Capacitive vehicle seat occupancy detection system with detection of vehicle seat heater member interruption
AssigneeIee International Electronics & Engineering S.A.
InventorsMichael PÜTZ, Oliver LION
Life of this patent
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Abstract
A capacitive detection system for detecting occupancy of a vehicle seat includes a signal generating unit and a signal evaluation unit. The vehicle seat has a seat heater member configured for receiving time-varying output signals of the signal generating unit. The signal evaluation unit is configured to generate an output signal that is indicative of the seat heater member to be defective, if the sensed capacitance of the seat heater member is less than a second predetermined threshold value for the sensed capacitance.
Claims13
A combined seat heater and capacitive seat occupancy detection system for detecting an occupancy of a vehicle seat, wherein the seat heater comprises at least one seat heater member, and the capacitive detection system includes
- a signal generating unit provided for generating a time-varying output signal at an output port, wherein the time-varying output port is configured to be electrically connectable to the at least one seat heater member for providing the time-varying output signal, and
- a signal evaluation unit that is provided for sensing an electrical quantity that is indicative of a capacitance of the at least one seat heater member, and that is provided for generating an output signal that is representative of the sensed capacitance and that is usable as a basis for at least one out of detecting and classifying a seat occupancy by comparison to at least a first predetermined value (Cthresh) for a sensed capacitance,
- wherein the signal evaluation unit is configured to generate an output signal that is indicative of the at least one seat heater member being defective, when the sensed capacitance of the at least one seat heater member is less than a second predetermined threshold value (Cmin) for the sensed capacitance.
A method for detecting a defective seat heater member of a vehicle seat having a capacitive vehicle seat occupancy detection system that is configured for detecting an occupancy of the vehicle seat, the vehicle seat comprising at least one seat heater member, wherein the capacitive vehicle seat occupancy detection system includes a signal generating unit provided for generating a time-varying output signal and a signal evaluation unit that is provided for sensing an electrical quantity that is indicative of a capacitance, the method comprising steps of
- applying a time-varying electrical signal at least to the at least one seat heater member by the signal generating unit,
- sensing an electrical quantity that is indicative of a capacitance of the at least one seat heater member by the signal evaluation unit,
- checking a first condition representing that the sensed capacitance of the at least one seat heater member is less than a second predetermined threshold value (Cmin), and
- generating an output signal that is indicative of the at least one seat heater member when at least the first condition is fulfilled.
Dependencies are inferred from the claim text.