Research On The Calibration Methods Of Digital Close-range Industrial Photogrammetry System

Digital close-range industrial photogrammetry is a three dimensions coordinate measuring technology,and the accuracy of the technology is high.After more than ten years study and popularize,it has been widely used in aviation,spaceflight,automobile production and shipbuilding,etc.Usually,after a work the digital close-range industrial photogrammetry system will give a quantified measuring result.However,the measuring accuracy of the result is the most concerned thing of the users.At present,there are more and more digital close-range industrial photogrammetry systems enter the market,and the measuring accuracy of the systems are nominated higher and higher by the manufacturers.However,there has no standard on this filed in our country.In order to give the digital close-range industrial photogrammetry system a widely use field,the evaluation methods were studied.The main parts of the paper are:(1)Summarized the measure theory and system compositions key technology of digital close industrial photogrammetry system,which is the foundational support to the accuracy evaluate.And also summarized influence factors in accuracy evaluate of the system,which can help us do better.(2)The calibrate methods of the scale-bar which is used in digital close-range industrial photogrammetry system has been summarized.Analyzed the differences characteristic between the methods,and writer had put forward a new method to calibrate scale-bar's length,which is called image processing method.The result of the method is very good.(3)Derived the formula which is used to test the system's measuring repeatability.Researched the methods which are used to calibrate the system's measuring repeatability.A new method to calibrate the system's measuring repeatability has been put forward,which is called 9 points method.The new method has been optimized in many places than other methods.(4)Remould the 80 meter measuring track in National Institute of Metrology,and a new method to calibrate the system's measuring error has been put forward.This method is very easy,and it has been used universally.