Enhanced Pseudo-sensorless Bilateral Teleoperation by PLL <i>αβ</i>-tracker and FPGA

Abstract

AbstractIn this paper, the problem of external sensors within bilateral teleoperation is addressed. We propose a Phase Locked Loop (PLL) αβ-tracker that presents an enhanced approach for position and velocity estimation. The proposed approach offers some advantages over the method presented in our previous research that was introduced to enable pseudo-sensorless teleoperation. Such approach applies PMLSM actuators with analog Hall sensors built in a motor housing. They allow obtaining sufficient position, velocity, and force information for teleoperation by a haptic interface. Furthermore, FPGA has been utilized for the implementation in order to achieve high control rate that was already introduced as a necessity in cutting edge performance systems. However, main advantages of the method presented in this paper is attributed to improved system performance due to the better signal-noise ratio and to enhanced flexibility of hardware resources consumption. Thus, high-performance bilateral control can be achieved. Such bilateral teleoperation with a dedicated haptic interface can significantly improve surgical robotics. The proposed approach was experimentally validated by the simple 1-DoF laboratory bilateral teleoperation system.Glavni predmet ovog rada je problematika korištenja eksternih senzora u procesu bilateralne teleoperacije. U raduje predložen αβ estimator temeljen na principu fazno zatvorene petlje (eng. Phase Locked Loop, PLL) koji se učinkovito koristi za problem istovremene estimacije pozicije i brzine. Predloženi pristup pruža određene prednosti u odnosu na metode koje smo prethodno razvili za ostvarenje pseudo-bezsenzorne teleoperacije. Pristup primjenjuje PMLSM aktuatore s analognim Hallovim sondama ugrađenih u metalno kućište. Oni se koriste za dobivanje dovoljno informacija o poziciji, brzini i sili, za teleoperaciju s haptičkim sučeljem. Nadalje, za omogućavanje izvođenja upravljačkog algoritma s vrlo visokom frekvencijom u svrhu implementacije korištenje FPGA sklop, koji se već pokazao kao nužnost u primjeni na sustavima s visokom razinom performansi. Unatoč tome, glavna prednost metode koja je predložena u ovom radu odnosi se na poboljšanje performansi sustava zbog boljeg omjera signala i šuma te povećanu fleksibilnost potrošnje sklopovskih resursa. Prema tome, moguće je ostvariti bilateralno upravljanje s visokim performansama. Takva bilateralna teleoperacija s prilagođenim haptičnim sučeljem može utjecati na značajna poboljšanja u kirurškoj robotici. Predloženi pristup je eksperimentalno validiran na jednostavnom bilateralnom teleoperacijskom sustavu s jednim stupnjem slobode.Key words: Velocity EstimationPhase Locked LoopBilateral TeleoperationHapticsFPGAKljučne riječi: estimacija brzinefazno zatvorena petljabilateralna teleoperacijahaptično sučeljeFPGA Additional informationNotes on contributorsAleš HaceAleš Hace received the B.S., M.S., and Ph.D. degrees in electrical engineering from the University of Maribor, Maribor, Slovenia, in 1994, 1998, and 2001, respectively. In 1994, he joined the Institute of Robotics, Faculty of Electrical and Computer Science, University of Maribor, where he has been holding the position of an Assistant Professor for Automation and Robotics since 2006. In 2010 he has been elected Associate Professor. In 1999, he was a Visiting Research Fellow at Loughborough University, Leicestershire, U.K. The main areas of his research are related to the areas of mechatronics, robotics, servodrives, and sliding-mode control. Dr. Hace was the recipient of the Bedjanic Slovenian National Research Award in 1998. He is IEEE Member of its Industrial Electronics Society, and member of national Automatic Control Society of Slovenia.Marko FrancMarko Franc Marko Franc received the B.S., and Ph. D. degrees in electrical engineering from the University of Maribor, Maribor, Slovenia, in 2009, and 2013, respectively. In 2009 he joined Institute of Robotics, Faculty of Electrical and Computer Science,