ISY
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Project 1

Downloads

  • The drive cycles NEDC_MAN, FTP75, WLTC 5 gears and WLTC 6 gears are needed to solve the task.
  • To be able to run QSS you need to download it. It is necessary to add the path to the directory that contains QSS in Matlab.
  • The model to be used in Extra task 3 is available here. Note that the driving cycles included in the archieve is to be used, since these mat-files include more information than the mat-files of the driving cycles included in QSS.

Clarifications on Project

  • Task 1:
    1. alpha, beta and gamma should be calculated based on the formulation in slide 23 of lecture 2 (also section 2.2.2 in course book)
    2. make sure that the mean values of velocity and acceleration is used
    3. the calculation of traction is by comparison of traction force * mean velocity at that time with 0 (slide 21)
    4. idling time is when mean velocity is 0
    5. It is important to explain why these two configs will lead to extreme cases
  • Task 2:
    1. Use the mean of the alpha, beta and gamma of two extreme cases
  • Task 3:
    1. Methodology can be followed as in section 3.3.2 in the course book (Average point method)
  • Task 4:
    1. Input the values in correct unit
    2. In the combustion engine block: cutoff frequency is -5
  • Task 5:
    1. Calculate the battery capacity using the range in NEDC and Traction force Ft from values mentioned in Table 1.7 in the compendium. After knowing the battery capacity and the Ft from WLTP, calculate the new range
  • Task 6:
    1. Calculation of efficiency will lead to some values more than 1. This is because we neglect recuperation.
  • Task 7:
    1. No iteration process needed for new mass calculation, just go through it once.

Important modification to Extra Task 3

The solver used in the simualtion model given to you is not able to find a solution for all driving cycles. This problem is fixed by changing numerical solver to ode23t in Simulation->configuration parameters and change ode45 to ode23t in the drop down list.

FAQ

  • There is an extra undocumented variable D_z in the data files for the drivecycles in QSS. What does this variable contain?
    -It is undocumented but it contains the time derivative of the speed profile during the interval after each sample. This variable is not used in the QSS block “Driving cycle”, instead the acceleration is calculated directly from the speed profile.
  • The gear ratios in Tables 1.3 and 1.5 differ, why?
    -The values in table 1.5 has a separate final drive gear ratio, while table 1.3 includes the product of the gear ratios.
  • The averaging in Task 2 requires more explanation?
    -In Task 2 it is meant that the average drivecycle coefficients of the two previous calculations are to be used. However it is fine to make a third calculation to get the correct values for the vehicle that is used in the task.

FAQ - QSS

  • How do I get started with QSS?
    QSS with its subdirectories must be added to the path. Look in the README.m file for more information about starting QSS.