor, ECE, Vel Tech Dr.RR Dr.SR University, Tamilnadu, India B.E, ECE, Vel Tech High Tech Dr.RR Dr.SR Engineering College, Tamilnadu, India B.E, ECE, Vel Tech High Tech Dr.RR Dr.SR Engineering College, Tamilnadu, India, B.E, ECE, Vel Tech High Tech Dr.RR Dr.SR Engineering College, Tamilnadu, India,

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AbstractÇŚ In this paper we have described the design and implementation of a remotely operated vehicle (ROV) for maintenance of petroleum pipelines. The petroleum sensor embedded in to the underwater vehicle is used to detect the concentration of petroleum dissolved in water at desired location. The vehicle is designed to move along the nearby surface of the pipeline and continuously sense any leakages present.

The real time video is transmitted to the ground station via a Radio Frequency (RF) channel along with the location of the leakage, if any. The location of the vehicle is monitored using Global Positioning System (GPS) and an Inertial Measurement Unit (IMU).

I. Introduction

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The objective of our research is to build an unmanned underwater vehicle to inspect petroleum pipelines placed under the sea. We have specifically focused on leakage of petroleum from the pipelines so we are using array of sensor to perform the task. The oil spill from pipelines at the sea bed can affect the entire aquatic ecosystem and cause the death of aquatic animals and plant life. The contamination of water due to such oils can be cleaned up to an extent but the effect will continue to remain at the microscopic level for several years. This can cause a lot of mutations in growth of the living organisms for several generations. So the impact of an oil spill is clearly very devastating on a large scale. This makes the maintenance and upkeep of the pipelines all the more significant. We were thus motivated to develop a remotely operated vehicle which will move along the pipeline and detect any leakages by simply using the sensor embedded into the system. In many of the existing pipelines sensors are placed at regular intervals along the pipeline to collect data and reticulate it to the surface. Now this requires constant monitoring of the network and will give an idea of the current pipeline condition. However, the leakage may happen at any point along the pipeline length. This requires a more efficient monitoring of the entire pipeline. The performance and life span of the sensor may get affected by continuous exposure to the sea water. The ROV will be useful in this regard to monitor the whole pipeline and detect leakage at any arbitrary point.

II. Overview

The overall block diagram is shown in Figure1.The ROV consists of the following sensors: petroleum sensor, ultrasonic sensor and accelerometer. Also a GPS and IMU are used to monitor the vehicle location. The vehicle is submerged until the depth of the pipeline and then the petroleum sensor is activated. The readings from the ultrasonic sensor as well as the camera feed are used to maintain the vehicle in close proximity to the pipeline. Whenever a leakage is detected by the petroleum sensor the current location of the vehicle is transmitted to the ground station. Initially the depth of the pipeline is obtained from the user.

NCMMI '14

ISBN : 978-81-925233-4-8

www.edlib.asdf.res.in

41

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Proceedings of The National Conference on Man Machine Interaction 2014 [NCMMI 2014]

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Figure 1Corre Devices of f ROV System m

III. Vehicle D Design

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The basic design of th he ROV as g given in Figurre 2 was mod delled in CAT TIA software to test the b buoyancy of the vehiccle. The given n frame desig gn functions a as the water compartmen nt of the vehiccle. Holes aree drilled on all corners to allow th he water to flo ow out. Two floats are atttached to the frame to maintain the vehicle above the wateer. Three geaared motors mounted wiith 3 blade b boat propelleers are used to control tthe vehicle dynamics and directio on. To submeerge the vehiicle in water t the geared m motors are sw witched on. Th he depth to which th he vehicle sin nks depends u upon the speeed at which the motors a are running. One motor i is placed in the upwaard direction n in the front of the vehiclle. This frontt motor proviides the maxiimum thrust. The other two moto ors are placed d on either siide. They aree used to conttrol the vehiccle direction.. The load is a attached to the botto om of the veh hicle. This is a an airtight co ontainer conssisting of the electronic co omponents.

Figure 2 2 Vehicle Frame (a) all vieews (b) isomeetric views

IV V. Vehicle Control an nd Automattion An AtmeegaÇŚ328 16ÇŚbitt processor iss programmeed and used a as an embedd ded controller for all the s sensors and the actu uators. Ultrassonic sensor helps to maintain m the proximity between pipeeline and veh hicle using distance measuremen nt algorithm m. The calibraated output of ultrasonicc sensor is shown s in Fig gure 3. An ultrasoun nd signal iss sent and rreflections from f the ob bstacle are rreceived. The time delaay between

NCMMI '14

ISBN : 978-81-925233-4-8

www.edlib.asdf.res.in

Proceedings of The National Conference on Man Machine Interaction 2014 [NCMMI 2014]

42

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transmisssion and reception is useed to calculatte the distancce of the obsstacle. The prrocessor is prrogrammed to specify fy the time peeriod of the s signal to be t transmitted. A Any obstaclee in the path is avoided byy using the sensor reeading to chaange the direection of rotaation of the m motors. The procedure fo or obstacle avvoidance is shown in n Figure 4.

Setup() { pinM Mode( trigPin n, OUTPUT) pinM Mode(echoPiin, OUTPUT)) } Loop() { trigPin(L LOW, 2) trigPin(H HIGH, 10) trigPin(L LOW) duration n = pulseIn(ecchoPin) distanceIInCm = (340 * duration) / / 20000 }

Figure 3 Ulttrasonic Senssor Calibratio on

Setup() { pinM Mode( trigPin n, OUTPUT) pinM Mode(echoPiin, OUTPUT)) } Loop() { trigPin(L LOW, 2) trigPin(H HIGH, 10) trigPin(L LOW) duration n = pulseIn(ecchoPin) distanceIInCm = (340 * duration) / / 20000 if (distan nceInCm = = 1 10) obstacle detected } ure Figure 4 Obsstacle Avoidaance Procedu

U reading is u used to obtaiin the depth and the distance travelleed by the veh hicle. The GP PS and IMU The IMU are interfaced to proccessor board.. The IMU co onsists of an a accelerometeer, program s shown in figu ure5, with 3 degrees o of freedom aand it gives th he instantaneeous value of acceleration n along each h axis. This iss integrated twice to find the disstance travellled. The disttance value is cumulativeely added to find the tottal distance travelled d. When GPS signal is not available theen the distancce travelled b by the vehiclee on X axis caan be added to the lasst known coÇŚÇŚordinate to f find the current position. The distancee travelled in n the Y axis is s the depth gives thee current deptth to which t the vehicle is submerged.

NCMMI '14

ISBN : 978-81-925233-4-8

www.edlib.asdf.res.in

Setup() { } Loop() { analog gRead(xaxis) analog gRead(yaxis) analog gRead(zaxis) }

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Proceedings of The National Conference on Man Machine Interaction 2014 [NCMMI 2014]

F Figure 3 Acce lerometer Offfset Calculattion

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The petrroleum sensor is given pow wer supply o only after thee vehicle reacches the pipelline depth. T This is done ning the dep by obtain pth reading from the acccelerometer and compariing it to thee actual pipeline depth.

When th he petroleum m sensor dettects leakage,, the microccontroller traansmits the current c locattion of the vehicle b back to the grround station n.

The movvement of th he vehicle is achieved usiing three geaared motors attached to the vehicle frame. The geared m motors are intterfaced to th he microconttroller using a L293D mottor driver IC. This IC conssists of two HǦBridgee circuits wh hich can conttrol the direction of mottor rotation. The signal ffor motor movement is given fro om the ground station via the wireless channel.

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A wirelesss camera is mounted on n the vehicle. This is used d to transmit the real tim me video to tthe ground station over o a 2.45GH Hz RF chann nel. The video can be useed for obstaccle avoidancee as well as vviewing the pipeline condition. Based B on the image of thee pipeline, th he dimension ns of the leak kage can be f found. This can be ussed to determ mine the meth hod of repairr. Noise reducction filters a are used to remove any blu ur.

The circu uit consisting g of the progrramming boaard, sensors a and actuatorss are all placeed in airtight containers.

Then water proofing o of the contain ners is done f finally.

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Reference es

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JJingwen Tian n, Meijuan G Gao and Haao Zhou, “Corrosion Detection Systeem for Subm marine Oil T Transportatio on Pipeliness based on MultiǦSenso or Data Fusiion by Supp port Vector Machine”, P Proceedings o of the 6th Wo orld Congresss on Intelligen nt Control an nd Automatio on, June 21Ǧ233, 2006.

J Jingwen Tian n, Meijuan G Gao and Jin Li, L “Corrosio on Detection System for Oil Pipeliness based on M MultiǦSensor r Data Fusion n by Improved d Simulated A Annealing Neeural Networrk”.

J Jingwen Tian n, Meijuan Gao, Hao Zho ou and Kai Lii, “Corrosion n Detection S System for Oil Pipelines b based on Mu ultiǦSensor Daata Fusion byy Wavelet Neural Network k”, 2007 IEEE E Conference on Control a and Automat tion.

W Wallace M. Bessa, Max S. Dutra an nd Edwin Krreuzer, “Dep pth Control of Remotelyy Operated U Underwater V Vehicles usin ng an Adaptivve Fuzzy Slidiing Mode Co ontroller”, Rob botics and Au utonomous S Systems, 200 8.

N Nuno Graciaas and Jose S SantosǦVictorr, “Underwatter Video Mosaics as Vissual Navigation Maps”, C Computer Vi ision and Imaage Understan nding, 2008.

NCMMI '14

ISBN : 978-81-925233-4-8

www.edlib.asdf.res.in