Validating Brake Performance on a Prototype Passenger Car

ADwin-Gold DAQ System Handles the High-Speed Requirements

CAS DataLoggers recently supplied the data acquisition solution for an automotive manufacturer of passenger vehicles who needed to evaluate the reliability of a prototype vehicle’s brake system. This would give them a highly accurate view of both component life and servicing expectations. The front disk pad temperatures, MPH, average deceleration and braking duration all needed to be recorded immediately before the brakes were applied. Since performance needed to be tested in a wide variety of traffic conditions automatic data collection was required so that the driver was free during testing. Therefore the customer needed a data acquisition system which could quickly ‘drill down’ on the braking event’s data and store the data on external RAM, and which also offered flexible communications capabilities with a PC.

The manufacturer installed an ADwin-Gold Real-time Data Acquisition and Control System in the car’s backset, enclosed in a Pelican industrial case. Through the enclosure’s side port, the DAQ system was connected to a variety of sensors including thermocouples, an accelerometer, and a road speed sensor.

The ADwin-Gold was then programmed to start recording when the ignition was turned on and to go back to sleep mode when the car turned off. During operation, the ADwin was also programmed to constantly read all the sensors and record data whenever the brakes were applied. By using a simple shift register, the temperatures and speed of the vehicle were recorded.

All measurements on the 16-channel DAQ system were recorded in real-time at 12-bit resolution. The ADwin-Gold system’s local real-time DSP CPU supported parallel, individually-controlled real-time processes while running independently of the PC’s operating system, providing deterministic operation with 1 usecond or less response times. Versatile communication with the PC was performed using the system’s built-in Ethernet and USB interface.

The ADwin software environment could operate using Windows, LINUX, or as a stand-alone data acquisition system. The system also enabled calibration of the system’s analog inputs and outputs and had drivers for many popular programming environments including VB, VC/C++, LabVIEW, TestPoint and others.

The ADwin Gold stored all the project data on 16 MB of external DRAM for data storage. This data was stored and then given to test engineers on a weekly basis; users were able to quickly sift through the large volume of data using the system’s powerful software.

Using the ADwin-Gold system, the customer successfully monitored and analyzed all the desired performance data in their prototype following installation. The ADwin provided real-time recording at the extreme speed necessary for highly accurate data capture, and was protected from accident within the enclosure. Additionally, data transmission and accessibility were greatly simplified via the system’s communications capabilities.