SmartFrame+ – Security for lightweight vehicles

The Bicycle as a Demonstration Object

The partners chose the bicycle for the leisure sector. It is a familiar object and allows for an easy evaluation of new concepts. The approach: the system should not just react to a crash, but prevent it. To do this, it signals impending limit loads in good time.

The concept is based on a very lightweight frame made of fiber-reinforced composite material. Piezo sensors detect loads that could lead to fractures. Actuators in the handlebar grips transmit vibration signals to the hands, thereby influencing the driving style in a safety-relevant manner. Simultaneously, the grip actuators can send navigation signals. In the event of theft, piezo actuators in the frame cause the system to vibrate, and a warning tone alerts the surroundings.

Setup of the Demonstrator

The demonstrator includes:

• a sensor-equipped lightweight frame,

• handlebars with active elements,

• a screen, and

• a shaker instead of a saddle.

Movement is simulated via a video animation and the load data of a selected route (e.g., Rennsteig). The video image and shaker profile are temporally coupled. If the system detects a danger based on sensor values, speed, or geodata, the piezo oscillators built into the grips provide a warning.

The grips are made of elastic plastic formed using the injection molding process. Their design ensures that vibrations are clearly felt on the palms. If the cyclist leaves the safe range, an additional alarm sounds. Different vibration patterns signal different prompts: turning, adjusting speed, or hazardous situations. Test subjects trialed six different pulse sequences and rated their clarity.

The demonstrator is available at trade fairs, workshops, and exhibitions. Visitors can experience a virtual downhill ride and test the system’s effects for themselves. The concept can also be transferred to other means of transport, such as walkers or wheelchairs.

Elite Sports: The Roller Ski as a Second Example

For elite sports, the choice fell on the roller ski, a summer variant of the cross-country ski. Until now, roller skis have mostly consisted of simple aluminum profiles. These are stiff, offer little design freedom, and make it difficult to integrate sensors.

A new roller ski structure was created in the “SmartFrame+” project. Glass and carbon fiber rovings were combined in such a way that they can absorb all forces despite minimal mass. At the same time, the structure provides a springing effect.

An integrated piezo sensor, manufactured using the pultrusion process, measures loads during training. In the future, the data will be transmitted wirelessly to an app. This will enable the analysis of push-off force, position, or length. Athletes receive direct feedback, can identify errors, and improve their technique. Furthermore, complete training profiles can be recorded and evaluated later.

A prototype currently exists. In the next step, the measurement and analysis technology will be further developed and supplemented by intelligent braking technology.