Design and Development of a Growing Pneumatic Soft Robot

Area of Science:

• Robotics
• Soft Robotics
• Mechanical Engineering

Background:

• Soft continuum robots offer compliance and flexibility for applications like minimally invasive surgery and search and rescue.
• A key limitation of current soft continuum robots is their inability to significantly change size and length.
• Robotic locomotion through growth presents a novel approach to overcome size limitations.

Purpose of the Study:

• To introduce a novel growing pneumatic soft robot with enhanced locomotion capabilities.
• To develop and validate models for estimating the robot's tip force and position.
• To demonstrate the robot's navigation and operational capabilities in various environments.

Main Methods:

• Design and fabrication of a growing pneumatic soft robot using pressurized thin-walled tubings.
• Development of kinematic and force models to predict robot behavior.
• Experimental verification of the force model and robot kinematics, including speed and position control.
• Testing of the robot's navigation in open field and constrained environments.

Main Results:

• The robot demonstrates 3D movement with an extension ratio limited only by manufacturing.
• An open-loop speed controller achieved a root mean square error of 2.69% for speeds between 20-300 mm/s.
• The position controller exhibited a mean error of 13.9 mm at 100 mm and 22.6 mm at 200 mm longitudinal distance.
• The robot can generate a tip force of 20.1 N at 150 kPa and reach a maximum speed of 1490 mm/s at 100 kPa.

Conclusions:

• The developed growing pneumatic soft robot overcomes the size limitations of conventional continuum robots.
• The robot offers active steering, controllable stiffness, and a tool channel for versatile applications.
• Experimental validation confirms the accuracy of the developed models and the robot's effective navigation capabilities.