Modelling the variability of hillslope drainage using grid-based hillslope width function estimation algorithm

2018 ◽  
Vol 25 (1) ◽  
pp. 71-78 ◽  
Author(s):  
Soumyaranjan Sahoo ◽  
Bhabagrahi Sahoo
Author(s):  
Vinod Vishwakarma ◽  
Alok Sinha

Modified modal domain analysis (MMDA) is a method to generate an accurate reduced-order model (ROM) of a bladed disk with geometric mistuning. An algorithm based on the MMDA ROM and a state observer is developed to estimate forcing functions for synchronous (including integer multiples) conditions from the dynamic responses obtained at few nodal locations of blades. The method is tested on a simple spring-mass model, finite element model (FEM) of a geometrically mistuned academic rotor, and FEM of a bladed rotor of an industrial-scale transonic research compressor. The accuracy of the forcing function estimation algorithm is examined by varying the order of ROM and the number of vibration output signals.


2020 ◽  
Vol 11 (3) ◽  
pp. 133-150
Author(s):  
Kishore Bingi ◽  
Rosdiazli Ibrahim ◽  
Mohd Noh Karsiti ◽  
Sabo Miya Hassan ◽  
Vivekananda Rajah Harindran

Fractional-order systems and controllers have been extensively used in many control applications to achieve robust modeling and controlling performance. To implement these systems, curve fitting based integer-order transfer function estimation techniques namely Oustaloup and Matsuda are most widely used. However, these methods are failed to achieve the best approximation due to the limitation of the desired frequency range. Thus, this article presents a simple curve fitting based integer-order transfer function estimation method for fractional-order differentiator/integrator using frequency response. The advantage of this technique is that it is simple and can fit the entire desired frequency range. Using the approach, an approximation table for fractional-order differentiator has also been obtained which can be used directly to obtain the approximation of fractional-order systems. A simulation study on fractional systems shows that the proposed approach produced better parameter approximation for the desired frequency as compared to Oustaloup, refined Oustaloup and Matsuda techniques.


2019 ◽  
pp. 97-104
Author(s):  
Mikhail V. Tarasenkov ◽  
Egor S. Poznakharev ◽  
Vladimir V. Belov

The simulation program by the Monte Carlo method of pulse reactions of bistatic atmospheric aerosol-gas channels of optical-electronic communication systems (OECS) is created on the basis of the modified double local estimation algorithm. It is used in a series of numerical experiments in order to evaluate statistically the transfer characteristics of these channels depending on the optical characteristics of an atmosphere plane-parallel model for wavelengths λ = 0.3, 0.5, and 0.9 μm at a meteorological visibility range SM = 10 and 50 km. The results are obtained for a set of basic distances between the light source and the light receiver up to 50 km and for the angular orientations of the optical axes of a laser radiation beam and of the receiving system in a wide range of their values. The dependences of the pulse reactions maximum values over-the-horizon channels of the OECS on the variations of these parameters are established.


2020 ◽  
Vol 48 (4) ◽  
pp. 287-314
Author(s):  
Yan Wang ◽  
Zhe Liu ◽  
Michael Kaliske ◽  
Yintao Wei

ABSTRACT The idea of intelligent tires is to develop a tire into an active perception component or a force sensor with an embedded microsensor, such as an accelerometer. A tire rolling kinematics model is necessary to link the acceleration measured with the tire body elastic deformation, based on which the tire forces can be identified. Although intelligent tires have attracted wide interest in recent years, a theoretical model for the rolling kinematics of acceleration fields is still lacking. Therefore, this paper focuses on an explicit formulation for the tire rolling kinematics of acceleration, thereby providing a foundation for the force identification algorithms for an accelerometer-based intelligent tire. The Lagrange–Euler method is used to describe the acceleration field and contact deformation of rolling contact structures. Then, the three-axis acceleration vectors can be expressed by coupling rigid body motion and elastic deformation. To obtain an analytical expression of the full tire deformation, a three-dimensional tire ring model is solved with the tire–road deformation as boundary conditions. After parameterizing the ring model for a radial tire, the developed method is applied and validated by comparing the calculated three-axis accelerations with those measured by the accelerometer. Based on the features of acceleration, especially the distinct peak values corresponding to the tire leading and trailing edges, an intelligent tire identification algorithm is established to predict the tire–road contact length and tire vertical load. A simulation and experiments are conducted to verify the accuracy of the estimation algorithm, the results of which demonstrate good agreement. The proposed model provides a solid theoretical foundation for an acceleration-based intelligent tire.


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