The Research On Inner Dimension Inspection Based On Laser-based Multi-direction Rays

The on-machine measurement of large and inner dimensions is usually difficult.The main reason for this is due to two facts.Firstly,transferring large workpiece onto measuring equipment brings about lack of productivity.And the measuring device always need calibrated on-site when on-machine measurement is performed.As a result,this lowers the time-efficiency.Secondly,to the limitation of the setup space and measurement principle,many mature techniques cannot be competent to measure inner dimensions.Consequently,the project on on-machine measurement of large and inner dimensions is often easily to develop,but hard to perform.In this article,an on-machine measuring method based on laser-based multi-direction rays(LMRs)is proposed for large and inner dimension inspection.According to various measurement demands,corresponding laser-based heads based on LMRs are developed to measure inner dimensions.The main contributions in this article include:1.Current research on the measurement of large and inner dimensions is firstly reviewed.Then,an on-machine measuring method based on LMRs is presented for large and inner dimensions.Finally,the core concept based on LMRs is introduced.2.An on-machine measuring method based on revolved single laser beam(RSLB)is proposed for inner dimension inspection.Then a single-laser measuring head is developed based on RSLB.Furthermore,the measurement models on common inner dimensions are established,such as hole-center location,hole-center distance,inner diameter and inclined-hole radius.In addition,the measuring information based on RSLB is enriched by adding time-based angles.Afterwards the measurement models of dihedral angle,inner outline and inner diameter are established by using improved RSLB.The measurement models are finally validated by experiments.3.The limitation of RSLB is firstly analyzed.An on-machine measuring method is proposed for inner dimension inspection by using revolved double laser beams(RDLB).Then an on-machine measuring head is developed based on RDLB.Furthermore,the measurement models of planar spacing and inner diameter are established,and the measurement principles of initialization and data extraction are analyzed afterwards.The method for the set-up and calibration of the measuring head is then presented.The measurement models are finally proved by experiments.4.The limitation of RDLB is firstly discussed.An in-situ measuring method based on static laser-based ray cluster(SLRC)is then proposed for large workpiece.Furthermore,a static laser-based measuring head is developed based on SLRC.The measurement models on the key parameters of the connecting rod are established by using the static laser-based measuring head.The details on calibration principle and pivotal measurement factors are circumstantially analyzed.The measuring method and system is finally validated by actual application.5.In terms of LMRs,the possibility to get rid of the numerical control machine is analyzed.An on-site measuring system based on SLRC is designed to measure multi-layer diameters inside shaft holes.Then corresponding measurement model based on SLRC is established.A general algorithm named JADE is adopted in solving the mathematical measurement model.Finally,on-site measurement of multi-layer diameters inside shaft holes is performed by using SLRC under complex industrial condition.