Research On The Bending Control Of The Pipe Detection Robot

When the robot walks in a straight path,the speed of each wheel and diameter are exactly the same.However,when a corner is encountered,if the drive unit has no differential speed function and variable diameter,some of the robot's drive wheels may slip,and even worse the robot will roll over as a whole,making the smooth turning of the pipeline robot seriously affected.Therefore,it is necessary to use the differential speed structure and variable diameter control in the drive unit to improve the adaptability of the robot.A three-axis differential speed type single-motor-driven pipeline inspection robot was overall designed.A pipeline inspection robot control system with a single-chip microcomputer C8051F040 as a controller was designed.The modular design concept was selected,and the core control module,signal detection module,parameter acquisition module and motor drive module of the robot were analyzed.The single-motor three-axis differential speed mechanism was applied to the drive unit in view of the problem that the three motors separately drove the pipeline inspection robot to cause insufficient turning flexibility and large occupying space.The differential speed characteristics of the three-axis differential speed type pipeline robot driving unit were analyzed,and the rotation radius of the three driving wheels was determined according to the movement state diagram.The speed ratio of the driving wheels was obtained and analyzed.A number of experiments were conducted to collect the average speed of the three driving wheels when the robot was making a turn,and it is found that the collected speed ratio complies with the principle of three-axis differential speed,which proves the reliability and correctness of the theoretical analysis.In view of the problem that in the three-axis differential speed type pipeline inspection robot driving unit,the compression of the spring in the pre-tightening variable diameter structure was sometimes too large or too small,leading the robot not to make a turn smoothly,the fuzzy control of the variable diameter mechanism was proposed.A pre-tightening variable diameter system model was established to design the fuzzy controller,and the Mamdani fuzzy controller was selected.The difference F between the maximum stress of the wheels and the optimal pressure value and the rate of change EF were determined as the input to the fuzzy controller.The voltage U in the pipeline robot drive system was used as the output,and simulations and experiments were performed.The results show that the compression of the pipe robot spring can be kept within a certain range when it is making a turn,and finally the robot can smoothly change the diameter with the change of the pipe,avoiding the motion interference problem and making the turning of the pipeline successfully.