Wireless teleoperation of HSURF artificial fish in complex paths

TL;DR

The paper addresses wireless teleoperation of the HSURF underwater swarm for inspection tasks under the bandwidth and latency limits of acoustic communications. It proposes a shared-autonomy framework in which a remote operator sends a compact, discretized desired state encoded in a single byte, while onboard AUV controllers (cascade PID for heading and depth) realize the commanded state. Experimental validation in a testing pool demonstrates the feasibility of multi-target navigation with inter-transmission delays around $1.6$ s and end-to-end delays near $0.1$–$0.2$ s, along with low packet loss. The work lays a foundation for scalable, robust teleoperation and leader-follower autonomy in underwater multi-robot systems, with practical implications for harbor and subsea inspections.

Abstract

In this paper we show the application of the new robotic multi-platform system HSURF to a specific use case of teleoperation, aimed at monitoring and inspection. The HSURF system, consists of 3 different kinds of platforms: floater, sinker and robotic fishes. The collaborative control of the 3 platforms allows a remotely based operator to control the fish in order to visit and inspect several targets underwater following a complex trajectory. A shared autonomy solution shows to be the most suitable, in order to minimize the effect of limited bandwidth and relevant delay intrinsic to acoustic communications. The control architecture is described and preliminary results of the acoustically teleoperated visits of multiple targets in a testing pool are provided.

Figures (6)

• Figure 1: HSURF fish picture during preliminary open-water tests.
• Figure 2: Sketch of the experiment configuration.
• Figure 3: Testing Pool, Marine robotics pool in Khalifa University.
• Figure 4: Picture of the target-gates. Top panel: the gate 1, with the floating foam on the surface and 2 markers delimiting the bottom limit at a depth of 1m and a width of 1m. Bottom left panel: gates 2 and 4 which have a diameter of 0.75m, with gate 2 reaching the water surface. Bottom right panel: gate 3, with a full height of 0.9m and 1.1m width
• Figure 5: Schematic of a test. Gates 1, 2&4 and 3 are respectively placed on a line at approximately 2 meters distance each. The robot enters the gate 1, maintaining a depth between 1m and the surface, it performs a U-Turn and threads through gate 2. It then performs a second U-turn and descends to pass through gate 3. Finally, it raises and U-turns to pass through gate 4.