May The Force Be With You
G-Force that is!
G-force (as in gravitational) is not really a force; it is a felt weight based on acceleration or deceleration. Acceleration is the increase in rate of velocity/speed; deceleration is the decrease of rate of velocity/speed. The measurement involves location, speed, and time.
Here are some real-world examples:
• Decent rollercoasters reach between 3-6 g
• Top fuel dragsters reach and average of 4 g
• Formula One cars during extreme braking maneuvers reach 5 g
• A high-performance sports car jamming 0-60 in 2.5 seconds, only reaches 1.5 g
• DOT defines harsh (not dangerous) braking as .45 g incidents (your average NYC cab driver)
• >25 g means probable death or serious injury
In terms of crash detection, there are just too many variables to consider to be able to define an accurate and consistent threshold for a crash. For example, what did you hit, how fast were you going, what was the weight of the vehicle, how long did it take to stop? Whatever threshold you set, keep in mind that it doesn’t guarantee that an accident has definitively occurred.
The default for accel/decel alerts is .50g. The default g-force thresholds for Fleet Connect Plug N-Play devices configured for in-vehicle BUZZER alerts are: • Rapid acceleration (.30g) • Harsh braking (.45g) • Hard right and left turning events (.35g)
Aside from crashes, continued and/or prolonged g-forces do more damage than isolated, harsh incidents. Consider relying on summarization or trend Gunner/Braker data as a more effective way to monitor harsh acceleration and deceleration behavior.