Optimization And Step Control Research Of A Flexible Inchworm Pipe Robot

With the development of society, varies of pipes are used widely. As the important tools to work in the pipe, the pipe robot gets more attention. The pipe robot is a mechanical device based on moving mechanism to complete tasks like inspection, testing, spraying, welding and so on. The flexible inchworm pipe robot has simple structure, large driven force, moving stable and good adaptability to complex environment of the pipe.The thesis evaluates the motion performance of the first generation of the flexible inchworm pipe robot, and based on that optimization scheme are proposed. Take the robot optimized as the research object, dynamic model is built by dynamic analysis and control system is finished. On the bases of that, the second generation of the robot is made and a series of experiment is done to evaluate its motion performance. The main content of the thesis is as followed:(1)Moving and traction experiments are done for the early pipe robot and the motion property parameters are gotten. On the basis of that, the structures of moving wheels and the guide head are optimized. Brake wheels are optimized based on the former structure, which make the robot possible to avoid internal friction cased by different direction of the wheels. The unnecessary guide head is removed to ensure the structure more reasonable on the premise of the function of the robot.(2) The crossing ability of the robot is analyzed, including in the pipelines with concave and convex. The traction model and the efficiency model of the flexible shaft are built by mechanical characteristics analysis. What’s more, the concept of the flexible shaft’s instability in moving state is proposed and the critical instability qualifications of the flexible shaft in straight and L-type pipes are derived respectively. (3)The hand-in control system of the pipe robot is proposed. According to needs of the robot, the control system is divided into the main control subsystem, implementation subsystem, sensor subsystem, communication subsystem, power subsystem and the control terminal subsystem. The components of each subsystem and relationships are described in detail.(4) The experiments of the optimized pipe robot are studied. The physical prototype is developed and moving experiments, traction experiments, efficiency experiments and stability experiments of the flexible shaft are done. And based on theoretical analysis and experimental study, step planning is carried out, which is implement by the sensor subsystem.