Research On 3D Measurement Technology Based On Linear Structured Light

As a hot topic in the field of computer vision,3D measurement technology has been widely used in industrial casting,medical diagnosis,virtual reality and other fields.Among them,the three-dimensional measurement technology based on linear structured light has been the focus of attention because of its high measurement accuracy and high speed.Based on the analysis of existing measurement models,a measurement model based on binocular linear structured light sensor is proposed,and the cylindrical paper tube is used as the calibration target to simplify the calibration process of structural light parameters.The main work contents are as follows:The measurement model of structured light sensor is established.At present,the com-monly used vision sensor measurement models mainly include monocular structured light sensor measurement model and binocular vision sensor measurement model.The former per-forms structured light parameters calibration by high-precision calibration target or precision mechanical motion structure.The equipment cost is high and the process is complicated,so it cannot be widely promoted;the latter does not need to calibrate structured light parameters,and the calculation principle is simple and easy to operate,but for objects with simple struc-tures or texture features that are not obvious,the measurement accuracy is not high.In view of the above problems,a measurement model of binocular structural light sensor composed of two cameras and a structural light transmitter was proposed,which can effectively simplify the calibration process of structured light parameters and has certain applicability.Structured light sensor calibration.The calibration of the sensor is mainly divided into two parts:camera calibration and structural light parameter calibration.The classic zhang zhengyou checkerboard calibration algorithm was used to calibrate the camera.On this basis,stereo rectification was carried out on the image to facilitate subsequent stereo matching operations.The cylindrical paper tube was used as the calibration target,which was scanned in the binocular system,according to the principle of binocular parallax,the coordinates of the light stripe were restored,and then these points were fitted to complete the calibration of the structured light parameter.The method does not need to frequently move the calibration target,and the calibration point coordinates are simple to obtain and the operation is simpler.Robust point cloud data plane fitting method.In order to improve the accuracy of light plane calibration,several plane fitting methods were introduced in this paper,fitting point cloud data with outliers ratios of 0%,10%20%,40%,50%,and 60%with deviate degree of 200%and 400%,and then the robustness of the fitting results was analyzed.The experimental results show that when the outlier rate is less than 50%,the order of magnitude of fitting standard deviation of iterative eigenvalue method is 10^-12,and the robustness is better.By scanning the physical model and the plate model,the proposed method is basically the same as the binocular linear structured light method in scanning accuracy,but the time is about1/5 of it,the time efficiency is greatly improved;The scanning speed is basically the same as the monocular linear structured light scanning method,for the physical model,the scanning accuracy is visually improved,the accuracy of the measurement of the length and width of the plane model is increased by about 1.5 percentage points to over 99%,and the depth standard deviation is reduced by about 0.7 mm.It can be seen that the scanning method proposed in this paper can achieve an effective balance between scanning accuracy and time,and has certain practical value.