Occupant Load Criterion (OLC)

The calculation follows the method specified in the Euro NCAP Technical Bulletin (TB027) v1.1.1, which is intended for use with the Adult Occupant Protection Assessment Protocol v9.1.1. According to the TB 027, the Measured X-Acceleration of the Barrier COG of MPDB must be filtered using CFC 180. 

Firstly, the acceleration curve is filtered using the trapezoidal rule to derive the velocity course of the barrier and \(V_0\) which is the initial velocity is added to the integrated curve. 

The end time \(t_1\) is the end of free flight phase of the virtual dummy of the barrier along a displacement of 0.065 m. This is calculated by using the equation: 

Here, the displacement of the virtual occupant in its free flight phase is \(V_0t\) and the displacement of the Barrier model is calculated by integrating the velocity curve. The difference of the two displacements should be equal to 0.065 m. 

The end time \(t_2\), corresponds to the ideal restraint phase, which is determined by solving the equation:

The area under the velocity curve of the barrier is calculated by subtracting the displacement \(u_t\) of the barrier model at point \(t\) from the displacement \(u_{t1}\) at point \(t_1\):

Area of Velocity Curve (\(t_1\) to \(t\)) = \(u_{t1} - u_t\)

The area under the virtual occupant curve is calculated by determining the area of the trapezoid from point \(t_1\) to \(t\):

Area of Velocity of Virtual Occupant (\(t_1\) to \(t\)) = \(0.5*(V_{t1} + V_t)*(t − t_1)\)

The difference between these two areas should be 0.0235 m, which allows us to calculate the \(t_2\) value.

The OLC Value is finally calculated by using the following equation: