clarity.utils.car_noise_simulator package

Submodules

clarity.utils.car_noise_simulator.carnoise_parameters_generator module

Class to generate random parameters for the Car noise signal generation

These are 2 separated class to keep the logic separated

class clarity.utils.car_noise_simulator.carnoise_parameters_generator.CarNoiseParametersGenerator(primary_filter_cutoff: float = 0.14, primary_filter_constant_hz: float = 2.86, secondary_filter_cutoff: float = 0.8, secondary_filter_constant_hz: float = 200, random_flag: bool = True, random_seed: int | None = None)

Bases: object

A class to generate noise parameters for a car. The constructor takes a boolean flag to indicate whether some parameters should be randomized or not.

The method gen_parameters takes a speed in kilometers per hour and returns a dictionary of noise parameters.

The global variables GEAR_LOOKUP and RPM_LOOKUP are used to determine the gear and RPM for a given speed.

Example

>>> car_noise_parameters = CarNoiseParameters(random_flag=True)
>>> parameters = car_noise_parameters.gen_parameters(speed_kph=100)
>>> parameters
{
"speed": 70,
"gear": 4,
"rpm": 1890.0,
"primary_filter": {
    "order": 1,
    "btype": "lowpass",
    "cutoff_hz": 12.685320000000003,
},
"secondary_filter": {
    "order": 2,
    "btype": "lowpass",
    "cutoff_hz": 276.22400000000005,
},
"bump": {"order": 1, "btype": "bandpass", "cutoff_hz": [34, 66.64000000000001]},
"dip_low": {"order": 1, "btype": "lowpass", "cutoff_hz": 90},
"dip_high": {"order": 1, "btype": "highpass", "cutoff_hz": 220.12494775682322},

}

GEAR_LOOKUP: Final = {50: [3], 60: [4], 75: [4, 5], 85: [5], 100: [5, 6], 110: [6]}

REFERENCE_CONSTANT_DB: Final = 30

RPM_LOOKUP: Final = {3: 0.6, 4: 0.45, 5: 0.34, 6: 0.28}

gen_parameters(speed_kph: float) → dict

Generate a dictionary of noise parameters for a given speed.

Parameters:

speed_kph (float) – The speed of the car in kilometers per hour between 50 and 120 km/h.

Returns:

parameters – A dictionary of noise parameters.

Return type:

dict

set_new_randomisation_range_freq_multiplier()

Set a new frequency multiplier use in the primary and secondary filters

clarity.utils.car_noise_simulator.carnoise_signal_generator module

Class to generate the car noise signal.

class clarity.utils.car_noise_simulator.carnoise_signal_generator.CarNoiseSignalGenerator(sample_rate: int, duration_secs: float, random_flag: bool = True)

Bases: object

A class to generate car noise signal.

The constructor takes the sample_rate and duration of the generated signals.

The method generate_car_noise takes parameters for the noise and generates the signal. These parameters can be generated by the CarNoiseParameters class.

Example

>>> car_noise_parameters = CarNoiseParameters(random_flag=True)
>>> parameters = car_noise_parameters.gen_parameters(speed_kph=100)

>>> car_noise = CarNoiseGenerator(sample_rate=44100, duration_secs=5,
        random_flag=True)
>>> car_noise_signal = car_noise.generate_car_noise(parameters, 3, 0.5)

FINAl_MULTIPLIER: Final = 0.0005

REFERENCE_CONSTANT_DB: Final = 30

static apply_commonness(target_signal: ndarray, coherence_signal: ndarray, commonness_factor: float) → ndarray

Function to apply correlation between the target signal using the coherence signal.

Parameters:

• target_signal (np.ndarray) – Target signal

• coherence_signal (np.ndarray) – Coherence signal

• commonness_factor (float) – Commonness factor

Returns:

Target signal with the coherence signal

Return type:

target_signal (np.ndarray)

generate_car_noise(noise_parameters: dict, number_noise_sources: int, commonness_factor: float) → ndarray

Method that generates the car noise signal. It organizes the parameters and calls the methods to generate the independent parts.

Parameters:

• noise_parameters (dict) – Dictionary with the parameters for the noise as generated by the CarNoiseParameters class.

• number_noise_sources (int) – Number of noise sources. First source is the engine noise. Following sources are other noise sources.

• commonness_factor (float) – Commonness factor

Returns:

Car noise signal

Return type:

np.ndarray

generate_engine_noise(speed: float, rpm: float, reference_level_db: float, engine_num_harmonics: int, primary_filter: dict[str, ndarray], secondary_filter: dict[str, ndarray]) → ndarray

Method that generates the noise of the engine. :param speed: Speed of the car in km/h :type speed: float :param rpm: RPM of the engine :type rpm: float :param reference_level_db: Reference level in dB :type reference_level_db: float :param engine_num_harmonics: Number of harmonics of the engine :type engine_num_harmonics: int :param primary_filter: Primary filter :type primary_filter: Dict[str, np.ndarray] :param secondary_filter: Secondary filter :type secondary_filter: Dict[str, np.ndarray]

Returns:

Noise of the engine

Return type:

np.ndarray

generate_source_noise(reference_level_db: float, primary_filter: dict[str, ndarray], secondary_filter: dict[str, ndarray], bump_filter: dict[str, ndarray], dip_low_filter: dict[str, ndarray], dip_high_filter: dict[str, ndarray]) → ndarray

Method that generates the noise of a single source.

Parameters:

• reference_level_db (float) – Reference level in dB

• primary_filter (Dict[str, np.ndarray]) – Primary filter

• secondary_filter (Dict[str, np.ndarray]) – Secondary filter

• bump_filter (Dict[str, np.ndarray]) – Bump filter

• dip_low_filter (Dict[str, np.ndarray]) – Low dip filter

• dip_high_filter (Dict[str, np.ndarray]) – High dip filter

Returns:

Noise of a single source

Return type:

np.ndarray

get_bump_params(reference_level_db: float) → tuple[float, float]

Method that gets the parameters of the bump noise :param reference_level_db: Reference level in dB :type reference_level_db: float

Returns:

Standard deviation of the low pass noise bump_gaussian_std (float): Standard deviation of the bump noise

Return type:

lowpass_noise_gaussian_std (float)

get_engine_params(speed: float, rpm: float, reference_level_db: float, engine_num_harmonics: int) → tuple[ndarray, ndarray]

Method that gets the parameters of the engine noise

Parameters:

• speed (float) – Speed of the car in km/h

• rpm (float) – RPM of the engine

• reference_level_db (float) – Reference level in dB

• engine_num_harmonics (int) – Number of harmonics of the engine

Returns:

Frequency of the harmonic complex harmoniccomplex_ntones (int): Number of tones of the harmonic complex harmoniccomplex_power_db (np.ndarray): Power of the harmonic complex

Return type:

harmoniccomplex_freqs_hz (np.ndarray)

Module contents