A Comparison of Waterproof Motor Housings for Student Robotics Teams

Professionals and students alike create high-performance Remotely Operated Vehicles (ROV)s to complete a multitude of tasks underwater. The student ROV competition created by Marine Advanced Technology Education (MATE) simulates the tasks faced by the modern professional underwater robotics industry. Students often design their ROVs with techniques used by the professional underwater robotics industry. Unlike professionals, students do not have many resources comparing manufacturable ROV components that fit within their design restrictions. Without information about components that they choose to use on their ROVs, students might miss an opportunity to implement a better alternative technology. Such is the case with older Shaft Sealed Housings (SSH) and less common Magnetically Coupled Housings (MCH). In this paper, essential aspects of both alternative designs for waterproof motor housings are tested to determine overall performance. The waterproofness of each housing is tested experimentally over long periods of time in an environment simulating the most extreme depths experienced at the MATE ROV Competition. Maximum static torque is measured on a torque sensor. Cost and manufacturability of each housing are recorded in tables. Ultimately, student robotics teams are left to determine which motor housing best fits their design requirements, based on the data discovered and presented in this paper.

Design and Control Strategy of Bio-inspired Underwater Vehicle with Flexible Propulsor

Biomimetics aims to take inspiration from nature and develop new models and efficient systems for a sustainable future. Bioinspired underwater robotics help develop future submarines that will navigate through the water using flexible propulsor. This research has focused on the Manta Ray species as batoid has a unique advantage over other species. This study also aims to improve AUV (Autonomous Underwater Vehicle) efficiency through biomimetic design, the purpose of which is to observe and study the marine environment, be it for sea exploration or navigation. The design and prototyping process of bioinspired AUVs have been mentioned in this study, along with testing a propulsive mechanism for efficient swimming and turning capabilities. The Robot was designed taking structural considerations from the actual Manta-Ray locomotion and body design. The propulsion mechanism and control circuit were then implemented on the developed systems. The prototype of the Manta Ray was able to generate a realistic swimming pattern and was tested in an acrylic tank. The experimental results obtained in the tank basin are very close to the results we observe in the real-world scenario in terms of the vehicle's forward and turning motion.

Freshwater organisms potentially useful as biosensors and power-generation mediators in biohybrid robotics

Facing the threat of rapidly worsening water quality, there is an urgent need to develop novel approaches of monitoring its global supplies and early detection of environmental fluctuations. Global warming, urban growth and other factors have threatened not only the freshwater supply but also the well-being of many species inhabiting it. Traditionally, laboratory-based studies can be both time and money consuming and so, the development of a real-time, continuous monitoring method has proven necessary. The use of autonomous, self-actualizing entities became an efficient way of monitoring the environment. The Microbial Fuel Cells (MFC) will be investigated as an alternative energy source to allow for these entities to self-actualize. This concept has been improved with the use of various lifeforms in the role of biosensors in a structure called ”biohybrid” which we aim to develop further within the framework of project Robocoenosis relying on animal-robot interaction. We introduce a novel concept of a fully autonomous biohybrid agent with various lifeforms in the role of biosensors. Herein, we identify most promising organisms in the context of underwater robotics, among others Dreissena polymorpha, Anodonta cygnaea, Daphnia sp. and various algae. Special focus is placed on the ”ecosystem hacking” based on their interaction with the electronic parts. This project uses Austrian lakes of various trophic levels (Millstättersee, Hallstättersee and Neusiedlersee) as case studies and as a ”proof of concept”.

Innovative Energy-Saving Propulsion System for Low-Speed Biomimetic Underwater Vehicles

This paper describes research on a unique propulsion system design for a low-speed Biomimetic Unmanned Underwater Vehicle (BUUV). It is biomimetic in the sense that it mimics the movement of aquatic organisms. The undulating propulsion system has numerous advantages over the rotary impeller and is becoming more popular in underwater robotics. The analysis of an artificial seal’s propulsion system with two tail fins is described here. The contrast between the previous undulating propulsion system and the new one is detailed using mathematical analysis and experimental data. The experimental comparison was carried out on a laboratory test stand equipped with specialist sensor equipment to determine the energy efficiency of various types of propulsion systems. Due to a patent procedure, the innovative propulsion system presented in this work has never been published previously. The fins have extra joints, which is the subject of patent claims. The extra joint is intended to improve energy efficiency and reduce fatigue wear on the fins.

Basic requirements for television communications with laser illumination when creating integrated underwater vehicle search systems.

The intensive development of autonomous underwater robotic systems is of great importance for the development of the world’s oceans. One of the main problems of using underwater robotic systems is to increase the search performance of underwater vehicles based on the integration of the capabilities of onboard radio-electronic systems for obtaining information in various physical fields. Analyzing the physical basis of the search, including consideration of the environment of its conduct, objects, as well as means of detection, it can be noted that the result of conducting search operations of the same objects in the same water areas for different underwater robotic complexes depends on what means of detection they are equipped with. The presence of a certain composition of technical means will dictate the development of an optimal sequence of actions that make up the search algorithm. The creation of such algorithms in relation to the task of increasing the search potential of underwater robotics will determine the direction of scientific research that ensures the formation of an optimal underwater search system on it. The effective use of search resources justifies the conclusion that the radio-electronic means of underwater vehicles that form the underwater search system, in total, are a set of devices that are functionally combined with each other for its effective implementation. This association is aimed at forming the so-called integrated search system, which provides for the exchange of information between different search tools about all the objects found by them. The article presents the requirements for the creation of integrated search systems, taking into account practical experiments and experience in the design of underwater vehicles capable of implementing an optimal underwater search system based on laser technologies.

Robust Flow Field Signal Estimation Method for Flow Sensing by Underwater Robotics

The flow field is difficult to evaluate, and underwater robotics can only partly adapt to the submarine environment. However, fish can sense the complex underwater environment by their lateral line system. In order to reveal the fish flow sensing mechanism, a robust nonlinear signal estimation method based on the Volterra series model with the Kautz kernel function is provided, which is named KKF-VSM. The flow field signal around a square target is used as the original signal. The sinusoidal noise and the signal around a triangular obstacle are considered undesired signals, and the predicting performance of KKF-VSM is analyzed after introducing them locally in the original signals. Compared to the radial basis function neural network model (RBF-NNM), the advantages of KKF-VSM are not only its robustness but also its higher sensitivity to weak signals and its predicting accuracy. It is confirmed that even for strong nonlinear signals, such as pressure responses in the flow field, KKF-VSM is more efficient than the commonly used RBF-NNM. It can provide a reference for the application of the artificial lateral line system on underwater robotics, improving its adaptability in complex environments based on flow field information.

Review on Unmanned Underwater Robotics, Structure Designs, Materials, Sensors, Actuators, and Navigation Control

Since its beginning, around the 50s decade, until present days, the area of unmanned underwater vehicles (UUV) has considerably grown through time; those have been used for many tasks and applications, from bomb searching and recovery to sea exploration. Initially, these robots were used mainly for military and scientific purposes. However, nowadays, they are very much extended into civils, and it is not hard to find them being used for recreation. In this context, the present research is an effort to make a walkthrough of evolution in this area, showing a diversity of structure designs, used materials, sensor and instrumentation technologies, kinds and the number of actuators employed, navigation control techniques, and what is new in development trends. The paper gives a clear starting point for those who are initializing into this research area; also, it brings some helpful knowledge for those who already have experience.

Soft Robotic Hands and Tactile Sensors for Underwater Robotics

Research in the field of underwater (UW) robotic applications is rapidly developing. The emergence of coupling the newest technologies on submersibles, different types of telecommunication devices, sensors, and soft robots is transforming the rigid approach to robotic design by providing solutions that bridge the gap between accuracy and adaptability in an environment where there is so much fluctuation in object targeting and environmental conditions. In this paper, we represent a review of the history, development, recent research endeavors, and projected outlook for the area of soft robotics technology pertaining to its use with tactile sensing in the UW environment.