A Combined Rigid-Soft Thruster Based on Jetting Propulsion

Ahstract- A new underwater thrust device is proposed in this work that makes use of a soft outer structure in combination with a parallel linkage and driven by a classical actuator. By merging soft and rigid parts, we hope to increase the performance of pulsed jet propulsion that plays a crucial role in attitude control for AUVs. But also simpler models for design and control can be applied by this approach. A specific linkage design for actuation, along with two different soft structures (mantles) are introduced and evaluated in experiments which indicate efficient thrust creation. Particle Image Velocimetry (PIV) experiments show the formation of vortex rings that suggest efficient propulsion, whereby the wider and more flexible mantel is characterized by higher momentum and thrust.