Collocation Accuracy of Visuo-Haptic System: Metrics and Calibration

Area of Science:

• Human-Computer Interaction
• Virtual Reality
• Robotics

Background:

• Visuo-haptic collocation error, the spatial mismatch between visual and haptic feedback, is critical for immersive virtual experiences.
• Existing methods for characterizing this error lack quantitative precision, hindering the development of advanced rendering algorithms.

Purpose of the Study:

• To develop and validate quantitative metrics for measuring visuo-haptic collocation error.
• To establish a prototype system for metric validation and error compensation.

Main Methods:

• Defined collocation error based on the spatial relationship between a tool and a surface.
• Developed a mathematical model linking error to visual and haptic rendering components.
• Implemented a calibration method including Perspective Calibration (PC) and Model Calibration (MC) to address system tolerances.
• Utilized a FARO Arm for precise measurements to determine calibration parameters.

Main Results:

• The prototype system successfully validated the proposed metrics.
• Average collocation error measured at 1.8 mm in the XwYwOw plane.
• Maximum collocation error remained below 7 mm within an 80 mm × 80 mm × 80 mm workspace.

Conclusions:

• The proposed metrics and calibration methods effectively quantify and compensate for visuo-haptic collocation error.
• This work provides a foundation for designing more accurate and immersive visuo-haptic rendering systems.