Method for detecting contact with a manually activated steering device, in particular a vehicle steering wheel, and a device for carrying out the method

Abstract

A method for detecting contact with a manually activated steering or control device, in particular a vehicle steering wheel, comprises the following steps: applying an alternating voltage to at least one conductor arrangement (10) which is arranged on the steering or control device, and has at least one conductor line with a significant ohmic resistance; determining the current profile in the conductor arrangement (10); determining the real component and the virtual component of the instantaneous alternating current resistance of the conductor arrangement (10); determining the capacitance or the change in capacitance of the conductor arrangement (10); determining the phase shift; and evaluating the determined values. A device for carrying out the method comprises a steering or control device, in particular a vehicle steering wheel, a conductor arrangement (10) which is arranged on the steering or control device and which has at least one conductor line with a significant ohmic resistance, and a control and evaluation device which is configured to apply an alternating voltage to the conductor arrangement (10), to measure the current profile in the conductor arrangement (10) and to evaluate the determined values.

1 . A device for detecting contact with a manually activated steering wheel of a vehicle, the device comprising:
 the steering wheel;   a conductor arrangement ( 10 ) which is arranged on the steering wheel, the conductor arrangement ( 10 ) having two substantially parallel electrical conductor lines ( 12 ,  14 ) extending on the steering wheel, a first one of the two parallel electrical conductor lines ( 12 ,  14 ) having a significant ohmic resistance that is significantly higher compared to a copper wire and within a range of 10 Ω/m to 1 Ω/m, a second one of the two parallel electrical conductor lines ( 12 ,  14 ) having an ohmic resistance that is equal to or lower than that of a copper wire, the two electrical conductor lines ( 12 ,  14 ) forming a capacitance with respect to one another that changes when the steering wheel is contacted; and   a control unit which is configured
 to apply an alternating voltage to the conductor arrangement ( 10 ), 
 to determine the capacitance or the change in the capacitance; 
 to determine a current in the conductor arrangement ( 10 ), and 
 to evaluate the determined values. 
   
     
     
         2 . The device according to  claim 1 , wherein the electrical conductor lines ( 12 ,  14 ) are each insulated. 
     
     
         3 . A method for detecting contact with a manually activated steering wheel of a vehicle, the method comprising:
 providing the device according to  claim 1 ;   applying an alternating voltage to the conductor arrangement ( 10 );   determining a current in the conductor arrangement ( 10 );   determining a real component and an imaginary component of a resistance of the conductor arrangement ( 10 );   determining a capacitance or a change in capacitance of the conductor arrangement ( 10 );   determining a phase shift; and   evaluating the determined values.