The application of object detection in industrial transportation has witnessed substantial advancements, yielding significant enhancements in both safety and efficiency. While Transformer-based detectors have demonstrated remarkable success in object detection for autonomous driving, their quadratic computational complexity and limited small-object perception capabilities remain significant challenges. To address these limitations, we propose lightweight visual Mamba small object detection (LVMSOD) method, a novel selective state space model designed for small object detection task. The proposed framework employs a multi-level cascade of dual-layer nested Mamba modules to comprehensively capture contextual information across different scales, coupled with a hierarchical feature fusion strategy to enhance multi-scale feature integration for improved small object detection. The LVMSOD framework incorporates two key components to enhance feature representation: Visual Mamba Detection (VDM) block that preserves fine-grained image details, and Lightweight Gated Multi-Layer Perceptron (LGMLP) designed to model local feature dependencies efficiently. Furthermore, we propose an optimized feature extraction mechanism employing depthwise and pointwise convolutions with distribution factors, significantly reducing computational overhead while maintaining detection accuracy. Comprehensive evaluations on benchmark datasets demonstrate the effectiveness of our approach, achieving [email protected] scores of 93.3% on KITTI and 45.3% on VisDrone while maintaining superior computational efficiency. These results highlight the potential of LVMSOD for efficient and accurate small object detection.

Autonomous on-ramp merging requires a safe and efficient decision and planning framework to navigate dynamic and complex traffic scenarios. Reinforcement Learning (RL) offers adaptability in such environments but struggles to ensure safety in unseen situations, whereas Model Predictive Control (MPC) can enforce safety constraints but relies on accurate models. To leverage the strengths of both, we propose a hierarchical Safety-Augmented RL and MPC integration approach, i.e., SARMI, for decision and planning in the on-ramp merging scenario. The high-level decision-making layer employs a discrete Soft Actor-Critic (SAC-Discrete) algorithm enhanced with the Augmented Lagrangian method to generate actions. MPC generates reference trajectories based on RL actions and feeds predicted states back to RL for reward and cost design, ensuring consistency between RL and MPC. Our key innovations include: i) incorporating a Gaussian-based risk field model into the cost design of constrained RL, which quantifies collision risk based on MPC-predicted states, enabling agents to make proactive decisions; ii) an Augmented Lagrangian SAC-Discrete method with barrier-like quadratic penalties to promote compliance with safety constraints and alleviate oscillations in dual gradient descent; iii) theoretical analysis proving the equivalence between the optimal solutions of the primal and dual problems in Augmented Lagrangian SAC-Discrete and iv) a dual safety mechanism combining action masking (to filter invalid actions) and action shielding (to replace unsafe actions in RL), enhancing safety during the exploration and execution stages, respectively. Experiments demonstrate the superiority of our method over the baseline SAC-Discrete, showing improved safety and efficiency.

Four-wheel independent steering (4WIS) vehicles have attracted increasing attention for their superior maneuverability. Human drivers typically choose to cross or drive over low-profile obstacles (e.g., plastic bags) to efficiently navigate through narrow spaces, while existing planners neglect obstacle attributes, leading to suboptimal efficiency or planning failures. To address this issue, we propose a novel multimodal trajectory planning framework that employs a neural network for scene perception, integrates 4WIS hybrid A* search to generate a warm start, and formulates an optimal control problem (OCP) for trajectory optimization. Specifically, a multimodal perception network fusing visual information and vehicle states is employed to capture semantic and contextual scene information, enabling the planner to adapt the strategy according to scene complexity (hard or easy planning task). For hard tasks, guided points are introduced to decompose complex tasks into local subtasks, improving search efficiency. The multiple steering modes of 4WIS vehicles—Ackermann, diagonal, and zero-turn—are also incorporated as kinematically feasible motion primitives. Moreover, a hierarchical obstacle handling strategy, which categorizes obstacles as “non-traversable”, “crossable”, and “drive-over”, is incorporated into the node expansion process, explicitly linking obstacle attributes to planning actions to enable efficient decisionmaking. Furthermore, to address dynamic obstacles with motion uncertainty, we introduce a probabilistic risk field model, constructing risk-aware driving corridors that serve as linear collision constraints in the OCP. Experimental results demonstrate the proposed framework’s effectiveness in generating safe, efficient, and smooth trajectories for 4WIS vehicles, especially in constrained environments.

Enhancing the resolution of scene text images is a critical preprocessing step that can substantially improve the accuracy of downstream text recognition in low-quality images. Existing methods primarily rely on auxiliary text features to guide the super-resolution process. However, these features often lack rich low-level information, making them insufficient for faithfully reconstructing both the global structure and fine-grained details of text. Moreover, previous methods often learn suboptimal feature representations from the original low-quality landmark images, which cannot provide precise guidance for super-resolution. In this study, we propose a Fine-Grained Feedback Domain-Complementary Network (FDNet) for scene text image super-resolution. Specifically, we first employ a fine-grained feedback mechanism to selectively refine landmark images, thereby enhancing feature representations. Then, we introduce a novel domain-trace prior interaction generator, which integrates domain-specific traces with a text prior to comprehensively complement the clear edges and structural coverage of the text. Finally, motivated by the limitations of existing datasets, which often exhibit limited scene scales and insufficient challenging scenarios, we introduce a new dataset, MDRText. The proposed dataset, MDRText, features multi-scale and diverse characteristics and is designed to support challenging text image recognition and super-resolution tasks. Extensive experiments on the MDRText and TextZoom datasets demonstrate that our method achieves superior performance in scene text image super-resolution and further improves the accuracy of subsequent recognition tasks.

Unmanned Aerial Vehicle (UAV) object detection has been widely used in traffic management, agriculture, emergency rescue, etc. However, it faces significant challenges, including occlusions, small object sizes, and irregular shapes. These challenges highlight the necessity for a robust and efficient multimodal UAV object detection method. Mamba has demonstrated considerable potential in multimodal image fusion. Leveraging this, we propose UAVD-Mamba, a multimodal UAV object detection framework based on Mamba architectures. To improve geometric adaptability, we propose the Deformable Token Mamba Block (DTMB) to generate deformable tokens by incorporating adaptive patches from deformable convolutions alongside normal patches from normal convolutions, which serve as the inputs to the Mamba Block. To optimize the multimodal feature complementarity, we design two separate DTMBs for the RGB and infrared (IR) modalities, with the outputs from both DTMBs integrated into the Mamba Block for feature extraction and into the Fusion Mamba Block for feature fusion. Additionally, to improve multiscale object detection, especially for small objects, we stack four DTMBs at different scales to produce multiscale feature representations, which are then sent to the Detection Neck for Mamba (DNM). The DNM module, inspired by the YOLO series, includes modifications to the SPPF and C3K2 of YOLOv11 to better handle the multiscale features. In particular, we employ cross-enhanced spatial attention before the DTMB and cross-channel attention after the Fusion Mamba Block to extract more discriminative features. Experimental results on the DroneVehicle dataset show that our method outperforms the baseline OAFA method by 3.6% in the mAP metric. Codes will be released at https://github.com/GreatPlum-hnu/UAVD-Mamba.git.

Switching communication topologies can cause instability in vehicle platoons, as vehicle information may be lost during the dynamic switching process. This highlights the need to design a controller capable of maintaining the stability of vehicle platoons under dynamically changing topologies. However, capturing the dynamic characteristics of switching topologies and obtaining complete vehicle information for controller design while ensuring stability remains a significant challenge. In this study, we propose an observer-based distributed model predictive control (DMPC) method for vehicle platoons under directed Markovian switching topologies. Considering the stochastic nature of the switching topologies, we model the directed switching communication topologies using a continuous-time Markov chain. To obtain the leader vehicle's information for controller design, we develop a fully distributed adaptive observer that can quickly adapt to the randomly switching topologies, ensuring that the observed information is not affected by the dynamic topology switches. Additionally, a sufficient condition is derived to guarantee the mean-square stability of the observer. Furthermore, we construct the DMPC terminal update law based on the observer and formulate a string stability constraint based on the observed information. Numerical simulations demonstrate that our method can reduce tracking errors while ensuring string stability.

A safe and interpretable end-to-end autonomous driving system is essential for real-world applications. However, existing methods struggle with incomplete feature understanding, the black box problem, and poor interpretability, making it hard to adapt to complex environments and be accepted by users. In this study, we propose an end-to-end autonomous driving framework, PA-TCP, which enhances safety and interpretability through a hybrid attention mechanism and efficient state representation. Specifically, we introduce a parallel-weighted compound attention module that dynamically captures and prioritizes critical environmental features for vehicle driving. This module leverages a parallel architecture to simultaneously combine spatial and channel attention mechanisms through learned adaptive weights, enabling fine-grained feature selection and robust scene understanding in challenging scenarios. Next, we integrate vehicle dynamics, navigation commands, and contextual information through a linear-based Squeeze-and-Excitation attention framework, which systematically identifies and emphasizes the most task-relevant features while achieving a balance between representation capability and computational overhead. Extensive experiments on the CARLA simulation platform demonstrate the superiority of our approach over the baseline method TCP, including a 25.08% increase in driving score, a 16.2% increase in route completion, and a 6.8% increase in infraction score. We also demonstrate its effectiveness regarding generalization capabilities.

It has been challenging to model the complex temporal-spatial dependencies between agents for trajectory prediction. As each state of an agent is closely related to the states of adjacent time steps, capturing the local temporal dependency is beneficial for prediction, while most studies often overlook it. Besides, learning the high-order motion state attributes is expected to enhance spatial interaction modeling, but it is rarely seen in previous works. To address this, we propose a lightweight framework, i.e., LTMSformer, to extract temporal-spatial interaction features for multi-modal trajectory prediction. Specifically, we introduce a Local Trend-Aware Attention mechanism to capture the local temporal dependency by leveraging a convolutional attention mechanism with hierarchical local time boxes. Next, to model the spatial interaction dependency, we build a Motion State Encoder to incorporate high-order motion state attributes, such as acceleration, jerk, heading, etc. To further refine the trajectory prediction, we propose a Lightweight Proposal Refinement Module that leverages Multi-Layer Perceptrons for trajectory embedding and generates the refined trajectories with fewer model parameters. Experiment results on the Argoverse 1 dataset demonstrate that our method outperforms the baseline HiVT-64, reducing the minADE by approximately 4.35%, the minFDE by 8.74%, and the MR by 20%. We also achieve higher accuracy than HiVT-128 with a 68% reduction in model size.

Proactive caching scheme proactively caches data before the request comes, which is essential for optimizing of the resource utilization and ensuring the stability of cached contents. However, current proactive caching methods suffer from high computational complexity and often fall into suboptimal solutions. This study proposes a hierarchical reinforcement learning (HRL)-based proactive caching scheme to determine whether to update the caching queue and how to update the caching queue. Specifically, we build a bi-level optimization model to maximize the content cache hit ratio while minimizing the content cache cost. We formulate the upper-level and lower-level optimization problems as Markov decision process (MDP) models and employ double deep Q-learning methods to solve the optimal caching strategy. In particular, the content history request features and the user preference generated by the collaborative filtering-based recommendation system are used as the state inputs of caching decisions. In addition, we design a two-stage curriculum learning paradigm for training the agents from easy tasks to hard tasks. At the first stage, a greedy decision tree with a posterior knowledge is designed to provide the upper-level decisions for training the lower-level agent in the easy task. Then, we train all agents together in the hard task while freezing the trained lower-level agent. We conduct both the simulation and on-road experiments to validate the effectiveness of our method, and results indicate that our method outperforms the baseline methods by 2.2%–37.2% in terms of cache hit ratio and 75.4%–77.6% in terms of cache cost.

Limited transmission bandwidth and actuator faults in intelligent and connected vehicles (ICVs) pose significant challenges to controller design. To address these issues, this paper proposes a transmission-efficient fault-tolerant control strategy for a platoon of ICVs. Adaptive laws are developed to estimate the bounds of unknown fault characteristics, which eliminates the need for prior fault knowledge. A quantized event-triggered (QET) mechanism that integrates a hysteresis quantizer and a dynamic event-triggered mechanism (DETM) is designed to improve signal transmission efficiency. By appropriately designing the dynamic variable in the DETM, the Zeno behavior is avoided. Furthermore, with the aid of smooth functions, an adaptive controller is constructed to address the impact of unknown actuator faults, as well as signal deviations induced by the QET mechanism. Simulation results in both representative and real-world driving scenarios demonstrate that the proposed strategy significantly reduces communication burden while ensuring robustness against unknown actuator faults.

Object detection is a critical component of autonomous vehicle perception systems. However, domain shifts between training environments and real-world scenarios often degrade detector performance. Cross-domain object detection aims to adapt detectors to unlabeled target domains utilizing only labeled source data. Recent popular cross-domain object detection methods employ the mean teacher framework, which uses pseudo-labels generated by the teacher model to guide training on unlabeled real-world data. Despite its effectiveness, continuous training with noisy pseudo-labels leads to abnormal performance degradation in the later stages of training. To address this issue, we propose a novel Hybrid Matching Teacher (HMT) framework for cross-domain visual detection transformers, which enhances cross-domain knowledge transfer across pseudo-label generation, filtering, and training processes. Specifically, we design a Feature Sparse Alignment (FSA) module to adapt DETR tokens and queries, generate domain-adaptive weights to initialize the teacher-student models, and mitigate the inherent initial source bias in the teacher model. Next, a Localization-aware Pseudo-label Filtering (LPF) module ensures high-quality pseudo-labels by considering the consistency between localization and classification tasks. Furthermore, to improve the efficiency of pseudo-label training, the Cross-view Hybrid Matching (CHM) module introduces an auxiliary matching branch to increase the number of positive queries that match with pseudo-labels. Extensive experiments demonstrate that our approach achieves state-of-the-art performance, outperforming previous benchmarks by 3.1%, 8.5%, and 4.4% in adverse weather, diverse scenes, and synthetic-to-real, respectively.

Multiagent reinforcement learning (RL) training is usually difficult and time-consuming due to mutual interference among agents. Safety concerns make an already difficult training process even harder. This study proposes a safe adaptive policy transfer RL approach for multiagent cooperative control. Specifically, a pioneer and follower off-policy policy transfer learning (PFOPT) method is presented to help follower agents acquire knowledge and experience from a single well-trained pioneer agent. Notably, the designed approach can transfer both the policy representation and sample experience provided by the pioneer policy in the off-policy learning. More importantly, the proposed method can adaptively adjust the learning weight of prior experience and exploration according to the Wasserstein distance between the policy probability distributions of the pioneer and the follower. Case studies show that the distributed agents trained by the proposed method can complete a collaborative task and acquire the maximum rewards while minimizing the violation of constraints. Moreover, the proposed method can also achieve satisfactory performance in terms of learning speed and success rate.

Cooperative control of vehicle platoon has gained widespread attention due to its ability to significantly optimize traffic flow. Vehicle platoon often operates in mixed traffic flow and is susceptible to disturbance introduced by external vehicles cutting in, which is dangerous and may lead to traffic collisions. This paper proposes an adaptive spacing policy to alleviate the disturbance caused by the external cut-in vehicle, which enables vehicles within the platoon to adjust the spacing distance adaptively based on the car-following (CF) behavior of the external vehicle such as a human-driven vehicle (HDV) or connected and automated vehicle (CAV). A consensus-based controller is used to achieve a smooth cooperative cut-in control. Two cut-in scenarios are considered and performance comparisons with an existing method are conducted. Simulation results demonstrate that the proposed method can effectively alleviate the disturbance caused by external vehicles, and outperforms the constant spacing policy in terms of safety and comfort.

Increasingly more AGVs (Automated Guided Vehicles) are being utilized in ACTs (Automated Container Terminals) in recent years. Intersection collaboration of AGVs is crucial for improving the efficiency of containers transportation. Most of the existing methods model intersections as topological nodes which allows only one AGV to pass through at a time, or as grids which may lead to heavy computation workload. Moreover, these methods usually do not consider the mutual influences of the collaboration decisions between adjacent intersections and can hardly realize the full potential of AGVs. To address this issue, this paper proposes an MCTS (Monte Carlo Tree Search)- based intersection collaboration method for AGVs in ACTs. The proposed method models each intersection with a polygon and periodically assigns priorities to AGVs waiting for passing through intersections. The priorities of AGVs are determined by simultaneously applying MCTS to multiple adjacent intersections considering conflicts avoidance, queue alleviation and congestion prevention. The results of experiments show that the proposed method achieves better average intersection crossing time and total tasks completion time.

Scene text editing aims to replace the source text with the target text while preserving the original background. Its practical applications span various domains, such as data generation and privacy protection, highlighting its increasing importance in recent years. In this study, we propose a novel Scene Text Editing network with Explicitly-decoupled text transfer and Minimized background reconstruction, called STEEM. Unlike existing methods that usually fuse text style, text content, and background, our approach focuses on decoupling text style and content from the background and utilizes the minimized background reconstruction to reduce the impact of text replacement on the background. Specifically, the text-background separation module predicts the text mask of the scene text image, separating the source text from the background. Subsequently, the style-guided text transfer decoding module transfers the geometric and stylistic attributes of the source text to the content text, resulting in the target text. Next, the background and target text are combined to determine the minimal reconstruction area. Finally, the context-focused background reconstruction module is applied to the reconstruction area, producing the editing result. Furthermore, to ensure stable joint optimization of the four modules, a task-adaptive training optimization strategy has been devised. Experimental evaluations conducted on two popular datasets demonstrate the effectiveness of our approach. STEEM outperforms state-of-the-art methods, as evidenced by a reduction in the FID index from 29.48 to 24.67 and an increase in text recognition accuracy from 76.8% to 78.8%.

Well-trained visual object detectors are generally confronted with a severe performance decline when deployed in a novel driving scenario due to the impact of domain shift. Despite excellent improvements in unsupervised domain adaptive object detection achieved by adversarial training, those approaches fail to capture the transfer core underlying the holistic scenes. To solve this problem, we propose a progressive critical region transfer framework for cross-domain visual object detection. Specifically, we exploit a potential foreground mining (PFM) module and a semantic-specific RoI aggregation (SRA) module to improve the robustness of the cross-domain detection framework. Upon the critical regions in the broad sense, the PFM module first highlights the foreground regions by reweighting the hierarchical feature maps in sequence, and then modifies location biases at the downstream position of the backbone network for more accurate upstream predictions. Deep into the critical regions in the narrow sense, the SRA module concentrates on establishing an appropriate matching between batch-wise RoIs and all semantic centers, and further strengthens the aggregation of cross-domain identical semantic with the complement of context references. Together these modules are obligated to transform the adaptation importance from the whole scope to the latent foreground areas, and afterward to the informative regions of interest along the detection pipeline. Experiments show that our progressive critical region transfer framework achieves a state-of-the-art performance in adverse weather, camera configuration, and complicated scene adaptation, which outperforms the baselines by 19.4%, 5.0%, and 6.1%, respectively.

Scene text detection has attracted increasing concerns with the rapid development of deep neural networks in recent years. However, existing scene text detectors may overfit on the public datasets due to the limited training data, or generate inaccurate localization for arbitrary-shape scene texts. This paper presents an arbitrary-shape scene text detection method that can achieve better generalization ability and more accurate localization. We first propose a Scale-Aware Data Augmentation (SADA) technique to increase the diversity of training samples. SADA considers the scale variations and local visual variations of scene texts, which can effectively relieve the dilemma of limited training data. At the same time, SADA can enrich the training minibatch, which contributes to accelerating the training process. Furthermore, a Shape Similarity Constraint (SSC) technique is exploited to model the global shape structure of arbitrary-shape scene texts and backgrounds from the perspective of the loss function. SSC encourages the segmentation of text or non-text in the candidate boxes to be similar to the corresponding ground truth, which is helpful to localize more accurate boundaries for arbitrary-shape scene texts. Extensive experiments have demonstrated the effectiveness of the proposed techniques, and state-of-the-art performances are achieved over public arbitrary-shape scene text benchmarks (e.g.,CTW1500,Total-TextandArT).

To enable safe and efficient navigations through the urban environment, autonomous vehicles need to anticipate the future motions of the walking pedestrians who might collide with them. The dynamic and stochastic behavior characteristics of the pedestrians make the trajectory prediction challengeable for most kinematics-based approaches. This paper presents a comparative study of six state-of-the-art learning-based methods for pedestrian trajectory prediction, including Gaussian Process (GP), LSTM, GP-LSTM, Character-based LSTM, Sequence-to-Sequence (Seq2Seq), and attention-based Seq2Seq. The trajectory prediction is formulated as the regression task or sequence generation problem that predicts future trajectories based on observed trajectories. We evaluate the performance of the learning-based methods on a public real-world pedestrian dataset. To address the concern of data scarcity, we employ three forms of data augmentation (i.e., translation, rotation, and stretch) to enlarge the dataset, which produce the transformed trajectories from the original trajectories. By comparison, those learning-based approaches are ranked based on prediction accuracy from high to low as Seq2Seq, attention-based Seq2Seq, C-LSTM, LSTM, GP, and GP-LSTM. Particularly, Seq2Seq model outperforms all baseline approaches, with the mean and final point errors less than 15cm in normal scenarios when predicting 1s ahead.

Vehicle driving safety is influenced by many factors, including drivers, vehicles, and road environments. The interactions among them are quite complex. Consequently, existing methods that evaluate driving safety perform inadequately because they only consider limited factors and their interactions. As such, it is difficult for kinematics-based and dynamics-based vehicle driving safety assistant systems to adapt to increasingly complex traffic environments. In this paper, we propose a new concept, i.e.,the driving safety field. The concept makes use of field theory to represent risk factors owing to drivers, vehicles, road conditions, and other traffic factors. A unified model of the driving safety field is constructed, which includes the following three parts: 1) a potential field, which is determined by nonmoving objects on the roads, such as a stopped vehicle; 2) a kinetic field, which is determined by the moving objects on roads, such as vehicles and pedestrians; and 3) a behavior field, which is determined by the individual characteristics of drivers. Moreover, the applications of the model are proposed, and its application to a typical car-following scenario is illustrated, which evaluates the risks caused by multiple traffic factors. The driving safety field can reveal driver–vehicle–road interactions and their influences on driving safety, as well as predict driving safety trends owing to dynamic changes. In addition, the model can provide a new foundation for establishing driving safety measures and active vehicle control under complex traffic environments.