Method and apparatus for sensing an occupant position using capacitance sensing

An apparatus, for detecting a position of an occupant, in an occupant compartment of a vehicle having an air bag restraining device, said apparatus comprising:

• a variable capacitor having an electrode mounted at the location of said air bag restraining device so that the capacitance value of said variable capacitor varies as a function of distance between a side of an occupant facing said air bag restraining device and said air bag restraining device;
• capacitance sensing circuit means for sensing the capacitance value of said variable capacitor and outputting an electric signal indicative of the distance between the side of the occupant facing said air bag restraining device and said air bag restraining device in response to the sensed capacitance value;
• and
• control means operatively coupled to said capacitance sensing circuit means for generating an electric control signal in response to the distant between the side of the occupant facing said air bag restraining device and said air bag restraining device as sensed by said capacitance sensing circuit means.

An apparatus, for detecting a position of an occupant, in an occupant compartment of a vehicle, said apparatus comprising:

• a variable capacitor mounted at a known reference location within said vehicle, said variable capacitor adapted so as to have a capacitance value that varies as a function of an occupant position relative to the reference location;
• capacitance sensing circuit means for sensing the capacitance value of said capacitor and outputting an electric signal indicative of the sensed capacitance value, the sensed capacitance value being indicative of the occupant's position relative to the reference location;
• occupant position sensing means for sensing and providing an electric signal indicative of the position of the occupant relative to said reference location;
• and
• control means operatively coupled to said capacitance sensing circuit means for verifying said occupant position sensed by the occupant position sensing means with said occupant position indicated by said sensed capacitance value and providing a control signal in response to the verification;
• wherein said variable capacitor includes spaced apart conductive plates that serve as switch contacts of a horn switch.

An apparatus for controlling an actuatable restraint system in response to a sensed occupant seating characteristic, said apparatus comprising:

• a variable capacitor mounted at a known reference location within a vehicle, said variable capacitor having a capacitance value functionally related to an occupant seating characteristic;
• capacitance sensing circuit means for sensing the capacitance value of said capacitor and outputting an electric signal indicative of the sensed capacitance value;
• and
• control means operatively coupled to said capacitance sensing circuit means for controlling an actuatable restraint with a control signal in response to the sensed capacitance value;
• wherein said variable capacitor functions as a horn switch.

A method for detecting an occupant seating characteristic in an occupant compartment of a vehicle relative to an air bag restraining device, said method comprising the steps of:

• applying an oscillating voltage to two spaced apart conductive plates;
• mounting said conductive plates at a known location relative to said air bag restraining device so that a dielectric value between the plates varies as a function of distance between a side of an occupant facing said air bag restraining device and said air bag restraining device;
• sensing the capacitance value of said variable capacitor and outputting an electric signal indicative of the sensed capacitance value, said capacitance value being indicative of the distance between the side of the occupant facing said air bag restraining device and said air bag restraining device;
• and
• providing an electric control signal in response to the sensed capacitance value.

A method for detecting an occupant seating characteristic in an occupant compartment of a vehicle, said method comprising the steps of:

• mounting a first conductive electrode of a variable capacitor at a location relative to an air bag restraining device, said first conductive electrode forming a capacitance sensing electrode of the variable capacitor so that the capacitance value of the variable capacitor varies as a function of distance between a side of a seated occupant facing said air bag restraining device and said air bag restraining device;
• sensing the capacitance value of said variable capacitor and outputting an electric signal indicative of the sensed capacitance value, said sensed capacitance value being indicative of the distance between the side of said seated occupant facing said air bag restraining device and said air bag restraining device;
• and
• providing a control signal in response to the distance between the side of said seated occupant facing said air bag restraining device and said air bag restraining device.

A method for controlling an air bag restraining device in response to a sensed occupant seating position in an occupant compartment of a vehicle relative to said air bag restraining device, said method comprising the steps of:

• mounting a variable capacitor in the vehicle at a known location relative to the air bag restraining device so that its capacitance value is functionally related to distance between a side of a seated occupant facing the air bag restraining device and the air bag restraining device;
• sensing the capacitance value of said capacitor and outputting an electric signal indicative of the sensed capacitance value, said sensed capacitance value being indicative of the distance between the side of the the occupant facing the air bag restraining device and the air bag restraining device;
• and
• controlling the air bag restraining device in response to the distance between the side of the seated occupant facing the air bag restraining device and the air bag restraining device.

An apparatus, for detecting position of an occupant, in an occupant compartment of a vehicle having an air bag restraining device mounted in the vehicle, said apparatus comprising:

• a variable capacitor mounted at a position relative to said air bag restraining device, said variable capacitor having spaced apart conductive plates and a dielectric effectively located between said conductive plates and adapted so that the dielectric value varies as a function of distance between a side of an occupant facing said air bag restraining device and said air bag restraining device;
• capacitance sensing circuit means connected to said variable capacitor for sensing the distance between the side of the occupant facing said air bag restraining device and said air bag restraining device by sensing the capacitance value of said variable capacitor and for outputting an electric signal indicative of the distance between the occupant and said air bag restraining device;
• and
• control means operatively coupled to said capacitance sensing circuit means for generating an electric control signal in response to the electric signal output from said capacitance sensing circuit means.

An apparatus, for detecting position of an occupant, in an occupant compartment of a vehicle having an air bag restraining device mounted in the vehicle, said apparatus comprising:

• a variable capacitor mounted at a known reference location relative to said air bag restraining device, said variable capacitor adapted so as to have a capacitance value that varies as a function of distance between a side of an occupant facing said air bag restraining device and said air bag restraining device;
• capacitance sensing circuit means for sensing the capacitance value of said capacitor and outputting an electric signal indicative of the sensed capacitance value, the sensed capacitance value being indicative of the distance between the side of the occupant facing said air bag restraining device and said air bag restraining device;
• occupant position sensing means for sensing and providing an electric signal indicative of the distance between the side of the occupant facing said air bag restraining device and said air bag restraining device;
• and
• control means operatively coupled to said capacitance sensing circuit means for verifying the distance sensed by the occupant position sensing means with the distance indicated by said sensed capacitance value and providing a control signal in response to the verification.

An apparatus for controlling an air bag restraining device in response to a sensed occupant seating position relative to an air bag restraining device, said apparatus comprising:

• a variable capacitor mounted at a known location relative to an air bag restraining device within a vehicle, said variable capacitor having a capacitance value functionally related to distance between a side of an occupant facing said air bag restraining device and said air bag restraining device;
• capacitance sensing circuit means for sensing the capacitance value of said variable capacitor and outputting an electric signal indicative of the sensed capacitance value;
• and
• control means operatively coupled to said capacitance sensing circuit means for controlling said air bag restraining device in response to the sensed capacitance value.

An apparatus for detecting position of an occupant in an occupant compartment of a vehicle, said apparatus comprising:

• a variable capacitor having a capacitance sensing electrode mounted at a reference location so that the capacitance value of said variable capacitor varies as a function of an occupant location relative to the reference location;
• capacitance sensing circuit means for sensing the capacitance value of said variable capacitor and outputting an electric signal indicative of the occupant's position relative to the reference location in response to the sensed capacitance value;
• and
• control means operatively coupled to said capacitance sensing circuit means for generating an electric control signal in response to the sensed position of the occupant relative to the reference location as sensed by said capacitance sensing circuit means;
• wherein said variable capacitor also serves as a horn switch.