Vehicle occupant detection using relative impedance measurements
First Claim
1. A vehicle occupant detection method for sensing in an occupant seating area, the method comprising:
- (a) connecting a first electrode to a lower impedance;
(b) measuring a first signal at a second electrode while the first electrode is connected to the lower impedance, the second electrode or a third electrode transmitting during the measurement;
(c) connecting the first electrode to a higher impedance;
(d) measuring a second signal at the second electrode while the first electrode is connected to the higher impedance, the second electrode or the third electrode transmitting during the measurement; and
(e) determining a load state in a vehicle seat as a function of the first and second signals.
2 Assignments
0 Petitions
Accused Products
Abstract
A passenger detection system is provided. A sensor measures capacitance, electric field effects or other characteristic responsive to a load in a seating area. The sensor uses one or more electrodes (e.g., a transmit and receive electrode or one electrode for transmit and one or more electrodes for receive). Other electrodes are connected with different impedances. Measuring by a sensor, but with other electrodes connected with different impedances, may distinguish between an occupant and inanimate objects, may distinguish between characteristics of a passenger (e.g., size, height, weight or position), or may indicate a grounding state of an occupant.
51 Citations
32 Claims
-
1. A vehicle occupant detection method for sensing in an occupant seating area, the method comprising:
-
(a) connecting a first electrode to a lower impedance; (b) measuring a first signal at a second electrode while the first electrode is connected to the lower impedance, the second electrode or a third electrode transmitting during the measurement; (c) connecting the first electrode to a higher impedance; (d) measuring a second signal at the second electrode while the first electrode is connected to the higher impedance, the second electrode or the third electrode transmitting during the measurement; and (e) determining a load state in a vehicle seat as a function of the first and second signals. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
-
-
16. A vehicle occupant detection system for sensing a load state in an occupant seating area, the system comprising:
-
first and second electrodes; a switch operable to connect the first electrode to lower and higher impedance nodes; and a sensor comprising at least the second electrode and a measurement circuit, the measurement circuit operable to measure first and second signals when the first electrode is connected to the lower and higher impedance nodes, respectively, the first electrode unused for transmission or reception by the measurement circuit during measurement of the first and second signals. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
-
-
29. A vehicle passenger detection system for detecting a load state in a passenger seating area, the system comprising:
-
first and second electrodes; a signal source is operable to connect with the second electrode or a third electrode; a switch operable to connect the first electrode to a low impedance node and a high impedance node; a measurement circuit operable to measure first and second signals when the first electrode is connected to the low impedance node and when the first electrode is connected to the high impedance node, respectively, the signal source connected with the second or third electrode for measurement of the first and second signals, and the measurement circuit connected with the second or third electrode for measurement of the first and second signals; and a processor operable to determine the load state as a function of the first and second signals. - View Dependent Claims (30, 31)
-
-
32. A vehicle occupant detection method for sensing a load state in an occupant seating area, the method comprising:
-
transmitting and receiving during the transmitting with one or more electrodes; measuring first and second signals from at least one of the one or more electrodes during the transmitting and receiving; sequentially connecting a first electrode different from the one or more electrodes to lower and higher impedances during the transmitting and receiving, the first signals measured during connection of the first electrode to the lower impedance and the second signals measured during connection of the first electrode to the higher impedance; and determining the load state as a function of the first and second signals.
-
Specification