Research On The Method For Three-dimensional Measurement Of Close-range With A Miniaturized Bionic Compound-eye System

The machine vision as an important means of measurement is widely used inindustrial inspection, security, aviation and navigation and other fields. Morerequirements about the miniaturization of size and large fields of view in the visionsystem have been requested with the application fields increasing. A compound eyessystem has the advantages of large field, miniaturization and high sensitivity and hasbecome a hot topic in the vision measurement. Based on the imaging characteristics,this paper developed a small bionic compound eye system. Combining the traditionalmachine vision theory and image processing method, this system realized thethree-dimensional measurement of near field objects. The main work of this paper areas follows:1、I introduced the imaging properties of the insect compound eyes and reviewedthe research status of the three dimensional measurement.2、The overall structure of the compound eye system was presented, thetheoretical analysis of designed parameters were conducted, and the system wassuccessfully developed.3、Studied the calibration algorithms of the compound-eye.First, the platform forcalibration and measurement was built based on imaging characteristics of thecompound-eye. Three kinds of camera calibration methods of including Zhang‘smethod, the direct linear transformation method and Tsai two-step method, werecarried out to calibrate the central sub-eye. By comparing the experimental results, itwas determined that Tsai two-step method with a high precision and accuracy wassuitable for the calibration of the compound-eye system. Then to solve the problemthat the edge sub-vision axis was not perpendicular to the image sensor, a newdistortion model that effectively improved the edge sub-eye calibration accuracy isproposed.4、Studied the three-dimensional measurement of the compound-eye. Combiningtraditional machine vision theory, a multiple sub-eye detection model was established,and its impact on the compound-eye camera measurement accuracy is discussed. Itwas determined that three sub-eye condition had better accuracy and stability than thetwo-eye. Experimental results indicated that the relative error of the three-dimensional detection system was about2%when the object distance ranges from150mm-260mm,and this system could achieve the instrument miniaturization and basic near fieldmeasurement.