Telepresence or tele-immersion technologies allow people to attend a shared meeting without being physically present in the same location. Commercial telepresence solutions available in the market today have significant drawbacks - they are very expensive, and confine people to the area covered by stationary cameras. In this research project, We aim to design and implement a mobile tele-immersion platform that addresses these issues by using robots with embedded cameras. In our system, the users can move around freely because robots autonomously adjust their locations. We provide a geometric definition of what it means to get a good view of the user, and present control algorithms to maintain a good view.
Our mobile video-conferencing system consists of multiple iRobot Create robots (differential drive), each carrying an Asus EEE PC connected over a serial interface. These inexpensive netbooks are powerful enough to run a fully-flavored Linux operating system. They also have a built-in embedded 1.3 megapixel camera. The laptops control the robots using the iRobot Open Interface (OI) specification. Communication between the robots and a central workstation uses an ad-hoc wireless network.
The flowchart above shows the flow of data and control executed in every time-step of our system: (1) vision-based state estimation using markers, (2) combined user state estimates are classify the user as either 'Rotating' or 'Linear' (translating), (3) as a function of the classified user motion pattern, compute optimal robot trajectories, and, (4) send control commands over the wireless network for each robot to execute.