Wireless HROV Control with Compressed Visual Feedback Using Acoustic and RF Links

Abstract

Underwater cooperative robotics offers the possibility to perform challenging intervention applications, such as recovering archeological objects as within the context of the MERBOTS research project, or grasping, transporting and assembly of big objects, using more than one mobile manipulator, as faced by the TWINBOT project. In order to enhance safety during the intervention, it is reasonable to avoid the umbilical, also giving more mobility to the robots, and enabling a broader set of cooperative movements. Several solutions, based on acoustic, radiofrequency (RF) or Visual Light Communication (VLC) have been proposed for underwater communications in the literature. This paper presents the architecture of an underwater wireless communication framework for the control of multiple semi-autonomous robots in cooperative interventions. The proposed framework is composed of several modules as the virtual reality interface using UWSim, the Underwater Multirobot Cooperative Intervention Remote Control Protocol (UMCI-RCP) and a Generic Link Layer (GLL). UMCI-RCP allows the control of an underwater robot over limited communication links. UMCI-RCP integrates a progressive compression algorithm that provides visual feedback at a constant rate and ensures image reception even in channels with loses. The Time Division Multiple Access (TDMA) medium access strategy minimizes the jitter of transmitted packets. The GLL has been designed in order to provide support for multimodal transmission (i.e. acoustic, RF and VLC) and also to interface with the UWSim-NET simulator so that facilitates the experimentation either with a real or with a simulated modem. The possibility of exchange real and simulated devices in the proposed framework are demonstrated by means of a teleoperation experiment with a BlueROV equipped with the S100 RF modems. Hardware-In-the-Loop (HIL) capabilities are demonstrated repeating the experiment with the real modems and modeling the BlueROV, and also modeling both the modems and the BlueROV.

Underwater Simulators Analysis for Digital Twinning

“…The platforms thus developed were then tested by a group of users who drove the UVMS while grasping and moving an object; however, several users still claim to prefer an original interface to the 3D one [100]. Although the teleoperation of submarine vehicles generally requires the umbilical cable, architecture was also developed to allow it to exploit wireless communication, mainly acoustic communication [101], and Radiofrequency [102]. In particular, a transmission protocol was developed and tested both in simulation and in HIL by creating special modules.…”

Cross-Coupled Dynamics and MPA-Optimized Robust MIMO Control for a Compact Unmanned Underwater Vehicle

“…On the other hand, open-frame UUVs like the one investigated in this work can be configured with an even number of thrusters for actuating the heave behavior so that the lateral and longitudinal dynamics remain decoupled. Some examples of decoupled heave-yaw dynamics in openframe ROVs are Thetis [11], Garbi [12], Romeo [13], BlueROV2 [14], and Hybrid-ROV [15]. More recent work on an underwater robot named 'Intelligence Ocean-I' [16], although described as an open-frame vehicle, has stabilizing rear wings similar to those of a flight vehicle.…”

A Control Architecture for Developing Reactive Hybrid Remotely Operated Underwater Vehicles

“…The reduced visibility makes it challenging for the operator to maintain a clear reference to the ROV's location and the detected elements of interest. It is within this context that the concept of Hybrid Remotely Operated Underwater Vehicle (HROV) is introduced, denoting an underwater vehicle capable of being manually operated while also presenting the capacity to autonomously execute specific operations based on user requirements [19,20].…”