Pub Date : 2012-04-03DOI: 10.1109/IBCAST.2012.6177592
Jinhua Zhou, L. Lei, Weikang Liu, Jiamin Tian
Recently, there has been a clear trend towards the application of the ad hoc networking technology in the civil aviation communication system, and then a novel research field of aeronautical ad hoc networks (AANET) has arisen. Researchers have showed that it is possible to set up a mobile ad hoc network among the free flight airliners, thus providing a multi-hop communication link between the airliner and the ground base station. Through this communication link, air passengers can access Internet with low latency and cheap charges. So the commonly used satellite communication in free flight airliners may be replaced by AANET, as the satellite communication is costly and the transmission delay is large. Compared with the normal ad hoc networks, the airliners in AANET move at a very high speed, typically 700km/h to 1000km/h. So the multi-hop communications in AANET are extremely unstable as the network topology changes frequently. Meanwhile, the airliners which are near to the ground base station suffer from a heavy traffic load, as they forward the data traffic to and from the ground base station for other airliners. To solve these problems, researchers have proposed many kinds of link stability prediction strategies and traffic load aware routing protocols, but none of them simultaneously take into account both of these two problems. In this paper, we firstly implement a nodes mobility and traffic Load aware routing strategy in GloMoSim simulator for AANET. In this routing strategy, we adopt the Doppler value which is calculated by Doppler frequency shift as the nodes mobility metric, and adopt the length of the transmission queue of the nodes as the traffic load metric. Then we give a detailed analysis of the performance of the routing strategy through simulation experiments. Simulation results show the effectiveness of this routing strategy.
{"title":"A simulation analysis of nodes mobility and traffic load aware routing strategy in aeronautical ad hoc networks","authors":"Jinhua Zhou, L. Lei, Weikang Liu, Jiamin Tian","doi":"10.1109/IBCAST.2012.6177592","DOIUrl":"https://doi.org/10.1109/IBCAST.2012.6177592","url":null,"abstract":"Recently, there has been a clear trend towards the application of the ad hoc networking technology in the civil aviation communication system, and then a novel research field of aeronautical ad hoc networks (AANET) has arisen. Researchers have showed that it is possible to set up a mobile ad hoc network among the free flight airliners, thus providing a multi-hop communication link between the airliner and the ground base station. Through this communication link, air passengers can access Internet with low latency and cheap charges. So the commonly used satellite communication in free flight airliners may be replaced by AANET, as the satellite communication is costly and the transmission delay is large. Compared with the normal ad hoc networks, the airliners in AANET move at a very high speed, typically 700km/h to 1000km/h. So the multi-hop communications in AANET are extremely unstable as the network topology changes frequently. Meanwhile, the airliners which are near to the ground base station suffer from a heavy traffic load, as they forward the data traffic to and from the ground base station for other airliners. To solve these problems, researchers have proposed many kinds of link stability prediction strategies and traffic load aware routing protocols, but none of them simultaneously take into account both of these two problems. In this paper, we firstly implement a nodes mobility and traffic Load aware routing strategy in GloMoSim simulator for AANET. In this routing strategy, we adopt the Doppler value which is calculated by Doppler frequency shift as the nodes mobility metric, and adopt the length of the transmission queue of the nodes as the traffic load metric. Then we give a detailed analysis of the performance of the routing strategy through simulation experiments. Simulation results show the effectiveness of this routing strategy.","PeriodicalId":251584,"journal":{"name":"Proceedings of 2012 9th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117222084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-04-03DOI: 10.1109/IBCAST.2012.6177564
N. Raza, I. Mehmood, H. Rafiuddin, M. Rafique
Added mass determination of underwater moving objects becoming more and more important now a days. With the advancement in computational technology and computing fluid dynamics technology, a new method is presented by the commercial CFD code. This method can be used to compute the added mass of an object with complex shapes also. The method is based on unsteady, inviscid model and dynamic mesh technique for transient simulation of body motions. By taking the difference of forces under the condition of uniform motions and accelerated motions, added mass of an object is calculated. In principle two cases were run i.e uniform and accelerated, both for linear and angular motions. Differences of forces/torque of uniform and accelerated motions were used to calculate added mass of the given object for both linear and angular motions.
{"title":"Numerical simulation of added mass determination of standard ellipsoids","authors":"N. Raza, I. Mehmood, H. Rafiuddin, M. Rafique","doi":"10.1109/IBCAST.2012.6177564","DOIUrl":"https://doi.org/10.1109/IBCAST.2012.6177564","url":null,"abstract":"Added mass determination of underwater moving objects becoming more and more important now a days. With the advancement in computational technology and computing fluid dynamics technology, a new method is presented by the commercial CFD code. This method can be used to compute the added mass of an object with complex shapes also. The method is based on unsteady, inviscid model and dynamic mesh technique for transient simulation of body motions. By taking the difference of forces under the condition of uniform motions and accelerated motions, added mass of an object is calculated. In principle two cases were run i.e uniform and accelerated, both for linear and angular motions. Differences of forces/torque of uniform and accelerated motions were used to calculate added mass of the given object for both linear and angular motions.","PeriodicalId":251584,"journal":{"name":"Proceedings of 2012 9th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125186094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-04-03DOI: 10.1109/IBCAST.2012.6177523
G. Murtaza, A. I. Bhatti
DC motors have been extensively used in many industrial applications for their accurate, simple and continuous control characteristics. This paper addresses the controlling of the speed of DC motor which remains among the vital issues. It presents sliding mode control, integral sliding mode control and dynamic sliding mode control methods to control the speed of DC motors. Also the merits and demerits of each approach are discussed. Sliding mode control (SMC) is robust to the matched uncertainties and the desired performance/speed is attained. But the main drawback of SMC is chattering, resulting from discontinuous controllers, various techniques are presented to minimize chattering. The performance of the dynamic system with integral and first order dynamic SMC is compared with response of the system with SMC controller. The results show that the integral and specifically dynamic SMC are more robust against matched uncertainties, the desired speed is perfectly tracked and chattering reduction is achieved.
{"title":"Control of DC motors using sliding mode","authors":"G. Murtaza, A. I. Bhatti","doi":"10.1109/IBCAST.2012.6177523","DOIUrl":"https://doi.org/10.1109/IBCAST.2012.6177523","url":null,"abstract":"DC motors have been extensively used in many industrial applications for their accurate, simple and continuous control characteristics. This paper addresses the controlling of the speed of DC motor which remains among the vital issues. It presents sliding mode control, integral sliding mode control and dynamic sliding mode control methods to control the speed of DC motors. Also the merits and demerits of each approach are discussed. Sliding mode control (SMC) is robust to the matched uncertainties and the desired performance/speed is attained. But the main drawback of SMC is chattering, resulting from discontinuous controllers, various techniques are presented to minimize chattering. The performance of the dynamic system with integral and first order dynamic SMC is compared with response of the system with SMC controller. The results show that the integral and specifically dynamic SMC are more robust against matched uncertainties, the desired speed is perfectly tracked and chattering reduction is achieved.","PeriodicalId":251584,"journal":{"name":"Proceedings of 2012 9th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125316757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-04-03DOI: 10.1109/IBCAST.2012.6177589
G. Mehdi, J. Miao
Presence of Foreign object debris (FOD) at airport runways is an immense threat to flight safety operation. Such unwanted objects may cause potential damage to the aircraft during critical phases like take off and landing. Due to the miniaturized nature of FOD parts, a very high resolution sensor is required to resolve and locate such objects with higher extent of accuracy such as less than 1 meter. The reported FOD systems operate at W-band. This paper discusses the design considerations for millimeter wave FOD radar system operating at Ka-band and presents a simulation platform comprising of FOD radar model and test setup for design evaluation. The radar model is developed using the specifications of the selected commercially off-the-shelf (COTS) components and is evaluated under different scenarios in ADS®. The design addresses inherent issues associated with FMCW architecture such as mutual coupling between transmit and receive antennae and self mixing due to substrate coupling. For improved azimuth accuracy, two channels receiver for amplitude comparison monopulse is incorporated. Transmit power is 10 dBm and receiver's minimum detectable strength is -122 dBm. The simulation results indicate radar's ability to detect very small objects - 20 dBsm radar cross section (RCS) up to 300 meter range.
{"title":"Millimeter wave FMCW radar for Foreign object debris (FOD) detection at airport runways","authors":"G. Mehdi, J. Miao","doi":"10.1109/IBCAST.2012.6177589","DOIUrl":"https://doi.org/10.1109/IBCAST.2012.6177589","url":null,"abstract":"Presence of Foreign object debris (FOD) at airport runways is an immense threat to flight safety operation. Such unwanted objects may cause potential damage to the aircraft during critical phases like take off and landing. Due to the miniaturized nature of FOD parts, a very high resolution sensor is required to resolve and locate such objects with higher extent of accuracy such as less than 1 meter. The reported FOD systems operate at W-band. This paper discusses the design considerations for millimeter wave FOD radar system operating at Ka-band and presents a simulation platform comprising of FOD radar model and test setup for design evaluation. The radar model is developed using the specifications of the selected commercially off-the-shelf (COTS) components and is evaluated under different scenarios in ADS®. The design addresses inherent issues associated with FMCW architecture such as mutual coupling between transmit and receive antennae and self mixing due to substrate coupling. For improved azimuth accuracy, two channels receiver for amplitude comparison monopulse is incorporated. Transmit power is 10 dBm and receiver's minimum detectable strength is -122 dBm. The simulation results indicate radar's ability to detect very small objects - 20 dBsm radar cross section (RCS) up to 300 meter range.","PeriodicalId":251584,"journal":{"name":"Proceedings of 2012 9th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129265719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-04-03DOI: 10.1109/IBCAST.2012.6177553
T. Mahmood, N. Aizud, S. Zahir
The present study utilizes compressible flow solver coupled with 6-DOF algorithm to simulate generic store separation events that may include the release of stores from aircrafts, booster/stage separations from missiles and space launch vehicles. A well-documented store separation experimental and configuration data is selected for validation purpose. The chimera based mesh technique is used to translate between the major and minor grids. CFD results for a transient finned-store release from a static delta wing under transonic flow conditions are compared with the experimental results. Both inviscid and viscous flow conditions are considered to simulate the event. And, the results are found within design accuracy limits for trajectory, forces and moments. The simulations are than extended to examine the effect of release on the parent vehicle's rotational attitude. The simulation methodology is suggested to be reliable in the design process for the estimation of aerodynamic coefficients and trajectories of the child; and angular orientations/rates of both the child and the parent vehicle. The plume effects of the burning nozzles may also be included in the simulation if required with the penalty of huge computational time. The effort is quite helpful in reducing the prototype cost and to predict any possible flight test hazard.
{"title":"CFD simulations of the store separation and its effect on the attitude of the parent vehicle","authors":"T. Mahmood, N. Aizud, S. Zahir","doi":"10.1109/IBCAST.2012.6177553","DOIUrl":"https://doi.org/10.1109/IBCAST.2012.6177553","url":null,"abstract":"The present study utilizes compressible flow solver coupled with 6-DOF algorithm to simulate generic store separation events that may include the release of stores from aircrafts, booster/stage separations from missiles and space launch vehicles. A well-documented store separation experimental and configuration data is selected for validation purpose. The chimera based mesh technique is used to translate between the major and minor grids. CFD results for a transient finned-store release from a static delta wing under transonic flow conditions are compared with the experimental results. Both inviscid and viscous flow conditions are considered to simulate the event. And, the results are found within design accuracy limits for trajectory, forces and moments. The simulations are than extended to examine the effect of release on the parent vehicle's rotational attitude. The simulation methodology is suggested to be reliable in the design process for the estimation of aerodynamic coefficients and trajectories of the child; and angular orientations/rates of both the child and the parent vehicle. The plume effects of the burning nozzles may also be included in the simulation if required with the penalty of huge computational time. The effort is quite helpful in reducing the prototype cost and to predict any possible flight test hazard.","PeriodicalId":251584,"journal":{"name":"Proceedings of 2012 9th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130540388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-04-03DOI: 10.1109/IBCAST.2012.6177562
M. N. Qureshi, M. Bourgoin, C. Baudet, A. Cartellier, Y. Gagne
The two-time statistics of finite-sized inertial particles dynamics in grid generated wind tunnel turbulence are discussed in this paper. For different sets of particle normalized sizes ranging from 12η → 26η (η is the Kolmogorov's length scale of the flow); and densities normalized with that of air varying from 1 to 70, the Lagrangian velocity signals are recorded using Ultrasonic Doppler Velocimetry (UDV). These signals are then processed employing Maximum Likelihood Algorithm (MLA). The Lagrangian velocity increments PDF of all the data sets show that particle dynamics is intermittent. The signature of intermittency as determined through time evolution of flatness of Lagrangian Velocity is noticed to depend upon particle density. The Lagrangian integral time scale for same particle size depends upon the particle's density, with heavier particles having longer correlation times. From acceleration autocorrelations it is found that the particle's response time to the turbulent forcing τexp is always of the order of Kolmogorov's time scale. Thus, an effective or experimental stokes number Steff is defined which is based upon the actual response time of the particles τexp. For our data sets this effective stokes number varies from 0.1 → 0.2.
{"title":"Two-time statistics of inertial particles dynamics in wind tunnel grid generated turbulence","authors":"M. N. Qureshi, M. Bourgoin, C. Baudet, A. Cartellier, Y. Gagne","doi":"10.1109/IBCAST.2012.6177562","DOIUrl":"https://doi.org/10.1109/IBCAST.2012.6177562","url":null,"abstract":"The two-time statistics of finite-sized inertial particles dynamics in grid generated wind tunnel turbulence are discussed in this paper. For different sets of particle normalized sizes ranging from 12η → 26η (η is the Kolmogorov's length scale of the flow); and densities normalized with that of air varying from 1 to 70, the Lagrangian velocity signals are recorded using Ultrasonic Doppler Velocimetry (UDV). These signals are then processed employing Maximum Likelihood Algorithm (MLA). The Lagrangian velocity increments PDF of all the data sets show that particle dynamics is intermittent. The signature of intermittency as determined through time evolution of flatness of Lagrangian Velocity is noticed to depend upon particle density. The Lagrangian integral time scale for same particle size depends upon the particle's density, with heavier particles having longer correlation times. From acceleration autocorrelations it is found that the particle's response time to the turbulent forcing τexp is always of the order of Kolmogorov's time scale. Thus, an effective or experimental stokes number Steff is defined which is based upon the actual response time of the particles τexp. For our data sets this effective stokes number varies from 0.1 → 0.2.","PeriodicalId":251584,"journal":{"name":"Proceedings of 2012 9th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126707364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-04-03DOI: 10.1109/IBCAST.2012.6177518
M. Imran Rashid, S. Akhtar
In this paper, we propose an adaptive feedback control law for asymptotic attitude & altitude stabilization of a quadrotor using feedback of body axis angular rates, absolute orientation with respect to the inertial frame, altitude and altitude rate. No knowledge of quadrotor model parameters i.e. inertia matrix and mass is assumed. Stability of adaptive control law is shown via Lyapunov arguments. Simulation results are presented to demonstrate convergence of controller parameters and asymptotically perfect attitude & altitude stabilization of a quadrotor.
{"title":"Adaptive control of a quadrotor with unknown model parameters","authors":"M. Imran Rashid, S. Akhtar","doi":"10.1109/IBCAST.2012.6177518","DOIUrl":"https://doi.org/10.1109/IBCAST.2012.6177518","url":null,"abstract":"In this paper, we propose an adaptive feedback control law for asymptotic attitude & altitude stabilization of a quadrotor using feedback of body axis angular rates, absolute orientation with respect to the inertial frame, altitude and altitude rate. No knowledge of quadrotor model parameters i.e. inertia matrix and mass is assumed. Stability of adaptive control law is shown via Lyapunov arguments. Simulation results are presented to demonstrate convergence of controller parameters and asymptotically perfect attitude & altitude stabilization of a quadrotor.","PeriodicalId":251584,"journal":{"name":"Proceedings of 2012 9th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"281 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113986485","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-04-03DOI: 10.1109/IBCAST.2012.6177596
S. Latif, R. Tariq, W. Haq, U. Hashmi
INDOOR POSITIONING SYSTEM is a system in which we can locate the position of an object in an indoor environment utilizing ultrasonic waves generated by narrow directional ultrasonic transmitter. To achieve the objective of position detection, we have designed ultrasonic transmitter and receiver circuits, RF transmitter, and receiver for synchronization purposes. By implementing time of arrival method, we have located the position of an object. It is accomplished by using distances between the multiple receivers and a single transmitter located in a room. RF signal starts the timer and when ultrasonic waves will reach at the receiver end, it will stop the timer and then the extracted signal from the receiver is transmitted to the microcontroller for locating position of an object. The systems using ultrasonic waves have the advantage that it can be built on low cost and has relatively high accuracy to detect the position of an object in an indoor environment.
{"title":"INDOOR POSITIONING SYSTEM using ultrasonics","authors":"S. Latif, R. Tariq, W. Haq, U. Hashmi","doi":"10.1109/IBCAST.2012.6177596","DOIUrl":"https://doi.org/10.1109/IBCAST.2012.6177596","url":null,"abstract":"INDOOR POSITIONING SYSTEM is a system in which we can locate the position of an object in an indoor environment utilizing ultrasonic waves generated by narrow directional ultrasonic transmitter. To achieve the objective of position detection, we have designed ultrasonic transmitter and receiver circuits, RF transmitter, and receiver for synchronization purposes. By implementing time of arrival method, we have located the position of an object. It is accomplished by using distances between the multiple receivers and a single transmitter located in a room. RF signal starts the timer and when ultrasonic waves will reach at the receiver end, it will stop the timer and then the extracted signal from the receiver is transmitted to the microcontroller for locating position of an object. The systems using ultrasonic waves have the advantage that it can be built on low cost and has relatively high accuracy to detect the position of an object in an indoor environment.","PeriodicalId":251584,"journal":{"name":"Proceedings of 2012 9th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"53 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114027500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-04-03DOI: 10.1109/IBCAST.2012.6177537
M. Ismail, M. Zamurad Shah, A. Mughal
Surface waves, induced due to different sea states, greatly affect the dynamics and control of the vehicles operating undersea or on the sea surface. In certain missions involving longer operation time, vehicle may encounter disturbances that are induced by higher sea states, forcing to guide the vehicle to safer depths. In the moderate sea states, taken up to sea state 3, these disturbances are accounted for the motion closer to the sea surface and considered negligible as vehicle moves down to few meters. In case of a rough and higher sea states, disturbances may be experienced even down to hundred meters. This paper attempts to provide a three-dimensional generalization of disturbances in deep sea operating vehicles, by simulating their 6dof motion under higher sea states. A sea state model is realized in terms of inertial forces and moments that vehicle would experience during the motion. An analytical formalism is derived to estimate the induced forces and moments integrated over a given vehicle arbitrarily oriented in the motion. Three limiting cases are considered in this work: (1) the deep water waves: 0.5 <; ho/λ <;∞ (2) the intermediate depth waves: 0.05 <; ho/λ <; 0.5 and (3) the shallow water waves: 0 <; ho/λ <; 0.05. For illustration, derived forces and moments are applied to a well known autonomous underwater vehicle (AUV) known as REMUS (Remote Environmental Monitoring Unit) taken as reference vehicle for the analysis. Slender shape of REMUS closely approximates the known vehicles like submarine, remotely operated vehicle (ROV) and unmanned ocean vehicle (UOV) to which these results are applicable. Numerical results show that in case of deep water wave at lower sea state, the disturbance no longer remains significant after certain depth. On the other hand in shallow and deep water wave case at higher sea states, the disturbance is found significant, affecting the dynamics of the underwater vehicles, down to larger depths of operation. Deep water wave case is further taken up for detailed study of vehicle motion in three dimensions.
{"title":"Deep sea motion under higher sea states","authors":"M. Ismail, M. Zamurad Shah, A. Mughal","doi":"10.1109/IBCAST.2012.6177537","DOIUrl":"https://doi.org/10.1109/IBCAST.2012.6177537","url":null,"abstract":"Surface waves, induced due to different sea states, greatly affect the dynamics and control of the vehicles operating undersea or on the sea surface. In certain missions involving longer operation time, vehicle may encounter disturbances that are induced by higher sea states, forcing to guide the vehicle to safer depths. In the moderate sea states, taken up to sea state 3, these disturbances are accounted for the motion closer to the sea surface and considered negligible as vehicle moves down to few meters. In case of a rough and higher sea states, disturbances may be experienced even down to hundred meters. This paper attempts to provide a three-dimensional generalization of disturbances in deep sea operating vehicles, by simulating their 6dof motion under higher sea states. A sea state model is realized in terms of inertial forces and moments that vehicle would experience during the motion. An analytical formalism is derived to estimate the induced forces and moments integrated over a given vehicle arbitrarily oriented in the motion. Three limiting cases are considered in this work: (1) the deep water waves: 0.5 <; ho/λ <;∞ (2) the intermediate depth waves: 0.05 <; ho/λ <; 0.5 and (3) the shallow water waves: 0 <; ho/λ <; 0.05. For illustration, derived forces and moments are applied to a well known autonomous underwater vehicle (AUV) known as REMUS (Remote Environmental Monitoring Unit) taken as reference vehicle for the analysis. Slender shape of REMUS closely approximates the known vehicles like submarine, remotely operated vehicle (ROV) and unmanned ocean vehicle (UOV) to which these results are applicable. Numerical results show that in case of deep water wave at lower sea state, the disturbance no longer remains significant after certain depth. On the other hand in shallow and deep water wave case at higher sea states, the disturbance is found significant, affecting the dynamics of the underwater vehicles, down to larger depths of operation. Deep water wave case is further taken up for detailed study of vehicle motion in three dimensions.","PeriodicalId":251584,"journal":{"name":"Proceedings of 2012 9th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125697577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-04-03DOI: 10.1109/IBCAST.2012.6177574
S. H. H. Mashhadi, S. M. Y. Abbas, Z. Wu, L. Thamae
This paper discusses a broadband dielectric resonator antenna (DRA) designed for implementation as a textile wearable antenna in body area networks (BAN). DRA addresses the issues of small size, wide bandwidth and low conductive loss in particular. Due to its credentials, DRA serves well to be a choice as a wearable antenna for on-body communication system. The proposed design is simulated in CST Microwave Studio (CST MWS). The prototype is a textile-based construction offering a wide impedance bandwidth. Detailed measurements of transmission characteristics, carried out using a full-body phantom and a real human body, are reported in this paper.
{"title":"Transmission characteristics of wearable broadband textile dielectric resonator antennas in body area network","authors":"S. H. H. Mashhadi, S. M. Y. Abbas, Z. Wu, L. Thamae","doi":"10.1109/IBCAST.2012.6177574","DOIUrl":"https://doi.org/10.1109/IBCAST.2012.6177574","url":null,"abstract":"This paper discusses a broadband dielectric resonator antenna (DRA) designed for implementation as a textile wearable antenna in body area networks (BAN). DRA addresses the issues of small size, wide bandwidth and low conductive loss in particular. Due to its credentials, DRA serves well to be a choice as a wearable antenna for on-body communication system. The proposed design is simulated in CST Microwave Studio (CST MWS). The prototype is a textile-based construction offering a wide impedance bandwidth. Detailed measurements of transmission characteristics, carried out using a full-body phantom and a real human body, are reported in this paper.","PeriodicalId":251584,"journal":{"name":"Proceedings of 2012 9th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123487697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：