News › Fraun­ho­fer IOF · Mobile 3D scan­ner mea­su­res objects in the blink of an eye

GOSCOUT3D ENABLES FLEXIBLE THREE-DIMENSIONAL MEASUREMENT OF COMPLEX OBJECTS

Vir­tual 3D models of real objects, so-cal­led »digi­tal twins«, offer num­e­rous advan­ta­ges – be it for digi­tiza­tion or in the qua­lity con­trol of indus­trial manu­fac­tu­ring. But the more com­plex an object, the more dif­fi­cult it is to mea­sure its shape and con­vert it into a 3D model. Rese­ar­chers at the Fraun­ho­fer Insti­tute for Applied Optics and Pre­cis­ion Engi­nee­ring IOF, in col­la­bo­ra­tion with MTU Main­ten­ance, have now deve­lo­ped a por­ta­ble sen­sor that enables par­ti­cu­larly fle­xi­ble 3D cap­ture, for exam­ple of air­craft engi­nes. The hand­held scan­ner, cal­led goSCOUT3D, will be pre­sen­ted to the public for the first time at the OPIE’23 trade fairs in Yoko­hama from April 19 to 21 and at CONTROL in Stutt­gart from May 9 to 12.

Whe­ther on a vir­tual tour of a museum or digi­tally cap­tu­ring com­pon­ents and equip­ment in indus­try, detailed 3D models help trans­late objects and items from the real world into the digi­tal sphere. They enable a high level of detail, allo­wing even the smal­lest screws on tech­ni­cal equip­ment to be iden­ti­fied. MTU Main­ten­ance in Han­no­ver, Ger­many, the world’s lea­ding pro­vi­der of main­ten­ance ser­vices for air­craft engi­nes, also had this advan­tage in mind. For docu­men­ting the inco­ming and out­go­ing con­di­tion of engi­nes, MTU’s experts wan­ted an uncom­pli­ca­ted and user-fri­endly solu­tion for com­plete three-dimen­sio­nal digi­tiza­tion. Until now, the com­pany had been using clas­sic com­pact came­ras, which could only be used to take pho­tos of typi­cal (defect) loca­ti­ons and only incom­ple­tely cap­tu­red the engines.

Fully auto­ma­ted and mobile mea­su­re­ment of three-dimen­sio­nal objects

With these requi­re­ments in mind, MTU tur­ned to rese­ar­chers at the Fraun­ho­fer IOF, who deve­lo­ped a novel 3D scan­ner. In the future, this will enable fle­xi­ble, simple and time-saving three-dimen­sio­nal mea­su­re­ment of engi­nes. Con­ve­ni­ently ope­ra­ted by hand, goSCOUT3D can be gui­ded around the engine to be mea­su­red and auto­ma­ti­cally crea­tes a 3D model con­tai­ning high-reso­lu­tion shape, color and tex­ture infor­ma­tion. »goSCOUT3D enables a fully auto­ma­ted pro­cess during the mea­su­re­ment: from image acqui­si­tion to the gene­ra­tion of the com­plete color or tex­tu­red 3D model,« explains Dr. Ste­fan Heist of Fraun­ho­fer IOF. Tog­e­ther with his team, the rese­ar­cher has deve­lo­ped goSCOUT3D.

The goSCOUT3D looks a bit like an over­si­zed flash­light – because in addi­tion to a high-reso­lu­tion color camera as well as an iner­tial mea­su­re­ment unit and a dis­play with touch­screen, a ring light is the most visually striking fea­ture of the new sen­sor. This is used to illu­mi­nate the mea­su­re­ment scene to enable the short expo­sure times requi­red for hand­held ope­ra­tion. »This allows well over one thousand images to be cap­tu­red and pro­ces­sed. At a stan­dard mea­su­ring distance of one meter and an image field of about one square meter, we thus achieve an extra­or­di­na­rily high recor­ding speed of up to 6 m² of object sur­face per minute,« explains Marc Preiß­ler, co-deve­lo­per of goSCOUT3D. The inte­gra­ted 20-mega­pi­xel color camera enables a par­ti­cu­larly high spa­tial reso­lu­tion of less than 0.25 mil­li­me­ters. The weight of the sen­sor head is about 1.3 kg. Power is sup­plied by rech­ar­geable bat­te­ries, which enable unin­ter­rupted ope­ra­tion for seve­ral hours. This makes the hand-held scan­ner par­ti­cu­larly mobile and fle­xi­ble to use.

goSCOUT3D extends the prin­ci­ple of photogrammetry

But how exactly does goSCOUT3D gene­rate the desi­red 3D models? For this pur­pose, the sen­sor uses the prin­ci­ple of so-cal­led pho­to­gram­me­try. »In this mea­su­re­ment method, high-reso­lu­tion two-dimen­sio­nal color images are taken of the scene to be mea­su­red from many dif­fe­rent angles,« explains Ste­fan Heist. This means: by hand, the sen­sor is gui­ded once around the object. »Sub­se­quently, distinc­tive object points are iden­ti­fied in the photo sequence. If these appear in seve­ral images, we can use the prin­ci­ple of tri­an­gu­la­tion to cal­cu­late the asso­cia­ted 3D points and ulti­m­ately the 3D data of the entire scene.«

A par­ti­cu­lar chall­enge for the rese­ar­chers was the speedy pro­ces­sing of the 2D images. »For 3D acqui­si­tion, a large num­ber of high-reso­lu­tion sin­gle images in good image qua­lity are nee­ded. The cor­re­spon­ding pro­ces­sing of these indi­vi­dual images is typi­cally very time-con­sum­ing,« Ste­fan Heist explains the initial pro­blem. Howe­ver, the rese­ar­chers from Jena have suc­cee­ded in sup­ple­men­ting the prin­ci­ple of pho­to­gram­me­try with the posi­tion and ori­en­ta­tion data of an iner­tial mea­su­re­ment unit (IMU). These thus allow the coarse deter­mi­na­tion of sen­sor move­ment and ther­eby the sel­ec­tion of images with over­lap­ping image con­tent. »If you put this prior know­ledge into the pho­to­gram­me­tric eva­lua­tion, the com­pu­ting time can be redu­ced by more than half, espe­ci­ally for com­plex mea­su­re­ment objects,« Marc Preiß­ler sum­ma­ri­zes. In this way, a 3D model can be crea­ted in just a few minutes.

MTU is highly satis­fied with the new appli­ca­tion. »goSCOUT3D gives us a holi­stic and detailed view of our engi­nes in 3D and 2D, inclu­ding navi­ga­tion opti­ons,« says Dr. Frank Sei­del, head of Repair Deve­lo­p­ment at MTU Main­ten­ance. »The fle­xi­ble usa­bi­lity of the scan­ning sys­tem in the pro­duc­tion envi­ron­ment, the uni­form docu­men­ta­tion struc­ture when recor­ding the fin­dings data and its use in our qua­lity and ana­ly­sis tools will lead to a signi­fi­cant increase in efficiency.«

Fle­xi­ble 3D mea­su­re­ment sys­tem for digi­tiza­tion and documentation

But with goSCOUT3D, the rese­ar­chers have deve­lo­ped a sen­sor that offers appli­ca­tion poten­tial not only in the avia­tion indus­try, but far bey­ond. By visua­li­zing and ana­ly­zing object pro­per­ties, the scan­ner lends its­elf to use in medi­cine, rese­arch and sci­ence, or even to pro­vide data for aug­men­ted rea­lity appli­ca­ti­ons. »With goSCOUT3D, we are giving users – in the truest sense of the word – a fle­xi­ble 3D sen­sor sys­tem that offers new pos­si­bi­li­ties in the digi­tiza­tion and docu­men­ta­tion of objects,« sums up deve­lo­per Ste­fan Heist.

First pre­sen­ta­tion at trade fairs in Ger­many and Japan

goSCOUT3D will soon be pre­sen­ted to the public for the first time at two trade fairs: With OPIE’23, Japan invi­tes optics and pho­to­nics enthu­si­asts from all over the world to Yoko­hama from April 19 to 21. The Fraun­ho­fer IOF booth will be loca­ted in the Ger­man Pavi­lion, booth C‑32–9. Fur­ther­more, the hand­held scan­ner will be pre­sen­ted at CONTROL, an inter­na­tio­nal trade fair for tech­no­lo­gies for qua­lity assu­rance, from May 9 to 12 in Stutt­gart. Here, the Fraun­ho­fer IOF will exhi­bit at booth 6301 in hall 6.

This pro­ject was fun­ded by the Ger­man Fede­ral Minis­try of Edu­ca­tion and Rese­arch within the aero­nau­tics rese­arch pro­gram V‑3 of the Ger­man Fede­ral Minis­try of Eco­no­mics and Cli­mate under the fun­ding code 20X1723A.

Under the fol­lo­wing link you will find the press release as well as images:
https://s.fhg.de/goSCOUT3D-23