259 research outputs found
Optimization of Hybrid Electric Bus Driving System's Control Strategy
AbstractThe popularity of hybrid electric bus (HEB) is a most realistic way to solve emission and energy problem currently, so it's important to improve the HEB's fuel economy and efficiency. This paper optimizes the HEB's driving system to satisfy the conditions of this city. We applied the fuzzy logic control of modern control theory to the driving system's control of parallel-HEB, and optimized the driving system's control strategy of this city's hybrid bus based on this theory. We adopted the ADVISOR2002 for HEB's driving system's re-development, namely established the driving system's simulation model for this city's hybrid bus, then we tested the simulation model on the HEB urban driving cycle which had been developed in our preparatory work. The simulation results of our new control strategy and the simulation model proposed in this paper can further enhance the fuel economy and improve the driving system's efficiency, thus the results provided important reference for the upgrading of this type HEB's driving system
Top-view Trajectories: A Pedestrian Dataset of Vehicle-Crowd Interaction from Controlled Experiments and Crowded Campus
Predicting the collective motion of a group of pedestrians (a crowd) under
the vehicle influence is essential for the development of autonomous vehicles
to deal with mixed urban scenarios where interpersonal interaction and
vehicle-crowd interaction (VCI) are significant. This usually requires a model
that can describe individual pedestrian motion under the influence of nearby
pedestrians and the vehicle. This study proposed two pedestrian trajectory
datasets, CITR dataset and DUT dataset, so that the pedestrian motion models
can be further calibrated and verified, especially when vehicle influence on
pedestrians plays an important role. CITR dataset consists of experimentally
designed fundamental VCI scenarios (front, back, and lateral VCIs) and provides
unique ID for each pedestrian, which is suitable for exploring a specific
aspect of VCI. DUT dataset gives two ordinary and natural VCI scenarios in
crowded university campus, which can be used for more general purpose VCI
exploration. The trajectories of pedestrians, as well as vehicles, were
extracted by processing video frames that come from a down-facing camera
mounted on a hovering drone as the recording equipment. The final trajectories
of pedestrians and vehicles were refined by Kalman filters with linear
point-mass model and nonlinear bicycle model, respectively, in which
xy-velocity of pedestrians and longitudinal speed and orientation of vehicles
were estimated. The statistics of the velocity magnitude distribution
demonstrated the validity of the proposed dataset. In total, there are
approximate 340 pedestrian trajectories in CITR dataset and 1793 pedestrian
trajectories in DUT dataset. The dataset is available at GitHub.Comment: This paper was accepted into the 30th IEEE Intelligent Vehicles
Symposium. Personal use of this material is permitted. Permission from IEEE
must be obtained for all other use
Top-view Trajectories: A Pedestrian Dataset of Vehicle-Crowd Interaction from Controlled Experiments and Crowded Campus
Predicting the collective motion of a group of pedestrians (a crowd) under
the vehicle influence is essential for the development of autonomous vehicles
to deal with mixed urban scenarios where interpersonal interaction and
vehicle-crowd interaction (VCI) are significant. This usually requires a model
that can describe individual pedestrian motion under the influence of nearby
pedestrians and the vehicle. This study proposed two pedestrian trajectory
datasets, CITR dataset and DUT dataset, so that the pedestrian motion models
can be further calibrated and verified, especially when vehicle influence on
pedestrians plays an important role. CITR dataset consists of experimentally
designed fundamental VCI scenarios (front, back, and lateral VCIs) and provides
unique ID for each pedestrian, which is suitable for exploring a specific
aspect of VCI. DUT dataset gives two ordinary and natural VCI scenarios in
crowded university campus, which can be used for more general purpose VCI
exploration. The trajectories of pedestrians, as well as vehicles, were
extracted by processing video frames that come from a down-facing camera
mounted on a hovering drone as the recording equipment. The final trajectories
of pedestrians and vehicles were refined by Kalman filters with linear
point-mass model and nonlinear bicycle model, respectively, in which
xy-velocity of pedestrians and longitudinal speed and orientation of vehicles
were estimated. The statistics of the velocity magnitude distribution
demonstrated the validity of the proposed dataset. In total, there are
approximate 340 pedestrian trajectories in CITR dataset and 1793 pedestrian
trajectories in DUT dataset. The dataset is available at GitHub.Comment: This paper was accepted into the 30th IEEE Intelligent Vehicles
Symposium. Personal use of this material is permitted. Permission from IEEE
must be obtained for all other use
Back-stepping variable structure controller design for off-road intelligent vehicle
In this paper, off-road path recognition and navigation control method are studied to realize intelligent vehicle autonomous driving in unstructured environment. Firstly, the traversable path is achieved by vision and laser sensors. The vehicle steering and driving coupled dynamic model is established. Secondly, a coordinated controller for steering and driving is proposed via the back-stepping variable structure control method, which can be used to deal with the unmatched uncertainties of the control system model. To reduce the chattering phenomenon caused by variable structure, the boundary layer approach is introduced. The results of simulation and off-road experiment show the effectiveness and robustness of the proposed controller
Edge-guided Representation Learning for Underwater Object Detection
Underwater object detection (UOD) is crucial for marine economic development,
environmental protection, and the planet's sustainable development. The main
challenges of this task arise from low-contrast, small objects, and mimicry of
aquatic organisms. The key to addressing these challenges is to focus the model
on obtaining more discriminative information. We observe that the edges of
underwater objects are highly unique and can be distinguished from low-contrast
or mimicry environments based on their edges. Motivated by this observation, we
propose an Edge-guided Representation Learning Network, termed ERL-Net, that
aims to achieve discriminative representation learning and aggregation under
the guidance of edge cues. Firstly, we introduce an edge-guided attention
module to model the explicit boundary information, which generates more
discriminative features. Secondly, a feature aggregation module is proposed to
aggregate the multi-scale discriminative features by regrouping them into three
levels, effectively aggregating global and local information for locating and
recognizing underwater objects. Finally, we propose a wide and asymmetric
receptive field block to enable features to have a wider receptive field,
allowing the model to focus on more small object information. Comprehensive
experiments on three challenging underwater datasets show that our method
achieves superior performance on the UOD task
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