369 research outputs found
Integrating Perception, Prediction and Control for Adaptive Mobile Navigation
Mobile robots capable of navigating seamlessly and safely in pedestrian rich environments promise to bring robotic assistance closer to our daily lives. A key limitation of existing navigation policies is the difficulty to predict and reason about the environment including static obstacles and pedestrians. In this thesis, I explore three properties of navigation including prediction of occupied spaces, prediction of pedestrians and measurements of uncertainty to improve crowd-based navigation. The hypothesis is that improving prediction and uncertainty estimation will increase robot navigation performance resulting in fewer collisions, faster speeds and lead to more socially-compliant motion in crowds.
Specifically, this thesis focuses on techniques that allow mobile robots to predict occupied spaces that extend beyond the line of sight of the sensor. This is accomplished through the development of novel generative neural network architectures that enable map prediction that exceed the limitations of the sensor. Further, I extend the neural network architectures to predict multiple hypotheses and use the variance of the hypotheses as a measure of uncertainty to formulate an information-theoretic map exploration strategy. Finally, control algorithms that leverage the predicted occupancy map were developed to demonstrate more robust, high-speed navigation on a physical small form factor autonomous car.
I further extend the prediction and uncertainty approaches to include modeling pedestrian motion for dynamic crowd navigation. This includes developing novel techniques that model human intent to predict future motion of pedestrians. I show this approach improves state-of-the-art results in pedestrian prediction. I then show errors in prediction can be used as a measure of uncertainty to adapt the risk sensitivity of the robot controller in real time. Finally, I show that the crowd navigation algorithm extends to socially compliant behavior in groups of pedestrians.
This research demonstrates that combining obstacle and pedestrian prediction with uncertainty estimation achieves more robust navigation policies. This approach results in improved map exploration efficiency, faster robot motion, fewer number of collisions and more socially compliant robot motion within crowds
Metal chalcogenide hollow polar bipyramid prisms as efficient sulfur hosts for Na-S batteries
Funding Information: We appreciate the support from the National Natural Science Foundation of China (Nos. 21773188 and 21972111), Fundamental Research Funds for the Central Universities (XDJK2019AA002), Postgraduate tutor team-building project (XYDS201911). The work at UT was supported by the Welch Foundation (F-1841) and the Texas Advanced Computing Center.Peer reviewe
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