Shape Reconstruction of Extensible Continuum Manipulator Based on Soft Sensors

Area of Science:

• Robotics
• Mechanical Engineering
• Sensor Technology

Background:

• Continuum manipulators offer enhanced spatial adaptability and operational flexibility in constrained environments through contraction and extension.
• Quantifying the shape of these manipulators is crucial for improving obstacle avoidance and end-effector positioning accuracy.

Purpose of the Study:

• To propose and validate a methodology for estimating the shape of extensible continuum manipulators using silicone rubber strain sensors (SRSS).
• To enhance the obstacle avoidance capabilities and end-effector position accuracy of these robotic systems.

Main Methods:

• Developing slender SRSS through a rolling process to create cylindrical structures.
• Measuring strain at specific locations on the manipulator's deformable body.
• Reconstructing the manipulator's shape by integrating sensor strain data, considering torsion effects.

Main Results:

• A physically extensible continuum manipulator with three driving tendons and nine SRSS was designed and tested.
• The SRSS-based method accurately reconstructed the manipulator's shape, even under end-effector loads.
• Experimental results showed a mean absolute endpoint position error of 1.61% and a maximum error of 3.45% of the manipulator length.

Conclusions:

• The proposed methodology effectively estimates the shape of extensible continuum manipulators using SRSS.
• This approach significantly improves the precision of robotic manipulation in complex environments.
• The findings contribute to the advancement of adaptable robotic systems for intricate tasks.