Active Compliance Smart Control Strategy of Hybrid Mechanism for Bonnet Polishing

Area of Science:

• Robotics
• Manufacturing Engineering
• Materials Science

Background:

• Traditional compliance control in ultraprecision polishing faces limitations in load capacity, accuracy, and actuator maintenance.
• Existing methods often rely on robot platforms with restricted performance for polishing tasks.
• Hybrid mechanisms offer potential advantages by combining serial and parallel system benefits.

Purpose of the Study:

• To develop and validate a high-frequency-impedance robust force control strategy for ultraprecision polishing.
• To implement active compliance control on a novel hybrid mechanism.
• To improve adaptability and surface quality in polishing unknown freeform surfaces.

Main Methods:

• A hybrid serial-parallel mechanism was designed for polishing applications.
• A high-frequency-impedance robust force control strategy was proposed, directly linking contact pressure to position adjustment.
• An open architecture control system with custom software was developed for real-time control and adaptation.

Main Results:

• The hybrid mechanism successfully adapted to unknown freeform surfaces without overshooting.
• The proposed control strategy demonstrated effective active compliance control.
• Significant improvement in surface quality was achieved, with average surface roughness decreasing from 0.057 µm to 0.027 µm.

Conclusions:

• The developed hybrid mechanism and robust force control strategy effectively address limitations of traditional methods.
• The system provides automatic adaptation to environmental variations with precise contact pressure control.
• This approach offers a promising solution for enhancing surface quality in ultraprecision polishing.