scholarly journals Embedded acoustic long baseline localization system for autonomous underwater vehicles

2021 ◽  
Vol 24 (3) ◽  
pp. 1445
Author(s):  
Redouane Es-sadaoui ◽  
Jamal Khallaayoune ◽  
Tamara Brizard
Keyword(s):  
Digital Signal Processor ◽  
Acoustic Waves ◽  
Autonomous Underwater Vehicles ◽  
Digital Signal ◽  
Propagation Model ◽  
Time Of Arrival ◽  
Water Medium ◽  
Positioning System ◽  
Average Deviation ◽  
Long Baseline

<p>The attenuation of global positioning system (GPS) in water medium makes localization of autonomous uderwater vehicles (AUVs) particularly challenging. The long baseline (LBL) positioning system can extend GPS using beacons as references. This work aims at building an acoustic LBL-based system able to localize AUVs operating in swarms thanks to a small size acoustic transceiver embedded onboard AUVs and implementing range-based localization algorithms to estimate the swarm coordinates in real-time. The distances computation between navigating AUVs and fixed beacons were implemented in a digital signal processor (DSP) which computes the time-of-arrival (ToA) of incoming pure tone acoustic waves. The principle of design, hardware architecture, implementation, simulations and sea experiments are described in this paper. The experimental data showed an average deviation around 0.62 m when an AUV is placed at 45 m far away from a beacon. This deviation increases with distance: around 4.8 m measured at 500 m. This performance can be improved by taking into consideration the two main factors examined in this paper, which are sound velocity profile and propagation model.</p>

scholarly journals An Indoor Ultrasonic Positioning System Based on TOA for Internet of Things

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Jian Li ◽  
Guangjie Han ◽  
Chunsheng Zhu ◽  
Guiqing Sun
Keyword(s):  
Internet Of Things ◽  
Noise Signal ◽  
Practical Implementation ◽  
Time Of Arrival ◽  
Positioning System ◽  
Position Information ◽  
Long Baseline ◽  
Ultrasonic Time ◽  
Control Terminal ◽  
Display Control

With the development of Internet of Things, the position information of indoor objects becomes more important for most application scenarios. This paper presents an ultrasonic indoor positioning system, which can achieve centimeter-level precise positioning of objects moving indoors. Transmitting nodes, receiving nodes, and display control terminal are needed to constitute the entire system. The system is based on long-baseline positioning technology that uses code division multiplexing access mechanism. There is no limit to the number of receiving nodes as the system works in the up-transmit-down-receive mode. Positioning of a receiving node is found based on ultrasonic Time of Arrival ranging technology. To accurately determine the positioning, there must be at least four or five transmitting nodes. The working radius will not be less than 5 meters when the height is larger than 3 meters. The system uses wideband pseudorandom noise signal called Gold sequences for multiuser identification and slant range measurement. The paper first gives a brief introduction of popular indoor ultrasonic positioning methods and then describes the theory of proposed algorithm and provides the simulation results. To examine the correctness of the approach and its practicality, the practical implementation and experimental results are provided also in the paper.

scholarly journals A Single-Way Ranging Localization of AUVs Based on PSO of Outliers Elimination

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Xinnan Fan ◽  
Zhongjian Wu ◽  
Jianjun Ni ◽  
Chengming Luo
Keyword(s):  
Autonomous Underwater Vehicles ◽  
Underwater Vehicles ◽  
Time Of Arrival ◽  
Localization Algorithm ◽  
Angle Of Arrival ◽  
Simulation Experiments ◽  
Range Measurements ◽  
Acoustic Localization ◽  
Long Baseline ◽  
Key Factor

Localization of autonomous underwater vehicles (AUVs) is a very important and challenging task for the AUVs applications. In long baseline underwater acoustic localization networks, the accuracy of single-way range measurements is the key factor for the precision of localization of AUVs, whether it is based on the way of time of arrival (TOA), time difference of arrival (TDOA), or angle of arrival (AOA). The single-way range measurements do not depend on water quality and can be taken from long distances; however, there are some limitations which exist in these measurements, such as the disturbance of the unknown current velocity and the outliers caused by sensors and errors of algorithm. To deal with these problems, an AUV self-localization algorithm based on particle swarm optimization (PSO) of outliers elimination is proposed, which improves the performance of angle of arrival (AOA) localization algorithm by taking account of effects of the current on the positioning accuracy and eliminating possible outliers during the localization process. Some simulation experiments are carried out to illustrate the performance of the proposed method compared with another localization algorithm.

Cooperative Navigation for Multiple AUVs Based on Relative Range Measurements with a Single Leader

2014 ◽  
Vol 556-562 ◽  
pp. 3117-3123 ◽  
Author(s):  
Xing Li Huang ◽  
Li Yan Liu ◽  
Tao Tao Lv ◽  
Wen Bai Li
Keyword(s):  
Autonomous Underwater Vehicles ◽  
Underwater Vehicles ◽  
Cooperative Localization ◽  
Positioning System ◽  
Navigation Problem ◽  
Range Measurements ◽  
Cooperative Navigation ◽  
Long Baseline ◽  
Novel Method ◽  
Simulation Results

his paper deals with the cooperative navigation problem of multiple autonomous underwater vehicles (AUV). A novel method which does not depend on a beacon network like in long baseline positioning system is proposed. The principle of this approach is to realize the cooperative localization of AUVs by using relative range measurements between the leader and the follower vehicles by means of an extended Kalman filter. Simulation results that validate the effectiveness of this approach are presented.

Yield Enhancement Study: Process Variation and Design Margins Leading to Timing Issues in the RAM

2000 ◽  
Author(s):  
Srikanth Perungulam ◽  
Scott Wills ◽  
Greg Mekras
Keyword(s):  
Cross Sections ◽  
Digital Signal Processor ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Random Access ◽  
Digital Signal ◽  
Yield Enhancement ◽  
Final Conclusion ◽  
Stage Separation ◽  
Study Process

Abstract This paper illustrates a yield enhancement effort on a Digital Signal Processor (DSP) where random columns in the Static Random Access Memory (SRAM) were found to be failing. In this SRAM circuit, sense amps are designed with a two-stage separation and latch sequence. In the failing devices the bit line and bit_bar line were not separated far enough in voltage before latching got triggered. The design team determined that the sense amp was being turned on too quickly. The final conclusion was that a marginal sense amp design, combined with process deviations, would result in this type of failure. The possible process issues were narrowed to variations of via resistances on the bit and bit_bar lines. Scanning Electron Microscope (SEM) inspection of the the Focused Ion Beam (FIB) cross sections followed by Transmission Electron Microscopy (TEM) showed the presence of contaminants at the bottom of the vias causing resistance variations.

scholarly journals Robust Optimal Tracking Control of a Full-Bridge DC-AC Converter

2021 ◽  
Vol 11 (3) ◽  
pp. 1211
Author(s):  
En-Chih Chang ◽  
Chun-An Cheng ◽  
Rong-Ching Wu
Keyword(s):  
Steady State ◽  
Digital Signal Processor ◽  
Tracking Control ◽  
Harmonic Distortion ◽  
Digital Signal ◽  
Fast Convergence ◽  
Solution Quality ◽  
Hybrid Strategy ◽  
Optimal Tracking ◽  
Optimal Tracking Control

This paper develops a full-bridge DC-AC converter, which uses a robust optimal tracking control strategy to procure a high-quality sine output waveshape even in the presence of unpredictable intermissions. The proposed strategy brings out the advantages of non-singular fast convergent terminal attractor (NFCTA) and chaos particle swarm optimization (CPSO). Compared with a typical TA, the NFCTA affords fast convergence within a limited time to the steady-state situation, and keeps away from the possibility of singularity through its sliding surface design. It is worth noting that once the NFCTA-controlled DC-AC converter encounters drastic changes in internal parameters or the influence of external non-linear loads, the trembling with low-control precision will occur and the aggravation of transient and steady-state performance yields. Although the traditional PSO algorithm has the characteristics of simple implementation and fast convergence, the search process lacks diversity and converges prematurely. So, it is impossible to deviate from the local extreme value, resulting in poor solution quality or search stagnation. Thereby, an improved version of traditional PSO called CPSO is used to discover global optimal NFCTA parameters, which can preclude precocious convergence to local solutions, mitigating the tremor as well as enhancing DC-AC converter performance. By using the proposed stable closed-loop full-bridge DC-AC converter with a hybrid strategy integrating NFCTA and CPSO, low total harmonic distortion (THD) output-voltage and fast dynamic load response are generated under nonlinear rectifier-type load situations and during sudden load changes, respectively. Simulation results are done by the Matlab/Simulink environment, and experimental results of a digital signal processor (DSP) controlled full-bridge DC-AC converter prototype confirm the usefulness of the proposed strategy.

High Voltage Driver for RSFQ Digital Signal Processor

2007 ◽  
Vol 17 (2) ◽  
pp. 470-473 ◽  
Author(s):  
Igor I. Soloviev ◽  
M. Raihan Rafique ◽  
Henrik Engseth ◽  
Anna Kidiyarova-Shevchenko
Keyword(s):  
High Voltage ◽  
Digital Signal Processor ◽  
Digital Signal ◽  
Signal Processor

scholarly journals One Cycle Control of a PWM Rectifier a New Approach

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5523
Author(s):  
Rodrigo De A. Teixeira ◽  
Werbet L. A. Silva ◽  
Guilherme A. P. De C. A. Pessoa ◽  
Joao T. Carvalho Neto ◽  
Elmer R. L. Villarreal ◽  
...  
Keyword(s):  
Power Factor ◽  
Digital Signal Processor ◽  
Digital Signal ◽  
Pwm Rectifier ◽  
Phase Voltage ◽  
Unity Power Factor ◽  
New Approach ◽  
Phase Current ◽  
Common Mode Voltage ◽  
Power Factor Corrector

This paper analyzes a Digital Signal Processor (DSP) based One Cycle Control (OCC) strategy for a Power Factor Corrector (PFC) rectifier with Common-mode Voltage (CMV) immunity. It is proposed a strategy that utilizes an emulated-resistance-controller in closed-loop configuration to set the dc-link voltage to achieve unity power factor (UPF). It is shown that if the PFC can achieve UPF condition and if the phase voltage is only affected by CMV, then phase current is free from CMV, as well as a lead-lag compensator (LLC) to average phase current.

Design of New Frequency Converter Based on TMS320LF2407A

2012 ◽  
Vol 466-467 ◽  
pp. 809-813
Author(s):  
Zhan Jun Yuan ◽  
Jin Wang
Keyword(s):  
Digital Signal Processor ◽  
Pulse Width Modulation ◽  
Frequency Converter ◽  
Dynamic Performance ◽  
Digital Signal ◽  
Control Precision ◽  
Software And Hardware ◽  
Converter Design ◽  
Utilization Ratio ◽  
High Control

In order to improve voltage utilization ratio and dynamic performance of frequency converter, this paper presents a digital frequency converter design scheme based on digital signal processor TMS320LF2407A and the theory of space vector pulse width modulation (SVPWM) technology, provides its detailed design measures of software and hardware and SVPWM algorithm realization methods. The experimental results prove that this new frequency converter has simple structure, high control precision, higher voltage utilization ratio, better dynamic and static property.

Sign in / Sign up

Export Citation Format

Share Document