Capacitive object recognition using adjustable electrode

A method of capacitive object recognition comprising:

• modeling current pathways formed by interaction of an object and an electric field between a pair of electrodes as a network of capacitors;
• adjusting a parameter of one electrode of the pair of electrodes to a first setting;
• applying a set of alternating current voltages to the pair of electrodes and measuring a resulting first set of current values at the pair of electrodes;
• adjusting the parameter of the one electrode to a second setting;
• applying the set of alternating current voltages to the pair of electrodes and measuring a resulting second set of current values at the pair of electrodes;
• determining values for up to all capacitors of the network of capacitors based on the first and second sets of current values.

A vehicle seat occupant recognition system comprising:

• a first electrode positioned in one of a seat back and seat bottom of a vehicle seat, the first electrode having an adjustable parameter;
• a second electrode positioned in the other of the seat back and seat bottom;
• and
• a controller modeling current pathways formed by interaction of an object and an electric field between the first and second electrodes as a network of capacitors, the controller configured to set the adjustable parameter to a first setting and to apply a set of alternating current voltages to the first and second electrodes and measure a resulting first set of current values at the first and second electrodes, configured to set the adjustable parameter to a second setting and apply the set of alternating current voltages to the first and second electrodes and measure a resulting second set of current values at the first and second electrodes, and configured to determine values for up to all capacitors of the network of capacitors based on the first and second sets of current values.

A method for determining an occupancy status of a vehicle seat, the method including:

• disposing a pair of electrodes spaced from one another in a vehicle seat;
• modeling current pathways formed by interaction of an object with an electric field between the pair of electrodes as a network of capacitors;
• applying a set of alternating current voltages to the pair of electrodes and measuring a resulting first set of current values at the pair of electrodes;
• adjusting a physical parameter of one of the electrodes;
• applying the set of alternating current voltages to the pair of electrodes with the one electrode having the adjusted parameter and measuring a resulting second set of current values at the pair of electrodes;
• determining values of the capacitors of the network of capacitors based on the first and second sets of current values;
• and
• determining an occupancy status of the vehicle seat based on the values of the capacitors.

A vehicle seat occupant recognition system comprising

• a pair of electrodes disposed in a vehicle seat and spaced from one another;
• means for modeling current pathways formed by interaction of an object with an electric field formed between the first and second electrodes as a network of capacitors;
• means for applying a set of alternating current voltages to the pair of electrodes and measuring a resulting first set of current values at the pair of electrodes;
• means for adjusting a parameter of one of the electrodes;
• means for applying the set of alternating current voltages to the pair of electrodes with the one electrode having an adjusted parameter and measuring a resulting second set of current values at the pair of electrodes;
• means for determining values of the capacitors of the network of capacitors based on the first and second sets of current values;
• and
• means for determining an occupancy status of the vehicle seat based on the values of the capacitors.