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• TOP-DOWN VS BOTTOM-UP METHODOLOGIES FOR ADAS SYSTEM DESIGN

  D.E. Chickrin, А. А. Egorchev

  2021-07-18

  Abstract ▼

  Selection of the principal design methodology has a significant impact on final product
  quality, including its evolvability and scalability. The article discusses the features of traditional
  bottom-up and top-down design methodologies in the context of ADAS (driver assistance and automated
  driving systems). Necessity of the combined design methodology is shown due to unacceptability
  of “pure” methodologies for design of this kind of systems. For this purpose, the features
  and limitations of the top-down approach are considered: commitment to maximum compliance
  of the developed system with its requirements; methodological rigor of the approach; difficulty
  of system testing in the process of the development; sensitivity to changes in requirements.
  The features and limitations of the bottom-up approach are considered: possibility of iterative
  development with obtaining intermediate results; possibility of using standard components; scalability
  and flexibility of the developed system; possibility of discrepancy of functions of subsystems
  to requirements, which may appear only at later stages of development; possible inconsistency in
  development of separate subsystems and elements. The features and factors of ADAS system development
  are considered: increased requirements for reliability and safety of the system; heterogeneity
  of used components. Two stages of ADAS-systems development are distinguished: the
  stage of intensive development and the stage of extensive evolution. The applicability of one or
  another methodology to various aspects of ADAS system development and evolution (such as:
  requirements definition; compositional morphism; scalability and extensibility; stability and sustainability;
  cost and development time; development capability) is considered. A comparison of themethodologies concludes that there are aspects of technical system design and development in
  which there is a significant advantage of one or the other of the methodologies. Only the bottomup
  approach can ensure the proper evolution of the system. However, for complex systems, it is
  critical to define the initial requirements for the system, which can only be achieved using the topdown
  methodology.

• RANDOM ERROR OF PULSE DURATION MEASUREMENT WITH OSCILLATIONS AT THE TOP BY MULTI-THRESHOLD DURATION METERS

  D.V. Belyaev, D.E. Gubarev, К. Е. Rumyantsev

  2021-12-24

  Abstract ▼

  In systems for automatic measurement of the duration of video pulses, various devices for amplifying
  and shaping pulses of a normalized level are used, the duration of which is equal to the duration
  of the input signals. A rough measurement of the duration of video pulses can be made with onethreshold
  meters. More accurate are multi-threshold and floating-threshold meters. Pulse duration
  meters have found wide application in electronic warfare equipment, in measuring technology. The
  variation in the shape of electrical signals does not allow the use of a single measurement method,
  which is the best for all shapes, therefore, the search for technical solutions that satisfy the conflicting
  requirements continues: a wide range of durations and duty cycles. The aim of this work is to
  carry out a mathematical analysis of the random error in measuring the pulse duration with oscillations
  at the top by multi-threshold duration meters. In the course of the work, the results of a numerical
  experiment were obtained to measure the duration of a pulse with oscillations at the top using
  multi-threshold duration meters. And also a comparison was made of four multi-threshold duration
  meters for the investigated pulse shape. The calculation results are presented for a signal dynamic
  range of 60 dB and an amplitude quantization step of 3dB and 12 dB.