Modern electronically controlled braking systems are extremely efficient and are very close to reaching the optimum braking distances for a given tyre and road surface. It is therefore essential that the measurement of braking distances can be carried out with very high distance accuracy.
Due to their high precision, flexibility, and ease of installation (they can be moved from vehicle to vehicle in minutes), VBOX GPS data loggers are used by almost every automotive and tyre manufacturer in the world to carry out brake distance measurements.
There are two main kinds of braking test:
Speed Window Tests
Brake Trigger Tests
Conducting tests with a trigger ensures that the response time of the braking system is measured along with the performance of the tyres, brake pads, discs, and other components. However, during a trigger activated test, the car undergoes a complex change in attitude resulting in varying speeds across the body of the vehicle.
Centre of gravity corrections – or countering the 'lever-arm' effect - of testing tall vehicles with long suspension travel can be achieved with the combined use of GPS and an Inertial Measurement Unit.
How we verify brake distance accuracies
We regularly verify the brake test measurements obtained by the VBOX unit against a light barrier, laser, and RTK DGPS setup with Base Station to confirm a positional accuracy of better than 2cm.
We also captured the test on our LabSat GPS simulator, which records the raw GPS signals and the brake trigger input, and allows us to replay it through any VBOX on the bench. This gives us a repeatable reference to check against any new firmware or hardware updates, and maintains a high standard of brake testing accuracy.
Learn more about GPS Accuracy here.