000124983 001__ 124983
000124983 005__ 20190509132206.0
000124983 0247_ $$2doi$$a10.5075/epfl-thesis-4154
000124983 02470 $$2urn$$aurn:nbn:ch:bel-epfl-thesis4154-6
000124983 02471 $$2nebis$$a5584200
000124983 037__ $$aTHESIS
000124983 041__ $$aeng
000124983 088__ $$a4154
000124983 245__ $$aTwo degrees of freedom miniaturized gyroscope based on active magnetic bearings
000124983 269__ $$a2008
000124983 260__ $$bEPFL$$c2008$$aLausanne
000124983 300__ $$a159
000124983 336__ $$aTheses
000124983 520__ $$aThe introduction of the active blocking system, better known as ABS, into cars revealed the growing need for inertial sensing. Among other data, that permit to apprehend the movements of a vehicle, the measurement of the vehicle angular velocity describes the change rate of the vehicle attitude. This measurement has been called by Foucault in 1852 gyroscopic sensing (from the Greek words σκοπειν = observe and γυρος = rotation). The currently available gyroscopes are either very high precision instruments (hence very costly), used in planes, or cheaper products but with a lack of sensitivity to be used in vehicle navigation. Therefore, a real need for gyroscopes combining low cost and precision exists. This thesis proposes to develop a gyroscope based on miniaturized active magnetic bearings (AMB). The advantage of such a device is that the spun mass will be levitated what frees it from any mechanical link to the base of the instrument what render precise classical mechanical gyroscopes so expensive. This thesis presents two prototypes of AMB based gyroscopes. The first one relies on the ball orbit sensing method which is a new theory proposed in this work. Because of the uncertainties due to the nonlinearities inherent to active magnetic bearings, the position of the levitated mass is adaptively controlled. Measurements performed on the prototype have demonstrated the feasibility of this solution with a ball following either a circular or a vertical orbit. The second designed prototype relies on the Newton's second law of motion. Due to the AMB inherent uncertainties and to the force coupling present in the proposed prototype, it has been chosen to drive the levitated mass with a H∞ controller. Simulations are run to compare three different H∞ controllers with the quality of the angular velocity measurement as criterion. Finally, a feed forward H∞ controller showed the best performances in terms of angular velocity measurements during simulations run on the prototype developed during this thesis.
000124983 6531_ $$anavigation
000124983 6531_ $$agyroscope
000124983 6531_ $$aangular velocity
000124983 6531_ $$amagnetic levitation
000124983 6531_ $$aadaptive control
000124983 6531_ $$aH[infinity] control
000124983 6531_ $$anavigation
000124983 6531_ $$agyroscope
000124983 6531_ $$avitesse angulaire
000124983 6531_ $$alévitation magnétique
000124983 6531_ $$acontrôle adaptatif
000124983 6531_ $$acontrôle H[infini]
000124983 700__ $$aBosgiraud, Thomas
000124983 720_2 $$aBleuler, Hannes$$edir.$$g104561$$0240027
000124983 8564_ $$uhttps://infoscience.epfl.ch/record/124983/files/EPFL_TH4154.pdf$$zTexte intégral / Full text$$s5248244$$yTexte intégral / Full text
000124983 909C0 $$0252016$$pLSRO
000124983 909CO $$pSTI$$pthesis$$pthesis-bn2018$$pDOI$$ooai:infoscience.tind.io:124983$$qDOI2$$qGLOBAL_SET
000124983 918__ $$dEDPR$$cIMT$$aSTI
000124983 919__ $$aLSRO1
000124983 920__ $$b2008
000124983 970__ $$a4154/THESES
000124983 973__ $$sPUBLISHED$$aEPFL
000124983 980__ $$aTHESIS