Research On The Techonology Of Formation Keeping Of Multi-robot Based On NAO

With the development of robotics, research on cooperation and coordination of multi-robot has become a hot issue. Compared with single robot, multi-robot system has more advantages, such as distributed control system, adaptability, low cost and high efficiency. At home and abroad, research on multi-robot causes widespread attention.Formation keeping is the typical problem of multi-robot cooperative and coordinative technology. Most theoretical study of formation keeping is in computer simulation and lack of achievements on actual platform. The NAO produced by Aldebaran Robotics Corporation is taken as experiment platform to solve formation keeping. The research contents are target identification and location, generating formation and formation control.Location is critical question of formation keeping. This paper studies the location of NAO based on visual sensor. According to the characteristics of image acquired in NAO and target, the reasonable methods of image process and object detection are used. In view of monocular vision technology, a model of the space point location is built, to map the two-dimensional coordinates of target in image to the three-dimensional coordinates of target in NAO coordinate. The result of experiment verify the accuracy meet requirement of formation keeping.To achieve generating formation, a multilevel formation method based on leaderfollower come forward. By dividing robots into multiple sets of leader-follower, follower computes desired position by refer to the position of leader on the basis of l-φ positon control law. This method figures out the question of follower losing and low collaboration in formation control. The test shows that robots can constitute desired formation and prepare for formation control. In allusion to formation control, behavior-based approach is used. Four behaviors, move-to-goal, avoid-obstacle, follow-border and recoverformation are indicated. Behavior selection come true by using behavior-based subsumption architecture. The consequences of experiments confirm the effectiveness of approach to formation control in formation keeping based on NAO.