7 research outputs found

    EEG and EMG dataset for the detection of errors introduced by an active orthosis device

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    This paper presents a dataset containing recordings of the electroencephalogram (EEG) and the electromyogram (EMG) from eight subjects who were assisted in moving their right arm by an active orthosis device. The supported movements were elbow joint movements, i.e., flexion and extension of the right arm. While the orthosis was actively moving the subject's arm, some errors were deliberately introduced for a short duration of time. During this time, the orthosis moved in the opposite direction. In this paper, we explain the experimental setup and present some behavioral analyses across all subjects. Additionally, we present an average event-related potential analysis for one subject to offer insights into the data quality and the EEG activity caused by the error introduction. The dataset described herein is openly accessible. The aim of this study was to provide a dataset to the research community, particularly for the development of new methods in the asynchronous detection of erroneous events from the EEG. We are especially interested in the tactile and haptic-mediated recognition of errors, which has not yet been sufficiently investigated in the literature. We hope that the detailed description of the orthosis and the experiment will enable its reproduction and facilitate a systematic investigation of the influencing factors in the detection of erroneous behavior of assistive systems by a large community.Comment: Revised references to our datasets, general corrections to typos, and latex template format changes, Overall Content unchange

    Dynamic Modelling and Optimal Control of Autonomous Heavy-duty Vehicles

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    Autonomous vehicles have gained much importance over the last decade owing to their promising capabilities like improvement in overall traffic flow, reduction in pollution and elimination of human errors. However, when it comes to long-distance transportation or working in complex isolated environments like mines, various factors such as safety, fuel efficiency, transportation cost, robustness, and accuracy become very critical. This thesis, developed at the Connected and Autonomous Systems department of Scania AB in association with KTH, focuses on addressing the issues related to fuel efficiency, robustness and accuracy of an autonomous heavy-duty truck used for mining applications. First, in order to improve the state prediction capabilities of the simulation model, a comparative analysis of two dynamic bicycle models was performed. The first model used the empirical PAC2002 Magic Formula (MF) tyre model to generate the tyre forces, and the latter used a piece-wise Linear approximation of the former. On top of that, in order to account for the nonlinearities and time delays in the lateral direction, the steering dynamic equations were empirically derived and cascaded to the vehicle model. The fidelity of these models was tested against real experimental logs, and the best vehicle model was selected by striking a balance between accuracy and computational efficiency. The Dynamic bicycle model with piece-wise Linear approximation of tyre forces proved to tick-all-the-boxes by providing accurate state predictions within the acceptable error range and handling lateral accelerations up to 4 m/s2. Also, this model proved to be six times more computationally efficient than the industry-standard PAC2002 tyre model. Furthermore, in order to ensure smooth and accurate driving, several Model Predictive Control (MPC) formulations were tested on clothoid-based Single Lane Change (SLC), Double Lane Change (DLC) and Truncated Slalom trajectories with added disturbances in the initial position, heading and velocities. A linear time-varying Spatial error MPC is proposed, which provides a link between spatial-domain and time-domain analysis. This proposed controller proved to be a perfect balance between fuel efficiency which was achieved by minimising braking and acceleration sequences and offset-free tracking along with ensuring that the truck reached its destination within the stipulated time irrespective of the added disturbances. Lastly, a comparative analysis between various Prediction-Simulation model pairs was made, and the best pair was selected in terms of its robustness to parameter changes, simplicity, computational efficiency and accuracy.Under det senaste Ärtiondet har utveckling av autonoma fordon blivit allt viktigare pÄ grund av de stora möjligheterna till förbÀttringar av trafikflöden, minskade utslÀpp av föroreningar och eliminering av mÀnskliga fel. NÀr det gÀller lÄngdistanstransporter eller komplexa isolerade miljöer sÄ som gruvor blir faktorer som brÀnsleeffektivitet, transportkostnad, robusthet och noggrannhet mycket viktiga. Detta examensarbete utvecklat vid avdelningen Connected and Autonomous Systems pÄ Scania i samarbete med KTH fokuserar pÄ frÄgor gÀllande brÀnsleeffektivitet, robusthet och exakthet hos en autonom tung lastbil i gruvmiljö. För att förbÀttra simuleringsmodellens tillstÄndsprediktioner, genomfördes en jÀmförande analys av tvÄ dynamiska fordonsmodeller. Den första modellen anvÀnde den empiriska dÀckmodellen PAC2002 Magic Formula (MF) för att approximera dÀckkrafterna, och den andra anvÀnde en stegvis linjÀr approximation av samma dÀckmodell. För att ta hÀnsyn till ickelinjÀriteter och laterala tidsfördröjningar inkluderades empiriskt identifierade styrdynamiksekvationer i fordonsmodellen. Modellerna verifierades mot verkliga mÀtdata frÄn fordon. Den bÀsta fordonsmodellen valdes genom att hitta en balans mellan noggrannhet och berÀkningseffektivitet. Den Dynamiska fordonsmodellen med stegvis linjÀr approximation av dÀckkrafter visade goda resultat genom att ge noggranna tillstÄndsprediktioner inom det acceptabla felomrÄdet och hantera sidoacceleration upp till 4 m/s2 . Den hÀr modellen visade sig ocksÄ vara sex gÄnger effektivare Àn PAC2002-dÀckmodellen. v För att sÀkerstÀlla mjuk och korrekt körning testades flera MPC varianter pÄ klotoidbaserade trajektorier av filbyte SLC, dubbelt filbyte DLC och slalom. Störningar i position, riktining och hastighet lades till startpositionen. En MPC med straff pÄ rumslig avvikelse föreslÄs, vilket ger en lÀnk mellan rumsdomÀn och tidsdomÀn. Den föreslagna regleringen visade sig vara en perfekt balans mellan brÀnsleeffektivitet, genom att minimering av broms- och accelerationssekvenser, och felminimering samtidigt som lastbilen nÄdde sin destination inom den föreskrivna tiden oberoende av de extra störningarna. Slutligen gjordes en jÀmförande analys mellan olika kombinationer av simulerings- och prediktionsmodell och den bÀsta kombinationen valdes med avseende pÄ dess robusthet mot parameterÀndringar, enkelhet, berÀkningseffektivitet och noggrannhet

    Dynamic Modelling and Optimal Control of Autonomous Heavy-duty Vehicles

    No full text
    Autonomous vehicles have gained much importance over the last decade owing to their promising capabilities like improvement in overall traffic flow, reduction in pollution and elimination of human errors. However, when it comes to long-distance transportation or working in complex isolated environments like mines, various factors such as safety, fuel efficiency, transportation cost, robustness, and accuracy become very critical. This thesis, developed at the Connected and Autonomous Systems department of Scania AB in association with KTH, focuses on addressing the issues related to fuel efficiency, robustness and accuracy of an autonomous heavy-duty truck used for mining applications. First, in order to improve the state prediction capabilities of the simulation model, a comparative analysis of two dynamic bicycle models was performed. The first model used the empirical PAC2002 Magic Formula (MF) tyre model to generate the tyre forces, and the latter used a piece-wise Linear approximation of the former. On top of that, in order to account for the nonlinearities and time delays in the lateral direction, the steering dynamic equations were empirically derived and cascaded to the vehicle model. The fidelity of these models was tested against real experimental logs, and the best vehicle model was selected by striking a balance between accuracy and computational efficiency. The Dynamic bicycle model with piece-wise Linear approximation of tyre forces proved to tick-all-the-boxes by providing accurate state predictions within the acceptable error range and handling lateral accelerations up to 4 m/s2. Also, this model proved to be six times more computationally efficient than the industry-standard PAC2002 tyre model. Furthermore, in order to ensure smooth and accurate driving, several Model Predictive Control (MPC) formulations were tested on clothoid-based Single Lane Change (SLC), Double Lane Change (DLC) and Truncated Slalom trajectories with added disturbances in the initial position, heading and velocities. A linear time-varying Spatial error MPC is proposed, which provides a link between spatial-domain and time-domain analysis. This proposed controller proved to be a perfect balance between fuel efficiency which was achieved by minimising braking and acceleration sequences and offset-free tracking along with ensuring that the truck reached its destination within the stipulated time irrespective of the added disturbances. Lastly, a comparative analysis between various Prediction-Simulation model pairs was made, and the best pair was selected in terms of its robustness to parameter changes, simplicity, computational efficiency and accuracy.Under det senaste Ärtiondet har utveckling av autonoma fordon blivit allt viktigare pÄ grund av de stora möjligheterna till förbÀttringar av trafikflöden, minskade utslÀpp av föroreningar och eliminering av mÀnskliga fel. NÀr det gÀller lÄngdistanstransporter eller komplexa isolerade miljöer sÄ som gruvor blir faktorer som brÀnsleeffektivitet, transportkostnad, robusthet och noggrannhet mycket viktiga. Detta examensarbete utvecklat vid avdelningen Connected and Autonomous Systems pÄ Scania i samarbete med KTH fokuserar pÄ frÄgor gÀllande brÀnsleeffektivitet, robusthet och exakthet hos en autonom tung lastbil i gruvmiljö. För att förbÀttra simuleringsmodellens tillstÄndsprediktioner, genomfördes en jÀmförande analys av tvÄ dynamiska fordonsmodeller. Den första modellen anvÀnde den empiriska dÀckmodellen PAC2002 Magic Formula (MF) för att approximera dÀckkrafterna, och den andra anvÀnde en stegvis linjÀr approximation av samma dÀckmodell. För att ta hÀnsyn till ickelinjÀriteter och laterala tidsfördröjningar inkluderades empiriskt identifierade styrdynamiksekvationer i fordonsmodellen. Modellerna verifierades mot verkliga mÀtdata frÄn fordon. Den bÀsta fordonsmodellen valdes genom att hitta en balans mellan noggrannhet och berÀkningseffektivitet. Den Dynamiska fordonsmodellen med stegvis linjÀr approximation av dÀckkrafter visade goda resultat genom att ge noggranna tillstÄndsprediktioner inom det acceptabla felomrÄdet och hantera sidoacceleration upp till 4 m/s2 . Den hÀr modellen visade sig ocksÄ vara sex gÄnger effektivare Àn PAC2002-dÀckmodellen. v För att sÀkerstÀlla mjuk och korrekt körning testades flera MPC varianter pÄ klotoidbaserade trajektorier av filbyte SLC, dubbelt filbyte DLC och slalom. Störningar i position, riktining och hastighet lades till startpositionen. En MPC med straff pÄ rumslig avvikelse föreslÄs, vilket ger en lÀnk mellan rumsdomÀn och tidsdomÀn. Den föreslagna regleringen visade sig vara en perfekt balans mellan brÀnsleeffektivitet, genom att minimering av broms- och accelerationssekvenser, och felminimering samtidigt som lastbilen nÄdde sin destination inom den föreskrivna tiden oberoende av de extra störningarna. Slutligen gjordes en jÀmförande analys mellan olika kombinationer av simulerings- och prediktionsmodell och den bÀsta kombinationen valdes med avseende pÄ dess robusthet mot parameterÀndringar, enkelhet, berÀkningseffektivitet och noggrannhet
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