METHOD AND DEVICE FOR DETECTING COLLISION OF CAR

摘要

PURPOSE: To accurately protect an occupant at a proper time by providing an accelerometer means generating an output having an RMS value related to deceleration functionally and operating an air bag restraint system in accordance with the results of comparison between the RMS value obtained by converting the output and a set value. CONSTITUTION: In a device 20 controlling the operation of an air bag 22 in an occupant restraint system, a deceleration transducer circuit 24 giving an output signal 26 having a value representing deceleration generated at the time of vehicle crash is provided, and an output signal 30 having an RMS value related to a value of the output signal 26 functionally is generated in an RMS heat converter 28 from the output signal 26. This output signal 30 is monitored in a common mode removal circuit 32 to generate an output signal 34 having an RMS value causing no fluctuation due to a common mode voltage error. The output signal 34 corresponding to a deceleration value is compared with a set value in an ignition circuit 36, and the air bag 22 is operated when the deceleration value is larger than the set value.