Axiomatic design method to design a screw drive in-pipe robot passing through varied curved pipes

Abstract

A screw drive in-pipe robot is promising inspection equipment for small pipes. However, most of the existing screw drive in-pipe robots have problems of motion interference and slipping inside curved or irregular pipes. These problems result from the coupled relations among the steering motion, the motion speed and the load ability of the robot. In order to deal with the problems, the axiomatic design (AD) theory is applied to evaluate and analyze the existing designs. Then an uncoupled concept design based on the AD theory is proposed and the complete AD decomposition process is presented. After that, the proposed robot based on a tri-axial differential angle modulation mechanism is designed to realize the uncoupled concept. Finally, the uncoupled property is verified in a dynamics simulation system. The simulation results indicate that the motion speed, load ability and steering motion of the proposed robot can be adjusted individually compared with the robots that have inclining-angle-fixed rollers. Owing to the uncoupled design, the proposed robot can mechanically adapt to straight pipes and curved pipes with less roller slipping. screw drive, in-pipe robot, axiomatic design, tri-axial differential mechanism Citation:Li T, Ma S G, Li B, et al. Axiomatic design method to design a screw drive in-pipe robot passing through varied curved pipes.

An Energy Efficient Two-Stage Supply Pressure Hydraulic System for the Downhole Traction Robot

“…In high-pressure supply circuit, (2) is the power loss in the fluid pipe and (2) is the power loss in the accumulator. In low-pressure supply circuit, the power loss in the fluid pipe is (1) .…”

“…where is flow rate in the OSP, (1) is the flow rate in the low-pressure circuit of the TSP, (2) is the flow rate in the high-pressure circuit, is pipe length of the OSP, (1) is the length of the low-pressure circuit, and (2) is the length of the high-pressure circuit. During one cycle, the difference of pipe power loss in OSP and TSP is expressed as…”

“…where (1) is the flow rate streaming into the accumulator, (2) is the flow rate issuing from the accumulator, (1) is the pressure in energy storage, (2) is the pressure in energy releasing state, and 0 is the energy recharging time.…”

“…With the development of information technology, sensation technology, and control technology, mobile robots have been dramatically improved, which can be widely used in military, industry, and civil service [1][2][3]. As a kind of mobile robots, downhole traction robots have been applied to the development in petroleum field in recent years.…”

Development of an In-Pipe Robot With Differential Screw Angles for Curved Pipes and Vertical Straight Pipes

“…So, it is important to choose the suitable values for the spring stiffness and preload force. When the robot moves inside a curved pipe, the cross section of the screw rollers is similar as an egg [22]. The length of each elastic arm is changeable real-timely with the rotation of the body.…”