Analysis of phase-free filtration methods when testing vehicle components for mechanical impact

Abstract

Introduction. Mechanical impact tests of automotive emergency call systems, carried out in order to determine the overloads resistance arising from a vehicle collision and to verify automatically the possibility of determining the moment of an accident, require the use of (CFC) KCHKh60 or KChKh180 frequency characteristics, as a means of impact measuring characteristics. The requirements for low-pass filtering carried out by a 4th-order phase-free Butterworth filter, are specially distinquished from the other requirements for such a measuring system.

The purpose of the study was to analyze the possible limitations that arise when using the empirical method of binding transposed data before starting and after the comleting of data collection, regulated by ISO 6487 and developed by the international standardization organization. The domestic regulatory documents related to impact testing were based both on the above documents and SAE J 211-1, developed by the community of automotive engineers.

Methodology and research methods. The research method consisted of presenting the additive noise signal which accompanied the impact, in the form of a determinate sinusoidal signal with an initial phase characterized by specific resulting maximum spurious emission signal, and included the further analysis of the signal occurrence with a purpose of its minimization.

Scientific novelty and results. The result of the work carried out was the identified shortcomings in the methods of forced binding of transposed data regulated by ISO 6487 and SAE J 211-1 before and after the data collection and the possible limitations. Scientific novelty resulted in the proposition of the method for additional shift of transposed additional data for the purpose of significant reduction of the emerging transients effect. The proposed analytical expressions and the implementation of the algorithm minimized spurious emissions of the resulting shock acceleration pulse during testing.

The practical significance of the research consists of increasing the reliability of the test results by comparing the shape of the shock pulse filtered due to ISO 6487 and SAE J 211-1methods, as well as by the method proposed with the exception of the stray component.