121 research outputs found
Sensor Based System Identification in Real Time for Noise Covariance Deficient Models
System identification methods have extensive application in the aerospace industry’s experimental stability and control studies. Accurate aerodynamic modeling and system identification are necessary because they enable performance evaluation, flight simulation, control system design, fault detection, and model aircraft’s complex non-linear behavior. Various estimation methods yield different levels of accuracies with varying complexity and computational time requirements. The primary motivation of such studies is the accurate quantification of process noise. This research evaluates the performance of two recursive parameter estimation methods, viz.; First is the Fourier Transform Regression (FTR). The second approach describes the Extended version of Recursive Least Square (EFRLS), where E.F. refers to the Extended Forgetting factor. Also, the computational viability of these methods was analyzed for real-time application in aerodynamic parameter estimation for both linear and non-linear systems. While the first method utilizes the frequency domain to evaluate aerodynamic parameters, the second method works when noise covariances are unknown. The performance of both methods was assessed by benchmarking against parameter estimates from established methods like Extended Kalman Filter (EKF), Unscented Kalman Filter (UNKF), and Output Error Method (OEM)
Implementation of Adaptive Embedded Controller for a Temperature Process
The paper proposed and carried out an adaptive embedded control strategy with the help of Arduino open hardware platform. The proposed control strategy is to carry out a cost-effective interface between the simulation software and a real-time process. The data acquisition and control is done with the help of Arduino Uno which has been interfaced with MATLAB Simulink The control algorithms developed in Simulink model can be downloaded into the Arduino Uno, working as a standalone controller. In this paper, various control algorithms are used to control the temperature process, including embedded Modified Model Reference Adaptive Control (MMRAC). Its performance is compared to other control algorithms. The result shows that the MMRAC scheme improves the transient performance of the temperature control system
Implementation of Adaptive Embedded Controller for a Temperature Process
The paper proposed and carried out an adaptive embedded control strategy with the help of Arduino open hardware platform. The proposed control strategy is to carry out a cost-effective interface between the simulation software and a real-time process. The data acquisition and control is done with the help of Arduino Uno which has been interfaced with MATLAB Simulink The control algorithms developed in Simulink model can be downloaded into the Arduino Uno, working as a standalone controller. In this paper, various control algorithms are used to control the temperature process, including embedded Modified Model Reference Adaptive Control (MMRAC). Its performance is compared to other control algorithms. The result shows that the MMRAC scheme improves the transient performance of the temperature control system
Fluctuating Fractionalized Spins in Quasi Two-dimensional Magnetic V0.85PS3
Quantum spin liquid (QSL), a state characterized by exotic low energy
fractionalized excitations and statistics is still elusive experimentally and
may be gauged via indirect experimental signatures. Remnant of QSL phase may
reflect in the spin dynamics as well as quanta of lattice vibrations, i.e.,
phonons, via the strong coupling of phonons with the underlying fractionalized
excitations i.e., Majorana fermions. Inelastic light scattering (Raman) studies
on V1-xPS3 single crystals evidences the spin fractionalization into Majorana
fermions deep into the paramagnetic phase reflected in the emergence of a low
frequency quasielastic response along with a broad magnetic continuum marked by
a crossover temperature T* ~ 200 K from a pure paramagnetic state to
fractionalized spins regime qualitatively gauged via dynamic Raman
susceptibility. We further evidenced anomalies in the phonons self-energy
parameters in particular phonon line broadening and line asymmetry evolution at
this crossover temperature, attributed to the decaying of phonons into
itinerant Majorana fermions. This anomalous scattering response is thus
indicative of fluctuating fractionalized spins suggesting a phase proximate to
the quantum spin liquid state in this quasi two-dimensional (2D) magnetic
system
Physiological response of cocoa (Theobroma cacao L. ) genotypes to drought
Drought is one of the major environmental stresses affecting crop productivity worldwide. Climate change is expected to result in a rise in the number and intensity of drought events in the coming decades, so climate-resilient crops that can withstand this stress are in high demand. There are few genotypes in cocoa where it can tolerate water deficit conditions. The objective of the current investigation was to evaluate the effect of drought stress on the photosynthetic and physiological parameters of six cocoa genotypes (Theobroma cacao L.) with two irrigation regimes (100% field capacity and 40% field capacity) under greenhouse conditions at Cocoa Research Station, Kerala Agricultural University, Thrissur. The effect of water deficit conditions on gas exchange and physiological parameters such as relative water content, membrane stability index, chlorophyll stability index, and chlorophyll content were evaluated. Drought stress conditions resulted in reduced photosynthetic rate, relative water content, chlorophyll content, chlorophyll stability and membrane stability. All genotypes revealed significant differences for most parameters with two irrigation regimes. Among the cocoa genotypes, P.IV 19.9, which is classified as a highly tolerant genotype, recorded better results for all the parameters studied under water deficit conditions at 40 per cent FC. The findings of this study support the classification of these genotypes as highly tolerant, tolerant, and susceptible. These parameters may be used as the most promising indicators to screen for drought tolerance in cocoa. The results of the study revealed that photosynthetic and physiological parameters have a significant role in imparting drought stress tolerance to cocoa. Furthermore, these selected drought-tolerant genotypes can be used in future crop improvement programmes in cocoa
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