Student said:
Not to be at all negative, but he appears to be using averages as opposed to following the actual cycle. I have several thousand cells of data (source and derived). I think around 25k cells of data for the UDDS and HWFET cycles. I used the actual cycles as opposed to approximation.
:roll: The proper way to analyze EPA cycles is to sum the partials and average. I don't take v<ave>**2 to get the velocity squared, I take sum(v[n]**2)/samples. In effect, I'm assuming a discrete sample to calculate energy used: E<total> = sum(P<instant> <for all> samples) / <sample rate>. The power function I gave is assumed to be P<instant> and you need to take each sample velocity, its square, the instantaneous acceleration (?v * <sample rate>; 1 Hz for LA4, 10 Hz for HWFET), and apply the constants to get the interim result. I'll be happy to show my EPA charts to anyone who cares to see them, though they're rather messy but believe me there is a bundle of data I'm not showing to keep from boring you on the specifics of the LA4 cycle.
Effectively, what I'm doing is taking the sums of all the equations components (sum a, sum v, sum v**2, sum 1/v) and then dividing by the number of samples to get the average power used in a second; I then apply the same calculation to the cruise speeds and end up with a series of unknowns which I solve for for each test run using linear algebra.
Student said:
I will not comment further on TimeHorse's approach unless he brings it up in this thread.
he said from behind a locked door. :roll: So, does anyone else get redirected to the home page of TheEEStory when they click on the register link: http://www.theeestory.com/register