Kinematic corner smoothing for high speed machine tools

• Novel cornering trajectory generation method is developed for machine tools.
• Axis velocities around sharp corners are blended with jerk limited transitions.
• Method falls into the category of acceleration/deceleration after interpolation.
• Symmetrically rounded corner profile with controlled tolerance is interpolated.
• Cornering duration is minimized based on corner tolerance and axis kinematic limits.

This paper presents a novel kinematic corner smoothing technique for high-speed CNC machine tools. Typically, reference tool-paths compromised of short G01 moves are geometrically smoothed by means of arcs and splines within the NC system. In this study, a continuous feed motion is generated by directly planning jerk limited velocity transitions for the drives in the vicinity of sharp corners of the tool-path. This approach completely eliminates the need for geometry based path smoothing and feed planning. Contouring errors at sharp corners are controlled analytically by accurately calculating cornering speed and duration. Since proposed approach bases on kinematically planning axis motion profiles, it exploits acceleration and jerk limits of the drives and delivers a near-time optimal motion. Experimental validation and comparisons are presented to show significant improvement in the cycle time and accuracy of contouring Cartesian tool-paths.