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TIR_PROJ/herding/config.py
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Johnny Fernandes 2d23289052 Consensus tracker + active scan close Webots 140° LiDAR gap
Two deploy-time fixes that take v1 360°-trained BC/RL from 0/n to n/n
penned on the canonical 140° LiDAR proto for diff/field:

* SheepTracker now supports a consensus stage: new detections start as
  candidate tracks invisible to get_positions(). A candidate must
  accumulate consensus_k matches within consensus_radius_m of itself
  inside a consensus_max_age window to be promoted; otherwise it
  expires. Real sheep self-confirm within 3 frames (≪0.05 m/step);
  wall-return cluster centroids jitter beyond 0.3 m as the dog moves
  and never promote. consensus_k=1 (default) is a no-op so unconfigured
  callers and HERDING_DEFAULT keep prior behaviour.
* HERDING_WEBOTS preset gets consensus_k=3, radius=0.3, max_age=20,
  plus longer forget_steps=300 and predict_steps=180 so confirmed
  sheep persist through long FOV-occlusion gaps a narrow 140° cone
  produces. max_new_tracks_per_step=1 still rate-caps spawn bursts.
* shepherd_dog.py BC/RL empty-obs fallback now rotates the desired
  heading with step_count so the cone actively sweeps the field
  instead of driving due north into the wall.

Verified in headless Webots (HERDING_USE_GT=0, LiDAR only):
  BC diff/field:        5/5 @ 11698, 10/10 @ 15079
  RL diff/field:        5/5 @ 10039, 9/10 @ 18200 (timeout)
  Strömbom diff/field:  5/5 @ 7528
All previously 0/n. 120 unit tests pass; 9 new consensus tests cover
the candidate stage, promotion radius, and one-shot phantom rejection.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-05-16 20:19:11 +00:00

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"""Central configuration dataclasses for the herding simulation.
Every tunable constant that previously lived as a module-level literal in
perception/lidar_sim.py, perception/lidar_perception.py,
perception/sheep_tracker.py, world/geometry.py, or training/herding_env.py
is now represented here as a field with its original default value.
Usage — use the module defaults unchanged::
env = HerdingEnv() # same behaviour as before
Override a subset of parameters::
from herding.config import HerdingConfig, TrackerConfig
cfg = HerdingConfig(tracker=TrackerConfig(forget_steps=60))
env = HerdingEnv(herding_cfg=cfg)
Use a named preset for Webots-matched training::
from herding.config import HERDING_WEBOTS
env = HerdingEnv(herding_cfg=HERDING_WEBOTS)
Design notes
------------
* All dataclasses are frozen — instances are immutable after construction.
* This module must not import from other ``herding.*`` packages to avoid
import cycles. Field-geometry constants (pen coordinates, field size)
stay in ``herding.world.geometry`` because they depend on the world
variant selected at runtime via ``HERDING_WORLD``.
"""
from __future__ import annotations
import math
from dataclasses import dataclass, field, replace
# ---------------------------------------------------------------------------
# LiDAR hardware spec
# ---------------------------------------------------------------------------
@dataclass(frozen=True)
class LidarConfig:
"""Parameters of the simulated / physical LiDAR sensor.
The two canonical presets are :data:`LIDAR_FULL` (360°, oracle mode)
and :data:`LIDAR_WEBOTS` (140°/180-ray, matches the ShepherdDog proto).
"""
n_rays: int = 360
"""Number of rays in the scan."""
fov_rad: float = 2.0 * math.pi
"""Full field-of-view in radians, centred on the robot's forward axis."""
max_range: float = 12.0
"""Maximum detectable range in metres."""
noise_std: float = 0.005
"""Gaussian standard deviation (metres) applied to each hit reading."""
sheep_radius: float = 0.30
"""Effective disc radius of a sheep in the 2-D LiDAR plane (metres)."""
post_radius: float = 0.25
"""Effective disc radius of gate / corner posts (metres)."""
def __post_init__(self) -> None:
if self.n_rays < 1:
raise ValueError(f"n_rays must be ≥ 1, got {self.n_rays}")
if not (0.0 < self.fov_rad <= 2.0 * math.pi):
raise ValueError(f"fov_rad must be in (0, 2π], got {self.fov_rad:.4f}")
if self.max_range <= 0.0:
raise ValueError(f"max_range must be > 0, got {self.max_range}")
# Named presets -----------------------------------------------------------
LIDAR_FULL = LidarConfig(
n_rays=360,
fov_rad=2.0 * math.pi,
)
"""360° full-circle scan — oracle / ablation mode."""
LIDAR_WEBOTS = LidarConfig(
n_rays=180,
fov_rad=math.radians(140.0),
)
"""Matches the ShepherdDog.proto Lidar device (180 rays, 140° FOV).
Training with this preset closes the sim-to-real gap for the sensor
geometry. Because the observation is built from tracker output (not raw
rays), a policy trained here can be deployed on a wider-FOV LiDAR (e.g.
240° or 360°) without retraining — more FOV means more true detections,
which can only improve tracker quality.
"""
# ---------------------------------------------------------------------------
# Cluster-detection pipeline
# ---------------------------------------------------------------------------
@dataclass(frozen=True)
class DetectionConfig:
"""Parameters for the LiDAR-scan → detection clustering pipeline."""
gap_threshold: float = 0.6
"""Adjacent hit-points farther apart than this (metres) start a new cluster."""
max_cluster_span: float = 1.5
"""Clusters wider than this (metres) are rejected as walls / structures."""
range_hit_eps: float = 0.05
"""A ray is considered a hit if ``range < max_range - range_hit_eps``."""
split_range_gap: float = 0.20
"""Range increase within a cluster that triggers a multi-peak split."""
wall_reject: float = 0.5
"""Drop detections within this distance (metres) of any field wall."""
static_reject: float = 0.8
"""Drop detections within this distance (metres) of known static features
(gate posts, field corners)."""
def __post_init__(self) -> None:
if self.wall_reject < 0.0:
raise ValueError(f"wall_reject must be ≥ 0, got {self.wall_reject}")
if self.static_reject < 0.0:
raise ValueError(f"static_reject must be ≥ 0, got {self.static_reject}")
# ---------------------------------------------------------------------------
# Multi-target tracker
# ---------------------------------------------------------------------------
@dataclass(frozen=True)
class TrackerConfig:
"""Parameters for the nearest-neighbour sheep tracker."""
gate_m: float = 2.5
"""Primary NN association gate in metres (recently observed tracks)."""
reacquire_gate_m: float = 4.5
"""Wider gate used when re-acquiring tracks stale for ≥ ``reacquire_min_age`` steps."""
reacquire_min_age: int = 20
"""Minimum staleness (steps) before the wider re-acquisition gate activates."""
penned_gate_m: float = 4.0
"""Gate for matching new detections to already-penned tracks."""
forget_steps: int = 200
"""Delete an active track that has not been observed for this many steps (~3.2 s)."""
predict_steps: int = 120
"""Extrapolate a track's position using constant velocity for this many steps (~1.9 s)."""
velocity_clamp: float = 1.0
"""Maximum predicted speed (m/s) used during extrapolation."""
max_new_tracks_per_step: int = 10
"""Maximum number of new tracks that may be spawned in a single step.
Capping this limits the damage from LiDAR false-positive bursts (e.g.
wall reflections in Webots) that would otherwise flood the track set.
The default (10 = MAX_SHEEP) preserves the original behaviour; reduce
to 23 for Webots deployment robustness.
"""
pen_latch_depth: float = 0.0
"""Minimum depth past the gate line (metres) before a track is latched
as penned. 0.0 = original behaviour (latch at y ≤ GATE_Y). Increase
to 0.5 for Webots to prevent gate-hardware LiDAR reflections near y=-15
from permanently consuming tracker slots as false "penned" sheep.
"""
consensus_k: int = 1
"""New tracks must accumulate this many matches before they appear in
``get_positions``. ``1`` (default) disables the candidate stage —
behaviour-identical to the original tracker. ``3-4`` filters one-shot
LiDAR phantoms in Webots while a real sheep promotes within
``consensus_k * timestep`` ≈ 50-65 ms.
"""
consensus_radius_m: float = 0.5
"""Maximum distance (metres) between successive matches for a candidate
to age toward promotion. Tighter than ``gate_m`` so wall-cluster
centroid jitter cannot keep a phantom alive. Real sheep move
≪ 0.05 m / step at max speed so this gate is very loose for them.
"""
consensus_max_age: int = 8
"""A candidate that has not been matched for this many steps is dropped.
Short — phantoms get one window to confirm or die.
"""
def __post_init__(self) -> None:
if self.forget_steps < 1:
raise ValueError(f"forget_steps must be ≥ 1, got {self.forget_steps}")
if self.max_new_tracks_per_step < 1:
raise ValueError(
f"max_new_tracks_per_step must be ≥ 1, got {self.max_new_tracks_per_step}"
)
if self.consensus_k < 1:
raise ValueError(f"consensus_k must be ≥ 1, got {self.consensus_k}")
if self.consensus_radius_m <= 0.0:
raise ValueError(
f"consensus_radius_m must be > 0, got {self.consensus_radius_m}"
)
if self.consensus_max_age < 1:
raise ValueError(
f"consensus_max_age must be ≥ 1, got {self.consensus_max_age}"
)
# ---------------------------------------------------------------------------
# Robot physical specification
# ---------------------------------------------------------------------------
@dataclass(frozen=True)
class RobotConfig:
"""Physical parameters of the shepherd-dog robot.
Values mirror ``protos/ShepherdDog.proto`` and ``protos/ShepherdDogMecanum.proto``.
"""
wheel_radius: float = 0.038
"""Wheel radius in metres."""
wheel_base: float = 0.28
"""Axle-to-axle distance for differential drive (metres)."""
wheel_base_x: float = 0.28
"""Front-to-back axle distance for mecanum drive (metres)."""
wheel_base_y: float = 0.28
"""Left-to-right axle distance for mecanum drive (metres)."""
max_wheel_omega: float = 70.0
"""Maximum wheel angular velocity (rad/s)."""
action_smooth: float = 0.0
"""Exponential moving-average coefficient applied to actions inside the env.
``0.0`` means no smoothing (gym default).
``0.55`` matches the hard-coded EMA in ``shepherd_dog.py`` — use this
when training so the policy learns to act through the same filter it
sees at deployment.
"""
def __post_init__(self) -> None:
if not (0.0 <= self.action_smooth < 1.0):
raise ValueError(
f"action_smooth must be in [0, 1), got {self.action_smooth}"
)
@property
def max_linear(self) -> float:
"""Maximum achievable linear speed (m/s)."""
return self.wheel_radius * self.max_wheel_omega
# ---------------------------------------------------------------------------
# Domain randomisation
# ---------------------------------------------------------------------------
@dataclass(frozen=True)
class DomainRandomConfig:
"""Parameters that inject physics / sensor noise for domain randomisation.
All values default to 0 (disabled) so the base env is deterministic and
backwards-compatible. Enable them gradually to close the sim-to-real gap.
"""
fp_rate: float = 0.0
"""Mean number of false-positive detections injected per step (Poisson λ).
FPs are placed near static features (walls, posts) with positional
noise ``fp_std_pos``, mimicking the spurious clusters Webots' physical
LiDAR returns from 3D geometry.
"""
fp_std_pos: float = 0.3
"""Positional standard deviation (metres) of injected false-positive clusters."""
wheel_slip_std: float = 0.0
"""Gaussian noise standard deviation (rad/s) added to each wheel speed
before kinematic integration. Models real-world wheel slip and motor
variation. Suggested starting value: 0.05.
"""
compass_noise_std: float = 0.0
"""Gaussian noise standard deviation (radians) added to the heading
reading each step. Models magnetometer drift in Webots.
Suggested starting value: 0.02.
"""
def __post_init__(self) -> None:
if self.fp_rate < 0.0:
raise ValueError(f"fp_rate must be ≥ 0, got {self.fp_rate}")
if self.wheel_slip_std < 0.0:
raise ValueError(f"wheel_slip_std must be ≥ 0, got {self.wheel_slip_std}")
if self.compass_noise_std < 0.0:
raise ValueError(f"compass_noise_std must be ≥ 0, got {self.compass_noise_std}")
# ---------------------------------------------------------------------------
# Aggregate config
# ---------------------------------------------------------------------------
@dataclass(frozen=True)
class HerdingConfig:
"""Root configuration object passed to :class:`~training.herding_env.HerdingEnv`.
Sub-configs default to the original simulation parameters so that
``HerdingEnv()`` and ``HerdingEnv(herding_cfg=HerdingConfig())`` produce
identical behaviour.
"""
lidar: LidarConfig = field(default_factory=LidarConfig)
detection: DetectionConfig = field(default_factory=DetectionConfig)
tracker: TrackerConfig = field(default_factory=TrackerConfig)
robot: RobotConfig = field(default_factory=RobotConfig)
domain_random: DomainRandomConfig = field(default_factory=DomainRandomConfig)
def replace(self, **kwargs) -> "HerdingConfig":
"""Return a new config with selected top-level sub-configs replaced.
Example::
cfg = HERDING_WEBOTS.replace(
domain_random=DomainRandomConfig(fp_rate=2.0, wheel_slip_std=0.05)
)
"""
return replace(self, **kwargs)
# ---------------------------------------------------------------------------
# Named full-pipeline presets
# ---------------------------------------------------------------------------
HERDING_DEFAULT = HerdingConfig()
"""Original simulation defaults — zero behaviour change."""
HERDING_WEBOTS = HerdingConfig(
lidar=LIDAR_WEBOTS,
detection=DetectionConfig(wall_reject=0.5, static_reject=1.2),
tracker=TrackerConfig(
forget_steps=300,
max_new_tracks_per_step=1,
pen_latch_depth=2.0,
predict_steps=180,
consensus_k=3,
consensus_radius_m=0.3,
consensus_max_age=20,
),
robot=RobotConfig(action_smooth=0.55),
)
"""Webots-matched training preset.
Changes vs HERDING_DEFAULT:
* LiDAR: 180 rays / 140° FOV matching ShepherdDog.proto hardware
* Detection: wall_reject kept at 0.5 m (original default; static_reject
handles post FPs; 1.0 m was too aggressive near the south gate)
* Tracker:
- consensus_k=3, radius=0.3 m, max_age=20 (~320 ms window): a new
detection must be confirmed by two more nearby detections within
a tight 0.3 m radius to promote. Real sheep barely move
frame-to-frame (≪0.05 m/step) so they easily self-confirm while
the dog is rotating across them; wall-return phantoms whose
cluster centroid jitters by more than 0.3 m as the dog moves
can't accumulate three nearby hits and decay as separate
candidates.
- forget_steps=300 (~4.8 s) + predict_steps=180 (~2.9 s): once a
real sheep is confirmed, it lives in tracker memory long enough
for the policy — trained on 360° full-visibility obs — to plan
while the dog sweeps a sparse cone across the field. Set short
enough that any phantom that does leak through promotion dies
after the dog walks away from the wall that created it.
- max_new_tracks_per_step=1 still rate-caps spawn bursts.
* Robot: action_smooth 0.0 → 0.55 (matches Webots controller EMA)
"""