Gradeability Test module

t3co.objectives.gradeability

PHEV = 365 module-attribute

analysis_vehicle = run_scenario.get_vehicle(PHEV, vehicle_input_path) module-attribute

g6mphachs = [] module-attribute

init_socs = [i for i in np.linspace(v.min_soc, v.max_soc, 10)] module-attribute

scenario_inputs_path = Path(gl.T3CO_INPUTS_DIR / 'phev-testing/TDA_FY22_scenario_assumptions.csv').resolve() module-attribute

soc_used = [] module-attribute

v = analysis_vehicle module-attribute

vehicle_input_path = Path(gl.T3CO_INPUTS_DIR / 'phev-testing/TDA_FY22_vehicle_model_assumptions.csv').resolve() module-attribute

get_gradeability(analysis_vehicle: fastsim.vehicle.Vehicle, scenario: run_scenario.Scenario = None, verbose: bool = False, ess_init_soc: float = None, set_weight_to_max_kg: bool = True) -> Tuple[float, float, fastsim.simdrive.SimDrive, fastsim.simdrive.SimDrive]

This function runs SimDrives to determine the gradeability at given speed and the grade vehicle is evaluated at how much it meets or exceeds target speed at the target grade.

Parameters:

Name	Type	Description	Default
analysis_vehicle	fastsim.vehicle.Vehicle	FASTSim vehicle object for analysis vehicle	required
scenario	run_scenario.Scenario	Scenario object for current selection. Defaults to None.	None
verbose	bool	if True, prints process steps. Defaults to False.	False
ess_init_soc	float	ESS Initial SOC override. Defaults to None.	None
set_weight_to_max_kg	bool	if True, run_scenario.set_test_weight() overrides vehice weight to GVWR. Defaults to True.	True

Returns:

Name	Type	Description
grade_6percent_mph_ach	float	Achieved speed on 6% grade test
grade_1pt25percent_mph_ach	float	Achieved speed on 1.25% grade test
grade_6_simdrive	fastsim.simdrive.SimDrive	FASTSim SimDrive for gradeability test of 6% grade
grade_1p25_simdrive	fastsim.simdrive.SimDrive	FASTSim SimDrive for gradeability test of 1.25% grade

Source code in t3co/objectives/gradeability.py

def get_gradeability(
    analysis_vehicle: fastsim.vehicle.Vehicle,
    scenario: run_scenario.Scenario = None,
    verbose: bool = False,
    ess_init_soc: float = None,
    set_weight_to_max_kg: bool = True,
) -> Tuple[float, float, fastsim.simdrive.SimDrive, fastsim.simdrive.SimDrive]:
    """
    This function runs SimDrives to determine the gradeability at given speed and the grade vehicle is
    evaluated at how much it meets or exceeds target speed at the target grade.

    Args:
        analysis_vehicle (fastsim.vehicle.Vehicle): FASTSim vehicle object for analysis vehicle
        scenario (run_scenario.Scenario, optional): Scenario object for current selection. Defaults to None.
        verbose (bool, optional): if True, prints process steps. Defaults to False.
        ess_init_soc (float, optional): ESS Initial SOC override. Defaults to None.
        set_weight_to_max_kg (bool, optional): if True, run_scenario.set_test_weight() overrides vehice weight to GVWR. Defaults to True.

    Returns:
        grade_6percent_mph_ach (float): Achieved speed on 6% grade test
        grade_1pt25percent_mph_ach (float): Achieved speed on 1.25% grade test
        grade_6_simdrive (fastsim.simdrive.SimDrive): FASTSim SimDrive for gradeability test of 6% grade
        grade_1p25_simdrive (fastsim.simdrive.SimDrive): FASTSim SimDrive for gradeability test of 1.25% grade
    """
    SIX_GRADE = 0.06
    ONE_POINT_TWENTY_FIVE_GRADE = 0.0125
    CYC_SECONDS = 100
    CYC_MPH = 90

    t0 = time.time()

    if scenario is not None and set_weight_to_max_kg:
        kg_before = analysis_vehicle.veh_kg
        run_scenario.set_test_weight(analysis_vehicle, scenario)

    if verbose:
        print(f"f'{Path(__file__).name}:: Vehicle load time: {time.time() - t0:.3f} s")
    # load the cycles

    def get_grade_perf(target_grade: float) -> Tuple[float, fastsim.simdrive.SimDrive]:
        """
        This function obtains the maximum speed achieved on gradeability test for target grade

        Args:
            target_grade (float): Input constant grade for gradeability test

        Returns:
            target_grade_mph_ach (float): Achieved maximum speed mph on gradeability test
            grade_simdrive (fastsim.simdrive.SimDrive): FASTSim SimDrive object for constant grade cycle
        """
        # Test speed achieved at end of 5 minutes at 6% grade (default)
        first_time_step_mph = 0
        if scenario is not None:
            if target_grade == SIX_GRADE:
                first_time_step_mph = scenario.min_speed_at_6pct_grade_in_5min_mph
                if verbose:
                    print(
                        f"f'{Path(__file__).name}:: scenario.min_speed_at_6pct_grade_in_5min_mph: {scenario.min_speed_at_6pct_grade_in_5min_mph}"
                    )
            if target_grade == ONE_POINT_TWENTY_FIVE_GRADE:
                first_time_step_mph = scenario.min_speed_at_1p25pct_grade_in_5min_mph
                if verbose:
                    print(
                        f"f'{Path(__file__).name}:: scenario.min_speed_at_1p25pct_grade_in_5min_mph: {scenario.min_speed_at_1p25pct_grade_in_5min_mph}"
                    )
        if verbose:
            print(
                f"f'{Path(__file__).name}:: first_time_step_mph: {first_time_step_mph}"
            )
        target_grade_cyc_secs = np.arange(CYC_SECONDS)
        cyc_dict = {
            "cycSecs": target_grade_cyc_secs,
            "cycMps": np.append(
                [first_time_step_mph], np.ones(CYC_SECONDS - 1) * CYC_MPH
            )
            / params.MPH_PER_MPS,
            "cycGrade": np.ones(CYC_SECONDS) * target_grade,
        }

        grade_cycle = cycle.Cycle.from_dict(cyc_dict)

        if verbose:
            print(
                f"f'{Path(__file__).name}:: Cycle load time: {time.time() - t0:.3f} s"
            )

        grade_simdrive = run_scenario.get_objective_simdrive(
            analysis_vehicle, grade_cycle
        )

        run_scenario.run_grade_or_accel(
            "grade", analysis_vehicle, grade_simdrive, ess_init_soc
        )

        assert (
            grade_simdrive.trace_miss_dist_frac
            <= grade_simdrive.sim_params.trace_miss_dist_tol
        )

        target_grade_mph_ach = grade_simdrive.mph_ach[-1]
        return target_grade_mph_ach, grade_simdrive

    grade_6percent_mph_ach, grade_6_simdrive = get_grade_perf(SIX_GRADE)
    grade_1pt25percent_mph_ach, grade_1p25_simdrive = get_grade_perf(
        ONE_POINT_TWENTY_FIVE_GRADE
    )
    if scenario is not None and set_weight_to_max_kg:
        run_scenario.reset_vehicle_weight(analysis_vehicle)
        kg_after = analysis_vehicle.veh_kg
        assert (
            kg_after == kg_before
        ), f"total vehicle kg (veh_kg) kg_after must be equal to kg_before: kg_after/kg_before {round(kg_after,4)}/{round(kg_before, 4)}"

    return (
        grade_6percent_mph_ach,
        grade_1pt25percent_mph_ach,
        grade_6_simdrive,
        grade_1p25_simdrive,
    )