Method for discriminating long-period, low-velocity crashes

A method of discriminating low-velocity, long-period vehicle crashes in which actuation of a vehicle passenger restraint device is desired from low-velocity vehicle crashes in which actuation of said vehicle passenger restraint device is not desired, said method comprising the steps of:

• receiving vehicle acceleration information from at least one acceleration sensor;
• determining a value indicative of vehicle velocity based on said received vehicle acceleration information;
• comparing said value indicative of vehicle velocity to a first predetermined threshold value;
• determining a value indicative of increasing or decreasing vehicle acceleration based on said received acceleration information with respect to time if said value indicative of vehicle velocity exceeds said first predetermined threshold value;
• comparing said value indicative of increasing or decreasing vehicle acceleration to a second predetermined threshold value, said second predetermined threshold value being a positive value;
• and
• actuating said vehicle passenger restraint device if said value indicative of increasing or decreasing vehicle acceleration exceeds said second predetermined threshold value, wherein said first predetermined threshold value is equal to approximately half the velocity of a maximum allowable low-velocity vehicle crash in which actuation of said vehicle passenger restraint device is not desired.

A vehicle crash discrimination system for controlling actuation of a vehicle passenger restraint device comprising:

• means for receiving vehicle acceleration information from an acceleration sensor;
• means for determining a value indicative of vehicle velocity based on said received vehicle acceleration information;
• first comparing means for comparing said value indicative of vehicle velocity to a first predetermined threshold value;
• means connected to said receiving means for determining a value indicative of increasing or decreasing vehicle acceleration based on said received acceleration information with respect to time if said value indicative of vehicle velocity exceeds said first predetermined threshold value;
• second comparing means for comparing said value indicative of increasing or decreasing vehicle acceleration to a second predetermined threshold value, said second predetermined threshold value being a positive value;
• and
• means connected to said second comparing means for actuating said vehicle passenger restraint device if said value indicative of increasing or decreasing vehicle acceleration exceeds said second predetermined threshold value, wherein said first predetermined threshold value is equal to approximately half the velocity of a maximum allowable vehicle crash in which actuation of said vehicle passenger restraint device is not desired.