Simulating robotic biomass collection

Sometimes it is not possible to the real-world evaluation of robotics solutions. This can be due to time, economy or in our case – the weather. In order to mitigate this, a virtual environment representing a test site was programmed in Unity which is a cross-platform game engine developed by Unity Technologies. Simulation is becoming an increasingly important part of robotic application development and validating applications in simulation before deploying to the robot can shorten iteration time by revealing potential issues early. Although the simulated environment in this case is a simplified model of the real world, it can be used to compare the performance of different autonomous navigation methods.

The model of the harbor was based on a drone photo which constituted the model and the underlaying plane of the simulation environment.

The model consisted of the following objects:

  • A 3D model of a WasteShark provided by RanMarine
  • Models of biomass
  • 3D models of boats
  • 3D models of piers surrounding the harbor and boat walks
  • Virtual waypoints for navigation purpose

WasteShark. The WasteShark was modelled using a 3D CAD-model of the WasteShark-platform which was provided by RanMarine. The steering behavior was modelled to resemble the real platform, making is able to move forwards and backwards while rotating around its own axis.

Collection of algae was simulated by using Unity built-in collision detection. When the WasteShark collided with biomass, this counted as a collection of the biomass. This only happened, when the WasteShark was moving forward representing the opening of the platform which is only at one side.

The size of the WasteShark was scaled to represent the corresponding size in the harbor, based on the drone-photo. The speed of the vessel however was arbitrary, as only comparison between different navigation plans (not the absolute values) are of primary interest here.