摘要 |
A vehicle restraint system (20) that includes an impact sensor (22) for sensing a vehicle impact to provide an electrical impact signal, an occupant restraint (28) such as an air bag to restrain motion of a vehicle occupant, and an electronic control circuit (24) responsive to the impact signal for operating the occupant restraint. The impact sensor includes a permanent magnet (30) axially slidable within a linear cavity and resiliently biased to one end of the cavity, such that vehicle impact forces on the sensor urge the magnet to slide axially toward the opposing end of the cavity against the biasing forces. A magnetic sensor (36) is disposed adjacent to the cavity and is characterized by providing the electrical impact signal as an analog electrical signal that varies in magnitude as a continuous monotonic function of axial position of the magnet within the cavity. The electronic control circuit (24) is responsive to the impact signal for analyzing magnitude, slope and duration of the impact signal in order to predict necessity for activating the restraint system, and activating the restraint system when the magnitude slope and duration of the impact signal meet predetermined signal conditions or criteria. <IMAGE> |