In an era of urbanization and increasing focus on sustainable transport options, bicycles and e-bikes (especially pedelecs) have gained popularity as environmentally friendly alternatives to cars.
In order to develop digital twins of bicycles and electric bicycles, in particular pedelecs, and to study the cyclist’s behaviour in interaction with the electric drivetrain, investigations were carried out on an automotive chassis dynamometer. Evaluation data for the pedelec and its drivetrain as well as the riding behaviour of different riders were obtained within driving cycles on the road and on the test bed. An AVL chassis dynamometer was used, which is originally designed to test motor vehicles with a maximum power output of up to 150 kW and a maximum speed of 200 km/h. The tests were performed in the “road load simulation mode”, which simulates the speed-dependent driving resistances of the test vehicle. An additional interface was implemented for dynamic adjustment of the altitude gradient.
Two test objects were used:
- 1
“Haibike”: mountain bike pedelec with a mid-mounted Bosch motor (Bosch Performance Line CX and CAN-Bus Data-logger).
- 2
EcoSensorBike: an urban trekking bike equipped with e.g. a torque sensor on the crank.
Due to the built-in measurement technology, the pedelec is used first for a qualitative evaluation of the power and traction data. The lighter second bicycle is used for further tests with several subjects.
A measurement campaign was carried out to gain data for the validation of the digital twin of the pedelec as well as for the investigation of cyclist’s behaviour in the driving cycle. The traction force and speed data will be recorded at high resolution by the dynamometer and will provide information on the power output of the rider-bike combination, as well as the braking and shifting behaviour under simulated traffic conditions. The data is recorded in real time, allowing the rider’s power output per crank revolution to be analysed by evaluating the traction force data. As with classical vehicle testing, the definable environmental and driving profile conditions on the dynamometer allow excellent reproducibility of the measurements.
The investigations show the differences of driving behaviour on the road and on the test bed.
