Robust and Accurate Multi-Agent SLAM with Efficient Communication for Smart Mobiles

In a long-term large-scenario application, the multi-agent collaborative SLAM is expected to improve the robustness and efficiency of executing tasks for mobile agents. In this paper, a multi-agent collaborative visual-inertial SLAM system is proposed based on a centralized client-server (CS) architecture, where the clients run on smart mobiles. In general, multi-agent collaborative SLAM relies on robust and precise experience sharing and efficient communication among agents. The experience sharing requires the place recognition with a high recall and accuracy, the precise estimation of transformation between looping frames, and the map fusion with globally consistency. To this end, we devise an enhanced geometric verification, a re-projection optimization based on the error-aware weighting strategy, and a strategy of flexible fusion to meet these requirements. In addition, the multi-agent collaborative SLAM needs to exchange abundant information, which requires the efficient communication. Therefore, we design a CS collaborative loop detection mechanism which is more robust to network transmission. We perform extensive experiments on the EuRoc dataset and in real environments. Experimental results show that the proposed system achieves better results than state-of-the-art methods. Furthermore, we demonstrate the stability of the proposed collaborative SLAM in real environments with a bandwidth of 7.55Mbps.