A novel interpolator designed for laser scanning welding of hairpin windings in electric vehicle motors

Electric vehicles are recently prosperous due to decarbonization and electrification in transportation. However, manufacturing their motor windings with stable high quality is challenging, especially in hairpin laser welding. This study introduces a novel interpolator using polar angles as primary indicators, achieving process flexibility and high-performance synchronization between positions and powers. The interpolator is well-designed theoretically, more advantageous compared to those traditional ones in hairpin welding, while also compatible with them. Four speed planning modes are available depending on whether the speed is angular or linear, constant or variable. Additionally, energy distributions based on polar-angle power profiles can be adjusted and optimized according to practicality. Both the speed and power profiles, as two critical welding parameters, facilitate precise in-process modification dramatically. In the end, two groups of comparative experiments are performed to positively validate the interpolator’s feasibility and effectivity to improve weld quality. Significantly, this work establishes a fundamental framework linking diverse paths and hairpin welding processes which is essential for weld quality control and optimization.