Recently, deep reinforcement learning (DRL) has emerged as a promising approach for robotic control. However, the deployment of DRL in real-world robots is hindered by its sensitivity to environmental perturbations. While existing whitebox adversarial attacks rely on local gradient information and apply uniform perturbations across all states to evaluate DRL robustness, they fail to account for temporal dynamics and statespecific vulnerabilities. To combat the above challenge, we first conduct a theoretical analysis of white-box attacks in DRL by establishing the adversarial victim-dynamics Markov decision process (AVD-MDP), to derive the necessary and sufficient conditions for a successful attack. Based on this, we propose a selective state-aware reinforcement adversarial attack method, named STAR, to optimize perturbation stealthiness and state visitation dispersion. STAR first employs a soft mask-based state-targeting mechanism to minimize redundant perturbations, enhancing stealthiness and attack effectiveness. Then, it incorporates an information-theoretic optimization objective to maximize mutual information between perturbations, environmental states, and victim actions, ensuring a dispersed state-visitation distribution that steers the victim agent into vulnerable states for maximum return reduction. Extensive experiments demonstrate that STAR outperforms state-of-the-art benchmarks

Deep Reinforcement Learning (DRL) suffers from uncertainties and inaccuracies in the observation signal in real-world applications. Adversarial attack is an effective method for evaluating the robustness of DRL agents. However, existing attack methods targeting individual sampled actions have limited impacts on the overall policy distribution, particularly in continuous action spaces. To address these limitations, we propose the Distribution-Aware Projected Gradient Descent attack (DAPGD). DAPGD uses distribution similarity as the gradient perturbation input to attack the policy network, which leverages the entire policy distribution rather than relying on individual samples. We utilize the Bhattacharyya distance in DAPGD to measure policy similarity, enabling sensitive detection of subtle but critical differences between probability distributions. Our experiment results demonstrate that DAPGD achieves SOTA results compared to the baselines in three robot navigation tasks, achieving an average 22.03% higher reward drop compared to the best baseline.

Deep neural networks (DNNs) are vulnerable to adversarial examples, in which DNNs are misled to false outputs due to inputs containing imperceptible perturbations. Adversarial training, a reliable and effective method of defense, may significantly reduce the vulnerability of neural networks and becomes the de facto standard for robust learning. While many recent works practice the data-centric philosophy, such as how to generate better adversarial examples or use generative models to produce additional training data, we look back to the models themselves and revisit the adversarial robustness from the perspective of deep feature distribution as an insightful complementarity. In this paper, we propose Branch Orthogonality adveRsarial Training (BORT) to obtain state-of-the-art performance with solely the original dataset for adversarial training. To practice our design idea of integrating multiple orthogonal solution spaces, we leverage a simple multi-branch neural network and propose a corresponding loss function, branch-orthogonal loss, to make each solution space of the multi-branch model orthogonal. We evaluate our approach on CIFAR-10, CIFAR-100 and SVHN against$\ell_{\infty}$norm-bounded perturbations of size$\epsilon=8 / 255$, respectively. Exhaustive experiments are conducted to show that our method goes beyond all state-of-the-art methods without any tricks. Compared to all methods that do not use additional data for training, our models achieve 67.3 % and 41.5 % robust accuracy on CIFAR-10 and CIFAR-100 (improving upon the state-of-the-art by$\mathbf{+7.23 \%}$and$\mathbf{+9.07 \%}$).

Deep reinforcement learning (DRL) has emerged as a promising approach for robotic control, but its real-world deployment remains challenging due to its vulnerability to environmental perturbations. Existing white-box adversarial attack methods, adapted from supervised learning, fail to effectively target DRL agents as they overlook temporal dynamics and indiscriminately perturb all state dimensions, limiting their impact on long-term rewards. To address these challenges, we propose the Adaptive Gradient-Masked Reinforcement (AGMR) Attack, a white-box attack method that combines DRL with a gradient-based soft masking mechanism to dynamically identify critical state dimensions and optimize adversarial policies. AGMR selectively allocates perturbations to the most impactful state features and incorporates a dynamic adjustment mechanism to balance exploration and exploitation during training. Extensive experiments demonstrate that AGMR outperforms state-of-the-art adversarial attack methods in degrading the performance of the victim agent and enhances the victim agent’s robustness through adversarial defense mechanisms.

The exceptional mobility and long endurance of air-ground robots are raising interest in their usage to navigate complex environments (e.g., forests and large buildings). However, such environments often contain occluded and unknown regions, and without accurate prediction of unobserved obstacles, the movement of the air-ground robot often suffers a sub-optimal trajectory under existing mapping-based and learning-based navigation methods. In this work, we present AGRNav, a novel framework designed to search for safe and energy-saving air-ground hybrid paths. AGRNav contains a lightweight semantic scene completion network (SCONet) with self-attention to enable accurate obstacle predictions by capturing contextual information and occlusion area features. The framework subsequently employs a query-based method for low-latency updates of prediction results to the grid map. Finally, based on the updated map, the hierarchical path planner efficiently searches for energy-saving paths for navigation. We validate AGRNav’s performance through benchmarks in both simulated and real-world environments, demonstrating its superiority over classical and state-of-the-art methods. The open-source code is available at https://github.com/jmwang0117/AGRNav.

AI models deployed in real-world tasks (e.g., surveillance, implicit mapping, health care) typically need to be online trained for better modelling of the changing real-world environments and various online training methods (e.g., domain adaptation, few shot learning) are proposed for refining the AI models based on training input incrementally sampled from the real world. However, in the whole loop of AI model online training, there is a section rarely discussed: how to sample training input from the real world. In this paper, we show from the perspective of online training of AI models deployed on edge devices (e.g., robots) that several problems in sampling of training input on the device are affecting the time and energy consumption for the online training process to reach high performance. Notably, the online training relies on training input consecutively sampled from the real world and the consecutive samples from nearby states (e.g., position and orientation of a camera) are too similar and would limit the training accuracy gain per training iteration; on the other hand, while we can choose to sample more about the inaccurate samples to better final training accuracy, it is costly to obtain the accuracy statistics of samples via traditional ways such as validating, especially for AI models deployed on edge devices. These findings aim to raise research effort for practical online training of AI models, so that they can achieve resiliently and sustainably high performance in real-world tasks.

In coordinated robotic learning, multiple robots share the same wireless channel for communication, and bring together latency-sensitive (LS) network flows for control and bandwidth-hungry (BH) flows for distributed learning. Unfortunately, existing wireless network supporting systems cannot coordinate these two network flows to meet their own requirements: 1) prioritized contention systems (e.g., EDCA) prevent LS messages from timely acquiring the wireless channel because multiple wireless network interface cards (WNICs) with BH messages are contending for the channel 2) global planning systems (e.g., SchedWiFi) have to reserve a notable time window in the shared channel for each LS flow, suffering from severe bandwidth degradation (up to 42%). We present the coordinated preemption method to meet both requirements for LS flows and BH flows. Globally (among multiple robots), coordinated preemption eliminates unnecessary contention of BH flows by making them transmit in a round-robin manner, such that LS flows have the highest chance to win the contention against BH flows, without sacrificing overall bandwidth from the perspective of coordinated robotic learning applications. Locally (within the same robot), coordinated preemption in real time predicts the periodic transmission of LS flows from the upper application and conservatively limits packets of BH flows buffered in the WNIC only before LS packets arriving, reducing the bandwidth devoted to preemption. COORP, our implementation of coordinated preemption, reduced the violation of latency requirements from 53.9% (EDCA) to 8.8% (comparable to SchedWiFi). Regarding learning quality, COORP achieved a comparable (at times the same) learning reward with EDCA, which grew up to 76% faster than SchedWiFi.

Critical robotic tasks such as rescue and disaster response are more prevalently leveraging ML (Machine Learning) models deployed on a team of wireless robots, on which data parallel (DP) training over Internet of Things of these robots (robotic IoT) can harness the distributed hardware resources to adapt their models to changing environments as soon as possible. Unfortunately, due to the need for DP synchronization across all robots, the instability in wireless networks (i.e., fluctuating bandwidth due to occlusion and varying communication distance) often leads to severe stall of robots, which affects the training accuracy within a tight time budget and wastes energy stalling. Existing methods to cope with the instability of datacenter networks are incapable of handling such straggler effect. That is because they are conducting model-granulated transmission scheduling, which is much more coarse-grained than the granularity of transient network instability in real-world robotic IoT networks, making a previously reached schedule mismatch with the varying bandwidth during transmission. We present ROG, the first ROw-Granulated distributed training system optimized for ML training over unstable wireless networks. ROG confines the granularity of transmission and synchronization to each row of a layer’s parameters and schedules the transmission of each row adaptively to the fluctuating bandwidth. In this way the ML training process can update partial and the most important gradients of a stale robot to avoid triggering stalls, while provably guaranteeing convergence. The evaluation shows that, given the same training time, ROG achieved about 4.9%~6.5% training accuracy gain compared with the baselines and saved 20.4%~50.7% of the energy to achieve the same training accuracy.