Room segmentation plays a significant role in scene understanding, semantic mapping, and scene coverage for robots navigating in real-world indoor environments. However, most previous works take a passive segmentation that requires a complete and uncluttered grid map as input, often resulting in lower segmentation accuracy and cannot be deployed in unknown environments. In this paper, we propose an active room segmentation framework that can enable a robot to incrementally and autonomously perform room segmentation in cluttered indoor environments. Our framework consists of three key components: i) a door extraction module where a visual semantic feature, specifically, door, is extracted to better identify rooms in cluttered environments, ii) a within-room exploration module that detects frontiers within the currently exploring room, and iii) a topological module that represents connectivity between rooms and determines next room for exploration. We show through experiments that the proposed method depicts two distinct advantages against existing methods in segmentation accuracy and autonomy. The code is available at https://github.com/FreeformRobotics/Active_room_segmentation.

Spherical Modular Self-reconfigurable Robots (SMSRs) have been popular in recent years. Their Self-reconfigurable nature allows them to adapt to different en-vironments and tasks, and achieve what a single module could not achieve. To collaborate with each other, relative localization between each module and assembly is crucial. Existing relative localization methods either have low accuracy, which is unsuit-able for short-distance collaborations, or are designed for fixed-shape robots, whose visual features remain static over time. This paper proposes the first visual relative localization method for SMSRs. We first detect and identify individual modules of SMSRs, and adopt visual tracking to improve the detection and identification robustness. Using an optimization-based method, tracking result is then fused with odometry to estimate the relative pose between assemblies. To deal with the non-convexity of the optimization problem, we adopt semi-definite relaxation to transform it into a convex form. The proposed method is validated and analysed in real-world experiments. The overall localization performance and the performance under time-varying configuration are evaluated. The result shows that the relative position estimation accuracy reaches 2%, and the orientation estimation accuracy reaches 6.64°, and that our method surpasses the state-of-the-art methods.

The object navigation task requires robots to understand the semantic regularities in their environments. However, existing modular object navigation frameworks rely on instance segmentation models trained at fixed camera height viewpoints, limiting generalization performance and increasing labeling costs for new height viewpoints. To tackle this issue, we propose a semi-supervised method that transfers knowledge from a source height to a target height, minimizing the need for additional labels. Our approach introduces three key innovations: i) a projection policy to enhance the teacher model's detection capabilities at the target height, ii) a dynamic weight mechanism that emphasizes high-confidence pseudo-labels to reduce overfitting, and iii) a prototype contrast transferring method to transfer knowl-edge effectively. Experiments on the Habitat- Matterport 3D (HM3D) dataset show our method outperforms state-of-the-art semi-supervised techniques, improving both segmentation accuracy and navigation performance. The code is available at: https://github.com/FreeformRobotics/TransferKnowledge.