Accurate real-time trajectory generation of circular motion using FIR interpolation: a trochoidal milling case study

Area of Science:

• Manufacturing Engineering
• Control Systems
• Machining Processes

Background:

• Subtractive manufacturing is evolving towards sustainability and zero-defect production.
• Dynamic milling, utilizing circular and cycloidal paths, is crucial for efficiency but faces real-time implementation challenges due to kinematic constraints in CNC machines.
• Current finite impulse response (FIR) interpolation methods for circular motion (G02/G03) have limitations.

Purpose of the Study:

• To address the limitations of existing FIR interpolation methods for dynamic milling.
• To develop a novel hybrid FIR interpolation method that satisfies kinematic constraints and positional tolerances.
• To incorporate machine dynamics, such as resonant frequencies, into the interpolation strategy.

Main Methods:

• Rigorous analytical analysis of machine kinematics.
• Development of a hybrid FIR interpolation technique adapting to circular motion geometry.
• Benchmarking the proposed method against state-of-the-art approaches on a high-performance machine tool with commercial controllers.

Main Results:

• The novel hybrid FIR interpolation method successfully satisfies kinematic constraints and tool center point position tolerances.
• The method allows for the integration of machine dynamics into the interpolation strategy.
• Benchmarking demonstrated superior performance compared to current methods, achieving up to 38% reduction in manufacturing cycle times for high-speed trochoidal toolpaths.

Conclusions:

• The proposed hybrid FIR interpolation method offers a significant advancement for dynamic milling.
• This method enables more efficient and sustainable manufacturing by overcoming kinematic limitations.
• The demonstrated cycle time reductions highlight the practical benefits for high-speed machining applications.