scholarly journals Design and Development of a Littoral AUV for Underwater Target Localization and Homing Using Vision and SONAR Module

ISRN Robotics ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
R. K. Sinha ◽  
Aayush Jha ◽  
Faheem Ahmad ◽  
Vivek Mishra ◽  
Prateek Murgai ◽  
...  
Keyword(s):  
Power Systems ◽  
Degrees Of Freedom ◽  
Autonomous Underwater Vehicle ◽  
Mechanical Design ◽  
Water Environment ◽  
Experimental Results ◽  
Design And Development ◽  
Sound Sources ◽  
Six Degrees Of Freedom ◽  
Underwater Target

This paper presents the design and development of a modular littoral autonomous underwater vehicle called “ZYRA” having six degrees of freedom for performing the following tasks underwater: target (sound sources emitting frequencies between 1 Hz and 180 KHz) localization and homing, buoy detection. The development of the AUV has been divided into, namely, five sections: mechanical design and fabrication, embedded and power systems, control and software, image processing, and underwater acoustics. A fully functional AUV has been tested in a self-created arena with different tasks spread out in a shallow water environment. Two different kinds of experimental results have been presented: first the experimental results of the SONAR module and second based on the number of successful outcomes per total number of trials for each task.

DESIGN AND DEVELOPMENT OF AN EFFICIENT COMPUTER SIMULATION MODEL FOR RESPONSE ANALYSIS OF A MOORED SEMI-SUBMERSIBLE

2021 ◽  
Vol 161 (A1) ◽  
Author(s):  
V Domala ◽  
R Sharma
Keyword(s):  
Computer Simulation ◽  
Simulation Model ◽  
Degrees Of Freedom ◽  
Experimental Results ◽  
Response Analysis ◽  
Computer Simulation Model ◽  
Governing Equations ◽  
Design And Development ◽  
Mooring Lines ◽  
Steel Wires

This paper presents the design and development of an efficient modular ‘Computer Simulation Model (CSM)’ for response analysis of a moored semi-submersible. The computer simulation model is designed in two split models (i.e. computational and experimental models) and each of these models consists of various modules. The modules are developed from basic governing equations related to motion and modules are integrated and we aim for a seamless integration. The moored semi-submersible is represented mathematically as six degrees of freedom dynamic system and the coupling effects between the structure and mooring lines are considered. The basic geometric configuration of semi- submersible is modelled and analyzed for stability computations in MS-Excel*TM and then the basic governing equations related to motion are modelled mathematically in a module and solved numerically with Ansys-AQWA**TM. The computational model is validated and verified with some available experimental results. The CSM is utilized to study the surge and sway responses with respect to the horizontal range of mooring lines and our results show good validation with the existing experimental results. Our presented results show that the fibre wires have minimum steady state response in surge and sway degrees of freedom as compared with the steel wires. However, they have large drift as compared with steel wires. Finally, we show that the computer simulation model can help in detailed analysis of responses and results can be utilized for design and development of new age semi-submersibles for optimum performances for a given set of parameters.

Maglev 6-DOF Stage for Nanopositioning

2003 ◽  
Author(s):  
Wong-Jong Kim ◽  
Shobhit Verma ◽  
Jie Gu
Keyword(s):  
Degrees Of Freedom ◽  
Vibration Isolation ◽  
Mechanical Design ◽  
Wear Particle ◽  
Test Results ◽  
Mechanical Contact ◽  
Position Resolution ◽  
Nanoscale Structures ◽  
Particle Generation ◽  
Six Degrees Of Freedom

This paper presents a novel magnetically levitated (maglev) stage with nanoscale positioning capability in all six degrees of freedom (DOFs). The key aspect of this device is that its single moving part has no mechanical contact with its stationary base, which leads to no mechanical friction and stiction, and no wear particle generation. We present herein the mechanical design, instrumentation, and test results of this maglev stage. Currently it shows position resolution of 4 nm, position noise of 2 nm rms, hundreds-of-micrometer translational travel range, a-few-milliradian rotational travel range, and power consumption less than a fraction of a Watt per axis. This maglev stage can be used in numerous applications such as manufacture of nanoscale structures, assembly and packaging on micro-size parts, vibration isolation for delicate instrumentation, and telepresence microsurgery.

An Autonomous Underwater Vehicle for Competition

2013 ◽  
Vol 380-384 ◽  
pp. 595-600
Author(s):  
Hai Tian ◽  
Bo Hu ◽  
Can Yu Liu ◽  
Guo Chao Xie ◽  
Hui Min Luo
Keyword(s):  
Control System ◽  
Hydrodynamic Model ◽  
Degrees Of Freedom ◽  
Autonomous Underwater Vehicle ◽  
Autonomous Underwater Vehicles ◽  
Vertical Motion ◽  
Underwater Vehicle ◽  
Step Response ◽  
Six Degrees Of Freedom ◽  
Simulink Simulation

The research of this paper was derived from the small autonomous underwater vehicle (AUV)Raider well performed in the 15th International Underwater Vehicle Competition (IAUVC),San Diego. In order to improve the performance of underwater vehicle, the control system of performance motion played an important role on autonomous underwater vehicles stable motion, and the whole control system of AUV is the main point. Firstly, based on the motion equations of six degrees of freedom, the paper simplified the dynamical model reasonably in allusion; Due to the speed of Raider to find the target was very low, this paper considered the speed was approximately zero and only considered the vertical motion. Therefore, this paper established the vertical hydrodynamic model of Raider, obtaining the transfer equation of vertical motion. Through the experiment and Matlab/Simulink simulation, this paper got the actual depth of the step response curve and simulation curve, and verified the validity of the vertical hydrodynamic model and the correlation coefficient.

Design and Development of an Efficient Computer Simulation Model for Response Analysis of a Moored Semi-Submersible

2019 ◽  
Vol 161 (A1) ◽  
Keyword(s):  
Computer Simulation ◽  
Simulation Model ◽  
Degrees Of Freedom ◽  
Experimental Results ◽  
Response Analysis ◽  
Computer Simulation Model ◽  
Governing Equations ◽  
Design And Development ◽  
Mooring Lines ◽  
Steel Wires

This paper presents the design and development of an efficient modular ‘Computer Simulation Model (CSM)’ for response analysis of a moored semi-submersible. The computer simulation model is designed in two split models (i.e. computational and experimental models) and each of these models consists of various modules. The modules are developed from basic governing equations related to motion and modules are integrated and we aim for a seamless integration. The moored semi-submersible is represented mathematically as six degrees of freedom dynamic system and the coupling effects between the structure and mooring lines are considered. The basic geometric configuration of semisubmersible is modelled and analyzed for stability computations in MS-Excel*TM and then the basic governing equations related to motion are modelled mathematically in a module and solved numerically with Ansys-AQWA**TM. The computational model is validated and verified with some available experimental results. The CSM is utilized to study the surge and sway responses with respect to the horizontal range of mooring lines and our results show good validation with the existing experimental results. Our presented results show that the fibre wires have minimum steady state response in surge and sway degrees of freedom as compared with the steel wires. However, they have large drift as compared with steel wires. Finally, we show that the computer simulation model can help in detailed analysis of responses and results can be utilized for design and development of new age semi-submersibles for optimum performances for a given set of parameters.

scholarly journals The parameter identification of the autonomous underwater vehicle based on multi-innovation least squares identification algorithm

2020 ◽  
Vol 17 (2) ◽  
pp. 172988142092101
Author(s):  
Zhang Huajun ◽  
Tong Xinchi ◽  
Guo Hang ◽  
Xia Shou
Keyword(s):  
Least Squares ◽  
Degrees Of Freedom ◽  
Autonomous Underwater Vehicle ◽  
Underwater Vehicle ◽  
Recursive Least Squares ◽  
Model Parameters ◽  
Identification Algorithm ◽  
Six Degrees Of Freedom ◽  
Recursive Least Squares Algorithm ◽  
Least Squares Algorithm

An accurate model is important for the engineer to design a robust controller for the autonomous underwater vehicle. There are two factors that make the identification difficult to get accurate parameters of an AUV model in practice. Firstly, the autonomous underwater vehicle model is a coupled six-degrees-of-freedom model, and each state of the kinetic model influences the other five states. Secondly, there are more than 100 hydrodynamic coefficients which have different effects, and some parameters are too small to be identified. This article proposes a simplified six-degrees-of-freedom model that contains the essential parameters and employs the multi-innovation least squares algorithm based on the recursive least squares algorithm to obtain the parameters. The multi-innovation least squares algorithm leverages several past errors to identify the parameters, and the identification results are more accurate than those of the recursive least squares algorithm. It collects the practical data through an experiment and designs a numerical program to identify the model parameters. Meanwhile, it compares the performances of the multi-innovation least squares algorithm with those of the recursive least squares algorithm and the least square method, the results show that the multi-innovation least squares algorithm is the most effective way to identify parameters for the simplified six-degrees-of-freedom model.

scholarly journals The Ariadne's Clew Algorithm

1998 ◽  
Vol 9 ◽  
pp. 295-316 ◽  
Author(s):  
E. Mazer ◽  
J. M. Ahuactzin ◽  
P. Bessiere
Keyword(s):  
Path Planning ◽  
Degrees Of Freedom ◽  
Optimization Problems ◽  
Dynamic Environment ◽  
Dynamic Environments ◽  
Experimental Results ◽  
High Dimensional ◽  
New Approach ◽  
Six Degrees Of Freedom ◽  
Moving Obstacle

We present a new approach to path planning, called the ``Ariadne's clew algorithm''. It is designed to find paths in high-dimensional continuous spaces and applies to robots with many degrees of freedom in static, as well as dynamic environments --- ones where obstacles may move. The Ariadne's clew algorithm comprises two sub-algorithms, called SEARCH and EXPLORE, applied in an interleaved manner. EXPLORE builds a representation of the accessible space while SEARCH looks for the target. Both are posed as optimization problems. We describe a real implementation of the algorithm to plan paths for a six degrees of freedom arm in a dynamic environment where another six degrees of freedom arm is used as a moving obstacle. Experimental results show that a path is found in about one second without any pre-processing.

scholarly journals A novel three-legged 6-DOF parallel robot with simple kinematics

2020 ◽  
Vol 44 (4) ◽  
pp. 558-565
Author(s):  
Edelvays Cherchelanov ◽  
Ilian A. Bonev
Keyword(s):  
Degrees Of Freedom ◽  
Mechanical Design ◽  
Main Idea ◽  
Parallel Robot ◽  
Six Degrees Of Freedom ◽  
Reduced Risk

This paper presents a novel three-legged six degrees of freedom (6-DOF) parallel robot with simple kinematics. The main idea behind this novel architecture is that each of the three identical legs is controlled by two prismatic actuators with parallel directions. As a result, it is possible to control simultaneously or separately the position and the orientation of a leg. The reduced number of legs leads to a simple mechanical design with reduced risk for mechanical interferences.

Fault Tolerant Control of an AUV using Periodic Output Feedback with Multi Model Approach

2016 ◽  
Vol 5 (2) ◽  
pp. 41-62 ◽  
Author(s):  
Sneha Joshi ◽  
D. B. Talange
Keyword(s):  
Output Feedback ◽  
Degrees Of Freedom ◽  
Autonomous Underwater Vehicle ◽  
Controller Design ◽  
Fault Tolerant ◽  
Six Degrees Of Freedom ◽  
Thrust Distribution ◽  
Depth Control ◽  
High Degree ◽  
Model Approach

Active thruster control is an important problem in AUV. One of the way to tackle this problem is to make the dynamic system like AUV as adaptive and self-controlling. This article discusses the fault tolerant controller design with periodic output feedback for Autonomous Underwater Vehicle using multi model approach. The entire system is modelled in state space. Assuring high degree of reliability and persisting autonomy under thruster failure the controller has to be designed such that the thrust distribution is effectively controlled if any one of the signals and corresponding thrusters fails. The AUV is modelled in six degrees of freedom having six inputs and six outputs. Four thrusters are used for vertical and horizontal movements in AUV. Fault tolerant controller is designed for depth control of AUV, with periodic output feedback gains with multi model approach. To each thruster failure the multi model is presented with the gain matrix having all off diagonal terms zero. The designed robust fault tolerant controller with periodic output feedback with multi model approach provides satisfactory stabilization to AUV depth system.

A Study of an Arm Type Damper Consisting of Two Links, Two Joints and a Hinge

2002 ◽  
Author(s):  
Taichi Matsuoka ◽  
Kenichiro Omata ◽  
Yasuhisa Okano
Keyword(s):  
Degrees Of Freedom ◽  
Vibration Suppression ◽  
Experimental Results ◽  
Shaking Table ◽  
Friction Damper ◽  
Six Degrees Of Freedom ◽  
Human Arm ◽  
Three Degree Of Freedom ◽  
Ball Joints ◽  
Theoretical Results

In this paper, an arm type passive damper consisting of two links, two joints and a hinge, which is similar to a human arm, has developed. Two magnetic ball joints were used for the joints and a rotary friction damper was used for the hinge. The arm type damper has six degrees of freedom and gives damping in three translational and three rotational directions. The resisting force characteristics of the damper in three translational directions were analyzed. A trial damper was made and the load-displacement curves of the damper in three translational directions were measured. The experimental results agree with the theoretical results to some degree. Next, the damper was attached to a three-degree-of-freedom system composed of a mass, three guide rails and four coil springs, in which the mass is able to move in three translational directions along the guide rails. The seismic responses of the mass in three translational directions were measured using a two-dimensional electrohydraulic type shaking table and the experimental results were compared with the calculated results obtained by the Mathematica 3.0. The experimental results agree with the calculated results to some degree, and the effects of vibration suppression of the damper and the propriety of the calculations were substantiated.

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