Cable-Driven Robot to Simulate the Buoyancy Force for Improving the Performance of Underwater Robots

The underwater environment presents conditions very different from those found on the ground so the control algorithms and the design of submarine robots have to consider this circumstance. Usually, the experiments are performed in real pools after the computational simulations, imposing a high leap in the testing process that requires to implement various requirements and subsystems for the first real world tasks. For this reason, an on-ground simulator of the underwater environment is developed based on a cable-driven parallel robot. This technology allows us to create a scenario where the aquatic robots can test their algorithms in a secure, controlled and customizable environment to guarantee a good performance before the experiments performed with real immersions in swimming pools. The Buoyancy force is simulated on a rigid end-effector in different application points while its accuracy is measured with the reaction forces applied by the body to the ground and tracking the zero-moment point displacement. A method to select the motors and the mechanical components for this task is shown.