| 摘要 |
<p>An occupant presence detection apparatus (10) detects a change in capacitance between upper and lower conductor plates (38, 40) disposed on or near upper and lower surfaces (30a, 30b) of a fluid-filled elastomeric seat bladder (30), and a semi-rigid mat (32) disposed between the seat cushion (16) and the bladder (30) includes a peripheral cavity (50) at least partially surrounding the upper conductor plate (38). When occupant weight applied to the seat cushion (16) is transmitted to the bladder (30), it distends into the peripheral cavity (50) of the semi-rigid mat (32), producing a significant reduction in the separation between the upper and lower conductor plates (38, 40), and a corresponding significant increase of the capacitance therebetween. Once the bladder (30) has fully distended into the cavity (50), additional loading due to increased occupant weight produces only a minimal further increase of the measured capacitance.</p> |
