Occupant detection apparatus, occupant detection method and vehicle

摘要

An occupant detection apparatus includes an electrostatic capacitance type sensor having a main electrode, a sub electrode and a guard electrode, an impedance measurement device that outputs an alternating current signal to measure an impedance, and an occupant discrimination device that discriminates an occupant. The guard electrode is provided oppositely to main electrode and not oppositely to the sub electrode. The impedance measurement device outputs an alternating current signal to pass the signal through the main electrode so as to measure a main impedance. Further, the impedance measurement device outputs the alternating current signal to pass the signal through sub electrode so as to measure a sub impedance. The occupant discrimination device discriminates the occupant based on an electrostatic capacitance component of the main impedance and a resistance value component of the sub impedance.

主权项

1. An occupant detection apparatus comprising:
an electrostatic capacitance type sensor including
(i) a main electrode provided in a seating face portion of a seat,(ii) a sub electrode provided away from the main electrode in a planar direction, and(iii) a guard electrode provided between the seating face portion and a seat frame, wherein the guard electrode is provided between the main electrode and the seat frame, opposite to the main electrode and not opposite to the sub electrode; an impedance measurement device that outputs an alternating current signal to the electrostatic capacitance type sensor so as to measure an impedance of the electrostatic capacitance type sensor,
the impedance measurement device outputting the alternating current signal to pass the alternating current signal through the main electrode so as to measure a main impedance,the impedance measurement device outputting the alternating current signal to pass the alternating current signal through the sub electrode so as to measure a sub impedance; an occupant discrimination device that discriminates an occupant based on an electrostatic capacitance component of the main impedance and a resistance value component of the sub impedance measured by the impedance measurement device; a recording medium that stores a previously prepared map having two orthogonal axes respectively indicating the electrostatic capacitance component and the resistance value component so as to discriminate the occupant, the map being previously prepared by measuring electrostatic capacitance components and resistance value components under conditions where an occupant subject is seated under a plurality of combinations of temperature and humidity in environment in which the seat is set, wherein the occupant discrimination device uses the map stored in the storage medium to discriminate the occupant based on the electrostatic capacitance component of the main impedance and the resistance value component of the sub impedance measured by the impedance measurement device.