`pycasx.acas`

Main module to calculate advisories.

Submodules

Package Contents

Classes

`NNet`	Class that represents a fully connected ReLU network from a .nnet file.
`HCASAdvisories`	The advisories of the HCAS model.
`VCASAdvisories`	The advisories of the VCAS model.
`HCASStateVariables`	The state variables of the HCAS model.
`VCASStateVariables`	The state variables of the VCAS model.
`Aircraft`	A generic aircraft class to save important state information.
`Intruder`	An intruder representation relying also on advisory data.
`ACASXProtocol`	Protocol for an ACAS X model.
`AdvisoryDict`	The advisory dictionary.
`SystemInfo`	The information about a CAS system.
`RootInfo`	The information all CAS systems.
`APIHCASStateVariables`	The state variables of the HCAS model.
`APIVCASStateVariables`	The state variables of the VCAS model.
`AutoavoidInfo`	An extended aircraft representation including the current timestamp.
`ExtendedAircraft`	An extended aircraft representation including the current timestamp.
`ExtendedIntruder`	An extended intruder representation relying also on advisory data.

Functions

`check_for_loss_of_separation`(ac_1, ac_2[, h_lim, v_lim])	Checks whether two aircraft will lose separation.
`extend_intruder`(intruder)	Extend the intruder with additional information.

Attributes

`ModelDict`
`Quantity`
`DEFAULT_MODEL_PATH`
`DEFAULT_HCAS_MODEL_PATH`
`DEFAULT_VCAS_MODEL_PATH`
`ureg`
`HCAS_ACTIONS`
`VCAS_ACTIONS`

class pycasx.acas.NNet(filename)

Class that represents a fully connected ReLU network from a .nnet file.

Parameters:: filename (str) – A .nnet file to load

numLayers

Number of weight matrices or bias vectors in neural network

Type:: int

layerSizes

Size of input layer, hidden layers, and output layer

Type:: list of ints

inputSize

Size of input

Type:: int

outputSize

Size of output

Type:: int

mins

Minimum values of inputs

Type:: list of floats

maxes

Maximum values of inputs

Type:: list of floats

means

Means of inputs and mean of outputs

Type:: list of floats

ranges

Ranges of inputs and range of outputs

Type:: list of floats

weights

Weight matrices in network

Type:: list of numpy arrays

biases

Bias vectors in network

Type:: list of numpy arrays

evaluate_network(inputs)

Evaluate network using given inputs.

Parameters:: inputs (numpy array of floats) – Network inputs to be evaluated
Returns:: Network output
Return type:: (numpy array of floats)

evaluate_network_multiple(inputs)

Evaluate network using multiple sets of inputs.

Parameters:: inputs (numpy array of floats) – Array of network inputs to be evaluated.
Returns:: Network outputs for each set of inputs
Return type:: (numpy array of floats)

num_inputs()

Get network input size.

Return type:: int

num_outputs()

Get network output size.

Return type:: int

pycasx.acas.ModelDict: typing_extensions.TypeAlias

pycasx.acas.Quantity: typing_extensions.TypeAlias

pycasx.acas.DEFAULT_MODEL_PATH

pycasx.acas.DEFAULT_HCAS_MODEL_PATH

pycasx.acas.DEFAULT_VCAS_MODEL_PATH

pycasx.acas.ureg

pycasx.acas.check_for_loss_of_separation(ac_1, ac_2, h_lim=500 * ureg.feet, v_lim=100 * ureg.feet)

Checks whether two aircraft will lose separation.

This function determines whether two aircraft will lose separation based on their current positions and speeds. The function assumes that the aircraft are flying in a straight line without changes in speed or direction.

Parameters:

ac_1 (Aircraft) – The first aircraft.
ac_2 (Aircraft) – The second aircraft.
h_lim (Quantity) – The horizontal separation limit.
v_lim (Quantity) – The vertical separation limit.

Returns:

A tuple of two booleans. The first boolean: indicates whether the aircraft will lose horizontal separation, the second boolean indicates whether the aircraft will lose vertical separation (True if possible collision is detected).

Return type:

tuple[bool, bool]

Raises:

ValueError – Raised if the horizontal separation is not a length or the vertical separation is not a length.

class pycasx.acas.HCASAdvisories

Bases: enum.IntEnum

The advisories of the HCAS model.

INOP: inoperative

OFF: off

ACTIVE: active

COC: clear of conflict

WL: weak left

WR: weak right

SL: strong left

SR: strong right

INOP

OFF

ACTIVE

COC = 0

WL = 1

WR = 2

SL = 3

SR = 4

class pycasx.acas.VCASAdvisories

Bases: enum.IntEnum

The advisories of the VCAS model.

INOP: inoperative

OFF: off

ACTIVE: active

COC: clear of conflict

DNC: do not climb

DND: do not descend

DES1500: descend >=1500 ft/min

CL1500: climb >=1500 ft/min

SDES1500: strengthen descend to >=1500 ft/min

SCL1500: strengthen climb to >=1500 ft/min

SDES2500: strengthen descend to >=2500 ft/min

SCL2500: strengthen climb to >=2500 ft/min

INOP

OFF

ACTIVE

COC = 0

DNC = 1

DND = 2

DES1500 = 3

CL1500 = 4

SDES1500 = 5

SCL1500 = 6

SDES2500 = 7

SCL2500 = 8

class pycasx.acas.HCASStateVariables

The state variables of the HCAS model.

rho

range to intruder, measured in feet.

Type:: Quantity

theta

bearing angle to intruder, measured in degrees.

Type:: Quantity

psi

relative heading angle of intruder, measured in degrees.

Type:: Quantity

v_own

ownship speed, measured in feet per second.

Type:: Quantity

v_int

intruder speed, measured in feet per second.

Type:: Quantity

tau

time to loss of vertical separation, measured in seconds.

Type:: Quantity

s_adv

previous advisory.

Type:: HCASAdvisories

rho: Quantity

theta: Quantity

psi: Quantity

v_own: Quantity

v_int: Quantity

tau: Quantity

s_adv: HCASAdvisories

class pycasx.acas.VCASStateVariables

The state variables of the VCAS model.

h

relative intruder altitude, measured in feet.

Type:: Quantity

hdot_own

ownship vertical rate, measured in feet per minute.

Type:: Quantity

hdot_int

intruder vertical rate, measured in feet per minute.

Type:: Quantity

tau

time to loss of horizontal separation, measured in seconds.

Type:: Quantity

s_adv

previous advisory.

Type:: VCASAdvisories

h: Quantity

hdot_own: Quantity

hdot_int: Quantity

tau: Quantity

s_adv: VCASAdvisories

class pycasx.acas.Aircraft

A generic aircraft class to save important state information.

Although this dataclass relies on Pint for unit handling, default units are given in the docstring for each attribute.

call_sign

The call_sign of the aircraft.

Type:: str

altitude

The aircraft’s current altitude, measured in feet.

Type:: Quantity

vertical_speed

The aircraft’s current vertical speed, measured in feet per second.

Type:: Quantity

true_airspeed

The aircraft’s current true airspeed, measured in knots.

Type:: Quantity

heading

The aircraft’s current heading, measured in degrees.

Type:: Quantity

latitude

The aircraft’s current latitude, measured in degrees.

Type:: Quantity

longitude

The aircraft’s current longitude, measured in degrees.

Type:: Quantity

call_sign: str

altitude: Quantity

vertical_speed: Quantity

true_airspeed: Quantity

heading: Quantity

latitude: Quantity

longitude: Quantity

class pycasx.acas.Intruder

An intruder representation relying also on advisory data.

aircraft

The aircraft data.

Type:: Aircraft

hcas_advisory

The HCAS advisory.

Type:: HCASAdvisories

vcas_advisory

The VCAS advisory.

Type:: VCASAdvisories

hcas_state_variables

The HCAS state with respect to the ownship.

Type:: HCASStateVariables

vcas_state_variables

The VCAS state with respect to the ownship.

Type:: VCASStateVariables

property triggers_nmac: bool

Whether the intruder triggers a near mid-air collision for the ownship.

A near mid-air collision (NMAC) is defined as a loss of separation between two aircraft that endangers the safety of the aircraft involved. The boundary for a NMAC is defined as 500 ft horizontally and 100 ft vertically.

Returns:: Whether the intruder triggers a NMAC.
Return type:: bool

aircraft: Aircraft

hcas_advisory: HCASAdvisories

vcas_advisory: VCASAdvisories

hcas_state_variables: HCASStateVariables

vcas_state_variables: VCASStateVariables

class pycasx.acas.ACASXProtocol

Bases: Protocol

Protocol for an ACAS X model.

Provides crucial typing info for the mixin classes.

property model_dict: dict[str, Any]

The dictionary of models.

Return type:: dict[str, Any]

property ownship: Aircraft

The ownship’s state.

Return type:: Aircraft

evaluate(model_name, inputs)

Evaluate a CAS model.

Parameters:

model_name (str) – Name of the model to evaluate from the model dictionary.
inputs (npt.NDArray[np.float32]) – The inputs to the model.

Returns:

The outputs of the model.

Return type:

npt.NDArray[np.float32]

Raises:

NotImplementedError – Raised if the requested backend is not implemented.

pycasx.acas.HCAS_ACTIONS: dict[HCASAdvisories, float | str | None]

pycasx.acas.VCAS_ACTIONS: dict[VCASAdvisories, float | str | None]

class pycasx.acas.AdvisoryDict

Bases: typing_extensions.TypedDict

The advisory dictionary.

value

The advisory value.

Type:: int

name

The advisory name.

Type:: str

value: int

name: str

class pycasx.acas.SystemInfo

Bases: typing_extensions.TypedDict

The information about a CAS system.

advisory

The advisory information.

Type:: AdvisoryDict

connector

The connector name.

Type:: str

timestamp

The timestamp of the information.

Type:: float

advisory: AdvisoryDict

connector: Literal[adsb]

timestamp: float

class pycasx.acas.RootInfo

Bases: typing_extensions.TypedDict

The information all CAS systems.

hcas

The HCAS information.

Type:: SystemInfo

vcas

The VCAS information.

Type:: SystemInfo

timestamp

The timestamp of the information.

Type:: float

hcas: SystemInfo

vcas: SystemInfo

timestamp: float

class pycasx.acas.APIHCASStateVariables

The state variables of the HCAS model.

rho

range to intruder, measured in feet.

Type:: float

theta

bearing angle to intruder, measured in degrees.

Type:: float

psi

relative heading angle of intruder, measured in degrees.

Type:: float

v_own

ownship speed, measured in feet per second.

Type:: float

v_int

intruder speed, measured in feet per second.

Type:: float

tau

time to loss of vertical separation, measured in seconds.

Type:: float

s_adv

previous advisory.

Type:: HCASAdvisories

rho: float

theta: float

psi: float

v_own: float

v_int: float

tau: float

s_adv: HCASAdvisories

class pycasx.acas.APIVCASStateVariables

The state variables of the VCAS model.

h

relative intruder altitude, measured in feet.

Type:: float

hdot_own

ownship vertical rate, measured in feet per minute.

Type:: float

hdot_int

intruder vertical rate, measured in feet per minute.

Type:: float

tau

time to loss of horizontal separation, measured in seconds.

Type:: float

s_adv

previous advisory.

Type:: VCASAdvisories

h: float

hdot_own: float

hdot_int: float

tau: float

s_adv: VCASAdvisories

class pycasx.acas.AutoavoidInfo

An extended aircraft representation including the current timestamp.

active

Whether autoavoid is active.

Type:: bool

mode

The autoavoid mode to use.

Type:: Optional[Literal[“hcas”, “vcas”]]

action

The action to take.

Type:: Optional[float]

command

The command issued to FlightGear.

Type:: Optional[float]

timestamp

The timestamp of the information.

Type:: float

active: bool

mode: Literal[hcas, vcas] | None

action: float | None

command: float | None

timestamp: float

class pycasx.acas.ExtendedAircraft

An extended aircraft representation including the current timestamp.

call_sign

The call_sign of the aircraft.

Type:: str

altitude

The aircraft’s current altitude, measured in feet.

Type:: float

vertical_speed

The aircraft’s current vertical speed, measured in feet per second.

Type:: float

true_airspeed

The aircraft’s current true airspeed, measured in knots.

Type:: float

heading

The aircraft’s current heading, measured in degrees.

Type:: float

latitude

The aircraft’s current latitude, measured in degrees.

Type:: float

longitude

The aircraft’s current longitude, measured in degrees.

Type:: float

timestamp

The timestamp of the information.

Type:: float

call_sign: str

altitude: float

vertical_speed: float

true_airspeed: float

heading: float

latitude: float

longitude: float

timestamp: float

class pycasx.acas.ExtendedIntruder

An extended intruder representation relying also on advisory data.

aircraft

The aircraft data.

Type:: Aircraft

triggers_nmac

Whether the intruder triggers a near mid-air collision for the ownship.

Type:: bool

hcas_advisory

The HCAS advisory.

Type:: HCASAdvisories

vcas_advisory

The VCAS advisory.

Type:: VCASAdvisories

hcas_state_variables

The HCAS state with respect to the ownship.

Type:: HCASStateVariables

vcas_state_variables

The VCAS state with respect to the ownship.

Type:: VCASStateVariables

timestamp

The timestamp of the information.

Type:: float

aircraft: ExtendedAircraft

triggers_nmac: bool

hcas_advisory: HCASAdvisories

vcas_advisory: VCASAdvisories

hcas_state_variables: APIHCASStateVariables

vcas_state_variables: APIVCASStateVariables

timestamp: float

pycasx.acas.extend_intruder(intruder)

Extend the intruder with additional information.

This will make the intruder JSON serializable and add the triggers_nmac attribute.

Parameters:: intruder (Intruder) – The intruder to extend.
Returns:: The extended intruder.
Return type:: ExtendedIntruder

pycasx.acas

Submodules

Package Contents

Classes

Functions

Attributes

`pycasx.acas`