Design of a Labriform-Steering Underwater Robot Using a Multiphysics Simulation Environment

Bio-inspired solutions devised for Autonomous Underwater Robots are currently investigated by researchers as a source of propulsive improvement. To address this ambitious objective, the authors have designed a carangiform swimming robot, which represents a compromise in terms of efficiency and maximum velocity. The requirements of stabilizing a course and performing turns were not met in their previous works. Therefore, the aim of this paper is to improve the vehicle maneuvering capabilities by means of a novel transmission system capable of transforming the constant angular velocity of a single rotary actuator into the pitching–yawing rotation of fish pectoral fins. Here, the biomimetic thrusters exploit the drag-based momentum transfer mechanism of labriform swimmers to generate the necessary steering torque. Aside from inertia and encumbrance reduction, the main improvement of this solution is the inherent synchronization of the system granted by the mechanism’s kinematics. The system was sized by using the experimental results collected by biologists and then integrated in a multiphysics simulation environment to predict the resulting maneuvering performance.

Multiple Bio-Inspired Father–Son Underwater Robot for Underwater Target Object Acquisition and Identification

Underwater target acquisition and identification performed by manipulators having broad application prospects and value in the field of marine development. Conventional manipulators are too heavy to be used for small target objects and unsuitable for shallow sea working. In this paper, a bio-inspired Father–Son Underwater Robot System (FURS) is designed for underwater target object image acquisition and identification. Our spherical underwater robot (SUR), as the father underwater robot of the FURS, has the ability of strong dynamic balance and good maneuverability, can realize approach the target area quickly, and then cruise and surround the target object. A coiling mechanism was installed on SUR for the recycling and release of the son underwater robot. A Salamandra-inspired son underwater robot is used as the manipulator of the FURS, which is connected to the spherical underwater robot by a tether. The son underwater robot has multiple degrees of freedom and realizes both swimming and walking movement modes. The son underwater robot can move to underwater target objects. The vision system is installed to enable the FURS to acquire the image information of the target object with the aid of the camera, and also to identify the target object. Finally, verification experiments are conducted in an indoor water tank and outdoor swimming pool conditions to verify the effectiveness of the proposed in this paper.

Acceleration of the underwater system of technical stereo vision with the help of multithreaded organization of algorithms

В настоящей работе дано описание многопоточной параллельной организации работы алгоритмов, входящих в состав программной части подводной системы технического стереозрения подводного робота. Данные, полученные системой технического стереозрения, в последствии поступают на систему управления для выполнения операций по управлению роботом и оператору на экран монитора для последующего принятия им управленческих решений. В большинстве случаев выполнение алгоритмов происходит последовательно. Суммарное время обработки одного кадра складывается из времени работы всех алгоритмов, входящих в состав программной части. Таким образом, в однопоточном режиме даже самые быстрые алгоритмы будут ожидать своей очереди на выполнение. Следовательно, система управления и оператор в случаях, требующих большие вычислительные мощности, будут получать данные недостаточно быстро. Естественно для увеличения быстродействия всей программной части возникает потребность организовать работу входящих в состав алгоритмов параллельно, многопоточно, но такой способ организации работы дополнительно создаёт ряд проблем, которых бы не было, если работа алгоритмов была организована последовательно, однопоточно. В статье приведены способы решения этих проблем, проведено сравнение времени работы многопоточной и однопоточной реализации алгоритмов. This paper describes the multithreaded parallel organization of the algorithms that are part of the software of the underwater system of technical stereo vision of an underwater robot. The data obtained by the technical stereo vision system is subsequently transmitted to the control system to perform robot control operations and to the operator on the monitor screen for subsequent management decisions. In most cases, the algorithms are executed sequentially. The total processing time of one frame consists of the operating time of all algorithms included in the software part. Thus, in single-threaded mode, even the fastest algorithms will be waiting for their turn to execute. Consequently, the control system and the operator in cases requiring large computing power will not receive data quickly enough. Naturally, in order to increase the speed of the entire software part, there is a need to organize the work of the algorithms included in parallel, multithreaded, but this way of organizing work additionally creates a number of problems that would not exist if the algorithms were organized sequentially, single-threaded. The article presents ways to solve these problems, compares the operating time of multithreaded and single-threaded implementation of algorithms.

Development and Innovative Design Research of Underwater Bionic Fish Products under Hybrid Propulsion Technology

For a long time, underwater robot has been used as a scientific research tool and a teaching platform, but the real application products have not been well explored. The successful case of UAV gives underwater robot a higher expectation. How to apply underwater robot and enter the market has become a hot spot of underwater robot research at present. This paper mainly introduces a bionic fish-shaped robot, redefines underwater robot with innovative thinking, determines product functions from the perspective of the market, and develops product functions and designs and realizes the structure of each part according to the existing scientific research experience. Main innovation points of this design are to adopt the way of the hybrid propulsion for underwater robot movement, through the form of a hybrid propulsion and long range and the contradiction between the rapid maneuver, at the same time of umbilical cord cable, using float design improvement, and through the highly integrated ground station for the system operation control.