Relaxing Conservatism for Enhanced Impedance Range and Transparency in Haptic Interaction

Area of Science:

• Robotics
• Control Systems
• Human-Computer Interaction

Background:

• The Time Domain Passivity Approach (TDPA) is a standard for stabilizing controllers in haptics and teleoperation.
• TDPA's reliance on passivity introduces conservatism, limiting performance.
• High-frequency control actions degrade transparency in haptic systems.

Purpose of the Study:

• To propose a novel method for relaxing conservatism in haptic interactions.
• To enhance the stable impedance range while maintaining high transparency.
• To develop adaptive damping strategies based on energy exchange.

Main Methods:

• Introduction of an 'energy cycle' concept based on pressing and releasing paths in haptic interaction.
• Estimation of energy generation by comparing energies at the end of each energy cycle.
• Injection of adaptive damping to regulate energy generation over subsequent cycles.
• Implementation of low-frequency control actions.

Main Results:

• The proposed method successfully relaxes conservatism in haptic interactions.
• Enhanced stable impedance range and improved transparency compared to TDPA.
• Demonstrated validity through simulations and experiments.

Conclusions:

• The energy cycle approach offers a less conservative alternative to TDPA for controller design.
• Adaptive damping based on energy regulation effectively improves haptic system performance.
• The method achieves high transparency and expands the stable impedance range in haptic devices.