Site logo

Bioinspired Actuation

Keywords: bio-inspired locomotion, soft robotics, underwater robotics 

We invent new ways for moving through water, taking inspiration from animals who have adjusted for life in this environment.  

Those novel actuation mechanism allow moving efficient, robust or versatile locomotion. For example, it allows building vehicles that are very maneuverable, do not disturb water or scare away animals.  

Filose

FILOSE is a fish robot prototype that moves using a soft tail actuated only by one motor. We have shown that by mimicking material properties of fish, an actuation pattern similar to real swimming fish can be created without complicated distributed actuation. FILOSE robot has feedback from flow sensors and can control itself with respect to the flow (e.g. swim upstream). 

Please accept cookies to see this video.

U-CAT

U-CAT is a concept-vehicle inspired by turtle locomotion. It has four independently driven flippers which makes it very well maneuverable (controllable along all 6 degrees of freedom). U-CAT was originally built for underwater archaeologists for shipwreck surveys. It is highly maneuverable allowing moving close and following contours of underwater objects. The flippers do not create strong water jets and therefore it does not stir up sediments from the sea bottom and allows close visual observation. U-CAT has been used for investigating archeological sites, underwater vegetation and fishfarms.  

Please accept cookies to see this video.

Micro-CAT

Micro-CAT is a small version of U-CAT originally built for an exhibition in London Science museum and now serves as a platform for student projects and public outreach. 

Please accept cookies to see this video.

Work in bio-inspired locomotion has been funded by: 

  • ARROWS (Archeaological Robotics Systems for the Worlds' Seas) financed by European Commission through Framework 7 in 2009 - 2012 

  • FILOSE (FIsh LOcomotion and SEnsing) financed by European Commission through Framework 7  in 2012- 2015 

  • ROBOCADEMY (European Academy for Underwater Robotics) financed by European Commission through Framework 7 in 2014- 2018 

  • ROBOMINERS (Resilient Bio-inspired Modular Robotic Miners) financed by European Commission through Horizon 2020 in 2019 – 2023 

  • “Sensing and locomotion in continuous environments” financed by Estonian Research Agency ETAg in 2012- 2014. 

  • “Bioinspired Underwater Robots” financed by Estonian Research Agency grant IUT-339 in 2015-2020. 

Robot Control 

Keywords:  control of underactuated vehicles, non-linear control, fault-tolerant robot architectures, flow-relative control, robot navigation, path planning 

Robot control means using sensor information to plan the movements and tasks of the robot. Since the robot is moving while it is planning the next action, robot control has to be done in real-time. 

Underwater robots move in 3D and in an environments with disturbances. Water motion make the robot to deviate from its planned path. Also, when the robot is moving, the water around it is moving too in quite unpredictable way. The control algorithm corrects for the errors.  

Flow relative control

FILOSE is a fish robot can control itself with respect to the flow, for example find spots in turbulent flows where drag is smaller and hover there to save energy.  FILOSE can also use different locomotion modes of its soft tail actuator to follow an trajectory in water. 

Please accept cookies to see this video.

U-CAT robot control 

U-CAT is a 6 DOF robot driven by 4 independently moving flippers. UCAT control is challenging because the behaviour of the robot is very non-linear, the different degrees of freedom are coupled to each other, the vehicle’s response to movement is delayed and the water motion around the moving robot is difficult to model and predict. U-CAT uses a novel control architecture with a priorotization concept that makes its movement more stable. Since the robot is very well maneuverable, good control makes possible to make difficult maneuvers, for example top follow a target (diver) using visual and radio signals. 

Please accept cookies to see this video.

Flow-aided localisation and navigation 

Although moving water seems to be the most instable and volatile thing, it can actually contain features that are very stable in long-term. For example certain turbulence patterns, steady currents and wave patterns. Those distinct places are called landmarks in robot navigation. We have shown that underwater environment contains clearly distinguishable flow landmarks that can be used for underwater robot localization and navigation. 

Please accept cookies to see this video.

Work in robot sensing has been funded by: 

  • FILOSE (FIsh LOcomotion and SEnsing) financed by European Commission through Framework 7  in 2012- 2015 

  • ROBOCADEMY (European Academy for Underwater Robotics) financed by European Commission through Framework 7 in 2014- 2018 

  • “Sensing and locomotion in continuous environments” financed by Estonian Research Agency ETAg in 2012- 2014. 

  • “Bioinspired Underwater Robots” financed by Estonian Research Agency grant IUT-339 in 2015-2020. 

  • EXCITE (Estonian Centre for Excellence of IT Research) financed by SA Archimedes 2017-2023.