Experimental Validation of a Multi Model PI Controller for a Non Linear Hybrid System in LabVIEW

In this paper a real time Single Spherical Tank Liquid Level System (SSTLLS) has been chosen for investigation. This paper describes the design and development of a Multi Model PI Controller (MMPIC) using classical controller tuning techniques for a single spherical nonlinear tank system. System identification of these different regions of nonlinear process are done using black box modeling, which is identified to be nonlinear and approximated to be a First Order Plus Dead Time (FOPDT) model. A proportional and integral controller is designed using LabVIEW and Chen-Hrones-Reswick (CHR), Zhuang-Atherton (ZA), and Skogestad’s Internal Model Controller (SIMC) tuning methods are implemented in real time. The paper provides the details about the data acquisition unit, shows the implementation of the controller, and comparision of the results of PI tuning methods used for an MMPI Controller

A performance analysis of tidal turbine conversion system based on control strategies

Energy efficient generation from renewable energy sources is of major concern nowadays. A horizontal axis marine current turbine (HAMCT) of diameter 1.9 m is modelled using the blade element momentum (BEM) scheme and the turbine output parameters are given as an input to the electrical system for a tip speed ratio (TSR) of 5 and a power coefficient of 0.4. The design aspects of a buck-boost converter with proportional integral (PI) and sliding mode controller (SMC) is investigated for HAMCT system, with the highest power output of about 15.6 kW for a water velocity of 3 m/s. A comparison between PI controller and SMC are analyzed for the tidal turbine conversion system to obtain the desired output voltage with high efficiency is discussed here. The dynamic variation on load side to be controlled with dual loop controller to regulate the output voltage and to optimize the input current. In this paper performance and resemblance of control techniques which include sliding mode controller and PI controller are analysed with step and bode plot response. The system is designed for an output voltage range of 0.38 kV to 2.4 kV which is suitable for DC microgrids. The performance of HAMCT coupled with PMSG and the power converter with a controller is modelled and designed under MATLAB/SIMULINK environment

Resilient H-infinity filtering for networked nonlinear Markovian jump systems with randomly occurring distributed delay and sensor saturation

The H∞ filtering problem for a class of networked nonlinear Markovian jump systems subject to randomly occurring distributed delays, nonlinearities, quantization effects, missing measurements and sensor saturation is investigated in this paper. The measurement missing phenomenon is characterized via a random variable obeying the Bernoulli stochastic distribution. Moreover, due to bandwidth limitations, the measurement output is quantized using a logarithmic quantizer and then transmitted to the filter. Further, the output measurements are affected by sensor saturation since the communication links between the system and the filter are unreliable and is described by sector nonlinearities. The objective of this work is to design a quantized resilient filter that guarantees not only the stochastic stability of the augmented filtering error system but also a prespecified level of H∞ performance. Sufficient conditions for the existence of desired filter are established with the aid of proper Lyapunov–Krasovskii functional and linear matrix inequality approach together with stochastic analysis theory. Finally, a numerical example is presented to validate the developed theoretical results

ADAPTED DTW JOINT WITH WAVELET TRANSFORM FOR ISOLATED DIGIT RECOGNITION

ABSTRACT Dynamic Time Warping (DTW) is a template matching approach based on dynamic programming algorithm. This paper proposes an adapted DTW algorithm for calculating the global distance matrix. Speech signals are decomposed using Discrete Wavelet Transform (DWT) into various frequency sub-bands and the resulted sub-bands of unknown; template digit utterances are compared using the adapted DTW. The performance of the proposed approach is tested with TIDIGITs data. The results indicate that there is a reduction in the order of complexity compared to DTW and increase in the performance

Correlation between ocular parameters and amplitude of accommodation

Aim: To study the relationship between ocular parameters and amplitude of accommodation (AA) in the peri-presbyopic age group (35-50 years). Materials and Methods: Three hundred and sixteen right eyes of consecutive patients in the age group 35-50 years, who attended our outpatient clinic, were studied. Emmetropes, hypermetropes and myopes with best-corrected visual acuity of 20/20, J1 in both eyes were included. The AA was calculated by measuring the near point of accommodation. The axial length (AL), central anterior chamber depth (CACD) and lens thickness (LT) were also measured. Results: There was moderate correlation (Pearson′s correlation coefficient r = 0.56) between AL and AA as well as between CACD and AA (r = 0.53) in myopes in the age group 35-39 years. In the other age groups and the groups taken as a whole, there was no correlation. In hypermetropes and emmetropes, there was no correlation between AA and the above ocular parameters. No significant correlation existed between LT and AA across different age groups and refractive errors. Conclusion: There was no significant correlation between AA and ocular parameters like anterior chamber depth, AL and LT

Amplitude of Accommodation and its Relation to Refractive Errors

<b>Aims:</b> To evaluate the relationship between amplitude of accommodation and refractive errors in the peri-presbyopic age group. <b> Materials and Methods:</b> Three hundred and sixteen right eyes of 316 consecutive patients in the age group 35-50 years who attended our outpatient clinic were studied. Emmetropes, hypermetropes and myopes with best-corrected visual acuity of 6/6 J1 in both eyes were included. The amplitude of accommodation (AA) was calculated by measuring the near point of accommodation (NPA). In patients with more than &#x00B1; 2 diopter sphere correction for distance, the NPA was also measured using appropriate soft contact lenses. <b> Results:<i> </b></i> There was a statistically significant difference in AA between myopes and hypermetropes (<i> P</i> <0.005) and between myopes and emmetropes (<i> P</i> <0.005) in the 35-39 year age group. In the 40- 44 year age group, there was a significant difference in AA between emmetropes and hypermetropes (<i> P</i> <0.0001), emmetropes and myopes (<i> P</i> <0.01) and hypermetropes and myopes (<i> P</i> <0.0001). In patients above 45 years of age there was no significant difference (<i> P</i> &gt;0.5). <i> </i>Conclusion: Our study showed higher amplitude of accommodation among myopes between 35 and 44 years compared to emmetropes and hypermetrope