Analysis of bio-dynamic model of seated human subject and optimization of the passenger ride comfort for three-wheel vehicle using random search technique

2021 ◽  
Vol 235 (1) ◽  
pp. 106-121
Author(s):  
Rakesh Chandmal Sharma ◽  
Sakshi Sharma ◽  
Sunil Kumar Sharma ◽  
Neeraj Sharma ◽  
Gurpreet Singh
Keyword(s):  
Dynamic Model ◽  
Human Subject ◽  
Present Model ◽  
Ride Comfort ◽  
Random Search ◽  
Linear Optimization ◽  
Search Technique ◽  
Random Surface ◽  
Surface Irregularities ◽  
Iso 2631

Ride comfort is the major concern to the roadway vehicle passengers, travelling in as it affects their health and efficiency to work. In the present study, a 9 DoF model of a three-wheel vehicle is developed with Lagrangian approach to investigate its ride behavior when subjected to random surface irregularities. The irregularities of the track are measured with a three-wheeled setup equipped with profilometer known as opto-coupler. The present model is validated in two ways, first by comparing the vertical-lateral PSD acceleration received from simulation and actual testing and second by comparing vertical seat to head transmissibility obtained from analysis (VSTH) with past reported studies. A 7 DoF bio-dynamic model of the seated human subject is formulated and integrated with the vehicle model, ride comfort of the vehicle and human body segments are assessed based on ISO specifications. Passenger Ride Comfort is optimized through non-linear optimization using Random Search Technique. The modified values of vehicle suspension parameters are presented to obtain optimum passenger comfort based on ISO-2631-1 criteria.

An extended model of the ISO-2631 standard to objectify the ride comfort in autonomous driving

Work ◽  
2021 ◽  
Vol 68 (s1) ◽  
pp. S37-S45
Author(s):  
Georg Burkhard ◽  
Tobias Berger ◽  
Erik Enders ◽  
Dieter Schramm
Keyword(s):  
Ride Comfort ◽  
Autonomous Driving ◽  
Extended Model ◽  
Measuring Point ◽  
Significant Difference ◽  
Comfort Perception ◽  
Simulator Study ◽  
Iso 2631

BACKGROUND: With the development of autonomous driving, the occupants’ comfort perception and their activities during the drive are becoming increasingly the focus of research. Especially in one of the first applications, a drive on a motorway, vertical dynamics play a major role. OBJECTIVE: To be able to robustly objectify ride comfort, better models need to be developed. Initial studies have shown, that the current ISO-2631 standard creates good results in the objectification and can be regarded as benchmark. METHODS: To increase the accuracy in objectification, an extended model with the occupants’ head as additional measuring point is introduced. Instead of the known frequency filters, weighting (k-factors) is used to differentiate possible excitations. For comparing the model with the ISO-2631, a simulator study with 5 excitations and 50 inattentive subjects is carried out. RESULTS: Evaluating the study with the ISO-2631, 3 out of 5 excitations indicate a significant difference between the occupant’s impression and the calculated comfort value. In comparison the extended model has no significant difference. CONCLUSION: The results further show, that inattentive occupants move their heads significantly more. By measuring accelerations of the head, the extended model creates equivalent or more accurate comfort values than the ISO-2631.

Dynamic model for ride comfort evaluations of the rubber-tired light rail vehicle

2008 ◽  
Vol 46 (11) ◽  
pp. 1061-1082 ◽  
Author(s):  
Yeon-Su Kim ◽  
Tae-Keon Lim ◽  
Sung-Hyuk Park ◽  
Rag-Gyo Jeong
Keyword(s):  
Dynamic Model ◽  
Ride Comfort ◽  
Light Rail ◽  
Rail Vehicle

An examination of the adaptive random search technique

AIChE Journal ◽  
1976 ◽  
Vol 22 (4) ◽  
pp. 744-750 ◽  
Author(s):  
M. W. Heuckroth ◽  
J. L. Gaddy ◽  
L. D. Gaines
Keyword(s):  
Random Search ◽  
Search Technique ◽  
Adaptive Random Search

Rough Terrain Rovers Dynamics Analysis and Optimization

2005 ◽  
Author(s):  
Hadi Tavakoli Nia ◽  
Seyed Hamidreza Alemohammad ◽  
Saeed Bagheri ◽  
Reza Hajiaghaee Khiabani ◽  
Ali Meghdari
Keyword(s):  
Genetic Algorithm ◽  
Software Package ◽  
Random Search ◽  
Nonlinear Problems ◽  
Directional Derivatives ◽  
Rough Terrain ◽  
Dynamics Analysis ◽  
Search Technique ◽  
Dynamical Equations ◽  
New Approach

In this paper a new approach to dynamics optimization of rough terrain rovers is introduced. Since rover wheels traction has a significant role in rover mobility, optimization is based on the minimization of traction at rover wheel-ground interfaces. The method of optimization chosen is Genetic Algorithm (GA) which is a directed random search technique along with the usual optimization based on directional derivatives. GA is a suitable and efficient method of optimization for nonlinear problems. The procedure is applied on a specific rough terrain rover called CEDRA-I Shrimp Rover. Dynamical equations are obtained using Kane’s method. Finally, the results are verified by modeling of the rover in ADAMS® software package.

scholarly journals A Dynamic Model for Ice-Induced Vibration of Structures

2006 ◽  
Author(s):  
Guojun Huang ◽  
Pengfei Liu
Keyword(s):  
Resonant Frequency ◽  
Dynamic Model ◽  
Present Model ◽  
Field Observations ◽  
Resonant Vibration ◽  
Crushing Strength ◽  
Ice Velocity ◽  
Ice Failure ◽  
Lock In ◽  
Ice Induced Vibration

A dynamic model for the ice-induced vibration (IIV) of structures is developed in the present study. Ice properties have been taken into account, such as the discrete failure, the dependence of the crushing strength on the ice velocity and the randomness of the ice failure. The most important prediction of the model is to capture the resonant frequency lock-in, which is analogue to that in the vortex-induced vibration (VIV). Based on the model, the mechanism of resonant IIV is discussed. It is found that the dependence of the ice crushing strength on the ice velocity plays an important role in the resonant frequency lock-in of IIV. In addition, an intermittent stochastic resonant vibration is simulated from the model. These predictions are supported by the laboratory and field observations reported. The present model is more productive than the previous models of IIV.

scholarly journals Analysis and Optimisation of Ride Vibration of a Heavy-Duty Truck Based on a Vertical-Pitch-Roll Driver-Vehicle Coupled Dynamic Model

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Peng Guo ◽  
Jiewei Lin ◽  
Zefeng Lin ◽  
Jinlu Li ◽  
Chi Liu ◽  
...  
Keyword(s):  
Dynamic Model ◽  
Degrees Of Freedom ◽  
Ride Comfort ◽  
Design Method ◽  
Human Model ◽  
Design Parameters ◽  
Heavy Duty ◽  
Heavy Duty Truck ◽  
Heavy Duty Vehicle ◽  
Vehicle Dynamic Model

The ride comfort and the cargo safety are of great importance in the vibration design of heavy-duty vehicle. Traditional ride comfort design method based on the response of components of vehicles or interaction between human and seat overlooks the most direct criterion, the response of occupants, which makes the optimisation not targeted enough. It will be better to conduct the ride comfort design with the biodynamic response of driver. To this end, a 17-degrees-of-freedom (DOFs) vertical-pitch-roll vehicle dynamic model of a three-axle heavy-duty truck coupled with a 7 DOFs human model is developed. The ride comfort of human body under the vertical, the pitch, and the roll vibrations can be evaluated with the weighted root-mean-square (r.m.s.) acceleration of the driver in multiple directions. The flexibilities of chassis and carriage are also considered to improve the accuracy of the prediction of the ride comfort and to constrain the mounting optimisation of cab and carriage. After validation, the sensitivity analysis of the mounting system, the suspensions, and arrangement of sprung masses is carried out and significant factors to ride vibration are identified. The optimal combination of design parameters is obtained with the objective of minimizing the vibration of the driver and carriage simultaneously. The optimisation result shows that the weighted driver vibration is reduced by 27.9% and the carriage vibration is reduced by 31.8% at various speeds.

Optimal Design Parameters of Cab’s Isolation System for Vibratory Roller Using a Multi-Objective Genetic Algorithm

2018 ◽  
Vol 875 ◽  
pp. 105-112 ◽  
Author(s):  
Van Quynh Le ◽  
Khac Tuan Nguyen
Keyword(s):  
Genetic Algorithm ◽  
Optimal Design ◽  
Dynamic Model ◽  
Nonlinear Dynamic ◽  
Ride Comfort ◽  
Design Parameters ◽  
Nonlinear Dynamic Model ◽  
Nsga Ii ◽  
Isolation System ◽  
Multi Objective

In order to improve the vibratory roller ride comfort, a multi-objective optimization method based on the improved genetic algorithm NSGA-II is proposed to optimize the design parameters of cab’s isolation system when vehicle operates under the different conditions. To achieve this goal, 3D nonlinear dynamic model of a single drum vibratory roller was developed based on the analysis of the interaction between vibratory roller and soil. The weighted r.m.s acceleration responses of the vertical driver’s seat, pitch and roll angle of the cab are chosen as the objective functions. The optimal design parameters of cab’s isolation system are indentified based on a combination of the vehicle nonlinear dynamic model of Matlab/Simulink and the NSGA - II genetic algorithm method. The results indicate that three objective function values are reduced significantly to improve vehicle ride comfort.

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