Continuous Estimation of CG Location (CECL)

Depiction of a vehicle's center of gravity

Using vehicle center-of-gravity location to enhance performance and reduce risk.


Vehicles in the field face the risk of rolling over every day they are deployed. In trying to reduce this risk, a vehicle's center of gravity (CG) is a critical parameter in determining its likelihood to rollover—simply stated, vehicles with a higher CG are more prone to rolling over.  But as a vehicle travels through rough terrain, its CG constantly moves, often to higher, riskier positions. Having a way to dynamically and accurately estimate the location of a vehicle's CG as it operates would prove invaluable to reducing its risk of rollover.

Continuous Estimation

Archangel is investigating a modal-based approach called Continuous Estimation of Center of Gravity Location (CECL) for dynamically estimating the location of a vehicle's CG without increasing the size, weight, or power requirements of the basic rollover prediction system. With the location of the vehicle CG more accurately known, probability of rollover can be more accurately predicted. This CECL algorithm would:

  • Perform a realtime Fast Fourier Transform (FFT) on the linear acceleration and angular rate measurements from the on-board Inertial Measurement Unit (IMU)
  • Continuously monitor the results of the FFT for changes that are indicative of the CG's location such as frequency, amplitude, and phase
  • Update the CG location in the rollover sensor prediction algorithm


The primary advantages of this CECL method include:

  • The onboard rollover prediction system is automatically calibrated for various vehicle types in any loading configuration without the need for additional vehicular sensors
  • Vehicle CG location is continuously monitored and updated
  • No predefined driving maneuvers (such as driving in a circle at a specifified rate) to determine the location of the vehicle CG are necessary

More information

For further information about CECL and its related developments, contact Bill Dillard at This email address is being protected from spambots. You need JavaScript enabled to view it..