External Vehicle Noise Measurement System CAT-Pass By

This system measures external vehicle noise and proximity exhaust noise during acceleration and steady-state driving in automotive certification tests.

Measurement data is recorded using a Rion NA-28 precision sound level meter installed on the course, and a GPS speedometer, tachometer, etc., installed inside the measurement vehicle.
The NA-28 sound level meter is connected via USB serial communication, and the measured values ​​are recorded as digital data. The GPS speedometer is a NI cDAQ. It uses a CAN module 9862 and communicates via CAN.
Measurement starts triggered by a signal from a laser sensor installed on the course, and data measured from the tachometer, GPS speedometer, and accelerator position sensor inside the test vehicle are displayed in a graph via Wi-Fi.

Measurement results are reflected in the measurement list in real time, and the vehicle speed at each point is automatically determined, so if measurement is unsuccessful, it can be removed from the list. Furthermore, it is possible to display the level of each measurement result and the frequency analysis results of noise at any vehicle position clicked on the graph.