Abstract
People make judgements of the vibration levels perceived in a vehicle in a variety of situations. A common type of assessment is an overall judgement of the vibration level on those vehicle parts that interact directly with the driver's body, basically the steering wheel, the seat and the floor panel, and on other components whose performance might be severely affected by vibrational excitation, such as interior and exterior mirrors. From the car manufacturer's point of view it is important to note that subjective judgements of vibration influence the buyer's opinion of the performance of a vehicle and, consequently, there is a need to quantify this perception.
This paper presents a novel measurement technique that can be used to quantify in-service vibration levels of interior and exterior mirrors and their impact in the visual quality perceived by the driver using a virtual laser technique. This technique allows the calculation of the trajectory of a virtual beam of light reflected by the mirror on the driver's eyes in operational conditions. The main advantages of this method are its low implementation cost, flexibility in choosing the observation point and suitability for quantifying the individual effects of in-service engine vibration, road excitation and, most importantly, aerodynamic loads on the quality of the image reflected by the mirror. Thus, this technique offers important practical improvements with respect to the methods currently used for the analysis of in-service vibrational performance of mirrors, which require sophisticated experimental set-ups as well as expensive facilities such as wind tunnels.