Engineers transfer all-wheel drive to e-bike

August 23, 2013 // By Christoph Hammerschmidt
All-wheel drive is something for off-road vehicles and SUVs, right? A team of developers and researchers of the Ulm University believes that also two-wheel vehicles could benefit from all-wheel drive. An additional electric drive on the front wheel could make them more agile and safe. Now they are developing a prototype.

The challenge for the developers is that the all-wheel driven e-bike need to be as simple to use as a conventional one - and it must not be any more expensive. The task for the engineers is how to operate an e-bike in all driving situations safely, if both wheels are equipped with a separate motor? Both motors are controlled through a functionally integrated overall control unit. Besides the Ulm University, companies ID-Bike, IPDD and Gigatronik are participating in the project.

The concept provides sensors distributed across the vehicle that continuously determine the driving dynamics and transmit these data to a control unit. A software calculates probable driver action and sends the appropriate instructions and control commands to the two electric motors that operate independently or, if necessary to a conventional friction brake. To achieve a safe driving behaviour in curves, it is essential to implement a situation-dependent distribution of torque and brake effect. The designers believe that such a vehicle will offer superior driving behaviour in particular under slippery road conditions.

The designers plan to utilize known methods of sensor data processing, model-based estimation and control as well as complex process control methodologies and transfer these techniques to electric bikes. In addition, a good energy efficiency is also a design goal. The project partners support the design process with their own capabilities: Gigatronik Technologies provides design services and know-how in the areas of power electronics and battery management; IPDD contributes, among others, an electrically operated friction brake, and ID-Bike will build the prototype.

The project is designed for three years. After this time, the partners plan to jointly decide if there is a market for sophisticated two-wheel vehicles.