A study on the control strategies of a series–parallel hybrid platform for blade polishing

Abstract

Blades are key components of turbines, aircraft engines, and high-speed ship propulsion systems, such that their manufacturing quality has a considerable influence on a machine’s performance. This paper presented a series–parallel hybrid platform that employed abrasive belt as the tool and integrated the measuring equipment to achieve in-situ measurement for blade polishing. It studied the control strategies for solving the processing parameters aiming to the characteristics of the alternate measurement and processing in the process of polishing. According to singularity analysis of the parallel mechanism, the platform structure parameters were appropriately optimized to avoid the singular position. Then, based on the in-situ measuring data of the blade contour, a method was proposed for calculating the normal vector of machining points, while the platform kinematics were studied, and the total machining allowance was determined by comparing the actual and ideal contour profiles of the blade. Finally, a testing experiment was performed to validate the proposed method of the normal vector calculation, and blade polishing experiment was conducted on the developed platform, which proved the effectiveness and feasibility of the platform.