engine.control.robust_ddp.reference Namespace Reference

Classes
class	Reference

Functions
Reference	build_reference (NavState nav, Measurement meas, Command cmd, ControllerConfig cfg, int horizon_N, Optional[EngineWrapper] engine_wrapper=None, Optional[float] F_ref_prev=None, Optional[float] dt=None)
np.ndarray	_compute_thrust_command (Command cmd, int horizon_N, float dt)
np.ndarray	_compute_altitude_command (NavState nav, float altitude_goal, int horizon_N, float dt, ControllerConfig cfg)
Tuple[float, float]	_estimate_thrust_bounds (np.ndarray state, Measurement meas, ControllerConfig cfg, Optional[EngineWrapper] engine_wrapper, Optional[EngineEstimate] eng_est_current)
float	_project_thrust (float F_des, float F_min, float F_max, float F_prev, float dt, ControllerConfig cfg)
np.ndarray	_measurement_to_state (Measurement meas)

Variables
float	GRAVITY = 9.81

Detailed Description

Reference generation for robust DDP controller.

Supports two modes:
- A) Thrust command: user provides F_des(t) or piecewise schedule
- B) Altitude command: compute desired thrust from PD guidance

Computes feasible reference projection with bounds and slew rate limiting.

Function Documentation

_compute_altitude_command()

np.ndarray engine.control.robust_ddp.reference._compute_altitude_command ( NavState nav, float altitude_goal, int horizon_N, float dt, ControllerConfig cfg )

protected

Compute desired thrust from PD guidance for altitude command.

Uses: a_cmd = kp*(h_goal - h) + kd*(vz_goal - vz)
      F_des = m*(a_cmd + g) / cos(theta)

Parameters:
-----------
nav : NavState
    Current navigation state
altitude_goal : float
    Target altitude [m]
horizon_N : int
    Horizon length
dt : float
    Time step [s]
cfg : ControllerConfig
    Controller configuration (for PD gains if available)

Returns:
--------
F_des : np.ndarray, shape (horizon_N,)
    Desired thrust sequence [N]

Definition at line 223 of file reference.py.

Referenced by build_reference().

_compute_thrust_command()

np.ndarray engine.control.robust_ddp.reference._compute_thrust_command ( Command cmd, int horizon_N, float dt )

protected

Compute thrust command sequence from Command.

Parameters:
-----------
cmd : Command
    Command with thrust_desired
horizon_N : int
    Horizon length
dt : float
    Time step [s]

Returns:
--------
F_des : np.ndarray, shape (horizon_N,)
    Desired thrust sequence [N]

Definition at line 157 of file reference.py.

Referenced by build_reference().

_estimate_thrust_bounds()

Tuple[float, float] engine.control.robust_ddp.reference._estimate_thrust_bounds ( np.ndarray state, Measurement meas, ControllerConfig cfg, Optional[EngineWrapper] engine_wrapper, Optional[EngineEstimate] eng_est_current )

protected

Estimate feasible thrust bounds [F_min, F_max].

Parameters:
-----------
state : np.ndarray
    Current state vector
meas : Measurement
    Current measurements
cfg : ControllerConfig
    Controller configuration
engine_wrapper : EngineWrapper, optional
    Engine wrapper for performance estimation
eng_est_current : EngineEstimate, optional
    Current engine estimate

Returns:
--------
F_min : float
    Minimum feasible thrust [N]
F_max : float
    Maximum feasible thrust [N]

Definition at line 297 of file reference.py.

References max, and min.

Referenced by build_reference().

_measurement_to_state()

np.ndarray engine.control.robust_ddp.reference._measurement_to_state ( Measurement meas )

protected

Convert measurement to state vector (simplified).

Parameters:
-----------
meas : Measurement
    Sensor measurements

Returns:
--------
state : np.ndarray, shape (N_STATE,)
    State vector (partial, for bounds estimation)

Definition at line 425 of file reference.py.

Referenced by build_reference().

_project_thrust()

float engine.control.robust_ddp.reference._project_thrust ( float F_des, float F_min, float F_max, float F_prev, float dt, ControllerConfig cfg )

protected

Project desired thrust to feasible reference with slew rate limiting.

Uses sequential clipping:
1. Clamp to bounds: F = clip(F_des, [F_min, F_max])
2. Limit slew rate: F = clip(F, [F_prev - dF_max*dt, F_prev + dF_max*dt])

Parameters:
-----------
F_des : float
    Desired thrust [N]
F_min : float
    Minimum feasible thrust [N]
F_max : float
    Maximum feasible thrust [N]
F_prev : float
    Previous reference thrust [N]
dt : float
    Time step [s]
cfg : ControllerConfig
    Controller configuration

Returns:
--------
F_ref : float
    Projected reference thrust [N]

Definition at line 374 of file reference.py.

Referenced by build_reference().

build_reference()

Reference engine.control.robust_ddp.reference.build_reference	(	NavState	nav,
		Measurement	meas,
		Command	cmd,
		ControllerConfig	cfg,
		int	horizon_N,
		Optional[EngineWrapper]	engine_wrapper = None,
		Optional[float]	F_ref_prev = None,
		Optional[float]	dt = None )

Build reference trajectory for DDP controller.

Parameters:
-----------
nav : NavState
    Current navigation state (altitude, velocity, tilt, mass)
meas : Measurement
    Current sensor measurements (pressures)
cmd : Command
    Control command (thrust desired or altitude goal)
cfg : ControllerConfig
    Controller configuration
horizon_N : int
    Prediction horizon length
engine_wrapper : EngineWrapper, optional
    Engine wrapper for estimating feasible thrust bounds
F_ref_prev : float, optional
    Previous reference thrust (for slew rate limiting)
dt : float, optional
    Time step [s] (defaults to cfg.dt)

Returns:
--------
ref : Reference
    Reference trajectory with F_ref, MR_ref, bounds, and feasibility

Definition at line 35 of file reference.py.

References _compute_altitude_command(), _compute_thrust_command(), _estimate_thrust_bounds(), _measurement_to_state(), and _project_thrust().

Variable Documentation

GRAVITY

float engine.control.robust_ddp.reference.GRAVITY = 9.81

Definition at line 32 of file reference.py.