Research On Blade Corrosion Point Marking And Constant Force Grinding Technology

As a power source component of an aircraft,the aero-engine has a complex internal structure,and its main component blades have a harsh working environment,and many different failure forms such as pitting and scratching often occur.The manufacturing cost of blades is high,and blades with minor failures are usually ground first,then repaired by additive materials,in order to prolong their service life.In view of the localized minor failure of blades such as corrosion points and scratches,the overall grinding processing efficiency is not high,and the surface morphology of the blade is affected.Therefore,research on the corrosion point marking and constant force grinding technology of aero-engine blades is carried out.Collect the two-dimensional image of the blade surface through the industrial camera,manually mark the corrosion point area,and convert the coordinates to the standard three-dimensional model to plan the corrosion area;during the robot grinding process,the force sensor is used to collect the contact force during the grinding process in real-time,and the constant force control algorithm is used to collect the contact force during the grinding process.The calculated compensation value is superimposed with the reference trajectory and sent to the joint servo to complete the constant force grinding closed-loop control strategy.The main research contents of the paper are as follows:Firstly,in the labeling of blade corrosion points,the processing algorithm of 2D image and 3D model is studied,and the preprocessing of 2D image and 3D model is carried out.Based on the research on the mapping principle,camera model and Open GL coordinate transformation principle,a new method of transforming the 2D labeling coordinates of the blade erosion area into the 3D model of the blade is proposed,and the feasibility of the method is verified by surface labeling.Then,the force information collected by the force sensor at the end of the robot is analyzed,calibration and compensation are carried out,and the influence of the tool gravity on the collection and measurement of the contact force during the robot grinding process is solved.Based on the impedance control theory,a robot grinding control scheme with a force control function is designed,the force tracking controller is studied,and force tracking experiments under different conditions are carried out to verify the correctness of the grinding force control scheme.Finally,a blade corrosion point labeling and a constant force grinding system was built.A set of integrated data acquisition,data processing,algorithm control and visualization system were developed,A force control algorithm was integrated into the robot motion control,which solved the problems caused by secondary development.The real-time problem improved the force control accuracy,realized the combination of software and hardware,and completed the comprehensive experiment of repairing damaged blades.The experimental results show that the system can perform corrosion area marking and coordinate mapping and constant force grinding,which effectively improves the grinding efficiency and the accuracy meets the requirements of use.