Research On Key Technology Of Speed Control Of Gas Pipeline Inspection Robot

In order to ensure China's energy supply and boost its rapid economic development,China has built a dense long-distance oil and gas pipeline network.Pipeline running for a long time will produce safety risks,need to regularly detect and repair the hidden danger.Pipeline internal detector has the ability to detect quality defects,corrosion protection layer falling off,stress cracks,etc.,which is one of the important means to ensure the safe operation of long-distance oil and gas pipelines.The power source of the inner detector is the high-speed fluid medium,which drives the inner detector to run in the pipeline.However,the running speed of the inner detector is too fast,which may lead to the reduction of detection accuracy,the failure of detection data,and even the collision with the elbow and valve,resulting in serious safety accidents.In this paper,the speed control device of the internal detector was studied.By comparing the performance,advantages and disadvantages of the domestic and foreign discharge devices,the rotary bypass valve was determined as the research object,the influence of the valve opening and structure on the discharge was explored,and a set of speed control device was designed and manufactured.The specific content is as follows:(1)The force model of the internal detector running in the pipeline is analyzed and established,and the influencing factors of the speed variation of the internal detector are illustrated.It is proposed to control the running speed of the internal detector by controlling the pressure difference between the front and rear of the internal detector,and the head loss formulas of three different models are used to describe the causes and influencing factors of the pressure difference between the front and rear of the internal detector,which provides a theoretical basis for the subsequent speed control strategy.(2)Based on detector local dynamic model and numerical simulation analysis result,combined with the current international mainstream detector structure scheme,carry out the speed detector in the phi 660 large diameter control unit development,overall scheme design proposed in the adjustable speed detector,and through the numerical simulation to the performance parameters optimization design of key components,and then completed the discharge speed control unit design processing,drive unit selection and installation design.(3)The speed control theory of closed-loop internal detector based on speed feedback regulation is proposed,and the speed control system with builtin PID controller is developed based on the theory,which can realize the closedloop drive action of parameterized discharge device.