Research On Self-reconfiguring Docking System For Multiple Mobile Robots

In this thesis,we design a self-reconfiguring mobile robot based on the centipede bionic and the visual feedback to address the problem that mobile robots are difficult to achieve all-terrain movement.The efficient kinematic design with planetary wheels solves the problem of climbing and crossing obstacles in complex scenes.The proposed robot system consists of multiple units where each unit is a mobile robot.The elementary robot module can act independently,i.e.,distributed control,and at the same time can dock to form a centipede-like motion structure by the self-reconfiguration method.To form the "centipede" automatically,the self-reconfiguring docking solution was developed by reassembling the elementary robot without human control.After docking and reassembling,the climbing capability of the whole robot is instantly upgraded so that it can climb over an obstacle that is 1.5 times its own height.It will also be competent for other operations such as climbing stairs.The above performance cannot be achieved by the separated elementary robot unless when multiple elementary robots are connected in a whole.This thesis aims to solve the key technology of reassembling separate robots together,which is the self-reconfiguration docking technology.The detailed research contribution is as follows:First,summarized kinematic requirements of the robot according to the characteristics of the all-terrain movement,such as climbing and crossing.Taking inspiration from the centipede,derived the bionic mobile robot platform.In order to compact the design,the robot is designed as a convex structure,i.e.,narrow in front and wide at the back.This kind of staggered wheel spacing design effectively reduced the interference between the front and rear wheel movements.This thesis presented the overall structural layout of the elementary robot module design,as well as information about the robot itself.In terms of hardware,it introduced the hardware of the robot mainly through the following aspects: the motor module,vision module,inertial measurement module,and power supply module.In terms of software,it describes the design of the communication system,the positioning system,and the electronic control system.Second,the robot kinematics analysis is performed based on this convex structure mobile robot.The robot mobile platform design determines the control of movement patterns,and the analysis is preceded by relevant assumptions and a simplified robot model to facilitate kinematic analysis.The analysis is built on the robot coordinate system as well as the global coordinate system,including straight,spin and circular motion,and based on this model,the kinematic performance is tested.Then,a theoretical analysis,as well as an experimental verification of the important visual feedback loop for the robot self-reconfiguration is presented.This includes the conversion of the coordinate system in the camera imaging model,the solving and tuning of the internal and external parameters,and the calibration of the camera.The experiment section verifies the range of the obtained internal parameters and then proposes a scheme for improving the stable filtering.Finally,the complete robot was subjected to self-reconfiguration experiments,and a robot position estimation strategy,a motion control strategy,a self-reconfiguration docking separation strategy,a velocity optimization strategy,and a damage self-repair strategy were designed.The robot was operated for the self-reconfiguration and damage self-repair experiments according to the designed scheme.The experimental results demonstrated the structural design of the cell module mobile robot is reasonable,the motion model analysis is correct,and the self-reconfiguration docking separation scheme of the mobile robot is feasible.