Track Drive Cycle Errors

This example shows how to use the Drive Cycle Source block to identify drive cycle faults when you run the conventional vehicle reference application with the FTP–75 drive cycle.

  1. Open the conventional vehicle reference application project. By default, the application has a FTP–75 drive cycle with error tracking disabled.

    Project files open in a writable location.

  2. Open the Drive Cycle Source block. On the Fault Tracking tab, select these parameters:

    • Enable fault tracking

    • Enable failure tracking

  3. Review the parameters that specify the fault and failure conditions. If the vehicle speed is not within the allowable speed range during the time tolerance, the block sets a fault condition. Accept the default EPA dynamometer driving schedule parameter settings by clicking OK.

    This table provides the settings for the EPA standard and the Worldwide Harmonised Light Vehicle Test Procedure (WLTP) laboratory tests.

    ParameterDescriptionSetting

    EPA Standard1

    WLTP Tests2

    Speed tolerance

    Speed tolerance above the highest point and below the lowest point of the drive cycle speed trace within the time tolerance.

    2.0 mph

    2.0 km/h

    Time tolerance

    Time that the block uses to determine the speed tolerance.

    1.0 s

    1.0 s

    Maximum number of faults

    Maximum number of faults during the drive cycle.

    Not specified10
    Maximum single fault time

    Maximum fault duration.

    2.0 s1.0 s
    Maximum total fault time

    Maximum accumulated time spent under fault condition.

    Not specifiedNot specified

  4. Connect the vehicle longitudinal velocity signal to the Drive Cycle Source block VelFdbk input port.

    1. In the Visualization subsystem, connect the longitudinal velocity signal, <xdot>, to an Outport named xdot_output.

    2. Determine the <xdot> signal units. To display signal units, on the Debug tab, select Information Overlays > Units. The <xdot> signal units are m/s.

    3. Select the <xdot> signal line and Enable Data Logging.

    4. On the top level of the model, connect the Visualization output to the Drive Cycle Source block input.

  5. Connect the Drive Cycle Source block Info output port to a Terminator port. Enable data logging.

  6. Save the model and run the simulation.

  7. To inspect the results, use the Data Inspector. In the Simulink® Toolstrip, on the Simulation tab, under Review Results, click Data Inspector.

    These results indicate that the Drive Cycle Source block did not detect faults or failures during the drive cycle.

    • Fault — Vehicle speed, <xdot>, stayed within the upper and lower bounds of the allowable speed range.

    • Fail — Fault conditions did not exceed the maximum number of faults, maximum single fault time, or maximum total fault time.

  8. In the Drive Cycle Source block, set the Speed tolerance parameter to a tighter tolerance, for example 1 mph. The block calculates new error bounds for the speed.

  9. Rerun the simulation.

  10. To inspect the results, use the Data Inspector. These results indicate that the Drive Cycle Source block did detect failures and faults during the drive cycle.

    • Fault — Vehicle speed, <xdot>, did not stay within the upper and lower bounds of the allowable speed range.

    • Fail — Fault conditions exceeded the maximum number of faults, maximum single fault time, or maximum total fault time.

References

[1] Environmental Protection Agency (EPA). EPA urban dynamometer driving schedule. 40 CFR 86.115-78, July 1, 2001.

[2] European Union Commission. "Speed trace tolerances". European Union Commission Regulation. 32017R1151, Sec 1.2.6.6, June 1, 2017.

See Also

Related Topics