Automotive - Guttersberg

Customized Sensofoil PET-PET

Hoffmann + Krippner developed in cooperation with Guttersberg Consulting and Freescale Halbleiter Deutschland GmbH a hand recognition system for a variety of vehicle applications.

In this case hand detection (hands ON / OFF detection) refers to the detection whether or not the driver is holding the steering wheel.
To overcome the disadvantages of capacitive systems there has been developed a resistive hand recognition system on the steering wheel. The EP 2611642 A2 patented detection consists out films which are separated by a spacer. During contact the sensor, the layers connect and convert into a usable switching signal. These films are located under the leather jacket, covering about 65% of the steering wheel rim.

The electronic evaluation system which is also a part of steering wheel and the associated software were developed by Freescale Halbleiter Deutschland GmbH based on the MagniV microcontroller family. To compensate for the tolerances, the electronics in the end-of-line tester sets the specific level of the respective steering wheel to zero.  Tolerances caused by temperature differences, for example, are compensated by evaluating resistance values along several areas of the steering wheel. 

Features

  • Adaptable to specific wheel profiles (vehicles, aircrafts, ships as well as medical equipment) is possible
  • Materials suitable for automotive
  • Durable and sealed

Technical details

  • two films on top of each other separated by printed spacers
  • developed resistor paste which is printed during screen printing on the basic membrane
  • electrical tap between the layers where contact is made
  • signal is evaluated - intelligent software triggers appropriate responses