scholarly journals MODELING AND ANALYSIS OF A VEHICLE DYNAMICS AT FRONTAL IMPACT INTO THE RIGID BARRIER USING A SYSTEM IDENTIFICATION TOOLBOX

2021 ◽  
Vol 2021 (2) ◽  
pp. 4496-4500
Author(s):  
JOZEF KMEC ◽  
◽  
JOZEF PAVELKA ◽  
JAROSLAV SOLTES ◽  
◽  
...  
Keyword(s):  
System Identification ◽  
Trust Region ◽  
Real Data ◽  
Frontal Impact ◽  
Rigid Barrier ◽  
Kelvin Model ◽  
Modeling And Analysis ◽  
Engineering Software ◽  
Computer Crash ◽  
Stiffness And Damping

The main objective of this paper is to create computer crash models (up to the level of the Kelvin model, where the coefficient of stiffness and damping is calculated by implementing appropriate numerical methods: Trust - Region, Lavenberg-Marquardt and so on) of measured real data that are obtained at the frontal impact of a vehicle into the rigid barrier. The process of modeling a vehicle crash can be done in two ways. One of them is related to CAE (Computer Aided Engineering) software including FEA. The other one (applied in this article) is based on the System Identification Toolbox, which contains MATLAB® functions, Simulink® blocks, and a special app for constructing models of dynamic systems from the measured input-output data.

Rails Deformation Pattern in Frontal Impact

2002 ◽  
Author(s):  
Joseph Hassan ◽  
Guy Nusholtz ◽  
Ke Ding
Keyword(s):  
Wave Propagation ◽  
Real World ◽  
Stress Waves ◽  
Stress Wave Propagation ◽  
Deformation Pattern ◽  
Frontal Impact ◽  
Rigid Barrier ◽  
Final Deformation ◽  
Deformation Patterns ◽  
The Impact

During a vehicle crash stress waves can be generated at the impact point and propagate through the vehicle structure. The generation of these waves is dependent, in general, on the crash type and, in particular, on the impact contact characteristics. This has consequences with respect to different crash barrier interfaces for vehicle evaluation. The two barriers most commonly used to evaluate the response of a vehicle in a frontal impact are the rigid barrier and the offset deformable barrier. They constitute different crash modes, full frontal and offset. Consequently it would be expected that there are different deformation patterns between the two. However, an additional possible contributor to the difference is that an impact into a rigid barrier generates waves of significantly greater stress than impacts with the deformable one. If stress waves are a significant component of real world final deformation patterns then, the choice of barrier interface and its effective stiffness is critical. To evaluate this conjecture, models of two types of rails each undergoing two different types of impacts, are analyzed using an explicit dynamic finite element code. Results show that the energy perturbation along the rail depends on the barrier type and that the early phase of wave propagation has very little effect on the final deformation pattern. This implies that in the real world conditions, the stress wave propagation along the rail has very little effect on the final deformed shape of the rail.

scholarly journals Reduced order system identification for UAVs

2015 ◽  
Vol 119 (1218) ◽  
pp. 961-980 ◽  
Author(s):  
P-D. Jameson ◽  
A. K. Cooke
Keyword(s):  
System Identification ◽  
Equations Of Motion ◽  
Real Data ◽  
Flight Test ◽  
Rate Of Change ◽  
Order System ◽  
Parameter Estimates ◽  
Reduced Order Models ◽  
Test Scenario ◽  
Reduced Order

Abstract Reduced order models representing the dynamic behaviour of symmetric aircraft are well known and can be easily derived from the standard equations of motion. In flight testing, accurate measurements of the dependent variables which describe the linearised reduced order models for a particular flight condition are vital for successful system identification. However, not all the desired measurements such as the rate of change in vertical velocity (Ẇ) can be accurately measured in practice. In order to determine such variables two possible solutions exist: reconstruction or differentiation. This paper addresses the effect of both methods on the reliability of the parameter estimates. The methods are used in the estimation of the aerodynamic derivatives for the Aerosonde UAV from a recreated flight test scenario in Simulink. Subsequently, the methods are then applied and compared using real data obtained from flight tests of the Cranfield University Jetstream 31 (G-NFLA) research aircraft.

scholarly journals Modeling and analysis of COVID-19 epidemics with treatment in fractional derivatives using real data from Pakistan

2020 ◽  
Vol 135 (10) ◽  
Author(s):  
Parvaiz Ahmad Naik ◽  
Mehmet Yavuz ◽  
Sania Qureshi ◽  
Jian Zu ◽  
Stuart Townley
Keyword(s):  
Fractional Derivatives ◽  
Real Data ◽  
Modeling And Analysis

scholarly journals Fractional Calculus as a Simple Tool for Modeling and Analysis of Long Memory Process in Industry

Mathematics ◽  
2019 ◽  
Vol 7 (6) ◽  
pp. 511 ◽  
Author(s):  
Ivo Petráš ◽  
Ján Terpák
Keyword(s):  
Time Series ◽  
Fractional Calculus ◽  
Fractional Order ◽  
Long Memory ◽  
Real Data ◽  
Data Set ◽  
Modeling And Analysis ◽  
Long Memory Process ◽  
Real Process ◽  
Definition Of

This paper deals with the application of the fractional calculus as a tool for mathematical modeling and analysis of real processes, so called fractional-order processes. It is well-known that most real industrial processes are fractional-order ones. The main purpose of the article is to demonstrate a simple and effective method for the treatment of the output of fractional processes in the form of time series. The proposed method is based on fractional-order differentiation/integration using the Grünwald–Letnikov definition of the fractional-order operators. With this simple approach, we observe important properties in the time series and make decisions in real process control. Finally, an illustrative example for a real data set from a steelmaking process is presented.

System Identification Modeling and Flight Characteristics Analysis of Miniature Coaxial Helicopter

2014 ◽  
Vol 59 (4) ◽  
pp. 36-51 ◽  
Author(s):  
Navid Dadkhah ◽  
Bérénice Mettler
Keyword(s):  
System Identification ◽  
High Speed ◽  
Tracking System ◽  
Flight Test ◽  
Lumped Parameter Model ◽  
Test Facility ◽  
Modeling And Analysis ◽  
Characteristics Analysis ◽  
Parameterized Model ◽  
Coaxial Helicopter

This paper describes the identification modeling and analysis of a miniature coaxial helicopter. The first part of the paper focuses on the development of the parameterized model with an emphasis on the coaxial rotor configuration. The model explicitly accounts for the dynamics of the lower rotor and uses an implicit lumped parameter model for the upper rotor and stabilizer bar. The parameterized model was identified using frequency domain system identification. The flight data collection experiments were performed in an indoor flight-test facility built around a commercial vision-based tracking system. The second part of the paper focuses on the verification of the model's accuracy, the consistency of the identified parameters, and the analysis of the flight dynamics. The accuracy was verified by comparing model-predicted responses with flight experimental responses. The identified parameters and model's physical consistency were examined using experiments in which specific aspects of the dynamics were isolated. For example, we used video images from a high-speed camera to verify the rotor and stabilizer bar time constants. Finally, the identified derivatives were verified based on first principles to demonstrate that the derivatives are physically meaningful.

scholarly journals SEVERITY INDEX FOR VEHICLE DRIVERS AT FRONTAL IMPACT INTO RIGID BARRIER

2019 ◽  
Vol 2019 (01) ◽  
pp. 2845-2848
Author(s):  
Jozef Kmec ◽  
Stella Hrehova
Keyword(s):  
Severity Index ◽  
Frontal Impact ◽  
Rigid Barrier

scholarly journals CHARACTERISTICS OF AUTOMOBILE IN A FRONTAL IMPACT INTO RIGID BARRIER

2020 ◽  
Vol 2020 (4) ◽  
pp. 4057-4061
Author(s):  
Jozef Kmec ◽  
Jozef Pavelka ◽  
Jaroslav Soltes
Keyword(s):  
Frontal Impact ◽  
Rigid Barrier

Gear Rattle Modeling Based on Transient Stiffness and Damping Analysis

2012 ◽  
Vol 271-272 ◽  
pp. 936-947
Author(s):  
Ming Qin ◽  
Ning Xie ◽  
Hui Wang ◽  
Kai Zhang ◽  
Xue Ping Liu ◽  
...  
Keyword(s):  
Physical Model ◽  
Traditional Method ◽  
Relative Displacement ◽  
Simulation Program ◽  
Gear Pair ◽  
Modeling And Analysis ◽  
Gear Contact ◽  
Stiffness And Damping ◽  
Gear Rattle

Structural characters of gear contact have a determinative impact on gear rattle. Contrarily traditional method using average stiffness and damp coefficients which weakens the accuracy on modeling and analysis of gear rattle phenomenon, in this paper, a methodology modeling gear rattle process with transient stiffness and damp coefficients is proposed. Gear rattle process is modeled by considering the physical model of gear contact, gear pair movement, and actually geometrical meshing curve. A study of gear rattle is made by the simulation program and an experiment is also done to verify the method. Results show that this method can effectively analyze the frequency and the relative displacement of gear rattle, etc.

scholarly journals Solving ill-posed magnetic inverse problem using a Parameterized Trust-Region Sub-problem

2013 ◽  
Vol 43 (2) ◽  
pp. 99-123 ◽  
Author(s):  
Maha Mohamed Abdelazeem
Keyword(s):  
Weighting Function ◽  
Regularization Parameter ◽  
Stable Solution ◽  
Trust Region ◽  
Real Data ◽  
Linear Constraints ◽  
Singular Value Decomposition Method ◽  
Ill Posed ◽  
Value Decomposition ◽  
Natural Decay

Abstract The aim of this paper is to find a plausible and stable solution for the inverse geophysical magnetic problem. Most of the inverse problems in geophysics are considered as ill-posed ones. This is not necessarily due to complex geological situations, but it may arise because of ill-conditioned kernel matrix. To deal with such ill-conditioned matrix, one may truncate the most ill part as in truncated singular value decomposition method (TSVD). In such a method, the question will be where to truncate? In this paper, for comparison, we first try the adaptive pruning algorithm for the discrete L-curve criterion to estimate the regularization parameter for TSVD method. Linear constraints have been added to the ill-conditioned matrix. The same problem is then solved using a global optimizing and regularizing technique based on Parameterized Trust Region Sub-problem (PTRS). The criteria of such technique are to choose a trusted region of the solutions and then to find the satisfying minimum to the objective function. The ambiguity is controlled mainly by proper choosing the trust region. To overcome the natural decay in kernel with depth, a specific depth weighting function is used. A Matlab-based inversion code is implemented and tested on two synthetic total magnetic fields contaminated with different levels of noise to simulate natural fields. The results of PTRS are compared with those of TSVD with adaptive pruning L-curve. Such a comparison proves the high stability of the PTRS method in dealing with potential field problems. The capability of such technique has been further tested by applying it to real data from Saudi Arabia and Italy.

Sign in / Sign up

Export Citation Format

Share Document