ESC testing made easy

The National Highway Traffic Safety Administration (NHTSA) proposed plans to make Electronic Stability Control (ESC) systems compulsory for all passenger vehicles and light-duty trucks and drew up plans for testing procedures for ESC systems. It is likely that all vehicles sold in North America after 2011 will require ESC systems that pass their tests.

The newly developed RT2500 Inertial and GPS navigation system will make the job of performing the NHTSA tests a lot easier. It will also save time and increase accuracy and repeatability over conventional sensors.

The NTHSA test requires lateral acceleration, yaw rate and speed to be measured, all of which the RT2500 measures accurately. The lateral acceleration is integrated twice over a short period of time to give the lateral displacement.

The RT2500 has some other interesting properties that make it easier to use compared to several individual sensors.

Lateral acceleration measured by the RT2500 is in a true horizontal frame. Although this is not required by NHTSA’s proposal, it does mean that the roll axis RT2500 does not need aligning in the vehicle or require the zero-offset to be corrected, which will save valuable time. It also increases the accuracy when testing on different tracks that may have different camber angles.

The RT2500 figures out its yaw mount angle in the vehicle to better than 0.05 degrees and this can be corrected very quickly through software. Finding the yaw mount angle of an individual accelerometer is not easy and cannot be performed to the accuracy that the RT2500 can achieve. This makes tests more repeatable when benchmarking vehicles.

Forward velocity measured by the RT2500 can be displayed in real-time for the driver. This can be captured using the same acquisition system as for the results. There is no need to install yet another sensor just to measure speed. The ABD Accelerator robot accepts the RT2500 as a feedback device to control the speed, giving better than 0.3km/h velocity accuracy for those who really enjoy precision.

The RT2500 outputs its data over one CAN bus (or optionally via analogue). Connecting the RT2500 to a CAN data acquisition system is simple. The DBC file includes all the configuration information and the calibration is performed in the RT2500 itself, so you don’t need to waste time finding and entering it.

Installation of the RT2500 is also simple since it fits on our RT-Strut. When benchmarking vehicles, the transfer from one vehicle to another is very fast, taking less than a minute to unlock from one car and move to another.

These five points show that the installation of a complete measurement system for NHTSA’s tests is a lot quicker than conventional sensors and yet achieves higher accuracy at the same time.

The RT2500 can also measure a whole range of other measurements, including slip angle, which are required to test and improve vehicles.

Find out more about the RT2500 on our products page or read NHTSA's proposal for ESC testing here.