PEDESTRIAN CRASH MODEL FOR VEHICLE SPEED CALCULATION AT ROAD ACCIDENT

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1 International Journal of Civil Engineering and Technology (IJCIET) Volume 8, Issue 9, September 017, pp , Article ID: IJCIET_08_09_1 Available online at ISSN Print: and ISSN Online: IAEME Publication Scopus Indexed PEDESTRIAN CRASH MODEL FOR VEHICLE SPEED CALCULATION AT ROAD ACCIDENT Gezim Hoxha, Ahmet Shala *, Ramë Likaj Faculty of Mechanical Engineering University of Prishtina, 1000 Prishtina, Kosovo * Corresponding author: ahmet.shala@uni-pr.edu ABSTRACT In this paper is treated the problem of vehicles speed calculation in case of pedestrian crash at road accidents. For determination of speed is used the software model in concrete cases of road pedestrian s accidents. Also for analyses is used mathematical method and are compered results. Those methods take into account several factors such as: pedestrian length and weight, frontal profile of the vehicles, technical characteristics of vehicles, road friction, throw distance of pedestrian after the collision, road conditions e.c.t. The research was conducted based on concrete cases of pedestrian crash in Kosovo and simultaneously software simulations were used to analyses crash process. Caused damage in the vehicles involved in pedestrian crash are compared with software simulation process. Key words: Pedestrian, Velocity, Throw distance, Collision, Road, Angle. Cite this Article: Gezim Hoxha, Ahmet Shala, Ramë Likaj, Pedestrian Crash Model for Vehicle Speed Calculation at Road Accident. International Journal of Civil Engineering and Technology, 8(9), 017, pp INTRODUCTION Vehicle speed determination in accident analysis is important element to find the true cause of the accident process. In many cases of accident result to be involved pedestrian and vehicle. Use of the proper model for the match analysis is of more important. In many accidents cases the only elements remaining at the venue are final positions of vehicle and pedestrian after crash. In many accidents cases the only elements remaining at the venue are final positions of vehicle (where you can see if have damage in vehicle too) and pedestrian after crash. So, often based in those elements must use adequate model to calculate vehicle speed and to give conclusions about crash process. Depending on the elements found at the accident site and the characteristics of the vehicle and the pedestrian, an appropriate model must be used in order to have accurate results. In this paper are compered results of some mathematical models with software method for three different cases of pedestrian accidents editor@iaeme.com

2 Pedestrian Crash Model for Vehicle Speed Calculation at Road Accident. DATA COLLECTIONS Research is based in several road accidents where was involved pedestrians and vehicles with different characteristics (table1). Table 1 Vehicle characteristics and vehicles damages involved in real accidents which are used in the research Pedestrian characteristics N r. 1 Vehicles Vehicles and damages due to pedestrian crash Vehicle technical characteristics Weight [kg]: 114 Length [m]: 4.0 Width [m]: 1.7 Height [m]: 1.4 Age (years) Adult (33) Pedestrian Injures Head, lower extremities and other parts of the body VW Golf Weight [kg]: 100 Length [m]: 6 Width [m]:.00 /.14 Height [m]:.6 Adult (9) Head, pelvis and other parts of the body 3 Truck Iveco Weight [kg]: 110 Length [m]: 4.44 Width [m]: 1.7 Height [m]: 1.35 Adult (3) Head and lower extremities Ford 3. MATHEMATICAL MODEL (COLLINS, SEARLE, HAND AND BRACH) Different authors use different methods to calculate vehicle speed at the moment of hit pedestrian. Each of accident have particular specifics so is important to use adequate methods for concrete conditions of accidents. Some mathematical models treat the pedestrian as a mass point and velocity of vehicle calculated based in throw distance (Fig. 1). In this way the total throw distance S as a function of the initial speed v 0 and all of the other quantities (such as pedestrian launch angle θ, initial launch height H, coefficient of friction µ between the pedestrian and the ground, etc.) or the initial speed v 0 as a function of the total throw distance S and all of the other quantities is obtained editor@iaeme.com

3 Gezim Hoxha, Ahmet Shala, Ramë Likaj Figure 1 Pedestrian throw after crash moment S Collins [1] obtained equation for vehicle speed calculation by throw pedestrian distance: H v0 v (1) 0 g g v g( H S) g H () 0 Searle [] was based on the throw angle θ: S v0 (cos sin) v H (3) g From equation (3), Searle obtained equation for vehicle speed calculation in the moment of pedestrian crash: g( S H ) g H v 0 (4) cos sin v min g( S H ) 1 (5) Searle's model also neglects the longitudinal slope of the road. Han and Brach [3], pedestrian throw after crash divided it into three stages: t R S = X L + R + s (6) R=V0t Rcos gtr sin 1 (7) V0 sin V0 sin gh cos (8) gcos gcos editor@iaeme.com

4 Pedestrian Crash Model for Vehicle Speed Calculation at Road Accident 4. ACCIDENTS ANALYSIS OF VW GOLF, IVECO AND FORD WITH PEDESTRIAN Collision process between vehicles VW Golf and pedestrian happened while pedestrian was movements in different directions with vehicle at angle about 90 0 (Figure.). Throw distance of pedestrian in this case was about 40m. Figure Virtual Crash simulation of VW Golf - pedestrian crash Collision process between vehicles Iveco - pedestrian and Ford - pedestrian happened while pedestrian was movement in same directions with vehicle (Figure 3 and 4.). Figure 3 Virtual Crash simulation of Iveco (truck)- pedestrian crash editor@iaeme.com

5 Gezim Hoxha, Ahmet Shala, Ramë Likaj Figure 4 Virtual Crash simulation of Ford - pedestrian crash 5. SPEED OF VEHICLES BY MATHEMATICAL AND SOFTWARE MODEL With simulations by Virtual Crash software, based in final positions of vehicles and pedestrians and according to technical process of accident with damages in vehicles, are acquired results of velocities presented below (Fig.5). Figure 5 Vehicles speed Results of mathematical models and software model obtained for crash pedestrian analyzed, are shows in Table. Table Velocity of vehicles by different models Collins model [km/h] Velocity Searle model [km/h] Software model [km/h] VW Golf Ford Iveco editor@iaeme.com

6 Pedestrian Crash Model for Vehicle Speed Calculation at Road Accident As seen from the comparison of results obtained in table 1, deviations between the results obtained by mathematical method and software method are small in case of vehicles (cars) VW Golf and Ford, but they are bigger in case of truck Iveco. This happen because to the truck, striking force operates with the same intensity almost in the entire body of the baby at the same time. Characteristic of these cases is also the lack of pedestrian body throw in the vehicle or "flying" (fig.3.) as it happens to vehicles VW Golf and Ford (fig. and fig.4). Pick angle in case of pedestrian truck crash is zero or it is much lower than in the collision of the pedestrian from the passenger vehicles very low (diagram1, diag. and diag.3.). Figure 6 Pick angle (car-pedestrian, v=70km/h) Figure 7 Pick angle (car- pedestrian, v=80km/h) Figure 8 Pick angle (truck-pedestrian, v=70km/h) Figure 9 Pick angle (truck- pedestrian, v=80km/h) 6. CONCLUSIONS Based on results concluded by pedestrian mathematical model and in comparison with software model deviations between the results obtained by mathematical model and software method are small in case of vehicles (cars) VW Golf and Ford, but they are bigger in case of truck Iveco. This happen because to the truck, striking force operates with the same intensity almost in the entire body of the baby at the same time. Characteristic of these cases is also the lack of pedestrian body throw in the vehicle or "flying" (fig.3.) as it happens to vehicles VW Golf and Ford (fig. and fig.4). Pick angle in case of pedestrian truck crash is zero or it is much lower than in the collision of the pedestrian from the passenger vehicles very low (diag. 1, diag. and diag. 3.) editor@iaeme.com

7 REFERENCES Gezim Hoxha, Ahmet Shala, Ramë Likaj [1] Dr. Steffan Datentechnik PC-CRASH - A Simulation Program for Vehicle Accidents, Linz, Austria, November 008. [] Collins, J. C. Accident Reconstruction, Transportation Research Record Illinois, pp [3] Han, I., Brach, R. M. (001) Throw model for frontal pedestrian collisions, , Society of Automotive Engineers, Inc., Warrendale, PA. [4] Virtual-Crash (016) A Simulation Program for Vehicle Accidents. [5] Pohlak, M., Majak, J. and Eerme, M. (007) Optimization of car frontal protection system, International Journal for Simulation Multidisciplinary Design Optimization, Vol. 1, pp [6] Rusitoru, F. and Soica, A. (006) Aspects regarding the vehicle pedestrian collisions, The 4th European Academy of Forensic Science Conference, EAFS006, Helsinki, Finland. [7] Schuster, P. (006) Current Trends in Bumper Design for Pedestrian Impact A Review of Design Concepts from Literature and Patents, Mechanical Engineering Department California Polytechnic State University, San Luis Obispo, California. [8] Simms, C.K., Wood, D.P. and Walsh, D.G. (004) Confidence limits for impact speed estimation from pedestrian projection distance, International Journal of Crashworthiness, Vol. 9, No., pp [9] J. A. Searle, "The physics of throw distance in accident reconstruction ", , Society of Automotive Engineers, Inc., Warrendale. [10] Ahmet Shala and Mirlind Bruqi, Kinetostatic Analysis of Six-Bar Mechanism Using Vector Loops and the Verification of Results Using Working Model D, International Journal of Mechanical Engineering and Technology 8(8), 017, pp [11] Bajrami, Xh., Kopacek, P., Shala. A., Likaj. R., (013), Modeling and control of a humanoid robot. Publisher Springer Verlag Wien. [1] Shala, A., et al. Propulsion effect analysis of 3Dof robot under Gravity (015) Procedia Engineering, 100 (January), pp [13] Ramë Likaj, Xhevahir Bajrami*, Ahmet Shala* and Arbnor Pajaziti*, Path Finding for A Mobile Robot Using Fuzzy and Genetic Algorithms, International Journal of Mechanical Engineering and Technology 8(8), 017, pp [14] Ciro Caliendo, Crash Prediction Models for Roads Including Rainfall and Hazardous Points. International Journal of Civil Engineering and Technology, 8(9), 017, pp [15] F. Abbondati, F. S. Capaldo, D. Žilionienė and A. Kuzborski. Crashes Comparison Before and After Speed Control Cameras Installation: Case Studies on Rural Roads in Lithuania and Italy. International Journal of Civil Engineering and Technology, 8(6), 017, pp [16] Dr. A. K. Sharma, Dr. P.D. Pachpor and Prof. T.K. Rao, Deficient Shoulder Width and its Influence on Road Crash Frequency on Rural Highways. International Journal of Civil Engineering and Technology, 8(5), 017, pp editor@iaeme.com