A fish called Wanda

A robotic fish that can seek out and ‘swim’ towards a particular object of interest has been developed at the University of Wollongong in Australia.

The Wireless Aquatic Navigator for Detection and Analysis (WANDA) is propelled by a flexible joint tail fin that is activated through artificial muscles made from a conducting polymer.

The person controlling WANDA can change the direction and speed at which the fish swims. It has a small camera that wirelessly sends real-time video to a computer, and video-imaging software is used to analyse the image for object recognition and detection, initially based on their colour.

WANDA has been designed to continually swim and search for a predefined colour, and once detected, directional instructions are given to the operator to enable it to be moved towards the object of interest.

The researchers are currently generating a closed-loop computer control system that will allow the fish to autonomously respond to the video signal.

‘We are also looking at ways to make the fish more sophisticated in the future so it can dive to different depths or change direction rapidly and including other sensors on the body,’ said Dr Scott McGovern.

One example where the robotic fish could be used is to detect water quality and pollution levels in water catchments and dams. While existing systems detect pollution from stationary points along the catchment, WANDA can swim around and give a true idea of the whole area and can even swim towards and detect the exact point where pollution may be coming from.

It could also be used to detect structural damage in underwater pipes where divers cannot reach, or to map out underwater areas.

WANDA has been developed through a three-way collaboration between researchers at the Intelligent Polymer Research Institute (IPRI) at the University of Wollongong, the National Centre for Sensor Research at Dublin City University led by Prof Dermott Diamond, and the Defence Science and Technology Organisation Maritime Platforms Division.