| Structured light three-dimensional measurement technology has been widely used in the measurement of high-precision parts,such as aeroengine blades because of its advantages of high precision,high speed and high resolution.However,in the traditional structured light three-dimensional measurement,the parts need to be removed and moved to the measurement position for measurement,which is difficult to meet the needs of on-line automatic measurement.The combination of structured light measurement technology and multi degree of freedom mechanism is the trend to realize automatic three-dimensional measurement and intelligent machining detection.The key and difficult point of realizing 3D measurement automation of surface structured light is the planning of measurement viewpoint and path,so it has an important practical significance to study the related technologies involved.Firstly,for the adjustment of camera parameters during calibration,combined with the structure of camera lens module and the characteristics of parameters to be adjusted,a set of parameter adjustment device suitable for adaptive parameter adjustment of industrial camera lens module is designed,and its software is designed.The structure of the self built optical detection platform is analyzed,the forward and inverse kinematics modeling is carried out,and the kinematics model and monocular structured light measurement system are experimentally verified to ensure the feasibility of the adaptive adjustment function of the optical measurement platform.Secondly,in view of the randomness and low efficiency of the current industrial camera calibration and parameter adjustment,the influence of camera parameters on the calibration accuracy is analyzed.According to the image change characteristics of industrial camera parameter adjustment,appropriate parameters are selected to describe the image change of the measured object,and the influence law of parameter change on the camera calibration accuracy is studied.An adaptive adjustment method of camera calibration parameters is proposed to control the calibration accuracy in the optimal range,which completes the adaptive adjustment of camera calibration parameters in the optimal calibration accuracy range of industrial camera in the monocular structured light measurement environment.Then,according to the characteristics of surface structured light measurement technology,a viewpoint planning technology and method based on the known model of thin-walled blade surface parts are studied.It mainly includes the topology reconstruction of STL file,the setting of constraint conditions,the calculation of measurement direction and the generation of measurement viewpoint,so as to realize the automatic generation of measurement viewpoint of blade thin-walled surface parts.Finally,the direction generated by the viewpoint planning is transformed into the actual control angle of each axis of the optical detection platform,so that the surface structured light measurement equipment can traverse all viewpoints in turn under the shortest path.Through the relevant research basis of the traveling salesman problem and based on the principle of greedy algorithm,the path planning algorithm with full coverage and no repeated traversal of all viewpoints is realized,Based on the self built optical detection platform,according to the planned viewpoint and path,the three-dimensional measurement effect of thin-walled curved parts is experimentally verified. |
