With the increasing applications of UWB indoor positioning technologies in industrial areas, to further enhance the positioning precision, the UWB/IMU combination method (UICM) has been considered as one of the most effective solutions to reduce non-line-of-sight (NLOS) errors. However, most conversional UICMs suffer from a high probability of positioning failure due to uncontrollable and cumulative errors from inertial measuring units (IMU). Hence, to address this issue, we improved the extended Kalman filter (EKF) algorithm of an indoor positioning model based on UWB/IMU tight combination with a double-loop error self-correction. Compared with conventional UICMs, this improved model consists of new modules for fixing time desynchronization, optimizing the threshold setting for UWB ranging, data fusion in NLOS, and double-loop error estimation, sequentially. Further, systematic error controllability analysis proved that the proposed model could satisfy the controllability of UWB indoor positioning systems. To validate this improved UICM, inevitable obstacles and atmospheric interferences were regarded as Gaussian white noises to verify its environmental adaptability. Finally, the experimental results showed that this proposed model outperformed the state-of-the-art UWB-based positioning models with a maximum deviation of 0.232 m (reduced by 83.93% compared to a pure UWB model and 43.14% compared to the conventional UWB/IMU model) and standard deviation of 0.09981 m (reduced by 88.35% compared to a pure UWB model and 22.21% compared to the conventional UWB-IMU model).
Crowd accident surveys have shown that regardless of the initial triggering factors, pedestrian fall behavior is the most critical factor causing and aggravating crowd accidents in public traffic areas (PTAs). The application of pedestrian fall behavior detection methods in PTAs is significant. Once deployed, they would prevent many pedestrians from losing life in crowded traffic area accidents. However, most existing methods are still focused on medical assistance for the elderly. Therefore, this paper conducted bibliometric and content analyses, combining fall detection-related keywords from internationally recognized literature databases and benchmark pedestrian behavior datasets. Based on the analysis of the state-of-the-art (SOTA) achievements in fall detection methods, the fall detection methods were classified into different categories according to the research approach. This study undertakes a comprehensive analysis of five predominant methods, namely, computer vision, Internet of Things, smartphone, kinematic, and wearable device-based methods. Furthermore, the benchmark datasets, including fall scenarios, were introduced and compared. Finally, this study provides a detailed discussion of existing fall detection methods, and possible future directions are identified considering the application requirements in PTAs. This overview may help researchers understand the SOTA fall detection methods and devise new methodologies by improving and synthesizing the highlighted issues in PTAs.
Low-carbon production is currently the development direction of enterprises. The government provides low-carbon subsidies to low-carbon manufacturing enterprises to promote the formation of a green supply chain. To better encourage the development of the green supply chain by determining government subsidies and platform authentication fees, this paper constructs a Stackelberg game model that consists of a supplier and a manufacturer, and solves the optimal decisions of each entity using the backward induction method. This study uses the matching method to analyze the payoff matrix for supply chain members when choosing between low-carbon and traditional production. After introducing the online trading platform, the impact of the platform on the profit of supply chain members is studied, considering whether the authentication service provided by the platform is completely accurate. The results show that (1) in the green supply chain, there is a relationship between the enterprises’ profit and the level of emissions reduction, which increases first and then decreases. (2) The online trading platform is conducive to achieving green supply chain coordination. The government can pay fewer subsidies to prompt the formation of a green supply chain and the optimal emissions reduction level of the enterprise is higher. (3) When the authentication mechanism of the platform is imperfect, the authentication fee of the platform and the subsidy coefficient of the government need to be set within a reasonable range to avoid the enterprise adopting traditional production pretending to be the low-carbon type. This study contributes to research on the green supply chain and provides insights into pricing strategies for governments and platforms.
The dynamic illumination conditions in the Moon’s polar region present challenges for future rover explorations, which require enhanced efficiency and intelligent data preprocessing for Sun-synchronous path planning. Within the Chang’E-7 polar exploration mission context, this study investigates automated, intelligent preprocessing of 2.5D illumination data from high-resolution Digital Elevation Models for polar rover global path planning. A preprocessing pipeline is developed using a Sun-synchronous spatiotemporal U-Net,3STU-Net, incorporating time-slice and time-series sub-networks, to streamline data handling and identify regions with favorable illumination. Subsequently, an enhanced A* algorithm named 3ST-A*, leveraging preprocessed data, is applied in a designated area of interest for global path-planning experimental validation. The findings significantly improve illumination data processing efficiency and advance path-planning research, offering valuable support for future lunar exploration missions.