Research On Force Control Technology Of Robot Abrasive Belt Grinding And Polishing For Aeroengine Blade

Aeroengine blade is the core part of the engine,which belongs to the typical complex surface.It has the characteristics of complex surface,weak rigidity,thin blade edge and strict surface roughness requirements.Its contour accuracy and surface quality directly affect the aero-engine aerodynamic performance and service life.As the final key process of aeroengine blade manufacturing,grinding and polishing can ensure the blade to meet the requirements of contour accuracy and surface quality.There are some problems in manual grinding and polishing,such as poor surface consistency and low machining efficiency,which make it difficult to accurately control the removal allowance and contact force.CNC machine tool grinding and polishing can improve the machining accuracy,but it is difficult to realize the closed-loop control of machining and measurement due to its poor versatility.The robot has the advantages of large range of motion,general flexibility and low cost.Combined with abrasive belt grinding and polishing process,it can achieve high-precision grinding and polishing.However,the disadvantages of robot multi-axis coupling,slow end response speed and low positioning accuracy make it difficult to accurately control the contact force of grinding and polishing processing,which is difficult to achieve robot compliant force control processing.To sum up,this article focuses on the key technology of precise control of the transition state and steady state contact force of the aero-engine blade robot abrasive belt compliant grinding and polishing process.The specific research content is as follows:1.Analysis of robot abrasive belt force control grinding and polishing.Introduces the robot force control abrasive belt grinding and polishing system,based on the basic theory of robot abrasive belt grinding and polishing,the analysis and modeling are carried out.Analyze the abrasive belt grinding and polishing process and the tracking motion of the complex curved surface of the blade,complete the dynamic analysis of the force-controlled abrasive belt grinding and polishing unit and the parameter identification of the linear motion platform,and analyze the contact collision prevention of the robot-abrasive belt grinding and polishing unit.2.Contact transition state force impact and oscillation suppression.The adaptive weighted particle swarm algorithm is used to optimize the input shaping technology,and the system oscillation is guided to cancel each other,and it is compared and analyzed with the non-suppression and impedance shaping technology.The experimental results show that the system stability time before and after the optimization method is shortened by about 79.2%,and the maximum overshoot of the contact force is reduced by about 85.1%.The method has good effects in suppressing system shock oscillation,shortening the stabilization time and reducing the overshoot,and enhance the stability and reliability of the system.3.Contact steady-state adaptive force tracking.Based on impedance control,an environmental parameter estimator is designed to generate an adaptive reference trajectory,reduce the tracking error of contact steady-state force,and compensate the generated contact force error by genetic algorithm.The experimental results show that the proposed method further improves the tracking accuracy of the robot’s contact force during grinding and polishing,and the force tracking error is reduced by about 85.7%,which can realize the robot’s compliant and adaptive processing in an unknown environment.4.Experimental verification of robot belt grinding and polishing system.This paper analyzes the technological process of robot abrasive belt grinding and polishing of aeroengine blade,tool path planning of robot grinding and polishing processing,contact force signal filtering processing,control software programming and debugging.The mechanical control abrasive belt grinding and polishing experiment was carried out for the titanium alloy blades of the compressor of Aeroengine Blades.The contact force accuracy is ±0.6N,and the surface roughness can reach Ra 0.4μm.