?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.relation=http%3A%2F%2Fmiis.maths.ox.ac.uk%2Fmiis%2F731%2F&rft.title=Inertial+motion+estimation+for+extreme+sports+modelling&rft.creator=Black%2C+Jonathan&rft.creator=Christmas%2C+Jacqueline&rft.creator=Krastanov%2C+M.&rft.creator=Nowotarski%2C+J.&rft.creator=Sieber%2C+Jan&rft.creator=Sieber%2C+Robert&rft.creator=Tomczyk%2C+Jakub&rft.creator=Webborn%2C+Ellen&rft.subject=Information+and+communication+technology&rft.description=Performance+analysis+for+extreme+sports+athletes+goes+beyond+lap+times+and+heart+rates+to+include+details+of+their+motion+across+challenging+terrain.+Vert+Systems+is+currently+developing+technology+to+allow+the+visualisation+of+this+motion%2C+where+the+core+of+the+system+is+an+inertial+navigation+algorithm+which+needs+to+generate+not+just+a+position+estimate+but+also+an+estimate+of+the+velocity+and+acceleration+of+the+user.+The+key+requirement+is+to+track+the+local+features+of+the+motion%2C+with+absolute+position+accuracy+potentially+less+of+an+issue.+The+specific+problem+for+the+Study+Group+2013+is+based+on+a+mountain+biking+example%2C+which+provides+a+representative+example+of+both+the+highly+dynamic+movement+and+also+the+levels+of+noise+inherent+in+the+motion+over+rough+terrain.%0D%0A%0D%0ASensors+record+three-axis+accelerometer%2C+gyroscope+and+magnetometer+data+at+high+frequency+(100+Hz)+and+GPS+data+(position+in+three-dimensional+space)+at+low+frequency+(~+1+Hz).+The+goal+is+to+combine+these+measurements+into+a+trajectory+of+the+point+holding+the+sensors.+The+trajectory%2C+consisting+of+the+time+profiles+for+position%2C+orientation%2C+velocity+and+acceleration%2C+has+to+be+suitable+for+performance+analysis+and+animation+(so+needs+higher+time+resolution+and+accuracy+than+the+GPS+data).+Computations+are+performed+in+a+post-processing+step%2C+not+in+real-time.%0D%0A%0D%0ATwo+algorithms+to+incorporate+the+GPS+data+are+proposed.+The+first+is+a+simple+generalization+of+the+prior+solution+provided+by+the+problem+presenter.+It+always+produces+a+result+quickly+and+avoids+drift.+However%2C+it+relies+on+heuristically+tuned+%22gains%22.+The+head+orientation+is+not+guaranteed+to+be+correct%2C+which+is+likely+to+have+knock-on+effects+on+speed+and+acceleration.%0D%0A%0D%0AThe+second+approach+applies+a+linear+Kalman+smoother+iteratively.+This+algorithm+exploits+the+post-processing+nature+of+the+computations+taking+into+account+past+and+future+measurements+in+an+optimal+manner.+It+avoids+heuristic+gains+and+generates+covariance+matrices+that+give+an+estimate+of+the+error+in+the+results.%0D%0A%0D%0AFurther+investigations+looked+into+the+potential+of+wavelet+smoothing+the+measurements+and+potential+applications+for+Android+devices.&rft.date=2013&rft.type=Study+Group+Report&rft.type=NonPeerReviewed&rft.format=application%2Fpdf&rft.language=en&rft.identifier=http%3A%2F%2Fmiis.maths.ox.ac.uk%2Fmiis%2F731%2F1%2FESGI91-Vert_CaseStudy.pdf&rft.identifier=++Black%2C+Jonathan+and+Christmas%2C+Jacqueline+and+Krastanov%2C+M.+and+Nowotarski%2C+J.+and+Sieber%2C+Jan+and+Sieber%2C+Robert+and+Tomczyk%2C+Jakub+and+Webborn%2C+Ellen++(2013)+Inertial+motion+estimation+for+extreme+sports+modelling.++%5BStudy+Group+Report%5D+++++