Remote programming over multiple heterogeneous robots: a case study on distributed multirobot architecture

Purpose - The authors of this paper aim to describe the design of distributed architectures for the remote control of multirobot systems. A very good example of remote robot programming in order to validate these architectures is in fact the remote visual servoing control. It uses sequences of camera inputs in order to bring the robots to the desired position, in an iterative way. In fact, in this paper, we enabled the students and scientists in our university to experiment with their remote visual servoing algorithms through a remote real environment instead of using simulation tools.Design methodology approach - Since 2001, the authors have been using the UJI-TeleLab as a tool to allow students and scientists to program remotely several vision-based network robots. During this period it has been learnt that multithread remote programming combined with a distributed multirobot architecture, as well as advanced multimedia user interfaces, are very convenient, flexible and profitable for the design of a Tele-Laboratory. The distributed system architecture permits any external algorithm to have access to almost every feature of several network robots.Findings - Presents the multirobot system architecture and its performance by programming two closed loop experiments using the Internet as communication media between the user algorithm and the remote robots (i.e. remote visual servoing). They show which conditions of Internet latencies and bandwidth are appropriate for the visual servoing loop. We must take into account that the real images are taken from the remote robot scenario and the experiment algorithm is executed from the client side at the user place. Moreover, the distributed multirobot architecture is validated by performing a multirobot programming example using two manipulators and a mobile robot.Research limitations implications - Future work will pursue the development of more sophisticated visual servoing loops using external cameras, pan tilt and also stereo cameras. Indeed, the stereo cameras control introduces an interesting difficulty related to their synchronization during the loop, which introduces the need to implement Real Time Streaming Protocol (RTSP) based camera monitoring. By using camera servers that support RTSP (e.g. Helix Producer, etc.) it means sending the differences between the frames instead of sending the whole frame information for every iteration.Practical implications - The distributed multirobot architecture has been