Design and Additive Manufacturing of a Continuous Servo Pneumatic Actuator

Area of Science:

• Robotics
• Mechanical Engineering
• Pneumatic Systems

Background:

• Existing pneumatic rotary actuators have limitations in servo applications and angular range.
• There is a growing demand for lightweight, versatile actuators in soft and rigid robotics.

Purpose of the Study:

• To present the design, manufacturing, and functionality of a novel servo pneumatic rotary actuator.
• To enable continuous rotary motion and precise positioning for robotic applications.

Main Methods:

• Utilized nine radially arranged linear bellows actuators pushing a cam profile.
• Implemented proportional valves and a rotary encoder for angle-dependent pressure control.
• Developed a servo pneumatic commutation strategy for enhanced versatility and reduced component count.

Main Results:

• The prototype actuator (110 mm diameter, 41 mm width, <500 g) achieves 0.53 Nm torque at 1 bar.
• Demonstrated a static positioning accuracy of 0.31° with unlimited angular motion.
• The design is manufacturable using standard components, 3D printing, and elastomer molding.

Conclusions:

• The developed actuator overcomes limitations of current technologies, offering continuous motion and precise positioning.
• Freely programmable servo pneumatic commutation increases versatility and simplifies robotic system design.
• The actuator is suitable for diverse applications requiring lightweight, high-performance rotary motion.