牙1絲氏4

1 (課程博士(英文))Date of submission (month day, year)

July loth 2020

DepaHmentof

Computer science

SuldenuDNumber

D179303and Englneering
PP11Cant、s name

Ren ohmura
Supervisors

JunMiura

Michail sidの,OVAb毓Nd (Dodo"
Title ofThesis

TenS引〕se ‑A Family ofxvireless sensor Nodes Dedicated for Remote una杜ended structul'al
Health Monit01'ing ofBolted Joints

Approx.80o words

The advancementsin techn010gy, manufacturing and communication disciplines have created
new researcl〕 opportunities in majoT sdentiac fields.1nteraction between the aelds stal'ted toblur the lines between them giving bh'tl〕 to new aTeaS 飢Ich as lnta'net of TI)ings (10T).10T
Spans multゆle disciplines induding but not limited to Electronics Engineering, computer
Science, Mechanical Engineerin旦, civil Engineering, etc.1t is a multidisdplinal'y field thatdrives the development and integration of sma此 Connected things into eva'y sector of ourⅡVing and wm'king environlnents.10T applications vary 今reatly in nature,}〕owevel', themajoTity of theln are targeted at some sort of automation, contr01 0r sensing enal)1ed bySmart things. A group of those things ale categotized as sn〕art sensors which are used forSn〕a王t lnetering, agricultlu'e, asset tracking, etc. An area wha'e loT can lnake a huge in〕pact
is structural Health NlonitoTing (SHND. cun'ently tl〕e malntenance ofthe stluctures is done
On an ad hoc oT scheduled basis. However, by leveragln今 t})e sensoT data being constantlygatl〕ered and assessed, this process can be made more dynamic and enable to recognize theStruct11ral fault before it develops, PTopagates and Tesults in irreveTsible damage. ThisParticulaT research, tha'efore, concentrates on the application of pledictive or pTe・emptiven〕aintenance of large stainless lnaterial constructions, e.g. brid冨es, windmⅡIS, etc. current
approaches towaTds sHNl are analyzed, and a reseaTch gap is identified, T0 丘11this gap, a paiT
Of spedaⅡZed smart sensor nodes codenamed Tensense are designed and evaluated for thePurpose of monitoring tl〕e pre・tension load of l)olted joint connections in these stainlessStructures. Both nodes have diffeTent shapes, and provide different mountin冨 approaches,
resulting in a degree of aexibility for eveTy use case. TI〕e main functionality, however,remains the salne. Both nodes feature Long Range (LORa) wireless con〕munication for datatransmission and employ the same sensing approach. FUⅡ node designs are provided, andeveTy aspect behind the approac}〕 and decisions are justified by rese飢'CI〕, comparison, andSimulations undataken. Design indudes a Nlechanical stage, wheTein a custoln shapeTensense node is cl'eated, and Electronics stage, wherein a schematiCつ Printed circuit Board(PCB) 1ayouts, and embedded firn)ware are created. These two colnponents al、e then fused
t08etherto create Tensense. TI〕e resultant design isthoroughly evaluated employing physicalmeans, public blockchain is utiHzed for secure, decentralized, and transparent data storage
that enables smart C北y services to access and use the sHNl data for its puTposes. LORa
Colnmunication protocolimprovementls proposed, and 丘naⅡy Tensense nodes are con〕paredto the state・of・the・Art solutions further solidifying the novelty ofthe approach. Results sl〕OW
that Tensense is able to precisely track the bolts preload, with a maximum deviatlon of 2%

from the reference, and the design is safe under the maximum preload. communication
distance was measured to be 3.8 km fron〕 the base station and the node is estimated to last
Over 5 years