**1. Introduction**

Over the decades, safety standards of the vehicles have been raised from the demands of the automobile users and organizations like Federal Motor Vehicles Safety Standards and Regula‐ tions (FMVSS) [1], National Highway Traffic Safety Administration (NHTSA) [2], European New Car Assessment Program (Euro-NCAP) [3], Society of Automotive Engineers (SAE) [4], etc. Superior technology evolved vehicles, which need more resources, offer diverse facilities for the occupants. Respecting the autonomous systems, more interventions of the drivers are

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starting to narrow. Although the yield of luxury and reliability, sometimes it operates against the occupants. During computer governing trips, individuals want to attain locations faster. In unexpected inaccuracy situations, automatic systems could cause fatal results.

However, the most common and important topic of vehicles is the crash-worthiness. Ensuring the reliability of the vehicles and safety of the occupants, the vehicle structure should be constructed in a way to absorb the impact effects and shock gradually, not to create a sudden deceleration which causes also injuries and fatalities. To decrease the failure risks, entire vehicle should be investigated, primarily starting from the basic structure of the vehicle under the perspectives of statics and strength of the materials. Then, the natural frequencies and the dynamic loading of the system should be incorporated into step by step. Generally for the dynamic loading, pre-captured dynamic road data also helps developing the vehicle structure. During the development period, beforehand defined systems like the concept design of the vehicle, and the shape should be protected, but the adaptation of the alterations should affect the design in minor.

Before determining the impact response and the behavior of the vehicle during a collision, the reasons of the accidents should be investigated. Serious amount of the accidents occur by the carelessness, negligence, and recklessness of the driver. The first one decreasing the risk of the collision is preventive driving techniques. This technique is a part of the education for the expert driving, although it refers time, patience, and talent. Yet, without any attention and enough reflexes, even this preventive method, results in frustration. In addition, if the all scenarios are considered the environmental and road conditions, and the faults of the other vehicles, including the drivers, effect the vehicles as other factors. Thence, the UAV technology becomes the redeemer of the system to solve the problems completely or decrease the errors to a sufficient level for a more reliable drive.

The most proper way to determine the causes is an experimental study, despite it is not a cost effective and time-consuming way. With the all other test methods such as positioning, loading, and calibrating, crash tests are the most significant ones. After the real-time collision tests, widely known experimental approach on the crash-worthiness researches is the sled test [2, 3, 5, 6]. The sled tests are more under-control when it is compared with the other methods. But again, the financial hassle is beyond the limits of the most companies and facilities.

Decreasing the expenses of the crash tests, many companies untangle their crash-worthiness difficulties after mandatory collision tests, with the computer-aided simulations. Consequent‐ ly, computerized methods are immensely reliable, if almost, the last three decades are considered. To overcome the real-time simulations of the engineering problems, many developed computer-aided analysis softwares can be obtained from the market. Even though some of the softwares for an exact engineering solution such as structural analysis, impact analysis and thermal analysis remain part of the market is dealing with the multi discipline engineering solution packages serving for the finite element method (FEM). But for the general FEM and its solution methodology [7–9] is not focused on significant issues. Hence, the more applications in a software sometimes decreasing the expertise approach. According to our perspective, impact simulation codes indicate the prominent side of the vehicle collisions. Thereupon, for the impact procedures, explicit dynamics approach based on the FEM gets through the formidable problems, satisfactorily [10]. In **Figure 1**, FEM model (a) and a crash simulation (b) of a wheelchair and a seating system via sled scenario are given using the human mass adaptation to understand the crash worthiness [11].

starting to narrow. Although the yield of luxury and reliability, sometimes it operates against the occupants. During computer governing trips, individuals want to attain locations faster. In

However, the most common and important topic of vehicles is the crash-worthiness. Ensuring the reliability of the vehicles and safety of the occupants, the vehicle structure should be constructed in a way to absorb the impact effects and shock gradually, not to create a sudden deceleration which causes also injuries and fatalities. To decrease the failure risks, entire vehicle should be investigated, primarily starting from the basic structure of the vehicle under the perspectives of statics and strength of the materials. Then, the natural frequencies and the dynamic loading of the system should be incorporated into step by step. Generally for the dynamic loading, pre-captured dynamic road data also helps developing the vehicle structure. During the development period, beforehand defined systems like the concept design of the vehicle, and the shape should be protected, but the adaptation of the alterations should affect

Before determining the impact response and the behavior of the vehicle during a collision, the reasons of the accidents should be investigated. Serious amount of the accidents occur by the carelessness, negligence, and recklessness of the driver. The first one decreasing the risk of the collision is preventive driving techniques. This technique is a part of the education for the expert driving, although it refers time, patience, and talent. Yet, without any attention and enough reflexes, even this preventive method, results in frustration. In addition, if the all scenarios are considered the environmental and road conditions, and the faults of the other vehicles, including the drivers, effect the vehicles as other factors. Thence, the UAV technology becomes the redeemer of the system to solve the problems completely or decrease the errors

The most proper way to determine the causes is an experimental study, despite it is not a cost effective and time-consuming way. With the all other test methods such as positioning, loading, and calibrating, crash tests are the most significant ones. After the real-time collision tests, widely known experimental approach on the crash-worthiness researches is the sled test [2, 3, 5, 6]. The sled tests are more under-control when it is compared with the other methods. But again, the financial hassle is beyond the limits of the most companies and facilities.

Decreasing the expenses of the crash tests, many companies untangle their crash-worthiness difficulties after mandatory collision tests, with the computer-aided simulations. Consequent‐ ly, computerized methods are immensely reliable, if almost, the last three decades are considered. To overcome the real-time simulations of the engineering problems, many developed computer-aided analysis softwares can be obtained from the market. Even though some of the softwares for an exact engineering solution such as structural analysis, impact analysis and thermal analysis remain part of the market is dealing with the multi discipline engineering solution packages serving for the finite element method (FEM). But for the general FEM and its solution methodology [7–9] is not focused on significant issues. Hence, the more applications in a software sometimes decreasing the expertise approach. According to our perspective, impact simulation codes indicate the prominent side of the vehicle collisions. Thereupon, for the impact procedures, explicit dynamics approach based on the FEM gets

unexpected inaccuracy situations, automatic systems could cause fatal results.

the design in minor.

60 Autonomous Vehicle

to a sufficient level for a more reliable drive.

**Figure 1.** (a) Finite element model of a wheelchair crash simulation via sled test, (b) Finite element simulation result of the model for a defined specific time.

One of the most popular and extensively used software for the impacts is LSDYNA, the product of the Livermore Software Technology Corporation (LSTC) [12]. This code is used by some of the software companies as a fundamental explicit dynamics solver. With the help of the validated FEM results, reliable procedures will be determined to figure out the real vehicle crash scenarios in an inexpensive way, even for the UAV technology. During improvements invariably, reverse engineering applications are in the process from beginning till the end to mend the faults scores of times.
