AquaJelly

Year

2008

The idea

A cooperative swarm of artificial jellyfish glides seemingly effortlessly through the water just like their natural counterparts.

The objective

The AquaJellies can move in any spatial direction without colliding with each other.

Technical data

• Diameter: 25 cm
• Weight: 840 g
• Speed: max. 10 km/h
• Microprocessors: 3
• Pressure and temperature sensor: 1
• Acceleration sensor: 1
• Infrared transmission LEDs: 11
• Infrared receiver units: 11
• Servo motors: 2
• Power supply: lithium-ion polymer battery, 4.2 V, capacity 4000 mA/h
• Drive: bell armature motor, 3 V
• Gearbox: upstream planetary gearbox, ratio 1:180

Operating principle

The swarm develops cooperative behaviour without defined control of the overall system. To ensure this autonomy, the robots are provided with integrated communication and sensor technology. A processor monitors the position of the drive system. When an AquaJelly needs more energy, it autonomously returns to the charging station.

Localisation

Each AquaJelly is fitted with an annular control board that includes sensors for pressure, radio signals and light. The ring in the dome contains eleven infrared LEDs with an aperture angle of 20 degrees. The artificial jellyfish use pulsed infrared signals to locate each other up to a distance of around 80 centimetres and communicate with each other as in a natural swarm.

Structure

The AquaJelly consist of a transparent dome, a central pressure corpus and eight tentacles. The watertight pressure corpus contains two rechargeable batteries for the electric drive. Two cranks offset by 60 degrees move stroke plates on the top and bottom of the pressure corpus. Rhombic joints attached to these move the tentacles.

Tentacles

Eight tentacles, designed as an adaptive Fin Ray structure, are addressed in sequence to produce a wave-like pumping motion similar to the peristaltic propulsion of natural jellyfish.

Material

AquaJelly