Sound and Vibration Analysis in a Vehicle

Interior noise perceived in the passenger cabin is one of the most important factors in a customer’s determination of the total quality of the vehicle and largely influences his buying decision. In a recent measurement program, engineers from m+p international studied the NVH behavior of a motorhome.

Structural vibrations and sound pressure were recorded to analyze the vibrational behavior on different road surfaces. All measurement data was recorded using our new m+p VibMobile measurement front-end. With its optional battery power, compact form factor, robust design, embedded CPU and storage media, it is tailored for portable or standalone operation. The silent, temperature-controlled fans make the front-end ideally suited for acoustic measurements.

Functions include TEDS support for fast and secure setup, IEPE sensor conditioning switchable for every input channel, cable break and overload detection. To correlate the recorded signal with the driving situation, for example engine speed, the CANbus interface of the m+p VibMobile is used to read the data from the motorhome’s CANbus.

Online processing of the data measured in the motorhome was performed using the m+p Analyzer. This noise and vibration analysis software allows the operator to visualize and check time data, octave spectra, FFT-based spectra, RPM and much more online during the test run. The raw data and results are stored on a removable disk for later post-processing.

Download the article “Vibration and Sound Analysis”, published in the November 2016 issue of the Automotive Testing International magazine.