ENG  Vol.2 No.9 , September 2010
Optimization of Biodynamic Seated Human Models Using Genetic Algorithms
Abstract: Many biodynamic models have been derived using trial and error curve-fitting technique, such that the error between the computed and measured biodynamic response functions is minimum. This study developed a biomechanical model of the human body in a sitting posture without backrest for evaluating the vibration transmissibility and dynamic response to vertical vibration direction. In describing the human body motion, a three biomechanical models are discussed (two models are 4-DOF and one model 7-DOF). Optimization software based on stochastic techniques search methods, Genetic Algorithms (GAs), is employed to determine the human model parameters imposing some limit constraints on the model parameters. In addition, an objective function is formulated comprising the sum of errors between the computed and actual values (experimental data). The studied functions are the driving-point mechanical impedance, apparent mass and seat- to-head transmissibility functions. The optimization process increased the average goodness of fit and the results of studied functions became much closer to the target values (Experimental data). From the optimized model, the resonant frequencies of the driver parts computed on the basis of biodynamic response functions are found to be within close bounds to that expected for the human body.
Cite this paper: nullW. Abbas, O. Abouelatta, M. El-Azab, M. Elsaidy and A. Megahed, "Optimization of Biodynamic Seated Human Models Using Genetic Algorithms," Engineering, Vol. 2 No. 9, 2010, pp. 710-719. doi: 10.4236/eng.2010.29092.

[1]   G. Salvendy, “Handbook of Human Factors and Ergonomics,” 2nd Edition, John Wiley & Sons, Inc., New York, 2005.

[2]   ISO 2631-1, “Mechanical Variation and Shock - Evaluation of Human Exposure to Wholebody Vibration. Part I: General Requirements,” Technology Report, International Or-ganization for Standardization, 1997.

[3]   X. Wu, S. Rakheja and P.-E. Boileau, “Analyses of Relationships between Biody-namic Response Functions,” Journal of Sound and Vibration, Vol. 226, No. 3, 1999, pp. 595-606.

[4]   R. R. Coermann, “The Mechanical Impedance of the Human Body in Sitting and Standing Position at Low Frequencies,” Human Factors, Oc-tober 1962, pp. 227- 253.

[5]   C. W. Suggs, C. F. Abrams and L. F. Stikeleather, “Application of a Damped Spring-Mass Human Vibration Simulator in Vibration Testing of Vehicle Seats,” Ergonomics, Vol. 12, No. 1, 1969, pp. 79-90.

[6]   V. K. Tewari and N. Prasad, “Three-DOF Modelling of Tractor Seat-Operator System,” Journal of Terramecha- nics, Vol. 36, No. 4, 1999, pp. 207-219.

[7]   P. E. Boileau and S. Rakheja, “Whole-Body Vertical Biodynamic Response Characteristics of the Seated Vehicle Driver: Measurement and Model Develop-ment,” International Journal of Industrial Ergonomics, Vol. 22, No. 6, 1998, pp. 449-472.

[8]   Z. Zong and K. Y. Lam, “Bio-dynamic Response of Shipboard Sitting Subject to Ship Shock Motion,” Journal of Biomechanics, Vol. 35, No. 1, 2002, pp. 35-43.

[9]   X. X. Liu, J. Shi and G. H. Li, “Biodynamic Re-sponse and Injury Estimation of Ship Personnel to Ship Shock Motion Induced by Underwater Explosion,” Proceeding of 69th Shock and Vibration Symposium, Vol. 18, St. Paul, 1998, pp. 1-18.

[10]   R. Muksian and C. D. Nash, “A Model for the Re-sponse of Seated Humans to Sinusoidal Displacements of the Seat,” Journal of Biomechanics, Vol. 7, No. 3, 1974, pp. 209-215.

[11]   M. K. Patil, M. S. Palanichamy and N. G. Dhanjoo, “Minimization of the Verticale Vibrations Sustained by a Tractor Operator, By Provision of a Standard-Type Tractor Seat Suspension,” ANNALS of Biomedical Engineering, Vol. 6, 1978, pp. 138-153.

[12]   C. C. Liang and C. F. Chiang, “A Study on Biodynamic Models of Seated Human Subjects Ex-posed to Vertical Vibration,” International Journal of Industrial Ergonomics, Vol. 36, No. 10, 2006, pp. 869-890.

[13]   A. E. Baumal, J. J. McPhee and P. H. Calamai, “Application of Ge-netic Algorithms to the Design Optimization of an Active Ve-hicle Suspension System,” Computer Methods in Applied Me-chanics and Engineering, Vol. 163, No. 1, 1998, pp. 87-94.

[14]   P.-E. Boileau, “A Study of Secondary Suspensions and Human Drivers Response to Whole-Body Vehicular Vibra-tion and Shock,” Ph.D. Thesis, Concordia University, Montreal, Quebec, 1995.

[15]   W. Wang, “A Study of Force-Motion and Vibration Transmission Properties of Seated Body under Ver-tical Vibration and Effects of Sitting Posture,” Ph.D. Thesis Concordia University, Montreal, Quebec, 2006.

[16]   Y. Huang, “Mechanism of Nonlinear Biodynamic Response of the Human Body Exposed to Whole-Body Vibration,” Ph.D. Thesis, Uni-versity of Southampton, 2008.

[17]   C. C. Liang and C. F. Chiang, “Modeling of a Seated Human Body Exposed to Ver-tical Vibrations in Various Automotive Postures,” Industrial Health, Vol. 46, No. 2, 2008, pp. 125-137.

[18]   X. Wu, “A Study of Driver-Seat Interaction and Enhancement of Vehicular Ride Vibration Environment,” PhD. Thesis Concordia Univer-sity, Montreal, Quebec, 1998.

[19]   Y. Wan and J. M. Schim-mels, “A Simple Model that Captures the Essential Dynamics of a Seated Human Exposed to Whole Body Vibration,” Advances in Bioengineering, ASME, Vol. 31, 1995, pp. 333-334.