The world's first electric cargo bike with fast charging function and recuperation was presented at the University of Ulm. The 3 m long and 170 kg heavy vehicle is the result of a 4-year research project.
The project was coordinated by the Ulm-based Institute of Measurement, Control and Microtechnology, with the DLR's Institute of Vehicle Concepts as co-applicant. The Biberach-based company EMB-Elektromaschinenbau was also involved. At the end of the project, the new e-cargo bike was presented to the Ministry of Economics, Labor and Tourism of the State of Baden-Württemberg. The state ministry funded the project with around 1 million euros.
The electric moped - which was built in two versions - is capable of speeds of up to 45 km/h and can transport payloads of up to 100 kg easily, comfortably and safely. The user-friendly vehicle is designed in the so-called long-tail format, which means that the load lies between the driver and the rear wheel. Thanks to its low center of gravity, the cargo bike remains stable even at high speeds, which simplifies handling while increasing driving safety.
»Emission-free courier trips through the narrow streets of an old town, environmentally friendly removal of green cuttings in the city park or space-saving delivery of refrigerated groceries to the marketplace - all this could soon be possible with the new electric cargo bike,« says Dr. Michael Buchholz, research group leader at the Institute of Measurement, Control and Microtechnology at Ulm University. The engineer is coordinator of the »Zero-Emission Cargo Bike for Smart Cities« (ZEC-Bike) project, which was brought to a successful conclusion with the presentation of the demonstration vehicle.
What makes this electric cargo scooter unique in the world is the specially developed fast-charging system and the recuperative battery: a high-quality battery system with an active heating and cooling system makes it possible to charge the battery up to 80 percent within 30 minutes at a conventional public AC charging station. This saves a lot of time.
Another special feature is the so-called onboard fast charger (OBL). This makes it possible to provide power for consumers not only when the vehicle is stationary, but also while driving via a shockproof socket. This can be used, for example, to charge power tool batteries for work equipment or even to operate refrigeration units to keep perishable goods fresh.
The electric bike is also equipped with all-wheel drive. This not only increases driving safety, but also boosts energy efficiency. The special feature is that an electric motor is also installed at the front wheel, where most of the braking energy is generated, which recovers most of the braking energy by means of recuperation - i.e. in generator mode.
This means that the battery has to cope with high charging currents during braking and discharging processes for the drive in rapid alternation; this can only be achieved by active temperature control. The all-wheel drive also makes it possible to distribute drive and braking torque to the front and rear wheels in line with the driving situation, which in turn increases driving stability and safety.
Haptic feedback on the handlebars provides additional driving safety. The sensors installed on the handlebars record the steering angle and steering torque. In addition, sensors determine the forces acting on the cargo wheel via the load and the driver. Estimated values for roll angle, load weight and moment of inertia are then derived from the sensor data.
With the information on the driving condition, an intelligent algorithm can detect critical situations and convert them into haptic signals. This helps drivers recognize problematic driving situations and avoid dangerous steering maneuvers that could cause the vehicle to tip over.
To accelerate market introduction, the researchers looked for suitable business models and investigated them for the electric cargo bike. The loading area of the e-cargo bike, which is designed for a payload of up to 100 kg, was adapted to the format of Euro containers (footprint 60 cm by 40 cm).
The ZEC Bike project team sees great potential for use in the courier, express and parcel industry: from commercial delivery services to private load transport and municipal use. Different financing models were also worked through for the various target groups.
With the help of the two vehicle demonstrators that have now been completed, the development concepts can now be tested and evaluated under realistic conditions. The next step will be to develop and commercialize the prototype. Interested companies can now use the technology developed for the e-cargo bike.