ExtraEnergy invested a lot of money in new, unique measuring technology. The bulk of the technology was fitted to the test bikes. The quality and quantity of data produced by the range of sensors and a GPS receiver, were more than just a few notches above those collected in previous tests.
For the Spring 2009 Test, ExtraEnergy invested €180,000 in unique technology for even more reliable and credible test results and to be able to test 30 bikes at the same time. The technology was developed in collaboration with OTEC in Mannheim and Calantec in Berlin.
The bulk of the technology was fitted to the test bikes. There was a data box in the handle-bar bag, which collected the measured values from all the sensors on the bike. Measured were: the withdrawal of electric power from the battery; pedal rotation frequency, power with which the rider pedalled, and the riding speed. In addition, the GPS data were recorded during the test ride.
A battery sensor was built into the original battery of every test bike (inside the battery casing), and connected to a plug with a cable. This enabled the voltage (volt) and electric current (ampere) to flow into the data box as analog signals.
A magnetic sensor was attached to the pedal arm, and another sensor to the front fork, or to the back-wheel suspension. These sensors measured the pedal rotation frequency of the rider and speed of the bike. This information also flowed into the data box.
In addition, special measuring instruments were fitted between the foot pedal and pedal arm on both sides of every test bike. They had magnets and hall sensors (magnet sensors for measuring current) in their head sections, which measured the power with which the rider pedalled. In the flat part, parallel to the pedal arm, the measured value was prepared and transmitted to the data box per radio signal.
A GPS receiver connected to the data box, which looked like a mouse of a computer, supplied the coordinates of the route followed by the rider. In this way, the complete trip was documented parallel to the measured values and – for control purposes - compared with the GPS data of a previously recorded reference trip.
The data box recorded all data on an internal memory and USB stick, which came to about 12MB per test round! After the test ride, the USB stick was removed and the data saved on a PC for further evaluation with so-called Matlab software. Once the test technicians were convinced that all data had recorded properly and was credible, the test ride was ticked off as having been completed successfully. When data lacked, the test ride was repeated.
Photos of the testing equipment
Copy: Susanne Brüsch and Nikolaus Decius
Translation: Christoffel Volschenk
Photos: Patrick Knappick, Susanne Brüsch and Nikolaus Decius
8 May 2009