Unmanned ground vehicles (UGVs) and unmanned aerial vehicles (UAVs) have been widely used in delivery. In the context of the COVID-2019, in order to control the development of the epidemic, many places have adopted measures to isolate and close the area once a confirmed case is found. While reducing the contact between people, it also blocks the normal driving of vehicles. Only by changing the traditional logistics and distribution methods can customers who have been in a closed and isolated area for a long time be served. Therefore, we use the Cooperative UGV-UAV to achieve it. In this paper, when commanding cooperative UGV and UAV for emergency resource delivery, we mainly focus on two questions: how to accept the operation order (OPORD) from the commander, how to generate a nested vehicle routing planning. We first employ one intelligent task understanding module to drive the intelligent unmanned vehicles to accept and process the C-BML (Coalition Battle Management Language) formatted OPORD with 5W (what, who, where, why, when) elements. Then, we slove the nested vehicle routing planning problem as a mixed integer linear program (MILP) with the outputs of what is the UGV route, what is the UGV sortie, and how to control the customers’ distribution between the UGV and the UAV. Experimental results of random instances and case study show that using the iterative improvement algorithm increase the speed rate of solving more than 10%.
1 February 2023 in Journal of Systems Engineering and Electronics
In the field of satellite imagery, remote sensing image captioning (RSIC) is a hot topic with the challenge of overfitting and difficulty of image and text alignment. To address these issues, this paper proposes a vision-language aligning paradigm for RSIC to jointly represent vision and language. First, a new RSIC dataset DIOR-Captions is built for augmenting object detection in optical remote (DIOR) sensing images dataset with manually annotated Chinese and English contents. Second, a Vision-Language aligning model with Cross-modal Attention (VLCA) is presented to generate accurate and abundant bilingual descriptions for remote sensing images. Third, a cross-modal learning network is introduced to address the problem of visual-lingual alignment. Notably, VLCA is also applied to end-to-end Chinese captions generation by using the pre-training language model of Chinese. The experiments are carried out with various baselines to validate VLCA on the proposed dataset. The results demonstrate that the proposed algorithm is more descriptive and informative than existing algorithms in producing captions.
Hexagonal grids use a hierarchical subdivision tessellation to cover the entire plane or sphere. Due to the 6-fold rotational symmetry, hexagonal grids have some advantages (e.g. isoperimetry, equidistant neighbors, and uniform connectivity) over quadrangular and triangular girds, which makes them suitable to tackle tasks of geospatial information processing and intelligent decision-making. In this paper, we first introduce some applications based on the hexagonal grids. Then, we introduce the planer and spherical hexagonal grids and analyze the group representations for them, we review geometric deep learning, some Convolutional Neural Networks (CNNs) for hexagonal grids, and group-based equivariant convolution. Next in importance, we propose the HexagonNet for hexagonal grids, and define a new convolution operator and pooling operator. Finally, in order to evaluate the effectiveness of the proposed HexagonNet, we perform experiments on two tasks: aerial scene classification on the aerial image dataset (AID), and 3D shape classification on the ModelNet40 dataset. The experimental results verify the practical applicability of the HexagonNet given some fixed parameter budgets.
Atom gravimeter (AG) is a kind of high-precision absolute gravimeter based on atom interference, which can measure absolute gravitational acceleration. Vibration is one of the important factors which limits the measurement accuracy. Vibration compensation is an effective method to reduce the impact of vibration on measurement accuracy and it is especially suitable for complex vibration environments. In this paper, an improved vibration compensation method is proposed. Based on the simplified model of vibration transfer function, the method searches for the optimal parameters through an improved chaotic sparrow search algorithm (CSSA) to effectively restore the real vibration of the Raman mirror and achieve the best compensation effect. The experimental results show that the improved method proposed in this paper can achieve better compensation effectiveness in less calculation time than the previous methods. The modified atom interference fringe fitting uncertainty can attenuate by 70.21%, and the search time is reduced by nearly 6 times, effectively improves the accuracy and stability of the AG measurement. This method can correct the interference fringes in time when the environment changes, which provides a new idea for the design of vibration compensation method considering dynamic gravimetry with AG.
Vision-and-Language Navigation (VLN) is a task designed to enable embodied agents carry out natural language instructions in realistic environments. Most VLN tasks, however, are guided by an elaborate set of instructions that is depicted step-by-step. This approach deviates from real-world problems in which humans only describe the object and its surroundings and allow the robot to ask for help when required. Vision-based Navigation with Language-based Assistance (VNLA) is a recently proposed task that requires an agent to navigate and find a target object according to a high-level language instruction. Due to the lack of step-by-step navigation guidance, the key to VNLA is to conduct goal-oriented exploration. In this paper, we design an Attention-based Knowledge-enabled Cross-modality Reasoning with Assistant’s Help (AKCR-AH) model to address the unique challenges of this task. AKCR-AH learns a generalized navigation strategy from three new perspectives: (1) external commonsense knowledge is incorporated into visual relational reasoning, so as to take proper action at each viewpoint by learning the internal–external correlations among object- and room-entities; (2) a simulated human assistant is introduced in the environment, who provides direct intervention assistance when required; (3) a memory-based Transformer architecture is adopted as the policy framework to make full use of the history clues stored in memory tokens for exploration. Extensive experiments demonstrate the effectiveness of our method compared with other baselines.
Satellite communication systems are increasingly facing serious environmental challenges such as malicious jamming, monitoring, and intercepting. As a current development of artificial intelligence, intelligent jammers with learning ability can effectively perceive the surrounding spectrum environment to dynamically change their jamming strategies. As a result, the current mainstream satellite communication anti-jamming technology based on wide interval high-speed frequency hopping is unable to deal with this problem effectively. In this work, we focus on anti-jamming problems in the satellite communication domain, and reformulate the power allocation problem under two kinds of confrontation scenarios as one-shot and repeated games model. Specifically, for the problem of multi-channel power allocation under a one-shot confrontation scenario, we firstly model the problem of allocating limited power resource between communication parties and a jammer on multi-channel based on a BG (Blotto Game) model. Secondly, a DO-SINR (Double Oracle-Signal to Interference plus Noise Ratio) algorithm is designed to approximate the Nash equilibrium of the game between two parties. Experiments show that the DO-SINR algorithm can effectively obtain the approximate Nash equilibrium of the game. For the problem of multi-channel power allocation under a repeated confrontation scenario, we firstly transform the problem into an online shortest path problem with a graph structure to make the problem solving process more intuitive, and then design the Exp3-U (Exp3-Uniform) algorithm which utilizes the graph structure to solve the multi-channel power allocation problem. Experiments show that our algorithm can minimize the expected regret of communication parties during online confrontation, while maintaining good operating efficiency. The two power allocation problems constructed in this paper are common problem formed in confrontation scenarios. Our research and analysis can simulate some actual confrontation scenarios of the satellite communication power allocation, which can be used to improve the adaptability of satellite communication systems in complex environments.