Polar coordinate-based synchronous interpolation for multi-axis taper machining in WEDM with bus-type servo system

Abstract Conventional interpolation algorithms in wire-cut electrical discharge machining (WEDM) often exhibit linearization fitting errors that can compromise machining accuracy for variable taper workpieces. This paper presents a synchronous interpolation algorithm for WEDM with a bus-type servo system that reduces dependency on trajectory linearization processing. The algorithm develops a five-dimensional interpolation model based on polar coordinate parameterization to construct interpolation data through parametric equations, minimizing traditional fitting errors. The method generates multi-plane coordinates and calculates multi-axis trajectories via geometric projection. A residual accumulator mechanism effectively controls interpolation errors within ±1 pulse equivalent. Experimental validation with circular-to-square cross-sectional workpieces achieved dimensional accuracy within 0.004mm. This demonstrates improved performance compared to conventional methods. The methodology contributes to enhanced precision manufacturing capabilities for complex taper components in bus-type CNC systems.