Control member with electronic evaluation of the haptic feedback

A test method comprising the following steps:

• providing a control member comprising a carrier, an operating part movably supported on the carrier, an electromagnetic actuator comprising an armature and a coil for driving the operating part movingly relative to the carrier;
• providing an electronic control system connected in an electrically conductive manner to the electromagnetic actuator for applying a measuring voltage to the actuator;
• providing a measuring circuit connected in an electrically conductive manner to the electromagnetic actuator for measuring a current present at the electromagnetic actuator and for generating a measuring signal proportional thereto;
• and
• providing an evaluation unit connected in an electrically conductive manner at least to the measuring circuit;
• applying a measuring voltage to the electromagnetic actuator by means of the electronic control system for a predetermined test period;
• measuring by means of the measuring circuit the current which arises at the electromagnetic actuator as the test period elapses due to the application of the measuring voltage;
• generating a measuring signal proportional to the measured current by means of the measuring circuit;
• evaluation of the measuring signal and assignment, using the evaluation unit, to a value that is characteristic for the electromagnetic actuator, for example relates to an inductance of the actuator, preferably relates to its inductance in its rest position.

A control method, comprising the following steps:

• providing a control member comprising a carrier, an operating part movably supported on the carrier, an electromagnetic actuator comprising an armature and a coil for driving the operating part movingly relative to the carrier;
• providing an electronic control system connected in an electrically conductive manner to the electromagnetic actuator for applying a control voltage and a measuring voltage to the actuator;
• providing a measuring circuit connected in an electrically conductive manner to the electromagnetic actuator for measuring a current present at the electromagnetic actuator and for generating a measuring signal proportional thereto;
• and
• providing an evaluation unit connected in an electrically conductive manner at least to the measuring circuit;
• applying a measuring voltage to the electromagnetic actuator by means of the electronic control system for a predetermined test period;
• measuring by means of the measuring circuit the current which arises at the electromagnetic actuator as the test period elapses due to the application of the measuring voltage;
• generating a measuring signal proportional to the measured current;
• evaluation of the measuring signal and assignment, using the evaluation unit, to a value that is characteristic for the electromagnetic actuator, for example relates to an inductance of the actuator, preferably relates to its inductance in its rest position;
• determining a specific control voltage and/or a specific control period using the characteristic value, for example by a comparison with predetermined values;
• subsequently controlling the electromagnetic actuator with at least one of the specific control voltage and the specific control period by means of the electronic control system.