SUBMARINE TATICAL GEOMETRIES DURING ENEMY VEHICLE ATTACK USING NOVEL STATISTICAL STOCHASTIC NON LINEAR FILTER

Particle filter is proposed for tracking a torpedo using bearings-only measurements when torpedo is attacking an ownship. Towed array is used to generate torpedo bearing measurements. Ownship evasive maneuver is used for observability of the bearings-only process. Particle filter combined with Modified Gain Bearings-Only Extended Kalman Filter is used to estimate torpedo motion parameters, which are used to calculate optimum ownship evasive maneuver. Monte-Carlo simulation is carried out and the results are presented for typical scenarios

Comparative Analysis of Non Linear Estimation Schemes used for Undersea Sonar Applications

    The performance evaluation of various passive underwater target tracking algorithms like Pseudo Linear Estimator, Maximum Likelihood Estimator, Modified Gain Bearings-only Extended Kalman Filter, Unscented Kalman Filter, Parameterized Modified Gain Bearings-only Extended Kalman Filter and Particle Filter coupled with Modified Gain Bearings-only Extended Kalman Filter using bearings-only measurements is carried out with various scenarios in Monte Carlo Simulation. The performance of Parameterized Modified Gain Bearings-only Extended Kalman Filter is found to be better than all estimates

INVESTIGATION OF ADVANCED NON-LINEAR CONTROL AND ESTIMATION ALGORITHM FOR ROCKET BASED APPLICATIONS

Online Object tracking is an important task in radar and sonar signal processing As it  is a challenging problem due to the presence of noise, and dynamic changes. a variety of Stochastic algorithms for tracking targets have been proposed and implemented to reach  these challenges. Approaches towards   highly nonlinear  applications  is an   advanced   task . In this paper, we devote the effort to use the Particle Filtering with estimation of various states of a vehicle launched from an idealized spherical, airless, non-rotating earth to improve tracking efficiency. The simulation results show that the PF improved the tracking performance compared to the Kalman based Filters (EKF, UKF) for the rocket launch application

ARDUINO BASED WIRELESS MOBOT

Increased connectivity and remote monitoring and control mechanisms have revolutionized the field of measurement and automation. The proposed work is to design a system which will integrate a mobile bot with Arduino, and it is also possible with LabVIEW through a gateway to run wirelessly. An autonomous robot vehicle is to travel from source to destination through the wheels which are controlled by processor. This will be helpful launch in the application where human being travel will be difficult to meet the work. The proposed system will be able to follow a path with obstacle avoiding.Further, the vehicle can be integrated with NI instruments and with LabVIEW to make it autonomous. LabVIEW is a graphical programming language gives a platform for the engineers, which is effective and scalable to focus on robotics neglecting the minute implementation details.Â

ANALYSIS OF EXTENED KALMAN FILTER USING RANGE AND LINE OF SIGHT MEASUREMENT FOR UNDERSEA TARGET LOCALISATION

The feasibility of the extended Kalman filter using range and bearing measurements is explored for underwater applications. The Input estimation technique, developed by Bar-Shalom and Fortmann for radar applications is implemented for sonar applications. Input estimation is used to estimate the target acceleration whenever the target makes a maneuver. The algorithm estimates target motion parameters and detects target maneuver using zero mean chi-square distributed random sequence residual. Upon detection of target maneuver, this algorithm corrects the velocity and position components using acceleration components. Finally, the performance of this algorithm is evaluated in Monte-Carlo simulations and results are shown for various typical geometries and found that this input estimation technique can be used for underwater applications

IMPROVED NON-LINEAR SIGNAL ESTIMATION TECHNIQUE FOR UNDERSEA SONAR BASED NAVAL APPLICATIONS

The aim of this work is to develop passive target tracking algorithm, suitable for implementation in target motion analysis for underwater applications. The vehicle is assumed to be standstill in underwater watching for any target ship using bearings only measurements. Using these measurements, the algorithm calculates the course of the target, which is further used to find out target range and speed. Provision is given to generate range and course if the speed of the target is known by some other means. Pseudo Linear Estimator (PLE) is developed to reduce the noise in the measurements and to find out target motion parameters. Though PLE offers a biased estimate in certain scenarios, it has an advantage as it hardly diverges. It offers the features of Kalman filter viz., sequential processing, flexibility to adopt the variance of each measurement etc.  The Monte-Carlo simulation results are presented for a typical scenario and it is shown that this algorithm is useful for naval underwater applications.Â

Too little, too late, and in the wrong place : Alpha band activity does not reflect an active mechanism of selective attention

Acknowledgements This work was supported by the Economic and Social Research Council [grant number: ES/J500136/1].Peer reviewedPublisher PD

Novel titanium - hydroxyapatite biocomposites By mechanical milling

Titanium with nano hydroxyapatite (nHA) as well as with micron size hydroxyapatite was ball milled for various time intervals. The milled powders were characterized using X-Ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM) techniques. The XRD results show peak broadening with increase in milling time indicating the formation of nanocomposite with titanium and HA phases. Relatively, titanium was found to be more reduced in size with increase in milling time than HA in the composite. The EDX results indicated the presence of Ca and P in the titanium matrix. elemental mapping showed homogeneous distribution of Ti, Ca and P after 16 h of ball milling in all the composites. TEM micrographs also revealed the presence of nanocrystals. The powders were compacted, sintered and immersed in simulated body fluid (SBF), which has the same ion concentration as that of the human body plasma, to study bioactivity under physiological condition. After immersion in SBF for 1 week, the compacts were observed in SEM and all the composites were found to be bioactive with the formation of bone like apatite layer on the surface. The morphology of the apatite formed was globular and more dense for the composite prepared using nano HA compared to micron size HA

Suppression of piriform cortex activity in rat by corticotropin-releasing factor 1 and serotonin 2A/C receptors

The piriform cortex (PC) is richly innervated by Corticotropin-releasing factor (CRF) and Serotonin (5-HT) containing axons arising from central amygdala and Raphe nucleus. CRFR1 and 5-HT2A/2CRs have been shown to interact in manner where CRFR activation subsequently potentiates the activity of 5-HT2A/2CRs. The purpose of this study was to determine how the activation of CRFR1 and/or 5-HT2Rs modulates PC activity at both the circuit and cellular level. Voltage sensitive dye imaging showed that CRF acting through CRFR1 dampened activation of the layer II of PC and interneurons of endopiriform nucleus. Application of the selective 5-HT2A/CR agonist 2,5-dimethoxy-4-iodoamphetamine (DOI) following CRFR1 activation potentiated this effect. Blocking the interaction between CRFR1 and 5-HT2R with a Tat-CRFR1-CT peptide abolished this potentiation. Application of forskolin did not mimic CRFR1 activity but instead blocked it, while a protein kinase A antagonist had no effect. However, activation and antagonism of protein kinase C (PKC) either mimicked or blocked CRF modulation respectively. DOI had no effect when applied alone indicating that the prior activation of CRFR1 receptors was critical for DOI to show significant effects similar to CRF. Patch clamp recordings showed that both CRF and DOI reduced the synaptic responsiveness of layer II pyramidal neurons. CRF had highly variable effects on interneurons within layer III, both increasing and decreasing their excitability, but DOI had no effect on the excitability of this group of neurons. These data show that CRF and serotonin, acting through both CRFR1 and 5-HT2A/CRs, reduce the activation of the PC. This modulation may be an important blunting mechanism of stressor behaviours mediated through the olfactory cortex