Research on roll stability of articulated engineering vehicles based on dynamic lateral transfer load

2020 ◽  
Vol 234 (9) ◽  
pp. 2364-2376
Author(s):  
Xiangyang Xu ◽  
Xing Ai ◽  
Renxiang Chen ◽  
Guosong Jiang ◽  
Xia Hua
Keyword(s):  
Numerical Method ◽  
Dynamic Model ◽  
Load Transfer ◽  
Slope Angle ◽  
Variable Step Size ◽  
Vehicle Speed ◽  
Step Size ◽  
Computational Stability ◽  
Non Linear ◽  
On The Road

A 16-degree-of-freedom non-linear roll dynamic model is developed for an articulated engineering vehicle considering non-linear road excitations and non-linear characteristics of vehicle structures. In addition, a variable step-size numerical method is proposed to solve the non-linear dynamic model. The proposed numerical method can improve the calculation accuracy and the computational stability. Through the proposed dynamic model, an equation is derived considering time-varying tire load characteristics to reflect the roll stability of an articulated engineering vehicle. Using the proposed roll stability equation, the driving stability can be effectively evaluated for an articulated engineering vehicle with different system parameters. The analysis results show that the roll stability decreases significantly with the increase in vehicle speed, centroid height of engineering vehicle, or lateral slope angle. The influence of vehicle speed and lateral slope angle on roll stability is greater than that of the centroid height of engineering vehicle. When steering on the road with a lateral slope angle, the roll angle and the lateral load transfer ratio curves fluctuate with time. As the lateral slope angle increases, the fluctuation is stronger. Overall, the proposed model can accurately evaluate the roll stability of a driving articulated engineering vehicle and accurately determine the unstable tilting of an articulated engineering vehicle.

Rotorcraft control response using linearised and non-linear flight dynamic models with different inflow models

2017 ◽  
Vol 121 (1238) ◽  
pp. 553-575 ◽  
Author(s):  
T. Sakthivel ◽  
C. Venkatesan
Keyword(s):  
Dynamic Model ◽  
Dynamic Models ◽  
Model Identification ◽  
Flight Test ◽  
Step Size ◽  
Response Characteristics ◽  
Wide Range ◽  
Non Linear ◽  
Steady Level ◽  
Control Response

ABSTRACTThe aim of the present study is to develop a relatively simple flight dynamic model which should have the ability to analyse trim, stability and response characteristics of a rotorcraft under various manoeuvring conditions. This study further addresses the influence of numerical aspects of perturbation step size in linearised model identification and integration timestep on non-linear model response. In addition, the effects of inflow models on the non-linear response are analysed. A new updated Drees inflow model is proposed in this study and the applicability of this model in rotorcraft flight dynamics is studied. It is noted that the updated Drees inflow model predicts the control response characteristics fairly close to control response characteristics obtained using dynamic inflow for a wide range of flight conditions such as hover, forward flight and recovery from steady level turn. A comparison is shown between flight test data, the control response obtained from the simple flight dynamic model, and the response obtained using a more detailed aeroelastic and flight dynamic model.

Variable-step-size second-order-derivative multistep method for solving first-order ordinary differential equations in system simulation

2020 ◽  
Vol 11 (01) ◽  
pp. 2050001
Author(s):  
Lei Zhang ◽  
Chaofeng Zhang ◽  
Mengya Liu
Keyword(s):  
Differential Equations ◽  
Numerical Method ◽  
Multistep Method ◽  
Second Order ◽  
Order Derivative ◽  
Variable Step Size ◽  
Variable Order ◽  
Step Size ◽  
Variable Step ◽  
The Stability

According to the relationship between truncation error and step size of two implicit second-order-derivative multistep formulas based on Hermite interpolation polynomial, a variable-order and variable-step-size numerical method for solving differential equations is designed. The stability properties of the formulas are discussed and the stability regions are analyzed. The deduced methods are applied to a simulation problem. The results show that the numerical method can satisfy calculation accuracy, reduce the number of calculation steps and accelerate calculation speed.

scholarly journals Modified Variable Step-Size Incremental Conductance MPPT Technique for Photovoltaic Systems

Electronics ◽  
2021 ◽  
Vol 10 (19) ◽  
pp. 2331
Author(s):  
Isaac Owusu-Nyarko ◽  
Mohamed A. Elgenedy ◽  
Ibrahim Abdelsalam ◽  
Khaled H. Ahmed
Keyword(s):  
Slope Angle ◽  
Scaling Factor ◽  
Maximum Power ◽  
Variable Step Size ◽  
Step Size ◽  
Maximum Power Point ◽  
Angle Variation ◽  
Incremental Conductance ◽  
Variable Step ◽  
Power Point

A highly efficient photovoltaic (PV) system requires a maximum power point tracker to extract peak power from PV modules. The conventional variable step-size incremental conductance (INC) maximum power point tracking (MPPT) technique has two main drawbacks. First, it uses a pre-set scaling factor, which requires manual tuning under different irradiance levels. Second, it adapts the slope of the PV characteristics curve to vary the step-size, which means any small changes in PV module voltage will significantly increase the overall step-size. Subsequently, it deviates the operating point away from the actual reference. In this paper, a new modified variable step-size INC algorithm is proposed to address the aforementioned problems. The proposed algorithm consists of two parts, namely autonomous scaling factor and slope angle variation algorithm. The autonomous scaling factor continuously adjusts the step-size without using a pre-set constant to control the trade-off between convergence speed and tracking precision. The slope angle variation algorithm mitigates the impact of PV voltage change, especially during variable irradiance conditions to improve the MPPT efficiency. The theoretical investigations of the new technique are carried out while its practicability is confirmed by simulation and experimental results.

Design of Vehicle Weigh-in-Motion System Based on Neural Network

2012 ◽  
Vol 459 ◽  
pp. 557-560
Author(s):  
Cheng Cheng
Keyword(s):  
Neural Network ◽  
Lms Algorithm ◽  
Variable Step Size ◽  
Vehicle Speed ◽  
Step Size ◽  
Interface Circuit ◽  
Motion System ◽  
Weigh In Motion ◽  
The Neural Network ◽  
Self Adaptive

In order to improve the dynamical respond of the weighing sensor and to meet the demand of rapid weigh-in-motion(WIM), a new adaptive weighing system is introduced. The system consists of sensors, data processing module, control module and interface circuit. For restraining the influence of vehicle speed and vehicle liberation, the system adopts self-adaptive variable step size LMS algorithm based on neural network to filter out the noise of WIM signal. Based on this method of signal processing, a vehicle WIM system based on neural network self adaptive filtering was designed. The experimental results proved that the neural network based method can be used to reduce the weighing time and increase the accuracy simultaneously.

Variable Step-Size Discrete Dynamic Programming for Vehicle Speed Trajectory Optimization

2019 ◽  
Vol 20 (2) ◽  
pp. 476-484 ◽  
Author(s):  
Ziqi Ye ◽  
Kailai Li ◽  
Michael Stapelbroek ◽  
Rene Savelsberg ◽  
Marco Gunther ◽  
...  
Keyword(s):  
Dynamic Programming ◽  
Trajectory Optimization ◽  
Variable Step Size ◽  
Vehicle Speed ◽  
Step Size ◽  
Discrete Dynamic ◽  
Variable Step ◽  
Discrete Dynamic Programming

scholarly journals Half Step Numerical Method for Solution of Second Order Initial Value Problems

2021 ◽  
pp. 77-81
Author(s):  
Adeniran Adebayo O. ◽  
Edaogbogun Kikelomo
Keyword(s):  
Numerical Method ◽  
Initial Value Problems ◽  
Second Order ◽  
Variable Step Size ◽  
Initial Value ◽  
Step Size ◽  
Stable Order ◽  
Variable Step ◽  
Interpolation Technique ◽  
Order Four

This paper presents a half step numerical method for solving directly general second order initial value problems. The scheme is developed via collocation and interpolation technique invoked on power series polynomial. The proposed method is consistent, zero stable, order four and three. This method can estimate the approximate solution at both step and off step points simultaneously by using variable step size. Numerical results are given to show the efficiency of the proposed scheme over some existing schemes of same and higher order.

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