【目的】协同视觉同时定位与建图(CVSLAM)因其所需传感器成本低、可以获取丰富的环境信息,且具有快速性和灵活性的特点,在机器人领域引起了越来越多的研究者关注。而实现对图像信息的高效传输是提高CVSLAM建图效率需要解决的关键问题之一。在多机协同作业中,机器人之间的数据传输是其工作的重中之重,数据共享往往受到通信带宽的影响,所以研究高效的数据处理方法成为至关重要的环节。【方法】基于中心式协同ORB-SLAM2框架,研究个体机器人向中心站进行数据传输问题,探索一种基于特征压缩的高效数据传输一般方法。特别地,研究了一种基于算术编码对ORB特征进行差分编码并进行压缩传输的方法。该方法根据特征不同的编码模式评价其压缩后所需传输的数据量,并选择数据传输量最小的模式对特征进行编码。【结果】在不影响整体建图效果的前提下,所采用的方法明显降低了CVSLAM系统中数据传输过程中的数据量,同时缩短了数据传输时间。【结论】基于KITTI数据集的实验结果表明,基于压缩编码的通信方式可以有效降低数据传输量、提高传输速度,是提高CVSLAM通信效率的有效手段。

【Purposes】 Collaborative Visual Simultaneous Localization and Mapping (CVS-LAM) has attracted more and more researchers’ attention in the field of robotics owing to its low cost of required sensors, the ability to acquire rich environmental information, and its rapidity and flexibility. Realizing the efficient transmission of image information is one of the key prob-lems that need to be solved to improve the efficiency of CVSLAM map building. In multi-ma-chine cooperative operation, data transmission between robots is the most important part of their work, and data sharing is often affected by the communication bandwidth, so the study of effi-cient data processing methods has become a crucial part. 【Methods】 On the basis of the centralized collaborative ORB-SLAM2 framework, the problem of data transmission from individual ro-bots to the central station is studied, and a general method of efficient data transmission based on feature compression is explored. In particular, a method based on arithmetic coding for differen-tial coding of ORB features and compressed transmission is investigated. The method evaluates the amount of data to be transmitted after compression according to different coding modes of the features and selects the mode that minimizes the amount of data transmission to encode the fea-tures. 【Findings】 Without affecting the overall map building effect, the adopted method signifi-cantly reduces the amount of data during data transmission in the CVSLAM system, and at the same time shortens the data transmission time. 【Conclusions】 The experimental results based on the KITTI dataset show that the communication method with compression coding can effectively reduce the amount of data transmission and increase the transmission speed, which is an effective means to improve the efficiency of CVSLAM communication.