b.  Calculate the effective fuel energy that would be consumed by EM for a time interval, for example 1 second using the following steps:

•  Find fuel energy versus EM torque

•  Find ΔSOC versus EM torque, accounting for gain due to regenerative braking

•  Combine the curves obtained in above steps

•  Determine the equivalent energy by evaluating the curve from step3 at

•  Calculate total energy that would be consumed by the vehicle

Calculate the emissions that would be produced by the ICE.

Normalize the constituent factors for each candidate operating point: The goals of minimizing energy and minimizing emissions can conflict with each other. The most efficient operating point will likely produce more pollution than less efficient operating points. Moreover, minimizing the amount of one pollutant can increase the amount of another. Hence, a second goal of the strategy is to allow prioritization of the relative importance of minimizing the fuel use and each of the pollutants. This prioritization is described in Steps 4 and 5 below .

Apply user weighting K_user to the results from step iii.: The relative importance of each of the normalized metrices is determined by two weighing factors. The first is a user weighing fore energy and the emissions. This is basically a Boolean switch for the user to toggle if he/she chooses to ignore certain emissions.

Apply target performance weighting K_target : The target performance weighing factor is applied to result from step iv. The factor K_target is given by

(1)

Compute overall impact factor , which is a composite of results of step iii to step v for all operating points, that is

(2)

The flow chart of the control strategy is shown in Figure 5 .