Simulating and compensating kinematic defects in 5-Axis CNC machining A linear feedforward approach

Abstract

Multi-axis CNC machining accuracy is limited by inherent geometric and kinematic flaws. This thesis investigates volumetric error generation in a 5-axis bi-rotary CNC prototype, which accumulates 43 distinct geometric errors. A mathematical digital twin was constructed using Homogeneous Transformation Matrices (HTM) to model these deviations. To mitigate this, a novel offline Hybrid Analytical- Numerical Inverse Kinematics compensation algorithm was developed. Applied via Post-CAM G-code modification to finishing trajectories, MATLAB simulations demonstrated that the algorithm successfully reduced volumetric deviations to a sub-micron tolerance (below 0.0001 mm).