Transporting NV Standardized Testing from the Lab to the Production Environment

NVH labs at Tier 1 and Tier 2 suppliers have in the past 15 years implemented testing techniques to validate the NV performance of their products. Validation tests are most often conducted to check compliance of the product to vehicle OEM specifications, less often to truly assess NV performance. Vehicle OEM specifications are sometimes outdated, narrow in scope and require lab-type of conditions, i.e. anechoic or hemi-anechoic environment, fixed microphone position and specific operating conditions. Tier 1 and 2 suppliers often find themselves in a situation in which they have to transport lab tests to the plant floor, as they are requested by their customer to ensure 100% shipped quality. In order to do so, they are faced with several technical and commercial challenges as vehicle OEM specifications often have no provisions for plant-floor boundary conditions and cycle time requirements. For cost reasons, the component manufacturer typically aims at adding NV performance checks to an existing test station, which poses additional challenges over using a completely redesigned test station. This paper will discuss the challenges encountered by Tier 1 and Tier 2 suppliers having to implement end-of-line NV testing for quality control. The paper will discuss these challenges for a few different automotive components, namely steering wheel clock springs, sunroofs, axles and shock absorbers. The authors will describe some of the challenges faced and the solution implemented at the end of the line as it relates to boundary conditions, absolute levels at feedback sensor and pass/fail criteria