System for diagnosing unexpected noise in a multi-component assembly

Abstract

The recreation of vibration levels at certain points in a stationary vehicle interior that are representative of realistic road conditions are achieved using road measurements in conjunction with a technique known as 'reciprocal filtering.' The reciprocal filtering technique consists of using an inverse transfer function, or impulse response in the time domain, between an excitation transducer and an accelerometer to calculate the excitation signal needed to recreate the vibrations measured on the road when squeak and rattle are present in a component of the vehicle. A set of excitation signals may be recorded for each component in the vehicle which is suspected of producing squeak and rattle noise. When a complaint is made that a vehicle is producing squeak and rattle, a service technician may reproduce noise by inducing vibrations through a kit having a CD player, an amplifier, a bass shaker and a CD with the set of excitation signals stored on separate tracks thereof. The bass shaker is attached, for example with two side tape, to the component suspected of producing noise, and noise inducing vibrations are played from the CD, through the CD player and amplifier, to the bass shaker. In this way, squeak and rattle may be quickly identified and repaired.