The stability investigation of variable viscosity control in the human-robot interaction

Area of Science:

• Robotics
• Human-Robot Interaction
• Control Systems

Background:

• Variable damping in robots is crucial for co-manipulative applications.
• Implementing viscosity changes based on velocity can negatively impact natural human motion.
• Existing methods for variable viscosity control may introduce instabilities.

Purpose of the Study:

• To investigate the instability problem in variable viscosity control for robots.
• To develop a stable method for achieving desired variable viscosity behavior.
• To enhance human performance during robot-assisted tasks.

Main Methods:

• Theoretical analysis of a robotic model to understand viscosity-induced distortions.
• Introduction of a first-order linear filter to manage viscosity variations.
• Conducting human-robot experiments to evaluate the proposed method.

Main Results:

• The study identified viscosity drop as a cause of distortion in robot motion.
• The proposed linear filtering method effectively stabilized viscosity changes.
• Significant improvements in user performance were observed in human-robot experiments.

Conclusions:

• Variable viscosity control in co-manipulation presents an instability challenge.
• A novel filtering approach offers a stable solution, validated theoretically and experimentally.
• The findings demonstrate practical efficiency for real-world human-robot collaboration.