Design And Implementation Of Mobile Robot Group For Water Regime Monitoring In Cable Tunnel

With the widespread application of underground cable tunnels in urban power distribution networks,environmental monitoring of underground cable tunnels has become essential to ensure the stable operation of the power system.At present,most of the environmental monitoring equipment for cable tunnels can only be used for routine inspection.For the case of sudden water situation and communication obstruction in cable tunnels,the existing environmental monitoring equipment often fails to work normally.In order to realize the environmental monitoring of the cable tunnel under the sudden water condition,this thesis develops an emergency monitoring system for the water regime monitoring of the cable tunnel by using an amphibious spherical mobile robot group,avoiding the danger that maintenance personnel may enter the tunnel directly,and also provide guidance for the next repair and maintenance work.The main research work of this thesis is as follows:Firstly,the overall scheme design of the cable tunnel water regime monitoring system is divided into three parts: the monitoring node group subsystem,the ground display and control center subsystem,and the wireless communication network.For the monitoring node group subsystem,the built-in two wheel differential driving car is selected for the design of a single spherical robot compared with the driving mode of the existing amphibious spherical robot.Then,according to the working environment of the cable tunnel,UWB technology was selected to realize the spherical robot group moving in a straight line in the cable tunnel in the leaderfollower mode;For the ground display control center subsystem,it is divided into two parts:environment information display interface and mobile node control interface,which realize the real-time display of tunnel environment information and the motion control of mobile node respectively;For the wireless communication network,according to the needs of the monitoring function,the wireless module communication mode is established by using a Wi Fi module to establish a wireless ad-hoc network by comparing with the existing wireless communication technology.Secondly,a single spherical mobile monitoring node is used as the research object,a complete dynamic model of spherical robot with general characteristics is established by using Lagrangian equation.Then,the dynamic model is simplified according to the actual working state of the spherical robot in the cable tunnel.The simplified dynamic models are established on the ground and in the water respectively,and the correctness of the model is verified by Simulink.Finally,combined with the dynamic model,the direction controller,ground speed controller and water speed controller based on PID control were designed,and the feasibility of the controller was verified by simulation.Thirdly,taking the group by multiple spherical mobile monitoring nodes as the research object,the UWB technology is used to measure the relative position information of the node without a fixed base station,and then the relative position information is used as a feedback to design the automatic following of a single node method.Then the single node following method is extended to the group formed by multiple nodes.By using the leader-follower method,multiple mobile nodes follow one by one to realize the robot group moving in a straight line with a fixed speed and a fixed distance in the cable tunnel.The feasibility and accuracy of the method are verified by the joint simulation of group motion and dynamic model.Finally,the software and hardware of the whole system are designed and developed,and the group of amphibious spherical mobile robot and the interface of ground display control and center for human-computer interaction are developed.Then,experiments are carried out on the ground and on the water to verify the function of the whole monitoring system.In this thesis,a set of spherical mobile robot groups for water regime monitoring in cable tunnels is developed to achieve emergency environmental monitoring in case of sudden water regime in cable tunnels.It effectively makes up for the deficiency of routine inspection of cable tunnel,and provides an effective solution for emergency monitoring of cable tunnel in case of emergency.