Maintaining the relative positions and orientations of multiple robots using vision

Abstract

To keep several robots in geometric formation several issues have to be considered. This paper describes an experimental system for controlling multiple robots in geometric formation. This system has a mixed control structure, where both a central coordinator is used and also each robot has a high level of autonomy. The relative locations of the robots are estimated using vision. The central coordinator is used to decide the type of formation and to inform the robots about the formation type. Each robot is autonomous to make any decisions relative to the control of its position and velocity. Any of the robots can act as the central coordinator, but at any instant of time there is only one coordinator. The type of geometric formation can be dynamically changed and it depends on the overall goal of the system or on dynamic changes of the environment. To keep the robots in geometric formation their relative positions and orientations have to be known and they are estimated using vision.

Correlation Error Reduction of Images in Stereo Vision with Fuzzy Method and its Application on Cartesian Robot

“…is given by (Paulino et al, 2001): . A method that frequently used to overcome this difficulty is to perform matching via the correlation coefficient, defined as:…”

Correlation Error Reduction of Images in Stereo Vision with Fuzzy Method and Its Application on Cartesian Robot

“…Generally, the choice of the correlation window size is a trade off between increasing reliability in areas with constant depth and decreasing errors where depth changes. The use of a smaller correlation window reduces the problem, because smaller window does not overlap the depth discontinuity to the same extent (Paulino et al, 2001). …”

Mobile multi-robots formation control and its implementation

“…Because each robot behaves independently, so communication is need to maintain formation, thus, not only communication will require high and time will expend more, but formation will become unstable also. Reference [5] attempted to propose a Group Shape Generating Model (GSGM) for robot cooperative system. Now most studies still aim at methods effective to special tasks in order to improve system efficiency.…”