Design of an Expert System to Detect Electromagnetic Compatibility Problems in the Automobile


Significant time and effort is spent detecting electromagnetic compatibility problems and ensuring electromagnetic compliance in the automobile. Methods typically rely heavily on experimental measurements after a prototype has been built - a time consuming and expensive option that prevents solution to many problems. Better, less expensive vehicles could be produced if problems could be detected analytically early in the design process. We are developing a system-level automotive EMC expert system to be used early in the design of a vehicle. This system is being designed to help the automotive engineer with radiation and immunity problems, crosstalk, placement of modules, component grounding, and EMC testing issues. Rather than rely on sophisticated numerical models, the expert system uses simplifying assumptions and approximations and will apply the same “rules of thumb” that a human expert would apply in a similar situation. Our experience with an expert system for printed circuit boards suggests this approach works well. It allows rapid and automatic analysis of an automotive design, determination of potential problem areas, identification of critical components and structures that may be causing problems, and application of simple guidelines toward solving those problems. The system is designed to help the human EMC expert focus his efforts on a few particular areas of concern rather than on the many possible problems that could occur within the automobile and to help the majority of automotive engineers who are not EMC experts build cars that are electromagnetically sound. The top-level expert system architecture consists of three basic stages: a) an input stage that gathers information and prepares it for analysis, b) an evaluation stage which approximates radiated and coupled noise and tests for basic design rules of thumb, and c) an output stage which feeds results back to the user, identifies problems and responsible components or structures, and suggests methods to solve those problems. The input stage includes an expert-system algorithm to identify and classify circuits within the vehicle. The evaluation stage includes algorithms to determine resistive, inductive, and capacitive coupling between harnesses, to predict radiated emissions, to predict coupling from external fields, to predict power bus coupling, to predict harness resonances, and an algorithm to apply custom design rules developed by the local EMC expert.

Meeting Name

2002 IEEE Antennas and Propagation Society International Symposium and USNC/URSI National Radio Science Meeting (2002: Jun.17-20, San Antonio, TX)


Electrical and Computer Engineering

Keywords and Phrases

Electromagnetic Compatibility Problems; Electromagnetic Compliance; Automobiles

Document Type

Article - Conference proceedings

Document Version


File Type





© 2002 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

20 Jun 2002

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