Error Modeling and Experimental Study of a Flexible Joint 6-UPUR Parallel Six-Axis Force Sensor

Area of Science:

• Mechanical Engineering
• Sensor Technology
• Robotics

Background:

• Parallel six-axis force sensors with integrated flexible joints offer large measurement ranges and high accuracy.
• Key error sources include assembly inaccuracies and flexible leg deformation.
• Existing models often do not fully account for combined error effects.

Purpose of the Study:

• To develop and analyze comprehensive error models for a flexible joint 6-UPUR parallel six-axis force sensor.
• To investigate the impact of assembly and deformation errors on sensor performance.
• To provide a theoretical basis for improving sensor design and accuracy.

Main Methods:

• Established an assembly error model using the imaginary kinematic joint and Denavit-Hartenberg (D-H) methods.
• Built a stiffness model to derive the stiffness matrix and deformation error model.
• Solved the first-order kinematic influence coefficient matrix considering synthetic errors.
• Conducted experimental validation using laser interferometry for forced deformation detection.

Main Results:

• A synthetic error model was developed and experimentally verified.
• The first-order kinematic influence coefficient matrix under actual conditions was calculated.
• Analysis showed that incorporating synthetic errors significantly impacts sensor performance.
• Laser interferometry confirmed the model's accuracy in detecting forced deformation.

Conclusions:

• Considering synthetic errors during the sensor design phase is critical for enhancing performance.
• The developed error modeling approach is essential for meeting the demands of practical working environments.
• This research contributes to the development of more accurate and reliable force sensors.