The prototype developed by students at Saarland University's Chair of Drive Technology puts an end to strenuous handcart pulling. The handcart thinks for itself: Using a sensor, the handle of the handcart recognizes how hard it is being pulled and at what angle it is positioned in relation to the cart. It passes the information on to a microcontroller on the underside of the trolley - the "brain" of the handcart. This is also where the measurement data from the electric drives of the wheels come together. If the wheels turn, the system knows what position they are in or what force the drive is using. Sensors are not required for this; the system only needs the data that is generated in the intelligent motors. "All wheels can be controlled individually," explains student Sergej Fabich. This is done automatically via the microcontroller. The handcart recognizes whether the electric motors should switch on and, if so, at what power.

The wheels with the hub motors come from the project's partner company: Wellgo Gerätetechnik from Nohfelden. Drive engineer Matthias Nienhaus is the head of the chair. He specializes in intelligent motors that provide measurement data without any additional sensors. "We turn the motor itself into a sensor, a particularly cost-effective and efficient process," explains Professor Nienhaus. Together with partners, the chair is conducting research in several projects into how data can be obtained from the motor in order to control the drive in a targeted and efficient manner. The aim is also to monitor whether the motor is working properly without malfunctions or wear. For example, the researchers are reading how the electromagnetic field is distributed at certain points inside the motor and how this field changes during operation. This allows conclusions to be drawn about the exact position of the motor, malfunctions or signs of wear, for example.

Wellgo actually developed the wheels for a two-wheeled golf caddy. The students had to extend the system to four wheels in terms of design and information technology. "We had to penetrate the programmed code of the wheels and change it so that it works with four wheels," explains Fabich.

The "intelligent" handcart can be seen from April 25 to 29 at the Hannover Messe 2016 at the Saarland research stand (Hall 2, Stand B 46).