System Design And Dynamic Optimization Of A Mobile Micro-robot For In-pipe Surveillance With Wheeled Based Climbing Structure

In-pipe surveillance of narrow pipe is a challenging topic within the research of pipe-inspection robot. In one hand, the volume of robot is constrained by limited space inside the narrow pipe; in other hand, the robot must own the ability to move freely inside multiple pipe structure. Based on the above requirements, this thesis presents a wheeled based climbing micro-robot for in-pipe surveillance so as to suit applications in multiple pipe structures.After comparing varied pipe-surveillance robots, wheeled based climbing micro-robot would be the most suitable one to the application of surveillance on narrow and changeable pipe systems. A Tri-wheel structure is applied on robot for moving and a magnetic wheel structure which is combined with the actuator is presented as climbing mechanism.After determining the architecture of the micro-robot and based on multiple constraints related to the structure of micro-robot, this thesis conducts mechanical analysis, dynamic analysis and magnetic analysis, thus to optimize and determine the parameters of the micro-robot.Based on LPC2106 processor, an embedded control system is established for micro-robot control. The hardware includes the power module, MPU module, motor control module and wireless module. Using 2-3 phase control method for the step-motor, the precision of translational move and steering move can be ensured respectively as 0.59mm, and 1.5°. And a specified RF operation program is designed for the wireless module, thus to achieve the wireless receiving and transmitting.To research the dynamic performance of the micro-robot, a dynamic model with slip for the micro-robot is established based on rigid body dynamics and the robot structure. With this model, translational move simulations are conducted for micro-robot applied with normal wheels and magnetic wheels respectively. And these simulations also prove the deviation caused by the slip effect and verify that the magnetic wheel structure could limit slippage and improve the positioning precision of the micro-robot. At last, a vision feedback based control method is presented to limit the deviations brought by the assembly error of the micro-robot, which also is proven by simulations, thus to improve the positioning precision.