Underwater Teleoperation Research Articles

Design and Evaluation of Visual-and-Force-Assisted Virtual Operation System for Underwater Teleoperation Training

Design and Evaluation of Visual-and-Force-Assisted Virtual Operation System for Underwater Teleoperation Training

Sliding mode disturbance observer and Q learning-based bilateral control for underwater teleoperation systems

For underwater environments, it is difficult to acquire accurate contact force vectors between the end effecter and the object by multidimensional force sensors. Precise force measurement is the key point for accurate teleoperation tasks. However, existing force estimations are rarely concerned with multidimensional force vector estimations. Therefore, the transparency of the teleoperation system may be attenuated, even resulting in stability or task failure in practical engineering. In this paper, we focus on analyzing the contact force vector in three dimensions. A sliding mode disturbance observer is designed to estimate the contact force. A Q learning process is used to find the optimal multidimensional contact force. Furthermore, a bilateral controller is proposed based on the sliding mode disturbance observer and Q learning-based method for underwater teleoperation systems. The stability is analyzed by Lyapunov functions. Numerical simulations and real robot experiments are performed to verify the effectiveness of the proposed method.

Dynamics modeling of human–machine control interface for underwater teleoperation – ERRATUM

In the original version of this paper the name of the first author was incorrectly published as Muscolo Giovanni Gerardo. The correct name is Giovanni Gerardo Muscolo. The Publisher apologises for this error.

Dynamics Modeling of Human–Machine Control Interface for Underwater Teleoperation

SUMMARYThis paper presents an experimental study on new paradigms of haptic-based teleoperated navigation of underwater vehicles. Specifically, the work is focused on investigating the possibility of enhancing the user interaction by introducing haptic cues at the level of the user wrist providing a force feedback that reflects dynamic forces on the remotely operated underwater vehicle. Different typologies of haptic controllers are conceived and integrated with a real-time simulated model of an underwater robotic vehicle. An experimental test is designed to evaluate the usability of the system and to provide information on the global performance during the execution of simple tasks. Experiments are conducted with 7 candidates testing 12 different controllers. Among these, the most effective strategies have been identified and selected on the basis of minimization of errors on the vehicle trajectory and of the quality of the user’s interaction in terms of perceived comfort during operation. Overall, the results obtained with this study underline that haptic navigation control can have a positive influence on the performance of remotely controlled underwater vehicles.

A novel bilateral impedance controls for underwater tele-operation systems

Owing to characteristics of the flow and the variability, it is extremely difficult to achieve the stability and the transparency of the underwater tele-operation system. In practice, the accurate force may not easily be acquired due to model uncertainties, the time delay and external disturbances. In order to enhance the stability and the transparency of the underwater tele-operation, an adaptive neural fuzzy inference system disturbance observer-based impedance control is proposed to both the master side and slave side. The learning algorithm of the adaptive neural fuzzy inference system network and the disturbance observer may simultaneously suppress model uncertainties of the nonlinear system and disturbances of external underwater environment. Concerning the time delay, the stability is analyzed by Lyapunov theorem. Numerical simulations are performed and results demonstrate the effective performance of the proposed method.

Human-in-the-loop active electrosense

Active electrosense is a non-visual, short range sensing system used by weakly electric fish, enabling such fish to locate and identify objects in total darkness. Here we report initial findings from the use of active electrosense for object localization during underwater teleoperation with a virtual reality (VR) head-mounted display (HMD). The advantage of electrolocating with a VR system is that it naturally allows for aspects of the task that are difficult for a person to perform to be allocated to the computer. However, interpreting weak and incomplete patterns in the incoming data is something that people are typically far better at than computers. To achieve human–computer synergy, we integrated an active electrosense underwater robot with the Oculus Rift HMD. The virtual environment contains a visualization of the electric images of the objects surrounding the robot as well as various virtual fixtures that guide users to regions of higher information value. Initial user testing shows that these fixtures significantly reduce the time taken to localize an object, but may not increase the accuracy of the position estimate. Our results highlight the advantages of translating the unintuitive physics of electrolocation to an intuitive visual representation for accomplishing tasks in environments where imaging systems fail, such as in dark or turbid water.

On Applying Virtual Reality to Underwater Robot Tele-Operation and Pilot Training

Virtual reality systems are being increasingly used for enhancing human perception of complex real-world or synthetic events. Serious applications outside entertainment range from education training to science and engineering. In this paper, we present our research work concerning the use of virtual reality in underwater robot tele-operation and training. We have proposed a novel concept of ROV safety domain to overcome the robot sensor error issue involved in virtual environment based underwater teleoperation approach. The detailed mathematical model of the ROV safety domain and its proof will be presented. In addition, we will examine how ROV safety domain can be used in underwater robot teleoperation, and present the architecture of our prototype virtual tele-operation system. Its current status and evaluation, as well as issues involved in its practical application will also be discussed.