attitude

Attitude-aware MLP model with rotation-manifold projection for rsl-rl.

Mirrors lav2/runner/skrl/cfg/LAV2_base_att.py but adapted to rsl-rl's MLPModel interface so it can be referenced via class_name in a config dict.

Control modes and their action dimensions::

cmd_ctatt_euler → 4D [thrust, roll, pitch, yaw] cmd_ctatt_rotvec → 4D [thrust, rx, ry, rz] cmd_ctatt_quat → 5D [thrust, qx, qy, qz, qw] cmd_ctatt_rotmat → 10D [thrust, r00..r22]

Projection layers ensure the rotation component of the policy output lies on a valid manifold. The projection is applied between the MLP output and the distribution update for single-slice distributions (Gaussian), or to the first slice for multi-slice distributions (Beta, heteroscedastic Gaussian).

类：

名称	描述
EulerProjection	Bounded projection for euler-angle / rotation-vector actions.
QuatProjection	L2-normalize the 4-D quaternion at indices [1:5].
QuatPlusProjection	Quaternion projection with double-cover elimination.
QuatOffsetProjection	Quaternion projection centred at the identity rotation.
QuatPlusOffsetProjection	Quaternion projection combining offset and double-cover elimination.
RotmatProjection	SVD-orthogonalize the 9-D rotation-matrix at indices [1:10].
RotmatOffsetProjection	Rotation-matrix projection centred at the identity matrix.
AttitudeMLPModel	MLP model with optional rotation-manifold projection.

EulerProjection

Bases: Module

Bounded projection for euler-angle / rotation-vector actions.

Applies tanh to clamp all components to [-1, 1] so that the environment action scaling stays within the expected range.

方法：

名称	描述
forward	Clamp x to [-1, 1] via tanh.

forward

forward(x: Tensor) -> torch.Tensor

Clamp x to [-1, 1] via tanh.

QuatProjection

Bases: Module

L2-normalize the 4-D quaternion at indices [1:5].

Applies tanh to bound all components, then normalizes the quaternion slice to unit length. The thrust channel (index 0) is passed through unchanged.

The double-cover ambiguity (q and -q) is left for the policy to resolve.

方法：

名称	描述
forward	Normalize quaternion slice of x.

forward

forward(x: Tensor) -> torch.Tensor

Normalize quaternion slice of x.

QuatPlusProjection

Bases: Module

Quaternion projection with double-cover elimination.

The scalar component w is mapped through a sigmoid channel (tanh → [0, 1]) so that the output quaternion always satisfies w ≥ 0, breaking the q ≡ -q ambiguity.

方法：

名称	描述
forward	Match the primer quadrotor quat-plus head.

forward

forward(x: Tensor) -> torch.Tensor

Match the primer quadrotor quat-plus head.

QuatOffsetProjection

QuatOffsetProjection()

Bases: Module

Quaternion projection centred at the identity rotation.

Adds the identity quaternion [0, 0, 0, 1] to the policy output, clamps to [-1, 1], then L2-normalizes. A zero policy output therefore commands hover attitude.

Register the identity-quaternion offset buffer.

方法：

名称	描述
forward	Offset x by identity quaternion, then normalize.

forward

forward(x: Tensor) -> torch.Tensor

Offset x by identity quaternion, then normalize.

QuatPlusOffsetProjection

QuatPlusOffsetProjection()

Bases: Module

Quaternion projection combining offset and double-cover elimination.

Offsets the vector part by zero, maps w through a sigmoid channel, then L2-normalizes.

Register the zero-offset buffer for the vector part.

方法：

名称	描述
forward	Offset vector part by zero, force w ≥ 0, then normalize.

forward

forward(x: Tensor) -> torch.Tensor

Offset vector part by zero, force w ≥ 0, then normalize.

RotmatProjection

Bases: Module

SVD-orthogonalize the 9-D rotation-matrix at indices [1:10].

Reshapes the matrix slice to (..., 3, 3), applies tanh to bound elements, then computes the least-squares orthogonal Procrustes projection via SVD. A determinant correction ensures the result lies in SO(3) (det=+1). The thrust channel (index 0) is passed through unchanged.

方法：

名称	描述
forward	SVD-project the matrix slice of x onto SO(3).

forward

forward(x: Tensor) -> torch.Tensor

SVD-project the matrix slice of x onto SO(3).

RotmatOffsetProjection

RotmatOffsetProjection()

Bases: Module

Rotation-matrix projection centred at the identity matrix.

Adds the flattened 3×3 identity to the policy output, clamps to [-1, 1], then SVD-projects onto SO(3). A zero policy output therefore commands hover attitude.

Register the identity-matrix offset buffer.

方法：

名称	描述
forward	Offset x by identity matrix, then SVD-project.

forward

forward(x: Tensor) -> torch.Tensor

Offset x by identity matrix, then SVD-project.

AttitudeMLPModel

AttitudeMLPModel(obs, obs_groups, obs_set, output_dim, hidden_dims=(128, 128), activation='tanh', obs_normalization=False, distribution_cfg=None, projection_type: str | None = None)

Bases: MLPModel

MLP model with optional rotation-manifold projection.

The projection is applied between the MLP output and the distribution update. This enforces rotation components to lie on valid manifolds (e.g. unit quaternion, orthogonal matrix).

参数：

名称	类型	描述	默认
projection_type	str | None	Explicit projection name (one of "euler", "rotvec", "quat", "quat_plus", "quat_offset", "quat_plus_offset", "rotmat", "rotmat_offset"). When None, auto-detected from output_dim.	None

Construct the model and append the projection to the MLP trunk.