Crash detection system

A method of initiating a safety system in response to a vehicle undergoing a crash comprising:

• receiving a first fire signal from a ball-in-tube type sensor mounted in a crash zone of the vehicle;
• monitoring vehicle acceleration with a second vehicle mounted accelerometer sensor which provides an acceleration over time output signal having a magnitude and a shape, and determining a crash onset time based on vehicle acceleration exceeding a certain threshold of acceleration;
• determining a second fire signal from the second vehicle mounted sensor based upon the magnitude and shape of the acceleration over time output signal, as measured by the second vehicle mounted sensor;
• determining a first time to fire, for the first fire signal, by determining the time between the crash onset time and the first fire signal;
• determining a second time to fire for the second fire signal, by determining the time between the crash onset time and the second fire signal;
• determining a sum of the first time to fire and the second time to fire;
• on condition that the first fire signal and the second fire signal have been generated, and based on the sum of the first time to fire and the second time to fire, initiating at least one safety system.

A method of initiating a safety system in response to a vehicle undergoing a crash comprising:

• receiving a first fire signal from a ball-in-tube type sensor mounted in a door of the vehicle which forms a crash zone of the vehicle;
• monitoring vehicle acceleration with a second vehicle mounted accelerometer sensor of the type for measuring the lateral axial acceleration and providing an acceleration over time output signal having a magnitude and a shape, and determining a crash onset time based on vehicle acceleration exceeding a certain threshold of acceleration;
• determining a second fire signal from the second vehicle mounted sensor based upon the magnitude and shape of the acceleration over time output signal, as measured by the second vehicle mounted sensor;
• determining a first time to fire for the first fire signal, by determining the time between the crash onset time and the first fire signal;
• determining a second time to fire for the second fire signal, by determining the time between the crash onset time and the second fire signal;
• determining a sum of the first time to fire and the second time to fire;
• on condition that the first fire signal and the second fire signal have been generated, and based on the sum of the first time to fire and the second time to fire, initiating at least one safety system.