Capacitance-based sensor and occupant sensing system
A capacitive sensor, current sensing technology, applied in radio wave measurement systems, pedestrian/occupant safety arrangements, instruments, etc., can solve problems such as inability to effectively sense occupants
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
Method used
Image
Examples
no. 1 example
[0052] FIG. 1 is a schematic diagram showing the overall structure of an occupant sensing system having a capacitive sensor 10 according to a first embodiment. FIG. 2 is a schematic diagram showing the front passenger seat 9 showing the installation position of the electrode unit 1 serving as a sensing device of the capacitive sensor 10 .
[0053] As shown in FIG. 1 , the capacitive sensor 10 of the present embodiment includes an occupant sensing electrode 20, an empty seat capacitance reducing electrode 21, a current sensing device (current sensing circuit) 31, and a driving device (driving circuit) 32 . The occupant sensing electrode 20 is embedded in at least one of the seat bottom 12 and the seat back 17 of the front passenger seat 9 serving as the vehicle seat of the present invention. In this particular embodiment, occupant sensing electrodes 20 are embedded in the seat bottom 12 as shown in FIG. 1 . Empty seat capacitance reducing electrode 21 is opposed to occupant s...
no. 2 example
[0067] As shown in FIG. 5, the second embodiment is characterized in that the driving device 32 is electrically connected at the illustrated position (the first position of the present invention) between the occupant sensing electrode 20 and the empty seat capacitance reducing electrode 21, And the current sensing device 31 is electrically connected at the illustrated position (the second position of the present invention) between the empty seat capacitance reducing electrode 21 and the driving device 32 .
[0068]The operation of each part of the capacitive sensor 10 when measuring capacitance will be described with reference to FIG. 5 . When the driving device 32 electrically connected between the occupant sensing electrode 20 and the empty seat capacitance reducing electrode 21 generates a high-frequency low-voltage driving output, the occupant sensing electrode 20 is driven to have a high potential. Thus, a capacitance Cb is generated between the occupant sensing electrode...
no. 3 example
[0071] The third embodiment is characterized by modifying the structure of the first or second embodiment as described below. That is, as shown in FIG. 6 , the current sensing device 31 has an operational amplifier 31 a for maintaining the same potential and electrical isolation between the corresponding two electrodes with which the current sensing device 31 is interposed. between the electrodes. In this way, in the structure (first embodiment) in which the current sensing device 31 is connected between the occupant sensing electrode 20 and the empty seat capacitance reducing electrode 21, these electrodes 20, 21 can be made to be controlled by the operational amplifier 31a at the electrode 20. , 21 effectively provide the same potential and electrical isolation between the state. In this state, use a voltmeter to measure the voltage drop V generated by the resistor R. According to the relationship V=i·R, the current i flowing through the human body (measurement object) can...
PUM
Login to View More Abstract
Description
Claims
Application Information
Login to View More