2014中国汽车工程学会年会用户论文集：The design of a low-cost Electric Power Assist Steering for the modern cars, including the HEVs and the EVs, presents a lot of challenges. Understanding the sources of noise, vibration and its effects will help designers to use the right control techniques for the EPAS motor system. The designers are assisted to understand such sources of noise and fulfil some necessary corrections to minimize the noise. A typical EPAS system which adopts simple technique to identify and minimize such noise is introduced. It also helps designer to link between various domains such as the mechanical field to magnetic field to electric field, which provides a clear understandings of what is creating what effect and discusses methods of minimizing the acoustic foot print. The probable source of the audible noise emanating from the EPS column is when the system is maneuvered at a higher column velocity. EPAS system assembly need to be tested for variety of combinations to pin point the exact component responsible for noise and vibration at different speed (RPM) and torques (Nm). Approach adopted is to correlate Noise (Audio) and Vibration data with the Phase Current in the Frequency Domain (FFT) to reduce the analysis overheads on tools and expensive analysis software. The authors have a vast experience in the above subject and have used this simplified technique to practically solve a number of NVH, relating to C-EPAS, for low cost automotive segment.理解C-EPAS的噪声源及其缓解