Research On Spatial Position And Attitude Measurement Methods Based On Infrared Vision Guidance And Laser Ranging

With the increasing demands on the economic production,industrial products put forward higher requirements for measuring equipment,such as large range,high precision,automation,integration,especially in the fields of automatic milling process measurement,aero-engine blade detection,turbine rotor-stator axial clearance calibration,real-time guided robot assembly,aircraft,ship and wind turbine assembly and small feature detection on large components,and so on.The complexity of the measurement environment and measurement target also puts forward higher requirements for the measurement method.Meanwhile,in various dynamic systems or industrial application scenarios,position and attitude are key parameters for understanding its dynamic characteristics,analyzing its performance,and ensuring manufacturing accuracy.Aiming at the needs of on-site measurement of position and attitude in modern industrial production,this paper proposes a position and attitude measurement method by combining laser measurement technology and visual measurement technology.The main research contents are as follows:1.Based on infrared vision cameras and laser displacement sensors,a position and attitude measurement system is built,which can realize rotation in two directions,movement in two directions,and collection of measurement data.2.Based on the position and attitude measurement system,the spatial position measurement method of the measured object is proposed.A measurement target with built-in infrared diodes is designed and placed on the object to be measured.The measurement target has the characteristic that the spot image is only visible in infrared vision cameras.Through a series of image processing methods,the image position distance between the laser spot center and the measurement target center is continuously reduced to achieve precise positioning,and the spatial coordinates of the measured object are calculated according to the angle and laser displacement data measured during the adjustment process.3.Based on the position and attitude measurement system,the spatial attitude measurement method of the measured object is proposed.The laser displacement sensor scans the surface of the measurement target according to a predetermined trajectory,and several three-dimensional point cloud data are obtained through the coordinate calculation method.Then,the target plane is fitted by the plane fitting algorithm.At the same time,the direction angle and pitching angle of the target object in space can be calculated from the normal vector of the target plane.The infrared diodes in the measurement target have certain position distribution characteristics,and the rolling angle can be calculated according to the light spot distribution characteristics in the images of different attitudes.Then,the direction angle,pitching angle,and rolling angle represent the attitude of the measured object in space.4.The experimental measurement device is calibrated and corrected,and then the experimental schemes of position measurement,direction angle and pitching angle measurement,and rolling angle measurement are designed respectively.By means of indirect verification,the errors of position measurement and attitude measurement and the repeatability of measurement experiments are verified respectively,and the possible sources of errors are analyzed.The method proposed in this paper can meet the position and attitude measurement requirements of some large-sized workpieces and the task of docking and assembling large-scale components.Compared with the existing methods,the influence of external environment changes and coordinate transformation errors on the measurement results can be effectively avoided.It has important theoretical significance and application value in the field of spatial attitude measurement and industrial measurement applications.