An Adaptive Robotic Constant Force Polishing System for Turbine Blade

For workpieces with complex profiles, such as aero-engine blades, improving the accuracy of polishing by compensating for the lack of positioning accuracy of industrial robots remains a challenging problem. In this paper, a trajectory planning algorithm based on the STL file format is designed, and a force control strategy based on the dynamic adaptive admittance control algorithm is proposed. Firstly, the 3D spatial models of the turbine blade are expressed using the STL file format. The truncated parallel plane is then used to generate the tool path, which is fitted using the cubic B-spline curve method. Finally, the actual robot motion trajectory is obtained after transforming the robot coordinate system. Secondly, based on the traditional admittance control algorithm, a dynamic adaptive admittance control algorithm is designed. The system is simulated under MATLAB, and the simulation results show that compared to the traditional admittance controller, the dynamic adaptive admittance controller can achieve a better force tracking effect on complex surfaces. Finally, an experimental platform is built for polishing, and the experimental results show that the force control algorithm presented in this paper can achieve constant force polishing. Compared to the conventional admittance control algorithm of 1.332 µm, the dynamic adaptive force control algorithm produces a better polishing effect, with a surface roughness of 0.749 µm. Therefore, it is proven that the robot constant force polishing blade system based on dynamic adaptive admittance control is effective.