3D Profile Measurement Of Great Gears

Generally speaking,great gears include gears with large modulus and gears with large diameter,which mainly refer to gears whose diameters are greater than 500mm.As an important component of transmission,the great gears are widely used in various industrial fields,such as power generation,mining,shipbuilding,aerospace,large machinery and equipment etc.,which play a key role in the process of industrial production and national defense construction.However,due to the complex shapes and technical problems,the production and measurement of great gears are very difficult.The manufacturing accuracy and error analysis of great gears affect the industrial technical indexes and product quality in related fields.Therefore,it is important to measure and analyze the dimensions of great gears.According to the principle of laser triangulation method,a 3D profilometry system using a linear laser and two CCD cameras is designed in this paper based on linear laser scanning,this system is used for non-contact 360 degree scanning measurement of objects placed on the turntable.The main contents of this paper are as follows:the principle of laser triangulation measurement and the structure of system are introduced.A simple method of calibration that used a chessboard is proposed,and introduce a center extraction method of light stripe which combines thresholding with gray barycenter.The image processing and display software cooperated with the system is compiled on the Visual Studio 2010 platform,so the image display,data calculation and result display can be carried out in the measurement process.The error of system is corrected by measuring the plane of different depths,then the system is used to measure a metal step with the height of 20.00mm,the minimum error can reach 0.1min.Finally,the radius of dedendum circle and addendum circle of a great gear are measured by the system,and the relative error is less than 1%.The measuring system has the advantages of small size,simple calibration method,fast speed and real-time display of results.