Dynamic 3D reconstruction and point tracking in videos are typically treated as separate tasks, despite their deep connection. We propose St4RTrack, a feed-forward framework that simultaneously reconstructs and tracks dynamic video content in a world coordinate frame from RGB inputs. This is achieved by predicting two appropriately defined pointmaps for a pair of frames captured at different moments. Specifically, we predict both pointmaps at the same moment, in the same world, capturing both static and dynamic scene geometry while maintaining 3D correspondences. Chaining these predictions through the video sequence with respect to a reference frame naturally computes long-range correspondences, effectively combining 3D reconstruction with 3D tracking. Unlike prior methods that rely heavily on 4D ground truth supervision, we employ a novel adaptation scheme based on a reprojection loss. We establish a new extensive benchmark for world-frame reconstruction and tracking, demonstrating the effectiveness and efficiency of our unified, data-driven framework. Our code, model, and benchmark will be released.

Wireless power transfer (WPT) is the preferred charging method for battery-powered electric vehicles (EVs). In this paper, a novel WPT system with constant current charging capability is introduced for warehouse vehicles with lead-acid batteries. First, the schematic structure of the proposed system is discussed. A novel structure of asymmetrical loosely coupled transformer is designed to enable high-voltage feeding to low-voltage output and reduce the weight of the secondary side. Secondly, an optimized magnetic coupler using ferrite cores and magnetic shielding structure is proposed to ensure stable power transmission and high efficiency. Then, a dual-side independent control strategy on dual active bridge is proposed, aiming for maintaining constant charging current and high system efficiency. Finally, a 3kW inductive charging experimental platform is established to validate the theoretical analysis. Constant charging current of 45 A is achieved at the transmission distance of 50mm. The rated transferring power and system efficiency are 3 kW and 94.3%, respectively.