Abstract
Research and/or Engineering Questions/Objective
It is very important that the ignition switch should be essentially maintained as on-status during driving conditions because the safety features such as airbag system cannot be operated if it moves to off position while driving. Therefore, the various situations should be considered to avoid ignition off in driving condition because actual customers hang many keys on an ignition key. Since those suspended keys can act as a mass that affect ignition off, the dynamic model for prediction should be established and its dynamic behavior under the severe vibrations should be analyzed.
Methodology
In order to establish the dynamic model of the ignition switch system that describes the actual conditions such that many keys are suspended on an ignition key, the equations of motion of the system need to be firstly derived. Then, the numerical simulation is implemented by using MATLAB and the results are correlated to the motions obtained from the actual vehicle tests. Thus, the robustness of the ignition system can be verified theoretically and empirically. In addition, the possibility to move to ignition off position by the flicking motion of fingers is theoretically analyzed and the results are obtained by the numerical simulations. Regarding with the ignition off by flicking motion, the newly invented mechanism is also designed and the dynamic behavior and its advantage are verified by MATLAB simulation.
Results
In this paper, the dynamic behavior of an ignition key that hangs the single mass representing many suspended keys is theoretically analyzed and presented. Also, the robustness of the ignition system regarding with harsh vibrated driving condition is verified from the standpoint of numerical simulations and actual test results. Also, the unintentional ignition off due to the flicking motion is theoretically modeled and its dynamic behavior is solved numerically. Then, its effectiveness to prevent unintended rotation of key is verified and presented.
Limitations of this Study
An important limitation of this study is to define a single mass that represents suspended keys on an ignition key in a dynamic model. Since the dynamic model of the system needs to reflect on the actual conditions created by customers, the statistical method of Gaussian distribution should be applied on this analysis.
What does the paper offer that is new in the field including in comparison to other work by the authors?
Regarding with the ignition off phenomenon during driving conditions, it is very important to predict the dynamic behavior to secure the safety of passengers. The analysis is implemented theoretically experimentally, and the methodology to prove the robustness of the system is logically introduced from the standpoint of the customer usage.
Conclusions
The theoretical methodology to verify the ignition system to prevent unintentional ignition off during driving is introduced and the numerical results of the system are correlated to the actual tests. Then, the robustness of the ignition system is proved from the standpoint of the actual cases in the field.
KEYWORDS : Ignition Switch System, Dynamic Model, Equations of Motion, Gaussian Distribution, Flicking Motion