Three-dimensional measurement system for pipe assembly process

Abstract

In shipbuilding processes, the fabrication of connection pipe between two arbitrary pipes positioned at a distance in a huge steel block is one of the most difficult and inefficient processes. In this process, the measurement of the three-dimensional relative position of pipes is dependent on manual operations in most shipyards, and results in a very tedious and inefficient procedure. So, a proper measurement system should be developed to improve the productivity and the accuracy of assembly. This paper describes the research and development of a new pipe measurement system for pipe connections including the conceptual design, the establishment of measuring procedures, the design and fabrication of a measurement system, and a system calibration with an artificial neural network algorithm. Finally, the accuracy and productivity of the proposed system are also presented in this paper after implementation of this system for actual application in shipyards.

A Set-Up of 7 Laser Triangulation Sensors and a Draw-Wire Sensor for Measuring Relative Displacement of a Piston Rod Mechanical Lead-Through Transmission in an Offshore Wave Energy Converter on the Ocean Floor

“…The output from the laser triangulation sensors can be correlated with the output from the draw-wire sensor to interpret the performance of the piston rod mechanical lead-through transmission. Draw-wire sensors connected to mechanical applications, and comments on calibration, have been found in scientific literature [74,75] and commercial online material [76] but have to the authors' knowledge not been used before inside an offshore linear WEC.…”

An improved posture evaluation method for cylindrical intersecting holes on large aerospace components based on monocular vision

“…Liu et al [3] used a micro vision system and a force sensor to observe the posture of parts and to detect the contact force during assembly. For the accurate measurement of position and angular orientation of a pair of pipe flanges, by using an artificial neural network algorithm, Youn [4] proposed a 3D measurement system based on a draw-wire sensor, step motors and encoders. However, this kind of contact measurement method requires the insertion process between mating parts, which can easily cause wear on the surface of the parts, and has high requirements for the position control of the contact force.…”