Aero Submarine: a Theoretical Design

Aero submarines (aerosubs) are vehicles that can both fly both in air and travel under water. The concept of dual aerial and aquatic vehicles emerged in 1939 when Russian engineer Boris Ushakov proposed the “flying submarine”[1], and this was followed by further developments including RFS1 [2], convair project in 1964[3] , etc. however, to date, limited attempt has been diverted towards the advanced development of such aircraft. This is heavily influenced by challenges associated with the design and operation of the same. Based on the review of literature the authors aim to introduce a theoretical design for an aerosub (QFS-20) with a view to address the design and operation issues including power, entry to and exit from water.

Survey on the Development of Aerial–Aquatic Hybrid Vehicles

As the development of mobile robots matures, there is an increasing amount of interest in expanding the functionality of such robots through developing multimodal locomotion. As compared to land–water or land–air hybrids, the design of air–water vehicles is much less straightforward due to the fact that both mediums are three-dimensional fluid spaces and there is inherent disparity in fluid properties between them. As such, the development of these vehicles has received limited attention until very recently. Nevertheless, the potential applications of such vehicles range widely from military surveillance, oceanic data collection to heterogeneous robot team operation, which has led to an increasing number of projects working on aerial–aquatic hybrid mobility. In this paper, we discuss the fundamental challenges associated with aerial–aquatic hybrid locomotion as well as the necessary trade-offs in design decisions. We also summarize and review the existing work and prototypes of aerial–aquatic vehicles that have been designed thus far, analyzing the range of solutions that have been adopted to solve the aforementioned challenges. Lastly, the limitations of these solutions are analyzed to offer a perspective on how future developments in the area can enable greater functionality for the concept.

Safe sailing: GSM and GPS controlled autonomous boat with overweight detection and obstacle avoidance

<span>This paper aims to save thousands of lives by proposing a novel technique of ensuring the complete safety of medium-sized aquatic vehicles using innovative ideas as well as augmented adaptations of myriad existing technologies. The proposed system incorporates a warning and danger level detection circuit using transistors for switching purposes when the vehicles are overloaded, and a Global System for Mobile (GSM) based module so that the control room can receive alerts and control the engines of such vehicles centrally. A system for detecting and avoiding obstacles is made using ultrasonic radar with ultrasonic transducer JSN SR04t mounted on top of SG90 servo arm which rotates to detect any obstacles. When an obstacle is detected, two other ultrasonic sensors SR-04 gets activated which are placed on two sides of the aquatic vehicle and the ultrasonic transducer becomes fixed on the exact centre. All the three sensors work together to find a free path for the boat to travel. If there is no free path, the boat will stop and wait for the paths to get cleared. The location of the vehicle is tracked by the Global Positioning System (GPS) and a Proportional-Integral-Derivative (PID) controller has been included along with a system which uses values from the GPS module to come back to its original path if it deviates from the original path when avoiding obstacles. A barcode system has been added where it keeps a count on the passengers. The tickets for the vehicle will have barcodes on them which will let the passengers in only if the barcode matches. This is used mainly to keep track of how many people are boarding the vehicle and to prevent those without tickets from boarding.</span>

Experimental Evaluation of an Autonomous Surface Craft for Shallow-Water Bathymetry

Vast coastal water bodies such as mangroves and wetlands, despite their enormous importance, are inaccessible to even the smallest aquatic vehicles, which are not capable of navigating the extremely shallow environments. To understand their behavior and the transport and exchange processes with both sea and land, it is crucial to study local hydrodynamics, which are highly dependent on bathymetric configuration. In order to obtain accurate and high spatial resolution bathymetric samples, an existing small surface vehicle instrumented with GPS and echosounder was implemented with an autopilot system to achieve autonomy. A description of the autonomous system together with the evaluation of the whole vehicle's performance in a natural coastal environment (e.g., affected by the wind, waves, and currents that exist in coastal regions) is presented. The navigation system is based on an autopilot system, which follows a set of user-selected waypoints to drive the vehicle through a previously designed path. The trajectory is self-corrected to achieve sufficient accuracy (the limits are also defined by the user) using real-time kinematics. The tracking is performed by two independent proportional-integral-derivative (PID) control systems: the boat's displacement speed and the bearing control. A simple experimental procedure to tune the low-level PID control parameters is presented. Comparisons between the bathymetric maps obtained with the system and with other standard bathymetric surveys from a selected coastal site (ship-towed echosounder) are presented to test both the precision of the boat's navigation and the fine structure of the bottom topography. The results confirm the system's capability as a valuable tool for surveying large and very shallow environments.