feat(pi052): add training-time RTC

This commit is contained in:
Pepijn
2026-07-16 10:38:28 +02:00
parent 5b8e6ffe8e
commit 18e02ded4f
10 changed files with 396 additions and 25 deletions
+7 -6
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@@ -274,12 +274,13 @@ lerobot-rollout \
--device=cuda
```
| Flag | Description |
| ------------------------------------------- | -------------------------------------------------------------- |
| `--inference.rtc.execution_horizon` | Steps to blend with previous chunk (default: varies by policy) |
| `--inference.rtc.max_guidance_weight` | Consistency enforcement strength (default: varies by policy) |
| `--inference.rtc.prefix_attention_schedule` | Blend schedule: `LINEAR`, `EXP`, `ONES`, `ZEROS` |
| `--inference.queue_threshold` | Max queue size before backpressure (default: 30) |
| Flag | Description |
| ------------------------------------------- | ------------------------------------------------------------------------------- |
| `--inference.rtc.execution_horizon` | Steps to blend with previous chunk (default: varies by policy) |
| `--inference.rtc.mode` | `guided` (default) or trained-prefix `trained` for compatible Pi052 checkpoints |
| `--inference.rtc.max_guidance_weight` | Consistency enforcement strength (default: varies by policy) |
| `--inference.rtc.prefix_attention_schedule` | Blend schedule: `LINEAR`, `EXP`, `ONES`, `ZEROS` |
| `--inference.queue_threshold` | Max queue size before backpressure (default: 30) |
See the [Real-Time Chunking](./rtc) guide for details on tuning RTC parameters.
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@@ -116,12 +116,71 @@ the expected prompt, text target, and action endpoints before scaling up.
| `policy.fast_action_loss_weight` | `1.0` | FAST cross-entropy weight |
| `policy.knowledge_insulation` | `true` | Blocks action-loss gradients through the VLM K/V path |
| `policy.flow_num_repeats` | `5` | Reuses one VLM prefix for independent denoising targets |
| `policy.rtc_training_max_delay` | `0` | Maximum clean-prefix delay; `0` disables training-time RTC |
| `policy.lm_head_lr_scale` | `1.0` | Scales language-head learning rate; `1.0` uses the base rate |
The loss weights are starting points, not dataset-independent constants. Track
flow loss and text/FAST losses separately, and inspect generated subtasks rather
than selecting a checkpoint from total loss alone.
### Training-time RTC
Pi052 optionally supports training-time action conditioning from
[Training-Time Action Conditioning for Efficient Real-Time Chunking](https://arxiv.org/abs/2512.05964).
It simulates inference latency by sampling a clean action prefix for every flow
draw, passing a per-action flow timestep to the action expert, and computing the
flow loss only on the remaining postfix. The default value of `0` leaves the
standard Pi052 objective unchanged.
```bash
lerobot-train \
--dataset.repo_id=${HF_USER}/my_language_annotated_dataset \
--policy.type=pi052 \
--policy.pretrained_path=lerobot/pi05_base \
--policy.recipe_path=recipes/subtask_mem.yaml \
--policy.rtc_training_max_delay=10 \
--policy.dtype=bfloat16 \
--policy.device=cuda \
--batch_size=8 \
--steps=30000 \
--output_dir=outputs/pi052_rtc \
--job_name=pi052_rtc
```
`rtc_training_max_delay` is measured in controller steps and must be smaller
than `chunk_size`. Choose it to cover the largest inference latency expected at
deployment: at 50 Hz, for example, 10 steps correspond to 200 ms. A delay of
zero is included in the uniform sampling distribution, so the checkpoint also
continues to receive ordinary flow-matching examples. Set rollout's
`inference.rtc.execution_horizon` to at least this maximum so the previous
chunk cache retains enough actions to construct every supported prefix.
Run the resulting checkpoint with the asynchronous `lerobot-rollout` backend
and select the trained-prefix path explicitly:
```bash
lerobot-rollout \
--strategy.type=base \
--policy.path=outputs/pi052_rtc/checkpoints/last/pretrained_model \
--inference.type=rtc \
--inference.rtc.mode=trained \
--inference.rtc.execution_horizon=10 \
--robot.type=so100_follower \
--robot.port=/dev/ttyACM0 \
--task="pick up the cube" \
--fps=50 \
--device=cuda
```
The rollout engine measures latency continuously, carries the still-unexecuted
actions from the previous chunk into the next prediction, and discards the
prefix that elapsed during inference. If the measured delay exceeds the
checkpoint's `rtc_training_max_delay`, rollout stops with an explicit error
instead of silently extrapolating beyond the training distribution. Use
`--inference.rtc.mode=guided` for the original Jacobian-guided RTC path; it does
not require a training-time RTC checkpoint but adds backward-pass work during
denoising.
### Dataset-specific FAST tokenizer
The universal FAST tokenizer works out of the box. For a large or
+27 -1
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@@ -1,6 +1,6 @@
# Real-Time Chunking (RTC)
Real-Time Chunking (RTC) is an inference-time method that allows large, flow-matching based robotic policies, such as [Pi0](./pi0), [Pi0.5](./pi05), and [SmolVLA](./smolvla), to produce smooth, continuous, and reactive motion despite having high inference latency.
Real-Time Chunking (RTC) allows large, flow-matching based robotic policies, such as [Pi0](./pi0), [Pi0.5](./pi05), and [SmolVLA](./smolvla), to produce smooth, continuous, and reactive motion despite having high inference latency. LeRobot provides the original inference-time guided mode and, for compatible Pi052 checkpoints, training-time action conditioning with cheap hard-prefix inference.
These policies generate chunks of future actions (e.g., 50 steps at a time) instead of single actions.
Because the models are large, producing each chunk takes longer than the time it takes the robot to execute it.
@@ -92,6 +92,11 @@ for step in range(num_steps):
`RTCConfig` has the following parameters to tune:
**`mode`** selects the action-prefix conditioning method:
- `guided` (default) applies the original Jacobian guidance during denoising and works with ordinary flow-matching checkpoints.
- `trained` hard-inpaints the previous chunk's prefix with per-action flow timesteps. It currently requires a Pi052 checkpoint trained with `policy.rtc_training_max_delay > 0` and avoids the guidance backward pass.
**`execution_horizon`**: How many timesteps from the previous chunk to maintain consistency with. Higher values mean smoother transitions but potentially less reactivity.
Typical values: 8-12 steps
@@ -141,6 +146,7 @@ lerobot-rollout \
--strategy.type=base \
--policy.path=${HF_USERNAME}/policy_repo_id \
--inference.type=rtc \
--inference.rtc.mode=guided \
--inference.rtc.execution_horizon=10 \
--inference.rtc.max_guidance_weight=10.0 \
--robot.type=so100_follower \
@@ -151,6 +157,24 @@ lerobot-rollout \
--device=cuda
```
For a training-time RTC Pi052 checkpoint, change the mode to `trained`. The
checkpoint records its maximum supported delay, and rollout validates measured
latency against it:
```bash
lerobot-rollout \
--strategy.type=base \
--policy.path=${HF_USERNAME}/pi052_training_rtc \
--inference.type=rtc \
--inference.rtc.mode=trained \
--inference.rtc.execution_horizon=10 \
--robot.type=so100_follower \
--robot.port=/dev/tty.usbmodem58FA0834591 \
--task="Move green small object into the purple platform" \
--duration=120 \
--device=cuda
```
## How It Differs from the Async Inference in LeRobot
Both RTC and [async inference](./async) improve real-time robot control, but they solve different problems.
@@ -189,3 +213,5 @@ See `examples/rtc/eval_dataset.py` for a complete example of offline RTC visuali
- [Smooth-As-Butter Robot Policies](https://alexander-soare.github.io/robotics/2025/08/05/smooth-as-butter-robot-policies.html) - Excellent technical explanation with real robot results
- [Physical Intelligence - Real-Time Chunking](https://www.physicalintelligence.company/research/real_time_chunking) - Original paper and research
- [Kinetix RTC Implementation](https://github.com/Physical-Intelligence/real-time-chunking-kinetix) - Reference implementation from Physical Intelligence
- [Training-Time Action Conditioning](https://arxiv.org/abs/2512.05964) - Efficient RTC with clean-prefix conditioning during training
- [RLDX-1](https://github.com/RLWRLD/RLDX-1) - PyTorch reference used for the training-time RTC integration
+82 -8
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@@ -70,6 +70,54 @@ class ActionSelectKwargs(TypedDict, total=False):
execution_horizon: int | None
def _prepare_trained_rtc_prefix(
x_t: Tensor,
prev_chunk_left_over: Tensor | None,
inference_delay: int,
training_max_delay: int,
) -> tuple[Tensor | None, Tensor | None]:
"""Pad and validate a hard prefix for training-time RTC inference."""
if prev_chunk_left_over is None or inference_delay <= 0:
return None, None
if training_max_delay <= 0:
raise ValueError(
"RTC mode='trained' requires a Pi052 checkpoint trained with policy.rtc_training_max_delay > 0."
)
if inference_delay > training_max_delay:
raise ValueError(
f"Measured RTC inference delay ({inference_delay}) exceeds the checkpoint's "
f"rtc_training_max_delay ({training_max_delay})."
)
if inference_delay >= x_t.shape[1]:
raise ValueError(
f"RTC inference delay ({inference_delay}) must be smaller than chunk_size ({x_t.shape[1]})."
)
previous = prev_chunk_left_over.to(device=x_t.device, dtype=x_t.dtype)
if previous.ndim == 2:
previous = previous.unsqueeze(0)
if previous.ndim != 3:
raise ValueError(f"Expected RTC prefix shape (B, T, A), got {tuple(previous.shape)}")
if previous.shape[0] == 1 and x_t.shape[0] > 1:
previous = previous.expand(x_t.shape[0], -1, -1)
if previous.shape[0] != x_t.shape[0]:
raise ValueError(
f"RTC prefix batch size ({previous.shape[0]}) does not match policy batch ({x_t.shape[0]})."
)
if previous.shape[1] < inference_delay:
raise ValueError(f"RTC prefix has {previous.shape[1]} steps, but inference_delay={inference_delay}.")
if previous.shape[2] > x_t.shape[2]:
raise ValueError(
f"RTC prefix action dimension ({previous.shape[2]}) exceeds model dimension ({x_t.shape[2]})."
)
padded_prefix = torch.zeros_like(x_t)
padded_prefix[:, :inference_delay, : previous.shape[2]] = previous[:, :inference_delay]
prefix_mask = torch.arange(x_t.shape[1], device=x_t.device) < inference_delay
prefix_mask = prefix_mask[None, :, None].expand(x_t.shape[0], -1, x_t.shape[2])
return padded_prefix, prefix_mask
_SAFETENSORS_FILE = "model.safetensors"
_SAFETENSORS_INDEX = "model.safetensors.index.json"
@@ -164,21 +212,21 @@ def get_safe_dtype(target_dtype, device_type):
def create_sinusoidal_pos_embedding( # see openpi `create_sinusoidal_pos_embedding` (exact copy)
time: torch.Tensor, dimension: int, min_period: float, max_period: float, device="cpu"
) -> Tensor:
"""Computes sine-cosine positional embedding vectors for scalar positions."""
"""Computes sine-cosine embeddings for scalar or per-action positions."""
if dimension % 2 != 0:
raise ValueError(f"dimension ({dimension}) must be divisible by 2")
if time.ndim != 1:
raise ValueError("The time tensor is expected to be of shape `(batch_size, )`.")
if time.ndim not in (1, 2):
raise ValueError("The time tensor must have shape (batch_size,) or (batch_size, action_horizon).")
dtype = get_safe_dtype(torch.float64, device.type)
fraction = torch.linspace(0.0, 1.0, dimension // 2, dtype=dtype, device=device)
period = min_period * (max_period / min_period) ** fraction
# Compute the outer product
# Broadcast the frequency dimension over either (B,) or (B, H).
scaling_factor = 1.0 / period * 2 * math.pi
sin_input = scaling_factor[None, :] * time[:, None]
return torch.cat([torch.sin(sin_input), torch.cos(sin_input)], dim=1)
sin_input = time[..., None] * scaling_factor
return torch.cat([torch.sin(sin_input), torch.cos(sin_input)], dim=-1)
def sample_beta(alpha, beta, bsize, device): # see openpi `sample_beta` (exact copy)
@@ -948,6 +996,24 @@ class PI05Pytorch(nn.Module): # see openpi `PI0Pytorch`
)
x_t = noise
rtc_mode = "guided"
trained_prefix = trained_prefix_mask = None
if self._rtc_enabled():
rtc_mode = self.rtc_processor.rtc_config.mode
if rtc_mode == "trained":
training_max_delay = int(getattr(self.config, "rtc_training_max_delay", 0))
if training_max_delay <= 0:
raise ValueError(
"RTC mode='trained' requires a Pi052 checkpoint trained with "
"policy.rtc_training_max_delay > 0."
)
trained_prefix, trained_prefix_mask = _prepare_trained_rtc_prefix(
x_t,
kwargs.get("prev_chunk_left_over"),
int(kwargs.get("inference_delay") or 0),
training_max_delay,
)
for step in range(num_steps):
time = 1.0 + step * dt
if times is None:
@@ -955,7 +1021,13 @@ class PI05Pytorch(nn.Module): # see openpi `PI0Pytorch`
else:
time_tensor = times[step].expand(bsize)
def denoise_step_partial_call(input_x_t, current_timestep=time_tensor):
denoise_timestep = time_tensor
if trained_prefix is not None:
x_t = torch.where(trained_prefix_mask, trained_prefix, x_t)
denoise_timestep = time_tensor[:, None].expand(bsize, x_t.shape[1]).clone()
denoise_timestep[trained_prefix_mask[..., 0]] = 0.0
def denoise_step_partial_call(input_x_t, current_timestep=denoise_timestep):
return self.denoise_step(
prefix_pad_masks=prefix_pad_masks,
past_key_values=past_key_values,
@@ -963,7 +1035,7 @@ class PI05Pytorch(nn.Module): # see openpi `PI0Pytorch`
timestep=current_timestep,
)
if self._rtc_enabled():
if self._rtc_enabled() and rtc_mode == "guided":
inference_delay = kwargs.get("inference_delay")
prev_chunk_left_over = kwargs.get("prev_chunk_left_over")
execution_horizon = kwargs.get("execution_horizon")
@@ -980,6 +1052,8 @@ class PI05Pytorch(nn.Module): # see openpi `PI0Pytorch`
v_t = denoise_step_partial_call(x_t)
x_t = x_t + dt * v_t
if trained_prefix is not None:
x_t = torch.where(trained_prefix_mask, trained_prefix, x_t)
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)
@@ -121,6 +121,15 @@ class PI052Config(PI05Config):
# Reuse each VLM prefix across independent denoising draws; 1 restores single-draw flow.
flow_num_repeats: int = 5
# Training-time RTC (arXiv:2512.05964). Zero preserves standard flow matching.
rtc_training_max_delay: int = 0
"""Largest clean action-prefix length sampled during training.
A value greater than zero enables training-time action conditioning. Each
flow draw samples a delay uniformly from ``[0, rtc_training_max_delay]``;
the corresponding action prefix stays clean and is excluded from the loss.
"""
# PaLM-style z-loss stabilizes large-vocabulary CE; 0 disables it.
text_ce_z_loss_weight: float = 1e-4
@@ -151,6 +160,11 @@ class PI052Config(PI05Config):
self.train_expert_only = False
if self.flow_num_repeats < 1:
raise ValueError(f"flow_num_repeats must be >= 1, got {self.flow_num_repeats}")
if not 0 <= self.rtc_training_max_delay < self.chunk_size:
raise ValueError(
"rtc_training_max_delay must satisfy "
f"0 <= delay < chunk_size ({self.chunk_size}), got {self.rtc_training_max_delay}"
)
if self.manual_attention_scope not in {"all", "action"}:
raise ValueError(
f"manual_attention_scope must be 'all' or 'action', got {self.manual_attention_scope!r}"
+73 -10
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@@ -187,6 +187,54 @@ def _reduce_action_loss(per_sample: Tensor, predict_actions_t: Tensor | None, re
return (per_sample * mask).sum() / mask.sum().clamp(min=1.0)
def _sample_training_rtc_prefix_mask(
batch_size: int,
action_horizon: int,
max_delay: int,
device: torch.device,
) -> Tensor | None:
"""Sample per-draw clean prefixes for training-time RTC."""
if max_delay <= 0:
return None
delays = torch.randint(0, max_delay + 1, (batch_size,), device=device)
positions = torch.arange(action_horizon, device=device)
return positions.unsqueeze(0) < delays.unsqueeze(1)
def _build_flow_matching_inputs(
actions: Tensor,
noise: Tensor,
time: Tensor,
prefix_mask: Tensor | None,
) -> tuple[Tensor, Tensor]:
"""Build noisy actions and scalar/per-token flow times.
LeRobot's PI0.5 flow uses ``t=0`` for clean data and ``t=1`` for
noise, the reverse of the notation in arXiv:2512.05964. Consequently,
clean RTC prefix tokens receive ``t=0`` here.
"""
if prefix_mask is None:
model_time = time
expanded_time = time[:, None, None]
else:
model_time = time[:, None].expand_as(prefix_mask)
model_time = torch.where(prefix_mask, torch.zeros_like(model_time), model_time)
expanded_time = model_time.unsqueeze(-1)
x_t = expanded_time * noise + (1 - expanded_time) * actions
return x_t, model_time
def _flow_loss_per_sample(flow_per_dim: Tensor, prefix_mask: Tensor | None) -> Tensor:
"""Average each draw over postfix action positions and dimensions only."""
if prefix_mask is None:
return flow_per_dim.flatten(start_dim=1).mean(dim=1)
postfix = (~prefix_mask).unsqueeze(-1).expand_as(flow_per_dim)
reduce_dims = tuple(range(1, flow_per_dim.ndim))
numerator = (flow_per_dim * postfix).sum(dim=reduce_dims)
denominator = postfix.sum(dim=reduce_dims).clamp(min=1)
return numerator / denominator
# Materialized logits win at VLA token counts; larger dense targets use Liger.
_LOGITS_CE_MAX_POSITIONS = 2048
@@ -928,6 +976,7 @@ class PI052Policy(PI05Policy):
text_labels is None
and predict_actions_t is None
and not getattr(self.config, "enable_fast_action_loss", False)
and self.config.rtc_training_max_delay == 0
):
return super().forward(batch, reduction=reduction)
@@ -1118,12 +1167,17 @@ class PI052Policy(PI05Policy):
noise = self.model.sample_noise(actions.shape, actions.device)
time = self.model.sample_time(actions.shape[0], actions.device)
time_expanded = time[:, None, None]
x_t = time_expanded * noise + (1 - time_expanded) * actions
prefix_mask = _sample_training_rtc_prefix_mask(
actions.shape[0],
actions.shape[1],
self.config.rtc_training_max_delay,
actions.device,
)
x_t, model_time = _build_flow_matching_inputs(actions, noise, time, prefix_mask)
u_t = noise - actions
# ---- suffix: noisy actions ----------------------------------
suffix_embs, suffix_pad, suffix_att, adarms_cond = self.model.embed_suffix(x_t, time)
suffix_embs, suffix_pad, suffix_att, adarms_cond = self.model.embed_suffix(x_t, model_time)
# ---- bf16 alignment (mirrors PI05Pytorch.forward) -----------
first_layer = self.model.paligemma_with_expert.paligemma.model.language_model.layers[0]
@@ -1169,7 +1223,7 @@ class PI052Policy(PI05Policy):
# internally to max_action_dim).
original_action_dim = self.config.output_features[ACTION].shape[0]
flow_per_dim = flow_per_dim[:, :, :original_action_dim]
per_sample_flow = flow_per_dim.mean(dim=(1, 2))
per_sample_flow = _flow_loss_per_sample(flow_per_dim, prefix_mask)
flow_loss = _reduce_action_loss(per_sample_flow, predict_actions_t, reduction)
return prefix_out, flow_loss
@@ -1216,10 +1270,15 @@ class PI052Policy(PI05Policy):
noise = model.sample_noise((k * batch_size, *actions.shape[1:]), actions.device)
time = model.sample_time(k * batch_size, actions.device)
actions_rep = actions.repeat(k, 1, 1) # (k*B, chunk, motor_dim)
time_expanded = time[:, None, None]
x_t = time_expanded * noise + (1 - time_expanded) * actions_rep
prefix_mask_flat = _sample_training_rtc_prefix_mask(
k * batch_size,
chunk,
self.config.rtc_training_max_delay,
actions.device,
)
x_t, model_time = _build_flow_matching_inputs(actions_rep, noise, time, prefix_mask_flat)
u_t = (noise - actions_rep).view(k, batch_size, chunk, -1).transpose(0, 1) # (B, k, chunk, motor)
s_embs, suffix_pad, suffix_att, adarms = model.embed_suffix(x_t, time)
s_embs, suffix_pad, suffix_att, adarms = model.embed_suffix(x_t, model_time)
if use_bf16:
s_embs = s_embs.to(dtype=torch.bfloat16)
suffix_pad = suffix_pad[:batch_size]
@@ -1228,9 +1287,10 @@ class PI052Policy(PI05Policy):
s_embs.view(k, batch_size, chunk, -1).transpose(0, 1).reshape(batch_size, k * chunk, -1)
) # (B, k*chunk, D)
# Broadcast each draw's AdaRMS condition over its action chunk.
if adarms.ndim == 2:
adarms = adarms[:, None, :].expand(-1, chunk, -1)
adarms_cond = (
adarms.view(k, batch_size, 1, adarms.shape[-1])
.expand(k, batch_size, chunk, adarms.shape[-1])
adarms.view(k, batch_size, chunk, adarms.shape[-1])
.transpose(0, 1)
.reshape(batch_size, k * chunk, adarms.shape[-1])
) # (B, k*chunk, cond_dim)
@@ -1300,7 +1360,10 @@ class PI052Policy(PI05Policy):
v_t = model.action_out_proj(suffix_out.to(dtype=torch.float32))
v_t = v_t.view(batch_size, k, chunk, -1) # (B, k, chunk, motor)
flow_per_dim = functional.mse_loss(u_t, v_t, reduction="none")[..., :original_action_dim]
per_sample_flow = flow_per_dim.mean(dim=(1, 2, 3))
prefix_mask = None
if prefix_mask_flat is not None:
prefix_mask = prefix_mask_flat.view(k, batch_size, chunk).transpose(0, 1)
per_sample_flow = _flow_loss_per_sample(flow_per_dim, prefix_mask)
flow_loss = _reduce_action_loss(per_sample_flow, predict_actions_t, reduction)
return prefix_out, flow_loss
@@ -37,6 +37,10 @@ class RTCConfig:
# Infrastructure
enabled: bool = True
# ``guided`` is the original inference-time Jacobian guidance. ``trained``
# hard-inpaints a prefix and requires a compatible training-time RTC checkpoint.
mode: str = "guided"
# Core RTC settings
# Todo change to exp
prefix_attention_schedule: RTCAttentionSchedule = RTCAttentionSchedule.LINEAR
@@ -49,6 +53,8 @@ class RTCConfig:
def __post_init__(self):
"""Validate RTC configuration parameters."""
if self.mode not in {"guided", "trained"}:
raise ValueError(f"mode must be 'guided' or 'trained', got {self.mode!r}")
if self.max_guidance_weight <= 0:
raise ValueError(f"max_guidance_weight must be positive, got {self.max_guidance_weight}")
if self.debug_maxlen <= 0:
+12
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@@ -178,6 +178,18 @@ def build_rollout_context(
policy_config = cfg.policy
policy_class = get_policy_class(policy_config.type)
if is_rtc and cfg.inference.rtc.enabled and cfg.inference.rtc.mode == "trained":
if policy_config.type != "pi052":
raise ValueError(
"--inference.rtc.mode=trained currently requires a Pi052 checkpoint; "
f"got policy type {policy_config.type!r}."
)
if int(getattr(policy_config, "rtc_training_max_delay", 0)) <= 0:
raise ValueError(
"--inference.rtc.mode=trained requires a checkpoint trained with "
"--policy.rtc_training_max_delay > 0."
)
if hasattr(policy_config, "compile_model"):
policy_config.compile_model = cfg.use_torch_compile
@@ -0,0 +1,106 @@
#!/usr/bin/env python
# Copyright 2026 The HuggingFace Inc. team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
"""Unit coverage for Pi052 training-time RTC conditioning."""
from types import SimpleNamespace
import pytest
import torch
from torch import nn
pytest.importorskip("transformers")
from lerobot.policies.pi05.modeling_pi05 import ( # noqa: E402
_prepare_trained_rtc_prefix,
create_sinusoidal_pos_embedding,
)
from lerobot.policies.pi052.configuration_pi052 import PI052Config # noqa: E402
from lerobot.policies.pi052.modeling_pi052 import ( # noqa: E402
PI05Pytorch as PI052Pytorch,
_build_flow_matching_inputs,
_flow_loss_per_sample,
)
def test_training_rtc_uses_clean_prefix_and_per_token_time():
actions = torch.tensor([[[1.0], [2.0], [3.0], [4.0]]])
noise = torch.tensor([[[10.0], [20.0], [30.0], [40.0]]])
time = torch.tensor([0.25])
prefix_mask = torch.tensor([[True, True, False, False]])
x_t, model_time = _build_flow_matching_inputs(actions, noise, time, prefix_mask)
assert model_time.tolist() == [[0.0, 0.0, 0.25, 0.25]]
assert torch.equal(x_t[:, :2], actions[:, :2])
assert torch.equal(x_t[:, 2:], 0.25 * noise[:, 2:] + 0.75 * actions[:, 2:])
def test_training_rtc_loss_averages_over_postfix_only():
flow_loss = torch.tensor([[[100.0], [100.0], [2.0], [4.0]]])
prefix_mask = torch.tensor([[True, True, False, False]])
per_sample = _flow_loss_per_sample(flow_loss, prefix_mask)
assert per_sample.tolist() == [3.0]
def test_per_token_time_embedding_preserves_action_axis():
time = torch.tensor([[0.0, 0.5, 1.0]])
embedding = create_sinusoidal_pos_embedding(time, 8, 4e-3, 4.0, time.device)
assert embedding.shape == (1, 3, 8)
assert not torch.equal(embedding[:, 0], embedding[:, 1])
def test_action_expert_embeds_per_token_flow_times():
model = PI052Pytorch.__new__(PI052Pytorch)
nn.Module.__init__(model)
model.config = SimpleNamespace(chunk_size=3, min_period=4e-3, max_period=4.0)
model.gradient_checkpointing_enabled = False
model.action_in_proj = nn.Linear(2, 8)
model.time_mlp_in = nn.Linear(8, 8)
model.time_mlp_out = nn.Linear(8, 8)
suffix, _, _, adarms_cond = model.embed_suffix(
torch.randn(2, 3, 2),
torch.tensor([[0.0, 0.5, 0.5], [0.0, 0.0, 0.5]]),
)
assert suffix.shape == (2, 3, 8)
assert adarms_cond.shape == (2, 3, 8)
def test_trained_rtc_prefix_is_padded_and_masked():
x_t = torch.randn(1, 5, 4)
previous = torch.tensor([[1.0, 2.0], [3.0, 4.0], [5.0, 6.0]])
prefix, mask = _prepare_trained_rtc_prefix(x_t, previous, inference_delay=2, training_max_delay=3)
assert prefix.shape == x_t.shape
assert mask.shape == x_t.shape
assert torch.equal(prefix[0, :2, :2], previous[:2])
assert torch.count_nonzero(prefix[0, :2, 2:]) == 0
assert mask[0, :2].all()
assert not mask[0, 2:].any()
def test_trained_rtc_rejects_delay_outside_training_distribution():
with pytest.raises(ValueError, match="exceeds the checkpoint"):
_prepare_trained_rtc_prefix(
torch.randn(1, 5, 4),
torch.randn(4, 2),
inference_delay=4,
training_max_delay=3,
)
@pytest.mark.parametrize("max_delay", [-1, 5])
def test_pi052_config_rejects_invalid_training_rtc_delay(max_delay):
with pytest.raises(ValueError, match="rtc_training_max_delay"):
PI052Config(chunk_size=5, n_action_steps=5, rtc_training_max_delay=max_delay)
@@ -16,6 +16,8 @@
"""Tests for RTC configuration module."""
import pytest
from lerobot.configs.types import RTCAttentionSchedule
from lerobot.policies.rtc.configuration_rtc import RTCConfig
@@ -27,6 +29,7 @@ def test_rtc_config_default_initialization():
config = RTCConfig()
assert config.enabled is True
assert config.mode == "guided"
assert config.prefix_attention_schedule == RTCAttentionSchedule.LINEAR
assert config.max_guidance_weight == 10.0
assert config.execution_horizon == 10
@@ -34,10 +37,16 @@ def test_rtc_config_default_initialization():
assert config.debug_maxlen == 100
def test_rtc_config_rejects_unknown_mode():
with pytest.raises(ValueError, match="mode must be"):
RTCConfig(mode="unknown")
def test_rtc_config_custom_initialization():
"""Test RTCConfig initializes with custom values."""
config = RTCConfig(
enabled=True,
mode="trained",
prefix_attention_schedule=RTCAttentionSchedule.EXP,
max_guidance_weight=5.0,
execution_horizon=20,
@@ -46,6 +55,7 @@ def test_rtc_config_custom_initialization():
)
assert config.enabled is True
assert config.mode == "trained"
assert config.prefix_attention_schedule == RTCAttentionSchedule.EXP
assert config.max_guidance_weight == 5.0
assert config.execution_horizon == 20