Before 2002, automotive companies used fifth wheels, radar sensors, microwave sensors and optical systems to provide speed and distance measurements during proving ground testing.
Whilst these sensors gave good levels of accuracy in perfect conditions, they suffered on snow, loose, uneven and wet surfaces. In addition, they often took a long time to fit and were vulnerable to damage.
The rise of accurate GPS
When the US Government switched off the deliberate scrambling of the GPS signal, we at RACELOGIC saw an opportunity to use satellite signals to measure speed and distance, without any of the downsides associated with the previous technologies.
Now, RACELOGIC's distinctive blue aluminium VBOX (which stands for Velocity Box) is used by almost every vehicle manufacturer at proving grounds around the world.
Centres such as MIRA have replaced their previous systems with VBOX GPS data loggers, prompted by the performance on any surface, the improvement in accuracy, and the ease of use.
For Testworld, the largest cold winter test facility in Finland, the ability to provide accurate results in all conditions provides more challenges.
Optical and microwave sensors are expensive and struggle to operate in the harsh conditions and fifth wheels slide on the slippery surfaces. In addition, quick turnaround means that engineers need to take equipment on and off vehicles quickly to optimise the expensive track time, so they appreciate the fast installation.
GPS sensors are ideally suited for such testing, as the only external fitting required is the aerial which can be mounted on the roof.
How <2cm accuracy is achieved
VBOX provides an accuracy of 0.1kmh for speed measurement, and up to 1.8cm for brake testing in a stand-alone unit. In addition, by using a Base Station and tracking the refreshed Russian GLONASS constellation as well as GPS, positional accuracies down to 2cm are achieved. This allows ADAS systems such as collision mitigation, lane departure warning and active cruise control to be validated using the same equipment.
Autoliv - Advanced Driver Assistance Systems (ADAS) Testing
New testing challenges have arisen with the new breed of advanced driver assistance systems, which use sensors to record the driving environment and protect against varied hazards.
Autoliv has built a mock town complete with fake pedestrians to help vehicle manufacturers test the new active technology.
A RACELOGIC Vehicle Separation system is used at their proving centre in Sweden to provide accurate measurement of two vehicles at a time, in order to test adaptive cruise control and collision mitigation technology.
With two VBOX 3i GPS data loggers connected via radio telemetry and receiving differential GPS corrections from a local VBOX RTK Base Station, engineers are able to conduct tests at 1.8cm positional accuracy and have precise measurements of the relationship between two moving vehicles, including vehicle range, separation angle, lateral distance, and relative speed.
FT Techno Proving Ground: Video Integration
Another technology becoming more popular with proving grounds is integrating data with video. With RACELOGIC's Video VBOX, engineers can record tests with up to four bullet cameras, synchronised with GPS and vehicle data overlaid onto the video in real time.
FT Techno at the Fowlerville Proving Ground, USA, use the system for blind spot detection system tests, putting markers on the graphic overlay using RACELOGIC's software to visually determine vehicle position.
"Video VBOX is highly desirable on and off our proving ground" says Project Engineer Jason Musson. "It enables us to record video data and then bring this back to the track. The video data from off site is then correlated into objective data to control real life scenarios. This is vital for many aspects of ADAS testing, including Adaptive Cruise Control, Lane Departure Warning, Collision Mitigation, and Blind Spot monitoring technologies."
Jason notes, "Connecting other VBOX modules to the system enables us to input various signals including CAN, Analog, and Digital.
We can also couple out other test equipment via CAN into the system to give us more data, and then overlay this on the Video VBOX screen. The simple set up and adaptability of the system makes it ideal for benchmark testing."
Find out more about RACELOGIC data and video loggers online or contact us straight away. We are happy to discuss your application any time.