[RTC] Real Time Chunking for Pi0, Smolvla, Pi0.5 (#1698)

* Add Real-Time Chunking (RTC) support for flow matching models

Implement Real-Time Chunking (RTC) for action chunking policies using flow
matching denoising. RTC enables smooth action transitions between consecutive
chunks by using prefix guidance during denoising.

Key features:
- RTCProcessor class with denoise_step method for RTC guidance
- Tracker system for debug tracking using time-based dictionary storage
- RTCDebugVisualizer with comprehensive visualization utilities
- Integration with SmolVLA policy for flow matching models
- Support for multiple prefix attention schedules (ZEROS, ONES, LINEAR, EXP)
- Configurable execution horizon and max guidance weight
- Example scripts for dataset evaluation and real-time control

Technical details:
- Uses autograd-based gradient computation for RTC corrections
- Time-based tracking eliminates duplicate step issues
- Proxy methods in RTCProcessor for cleaner API
- Full integration with LeRobot's policy and dataset systems

Files added/modified:
- src/lerobot/configs/types.py: Add RTCAttentionSchedule enum
- src/lerobot/policies/rtc/: Core RTC implementation
  - configuration_rtc.py: RTC configuration
  - modeling_rtc.py: RTCProcessor with denoise_step
  - debug_handler.py: Tracker for debug information
  - debug_visualizer.py: Visualization utilities
- src/lerobot/policies/smolvla/modeling_smolvla.py: RTC integration
- examples/rtc/: Example scripts and evaluation tools

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Co-Authored-By: Alexander Soare <alexander.soare159@gmail.com>
Co-Authored-By: Claude <noreply@anthropic.com>

* Fix rtc_config attribute access in SmolVLA

Use getattr() to safely check for rtc_config attribute existence
instead of direct attribute access. This fixes AttributeError when
loading policies without rtc_config in their config.

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Co-Authored-By: Alexander Soare <alexander.soare159@gmail.com>
Co-Authored-By: Claude <noreply@anthropic.com>

* fixup! Fix rtc_config attribute access in SmolVLA

* Add RTCConfig field to SmolVLAConfig

Add rtc_config as an optional field in SmolVLAConfig to properly
support Real-Time Chunking configuration. This replaces the previous
getattr() workarounds with direct attribute access, making the code
cleaner and more maintainable.

Changes:
- Import RTCConfig in configuration_smolvla.py
- Add rtc_config: RTCConfig | None = None field
- Revert getattr() calls to direct attribute access in modeling_smolvla.py

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Co-Authored-By: Alexander Soare <alexander.soare159@gmail.com>
Co-Authored-By: Claude <noreply@anthropic.com>

* Refactor RTC enabled checks to use _rtc_enabled helper

Add _rtc_enabled() helper method in VLAFlowMatching class to simplify
and clean up RTC enabled checks throughout the code. This reduces
code duplication and improves readability.

Changes:
- Add _rtc_enabled() method in VLAFlowMatching
- Replace verbose rtc_config checks with _rtc_enabled() calls
- Maintain exact same functionality with cleaner code

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Co-Authored-By: Alexander Soare <alexander.soare159@gmail.com>
Co-Authored-By: Claude <noreply@anthropic.com>

* Rename track_debug method to track

Simplify the method name from track_debug to just track for better
readability and consistency. The method already has clear documentation
about its debug tracking purpose.

Changes:
- Rename RTCProcessor.track_debug() to track()
- Update all call sites in modeling_smolvla.py and modeling_rtc.py

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Co-Authored-By: Alexander Soare <alexander.soare159@gmail.com>
Co-Authored-By: Claude <noreply@anthropic.com>

* Use output_dir for saving all evaluation images

Update eval_dataset.py to save all comparison images to the
configured output_dir instead of the current directory. This provides
better organization and allows users to specify where outputs should be
saved.

Changes:
- Add os import at top level
- Create output_dir at start of run_evaluation()
- Save all comparison images to output_dir
- Remove duplicate os imports
- Update init_rtc_processor() docstring to be more concise

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Co-Authored-By: Alexander Soare <alexander.soare159@gmail.com>
Co-Authored-By: Claude <noreply@anthropic.com>

* fixup! Use output_dir for saving all evaluation images

* Fix logging buffering and enable tracking when RTC config provided

- Add force=True to logging.basicConfig to override existing configuration
- Enable line buffering for stdout/stderr for real-time log output
- Modify init_rtc_processor to create processor when rtc_config exists
  even if RTC is disabled, allowing tracking of denoising data

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Co-Authored-By: Claude <noreply@anthropic.com>
Co-Authored-By: Alexander Soare <alexander.soare159@gmail.com>

* Refactor SmolVLA plotting to use tracker data instead of local variables

Remove local tracking variables (correction, x1_t, error) from the
denoising loop and instead retrieve plotting data from the RTC tracker
after each denoise step. This makes the code cleaner and uses the
tracker as the single source of truth for debug/visualization data.

Changes:
- Remove initialization of correction, x1_t, error before denoising loop
- After each Euler step, retrieve most recent debug step from tracker
- Extract correction, x1_t, err from debug step for plotting
- Update tracking condition to use is_debug_enabled() method

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Co-Authored-By: Claude <noreply@anthropic.com>
Co-Authored-By: Alexander Soare <alexander.soare159@gmail.com>

* Move plotting logic from modeling_smolvla to eval_dataset script

Refactor to improve separation of concerns:

modeling_smolvla.py changes:
- Remove all plotting logic from sample_actions method
- Remove viz_xt_axs, viz_vt_axs, viz_x1t_axs parameters
- Remove matplotlib and RTCDebugVisualizer imports
- Remove viz_fig, viz_axs, denoise_step_counter instance variables
- Simplify denoising loop to only track data in rtc_processor

eval_dataset.py changes:
- Add _plot_denoising_steps_from_tracker helper method
- Retrieve debug steps from tracker after inference
- Plot x_t, v_t, x1_t, correction, and error from tracker data
- Enable debug tracking (cfg.rtc.debug = True) for visualization
- Remove viz axes parameters from predict_action_chunk calls

modeling_rtc.py changes:
- Remove v_t from track() call (handled by user change)

Benefits:
- Cleaner modeling code focused on inference
- Evaluation script owns all visualization logic
- Better separation of concerns
- Tracker is single source of truth for debug data

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Co-Authored-By: Claude <noreply@anthropic.com>
Co-Authored-By: Alexander Soare <alexander.soare159@gmail.com>

* Refactor plotting loging

* fixup! Refactor plotting loging

* Improve visualization: separate correction plot and fix axis scaling

Changes:
- Create separate figure for correction data instead of overlaying on v_t
- Add _rescale_axes helper method to properly scale all axes
- Add 10% margin to y-axis for better visualization
- Fix v_t chart vertical compression issue

Benefits:
- Clearer v_t plot without correction overlay
- Better axis scaling with proper margins
- Separate correction figure for focused analysis
- Improved readability of all denoising visualizations

Output files:
- denoising_xt_comparison.png (x_t trajectories)
- denoising_vt_comparison.png (v_t velocity - now cleaner)
- denoising_correction_comparison.png (NEW - separate corrections)
- denoising_x1t_comparison.png (x1_t state with error)

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Co-Authored-By: Claude <noreply@anthropic.com>
Co-Authored-By: Alexander Soare <alexander.soare159@gmail.com>

* fixup! Improve visualization: separate correction plot and fix axis scaling

* fixup! fixup! Improve visualization: separate correction plot and fix axis scaling

* fixup! fixup! fixup! Improve visualization: separate correction plot and fix axis scaling

* Fix traacking

* Right kwargs for the policy

* Add tests for tracker

* Fix tests

* Drop not required methods

* Add torch compilation for eval_dataset

* delete policies

* Add matplotliv to dev

* fixup! Add matplotliv to dev

* Experiemnt with late detach

* Debug

* Fix compilation

* Add RTC to PI0

* Pi0

* Pi0 eval dataset

* fixup! Pi0 eval dataset

* Turn off compilation for pi0/pi05

* fixup! Turn off compilation for pi0/pi05

* fixup! fixup! Turn off compilation for pi0/pi05

* fixup! fixup! fixup! Turn off compilation for pi0/pi05

* fixup! fixup! fixup! fixup! Turn off compilation for pi0/pi05

* fixup! fixup! fixup! fixup! fixup! Turn off compilation for pi0/pi05

* Add workable flow

* Small fixes

* Add more tests

* Add validatio at the end

* Update README

* Silent validation

* Fix tests

* Add tests for modeling_rtc

* Add tests for flow matching models with RTC

* fixup! Add tests for flow matching models with RTC

* fixup! fixup! Add tests for flow matching models with RTC

* Add one more test

* fixup! Add one more test

* Fix test to use _rtc_enabled() instead of is_rtc_enabled()

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Co-Authored-By: Claude <noreply@anthropic.com>

* fixup! Fix test to use _rtc_enabled() instead of is_rtc_enabled()

* fixup! fixup! Fix test to use _rtc_enabled() instead of is_rtc_enabled()

* Add RTC initialization tests without config for PI0.5 and SmolVLA

Add test_pi05_rtc_initialization_without_rtc_config and
test_smolvla_rtc_initialization_without_rtc_config to verify that
policies can initialize without RTC config and that _rtc_enabled()
returns False in this case.

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Co-Authored-By: Claude <noreply@anthropic.com>

* Fix PI0.5 init_rtc_processor to use getattr instead of direct model access

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Co-Authored-By: Claude <noreply@anthropic.com>

* Fix SmolVLA init_rtc_processor to use getattr instead of direct model access

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Co-Authored-By: Claude <noreply@anthropic.com>

* Fix PI0.5 RTC tests to use quantile stats (q01, q99) for normalization

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Co-Authored-By: Claude <noreply@anthropic.com>

* fixup! Fix PI0.5 RTC tests to use quantile stats (q01, q99) for normalization

* Fixup eval with real robot

* fixup! Fixup eval with real robot

* fixup! fixup! Fixup eval with real robot

* Extract simulator logic from eval_with real robot and add proper headers to files

* Update images

* Fix tests

* fixup! Fix tests

* add docs for rtc

* enhance doc and add images

* Fix instal instructions

---------
Co-authored-by: Ben Zhang <benzhangniu@gmail.com>
Co-authored-by: Alexander Soare <alexander.soare159@gmail.com>
Co-authored-by: Michel Aractingi <michel.aractingi@huggingface.co>
This commit is contained in:
Eugene Mironov
2025-11-19 17:19:48 +07:00
committed by GitHub
parent b464d9f8bc
commit 8a915c6b6f
26 changed files with 6517 additions and 50 deletions
@@ -20,6 +20,7 @@ from lerobot.configs.policies import PreTrainedConfig
from lerobot.configs.types import FeatureType, NormalizationMode, PolicyFeature
from lerobot.optim.optimizers import AdamWConfig
from lerobot.optim.schedulers import CosineDecayWithWarmupSchedulerConfig
from lerobot.policies.rtc.configuration_rtc import RTCConfig
@PreTrainedConfig.register_subclass("pi05")
@@ -46,6 +47,9 @@ class PI05Config(PreTrainedConfig):
min_period: float = 4e-3
max_period: float = 4.0
# Real-Time Chunking (RTC) configuration
rtc_config: RTCConfig | None = None
image_resolution: tuple[int, int] = (224, 224) # see openpi `preprocessing_pytorch.py`
# Add empty images. Used to add empty cameras when no image features are present.
+83 -14
View File
@@ -19,11 +19,12 @@ import logging
import math
from collections import deque
from pathlib import Path
from typing import TYPE_CHECKING, Literal
from typing import TYPE_CHECKING, Literal, TypedDict
import torch
import torch.nn.functional as F # noqa: N812
from torch import Tensor, nn
from typing_extensions import Unpack
from lerobot.utils.import_utils import _transformers_available
@@ -42,6 +43,7 @@ else:
from lerobot.configs.policies import PreTrainedConfig
from lerobot.policies.pi05.configuration_pi05 import PI05Config
from lerobot.policies.pretrained import PreTrainedPolicy, T
from lerobot.policies.rtc.modeling_rtc import RTCProcessor
from lerobot.utils.constants import (
ACTION,
OBS_LANGUAGE_ATTENTION_MASK,
@@ -50,6 +52,12 @@ from lerobot.utils.constants import (
)
class ActionSelectKwargs(TypedDict, total=False):
inference_delay: int | None
prev_chunk_left_over: Tensor | None
execution_horizon: int | None
def get_safe_dtype(target_dtype, device_type):
"""Get a safe dtype for the given device type."""
if device_type == "mps" and target_dtype == torch.float64:
@@ -502,9 +510,10 @@ class PaliGemmaWithExpertModel(
class PI05Pytorch(nn.Module): # see openpi `PI0Pytorch`
"""Core PI05 PyTorch model."""
def __init__(self, config: PI05Config):
def __init__(self, config: PI05Config, rtc_processor: RTCProcessor | None = None):
super().__init__()
self.config = config
self.rtc_processor = rtc_processor
paligemma_config = get_gemma_config(config.paligemma_variant)
action_expert_config = get_gemma_config(config.action_expert_variant)
@@ -556,6 +565,9 @@ class PI05Pytorch(nn.Module): # see openpi `PI0Pytorch`
self.paligemma_with_expert.gemma_expert.model.gradient_checkpointing = False
logging.info("Disabled gradient checkpointing for PI05Pytorch model")
def _rtc_enabled(self):
return self.config.rtc_config is not None and self.config.rtc_config.enabled
def _apply_checkpoint(self, func, *args, **kwargs):
"""Helper method to apply gradient checkpointing if enabled."""
if self.gradient_checkpointing_enabled and self.training:
@@ -731,7 +743,16 @@ class PI05Pytorch(nn.Module): # see openpi `PI0Pytorch`
return F.mse_loss(u_t, v_t, reduction="none")
@torch.no_grad() # see openpi `sample_actions` (slightly adapted)
def sample_actions(self, images, img_masks, tokens, masks, noise=None, num_steps=None) -> Tensor:
def sample_actions(
self,
images,
img_masks,
tokens,
masks,
noise=None,
num_steps=None,
**kwargs: Unpack[ActionSelectKwargs],
) -> Tensor:
"""Do a full inference forward and compute the action."""
if num_steps is None:
num_steps = self.config.num_inference_steps
@@ -770,13 +791,40 @@ class PI05Pytorch(nn.Module): # see openpi `PI0Pytorch`
time = torch.tensor(1.0, dtype=torch.float32, device=device)
while time >= -dt / 2:
expanded_time = time.expand(bsize)
v_t = self.denoise_step(
prefix_pad_masks,
past_key_values,
x_t,
expanded_time,
)
x_t = x_t + dt * v_t
# Define a closure function to properly capture expanded_time
# This avoids the lambda expression (E731) and loop variable binding (B023) issues
def denoise_step_partial_call(input_x_t, current_timestep=expanded_time):
return self.denoise_step(
prefix_pad_masks=prefix_pad_masks,
past_key_values=past_key_values,
x_t=input_x_t,
timestep=current_timestep,
)
if self._rtc_enabled():
inference_delay = kwargs.get("inference_delay")
prev_chunk_left_over = kwargs.get("prev_chunk_left_over")
execution_horizon = kwargs.get("execution_horizon")
v_t = self.rtc_processor.denoise_step(
x_t=x_t,
prev_chunk_left_over=prev_chunk_left_over,
inference_delay=inference_delay,
time=time,
original_denoise_step_partial=denoise_step_partial_call,
execution_horizon=execution_horizon,
)
else:
v_t = denoise_step_partial_call(x_t)
# Euler step
x_t += dt * v_t
# Record x_t and v_t after Euler step
if self.rtc_processor is not None and self.rtc_processor.is_debug_enabled():
self.rtc_processor.track(time=time, x_t=x_t, v_t=v_t)
time += dt
return x_t
@@ -839,7 +887,8 @@ class PI05Policy(PreTrainedPolicy):
self.config = config
# Initialize the core PI05 model
self.model = PI05Pytorch(config)
self.init_rtc_processor()
self.model = PI05Pytorch(config, rtc_processor=self.rtc_processor)
# Enable gradient checkpointing if requested
if config.gradient_checkpointing:
@@ -1035,6 +1084,22 @@ class PI05Policy(PreTrainedPolicy):
ACTION: deque(maxlen=self.config.n_action_steps),
}
def init_rtc_processor(self):
"""Initialize RTC processor if RTC is enabled in config."""
self.rtc_processor = None
# Create processor if config provided
# If RTC is not enabled - we can still track the denoising data
if self.config.rtc_config is not None:
self.rtc_processor = RTCProcessor(self.config.rtc_config)
model_value = getattr(self, "model", None)
if model_value is not None:
model_value.rtc_processor = self.rtc_processor
def _rtc_enabled(self) -> bool:
return self.config.rtc_config is not None and self.config.rtc_config.enabled
def _preprocess_images(self, batch: dict[str, Tensor]) -> tuple[list[Tensor], list[Tensor]]:
"""Preprocess images for the model.
@@ -1109,6 +1174,10 @@ class PI05Policy(PreTrainedPolicy):
@torch.no_grad()
def select_action(self, batch: dict[str, Tensor]) -> Tensor:
"""Select a single action given environment observations."""
assert not self._rtc_enabled(), (
"RTC is not supported for select_action, use it with predict_action_chunk"
)
self.eval()
# Action queue logic for n_action_steps > 1
@@ -1120,7 +1189,7 @@ class PI05Policy(PreTrainedPolicy):
return self._action_queue.popleft()
@torch.no_grad()
def predict_action_chunk(self, batch: dict[str, Tensor]) -> Tensor:
def predict_action_chunk(self, batch: dict[str, Tensor], **kwargs: Unpack[ActionSelectKwargs]) -> Tensor:
"""Predict a chunk of actions given environment observations."""
self.eval()
@@ -1128,8 +1197,8 @@ class PI05Policy(PreTrainedPolicy):
images, img_masks = self._preprocess_images(batch)
tokens, masks = batch[f"{OBS_LANGUAGE_TOKENS}"], batch[f"{OBS_LANGUAGE_ATTENTION_MASK}"]
# Sample actions using the model (no separate state needed for PI05)
actions = self.model.sample_actions(images, img_masks, tokens, masks)
# Sample actions using the model (pass through RTC kwargs, no separate state needed for PI05)
actions = self.model.sample_actions(images, img_masks, tokens, masks, **kwargs)
# Unpad actions to actual action dimension
original_action_dim = self.config.output_features[ACTION].shape[0]