Development and Performance Validation of a Navigation System for an Underwater Vehicle

2016 ◽  
Vol 69 (5) ◽  
pp. 1097-1113 ◽  
Author(s):  
R. Ramesh ◽  
V. Bala Naga Jyothi ◽  
N. Vedachalam ◽  
G.A. Ramadass ◽  
M.A. Atmanand
Keyword(s):  
Shallow Water ◽  
Navigation System ◽  
Estimation Algorithm ◽  
Initial Position ◽  
Position Estimation ◽  
Doppler Velocity ◽  
Unmanned Underwater Vehicles ◽  
Labview Software ◽  
Position Data ◽  
And Performance

Underwater position data is a key requirement for the navigation and control of unmanned underwater vehicles. The proposed navigation scheme can be used in any vessel or boat for any shallow water vehicle. This paper presents the position estimation algorithm developed for shallow water Remotely Operated Vehicles (ROVs) using attitude data and Doppler Velocity Log data with the initial position from the Global Positioning System (GPS). The navigational sensors are identified using the in-house developed simulation tool in MATLAB, based on the requirement of a position accuracy of less than 5%. The navigation system is built using the identified sensors, Kalman filter and navigation algorithm, developed in LabVIEW software. The developed system is tested and validated for position estimation, with an emulator consisting of a GPS-aided fibre optic gyro-based inertial navigation system as a reference, and it is found that the developed navigation system has a position error of less than 5%.

Recent Challenges and Advances in the Sensorless Commutation of Brushless DC Motors

2020 ◽  
Vol 13 ◽  
Author(s):  
Umesh Kumar Soni ◽  
Ramesh Kumar Tripathi
Keyword(s):  
Initial Position ◽  
Position Estimation ◽  
Current Response ◽  
Flux Linkage ◽  
Brushless Dc Motors ◽  
Position Sensing ◽  
Brushless Dc ◽  
Dc Motors ◽  
Reverse Torque ◽  
Position Detection

Background: Brushless DC motors are highly efficient motors due to its high torque to weight ratio, compact design, high speed operating capability and higher power density. Conventional Hall sensor based rotor position sensing is affected by the heating, vibration, interference and noise. Objective: The innovative, cost effective and easily implementable sensorless techniques are essential in order to achieve high efficiency, reduced current and reduced torque pulsations. Further, a delay free, high load fast startup is also important issue. Methods: In this paper an extensive review of various techniques based on the detection of freewheeling diode current, phase back EMF zero crossoing point detection, back EMF integration method and third harmonic back EMF was done. The study and effect of various PWM strategies on back EMF detection was studied. Later on the sensorless schemes based on flux linkage estimation and flux linkage increment were introduced. The load torque observers, unknown input observers, sliding mode observers, L∞-induced observers, H ∞ - deconvolution filter for back EMF estimation were also reviewed. As the brushless DC motors have no back EMF at starting and for back EMF based commutation a minimum speed is required for sufficient back EMF. Therefore various strategies of open and close-loop reduced current startup have been studied to achieve effective commutation without reverse torque. Initial position detection (IPD) schemes, which are mostly based on saliency and current response to inductance variation, is effective where reverse torque is strictly prohibited. A detailed review of these initial position detection techniques (IPD) has also been presented. Results: The detailed mathematical and graphical analysis has been presented here in order to understand the working of the state-of-art sensorless techniques. Conclusion: The back EMF detection using direct and indirect methods of terminal voltage filtering have the problem of delay and attenuation, PWM noise, freewheeling diode spikes and disturbance in detected back EMFs is a drawback. The parameter detuning, underestimation and overestimation, offset problem, system noise and observer gain variation etc. limit the applicability of observer based technique. Therefore, a more robust and precise position estimation scheme is essential.

Experimental research of indoor navigation system based on broadcast signals

2020 ◽  
Vol 49 (5) ◽  
pp. 49-57
Author(s):  
A. V. Ksendzuk ◽  
E. A. Surmin ◽  
V. V. Kachesov ◽  
S. O. Zhdanov ◽  
K. S. Shakhalov
Keyword(s):  
Navigation System ◽  
Open Space ◽  
Position Estimation ◽  
Indoor Navigation ◽  
Estimation Accuracy ◽  
Satellite Systems ◽  
Indoor Navigation System ◽  
Point To Point ◽  
Navigation Signals ◽  
Navigation Equipment

Results of an experimental study of a local navigation system based on the processing signals from broadcast sources presented. The results of the development of processing algorithms for point-to-point coordinates estimation of the object are presented. The results of the development of algorithms for trajectories estimation are presented. In performed simulation the possibility of obtaining submeter position estimation accuracy in the proposed system is shown. Development results of the navigation module demonstrator are presented. The results of experimental work in difficult navigation conditions, in the presence of shading, reflections and other factors, are presented. It is shown that the developed navigation module allows in the open space near buildings which partially obscuring the satellite systems signals to obtain accuracy higher than the GNSS navigation equipment. In indoor environment in the absence of satellite navigation signals, the developed module shows positioning accuracy not worse than 1.5 meters and provides a measurement rate 1 Hz and better.

Ranging technology using signals of opportunity of non-cooperative communication satellites

2020 ◽  
pp. 1-13
Author(s):  
Yuanyuan Gao ◽  
Yu Hua ◽  
Yu Xiang ◽  
Changjiang Huang ◽  
Shanhe Wang ◽  
...  
Keyword(s):  
Cooperative Communication ◽  
Estimation Algorithm ◽  
Time Difference ◽  
Difference Measurement ◽  
Test Platform ◽  
Positioning Technique ◽  
And Performance ◽  
Navigation Signals ◽  
To Receive ◽  
Signals Of Opportunity

Abstract The positioning technique employing the ubiquitous signals of opportunity of non-cooperative satellites does not send special navigation signals, instead it passively receives satellite signals as noise, presenting advantages of concealment and difficulty for potential attackers. Thus, this study investigates the ranging principle and model using non-cooperative communication satellites and a time difference estimation algorithm. The technology of time difference measurement under non-cooperative observation mode was determined and simulated. A test platform for time difference measurement was built to receive the signal from an unknown geostationary Earth orbit communication satellite and verify the ranging feasibility and performance. The ranging accuracy was found to be smaller than 6 m, as demonstrated by experimental data, which shows the viability of the proposed positioning technique for ranging technology.

scholarly journals Many Ways Lead to the Goal—Possibilities of Autonomous and Infrastructure-Based Indoor Positioning

Electronics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 397
Author(s):  
Hossein Shoushtari ◽  
Thomas Willemsen ◽  
Harald Sternberg
Keyword(s):  
Mobile Networks ◽  
Dead Reckoning ◽  
Simulated Data ◽  
Minimum Cost ◽  
Cost Effective ◽  
Satellite System ◽  
Position Estimation ◽  
Robust Solution ◽  
Position Data ◽  
Global Navigation Satellite

There are many ways to navigate in Global Navigation Satellite System-(GNSS) shaded areas. Reliable indoor pedestrian navigation has been a central aim of technology researchers in recent years; however, there still exist open challenges requiring re-examination and evaluation. In this paper, a novel dataset is used to evaluate common approaches for autonomous and infrastructure-based positioning methods. The autonomous variant is the most cost-effective realization; however, realizations using the real test data demonstrate that the use of only autonomous solutions cannot always provide a robust solution. Therefore, correction through the use of infrastructure-based position estimation based on smartphone technology is discussed. This approach invokes the minimum cost when using existing infrastructure, whereby Pedestrian Dead Reckoning (PDR) forms the basis of the autonomous position estimation. Realizations with Particle Filters (PF) and a topological approach are presented and discussed. Floor plans and routing graphs are used, in this case, to support PDR positioning. The results show that the positioning model loses stability after a given period of time. Fifth Generation (5G) mobile networks can enable this feature, as well as a massive number of use-cases, which would benefit from user position data. Therefore, a fusion concept of PDR and 5G is presented, the benefit of which is demonstrated using the simulated data. Subsequently, the first implementation of PDR with 5G positioning using PF is carried out.

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