File size: 11,784 Bytes
aceb411
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
import re
import torch
import torch.nn as nn
import torch.nn.functional as F
import numpy as np
from collections import OrderedDict
from torch.distributions.uniform import Uniform
import math
from typing import Dict, Optional, Tuple, Any
import logging

from utils.hub_mixin import CompatiblePyTorchModelHubMixin
from models.hrdt.model import HRDT


class SigmoidTimestepSampler:
    """
    LogitNormal sampler  
    Sampling: u ~ N(mean, std), t = sigmoid(u)
    """
    def __init__(self, timestep_max=1.0, mean=0.0, std=1.0):
        self.timestep_max = timestep_max
        self.mean = mean  # Normal distribution mean
        self.std = std    # Normal distribution standard deviation
    
    def sample(self, shape):
        """
        LogitNormal sampling, which is sigmoid(randn(m,s))
        
        1. u ~ N(mean, std)
        2. t = sigmoid(u) 
        """
        # Generate normal distribution random numbers u ~ N(mean, std)
        u = torch.normal(mean=self.mean, std=self.std, size=shape)
        # Apply sigmoid transformation to get timesteps in (0,1) range
        t = torch.sigmoid(u)
        # Scale to [0, timestep_max]
        return t * self.timestep_max
    
    def visualize_distribution(self, num_samples=10000):
        """
        Visualize sampling distribution
        """
        samples = self.sample((num_samples,))
        return {
            'samples': samples,
            'mean': samples.mean().item(),
            'std': samples.std().item(),
            'min': samples.min().item(),
            'max': samples.max().item(),
            'config': f'LogitNormal(mean={self.mean}, std={self.std})'
        }


class ActionEncoder(nn.Module):
    """Action encoder that combines state and action adaptors"""
    
    def __init__(self, state_dim, action_dim, hidden_size, config):
        super().__init__()
        self.state_adaptor = self.build_condition_adapter(
            config['st_adaptor'],
            in_features=state_dim,
            out_features=hidden_size
        )
        self.action_adaptor = self.build_condition_adapter(
            config['act_adaptor'],
            in_features=action_dim,
            out_features=hidden_size
        )
    
    def build_condition_adapter(self, projector_type, in_features, out_features):
        projector = None
        if projector_type == 'linear':
            projector = nn.Linear(in_features, out_features)
        else:
            mlp_silu_match = re.match(r'^mlp(\d+)x_silu$', projector_type)
            if mlp_silu_match:
                mlp_depth = int(mlp_silu_match.group(1))
                modules = [nn.Linear(in_features, out_features)]
                for _ in range(1, mlp_depth):
                    modules.append(nn.SiLU())
                    modules.append(nn.Linear(out_features, out_features))
                projector = nn.Sequential(*modules)

        if projector is None:
            raise ValueError(f'Unknown projector type: {projector_type}')

        return projector
    
    def encode_state(self, state_tokens):
        return self.state_adaptor(state_tokens)
    
    def encode_action(self, action_tokens):
        return self.action_adaptor(action_tokens)


class HRDTRunner(
        nn.Module,
        CompatiblePyTorchModelHubMixin,
        repo_url="https://huggingface.co/embodiedfoundation/H-RDT"
    ):
    def __init__(self, *, state_dim, action_dim,
                 pred_horizon, config, act_pos_emb_config=None, img_pos_emb_config=None, lang_pos_emb_config=None,
                 max_img_len=None, max_lang_len=None,
                 training_mode='lang',
                 mode='pretrain',
                 pretrained_backbone_path=None,
                 dtype=torch.bfloat16):
        super(HRDTRunner, self).__init__()
        # Create diffusion model
        hidden_size = config['hrdt']['hidden_size']
        self.gradient_checkpointing = False
        self.hidden_size = hidden_size
        self.training_mode = training_mode
        self.mode = mode  # 'pretrain' or 'finetune'
        
        # Validate mode
        if mode not in ['pretrain', 'finetune']:
            raise ValueError(f"mode must be 'pretrain' or 'finetune', got {mode}")

        # Create H-RDT model
        self.model = HRDT(
            horizon=pred_horizon,
            config=config['hrdt'],
            x_pos_emb_config=act_pos_emb_config,
            img_pos_emb_config=img_pos_emb_config,
            lang_pos_emb_config=lang_pos_emb_config,
            max_img_len=max_img_len,
            max_lang_len=max_lang_len,
            training_mode=training_mode,
            dtype=dtype,
        )

        # Image features adapter - use dimensions from config
        self.img_adapter = self.build_condition_adapter(
            config.get('img_adapter', 'mlp2x_silu'),
            in_features=config.get('vision', {}).get('feature_dim', 2048),  # Default to ResNet50 dim
            out_features=hidden_size
        )
        
        # Action encoder (state and action adaptors)
        self.action_encoder = ActionEncoder(
            state_dim=state_dim,
            action_dim=action_dim,
            hidden_size=hidden_size,
            config=config
        )

        # Language features adapter - use dimensions from config
        self.lang_adapter = self.build_condition_adapter(
            config.get('lang_adapter', 'mlp2x_silu'),
            in_features=config.get('text', {}).get('feature_dim', 768),  # Default to DistilBERT dim
            out_features=hidden_size
        )

        # Create noise scheduler
        noise_scheduler_config = config['noise_scheduler']
        self.num_inference_timesteps = noise_scheduler_config['num_inference_timesteps']
        self.timestep_max = noise_scheduler_config['timestep_max']
        
        sampler_type = noise_scheduler_config.get('sampler_type', 'sigmoid')
        if sampler_type == 'uniform':
            self.timestep_sampler = Uniform(0, self.timestep_max)
        elif sampler_type == 'sigmoid':
            mean = noise_scheduler_config.get('sigmoid_mean', 0.0)
            std = noise_scheduler_config.get('sigmoid_std', 1.0)
            self.timestep_sampler = SigmoidTimestepSampler(self.timestep_max, mean, std)
        else:
            raise ValueError(f"Unknown sampler type: {sampler_type}")

        self.pred_horizon = pred_horizon
        self.action_dim = action_dim

        # TimeNoise config
        self.time_noise_a = config["time_noise"]["a"]
        self.time_noise_beta_m = config["time_noise"]["beta_m"]
        
        self.img_pos_emb_config = img_pos_emb_config

        # Print model size
        print("Model params: %e" % sum(p.numel() for p in self.parameters()))

    @classmethod
    def from_pretrained_for_finetune(cls, pretrained_path, state_dim, action_dim, pred_horizon, config, **kwargs):
        """Create model in finetune mode with pretrained backbone"""
        return cls(
            state_dim=state_dim,
            action_dim=action_dim,
            pred_horizon=pred_horizon,
            config=config,
            mode='finetune',
            pretrained_backbone_path=pretrained_path,
            **kwargs
        )

    def build_condition_adapter(
        self, projector_type, in_features, out_features):
        projector = None
        if projector_type == 'linear':
            projector = nn.Linear(in_features, out_features)
        else:
            mlp_silu_match = re.match(r'^mlp(\d+)x_silu$', projector_type)
            if mlp_silu_match:
                mlp_depth = int(mlp_silu_match.group(1))
                modules = [nn.Linear(in_features, out_features)]
                for _ in range(1, mlp_depth):
                    modules.append(nn.SiLU())
                    modules.append(nn.Linear(out_features, out_features))
                projector = nn.Sequential(*modules)

        if projector is None:
            raise ValueError(f'Unknown projector type: {projector_type}')

        return projector
    
    def gradient_checkpointing_enable(self, value=True):
        """Enable gradient checkpointing for memory efficiency"""
        self.gradient_checkpointing = value
        if hasattr(self.model, "gradient_checkpointing_enable"):
            self.model.gradient_checkpointing_enable(value)

    def compute_loss(self, state_tokens=None, action_gt=None, image_tokens=None, lang_tokens=None, lang_attn_mask=None):
        """
            img_tokens: (batch_size, img_len, img_token_dim)
            state_tokens: (batch_size, chunk_size, action_dim), 
            action_gt: (batch_size, chunk_size, action_dim), ground-truth actions for supervision
            lang_tokens: (batch_size, L, hidden_size), language features (unpooled)
            lang_attn_mask: (batch_size, L), attention mask for language tokens
        """
        batch_size = image_tokens.shape[0]
        device = image_tokens.device
        dtype = image_tokens.dtype

        noise = torch.randn(action_gt.shape, dtype=dtype, device=device)
        timesteps = self.timestep_sampler.sample((batch_size,)).to(device)
        
        broadcasted = timesteps.view(-1, 1, 1)
        noisy_action = (action_gt * broadcasted + noise * (1 - broadcasted)).to(dtype=dtype)

        img_c = self.img_adapter(image_tokens)

        # Process language features - handle None case
        lang_c = None
        if lang_tokens is not None:
            lang_c = self.lang_adapter(lang_tokens)  # [B, L, D] - keep unpooled for cross attention

        # state/action using action encoder
        state_traj = self.action_encoder.encode_state(state_tokens)
        action_traj = self.action_encoder.encode_action(noisy_action)
        state_action_traj = torch.cat([state_traj, action_traj], dim=1)

        pred = self.model(state_action_traj, timesteps, img_c=img_c, lang_c=lang_c, lang_attn_mask=lang_attn_mask)
        target = action_gt - noise
        
        diff_loss = F.mse_loss(pred, target)
        
        return {"diff_loss": diff_loss, "loss": diff_loss}

    @torch.no_grad()
    def predict_action(self, state_tokens=None, image_tokens=None, lang_tokens=None, lang_attn_mask=None):
        '''
        state_tokens: (batch_size, chunk_size, action_dim)
        image_tokens: (batch_size, img_len, in_feat_dim)
        lang_tokens (torch.Tensor): language features [B, L, hidden_size] (unpooled)
        lang_attn_mask: (batch_size, L), attention mask for language tokens
        
        return: (batch_size, chunk_size, action_dim), predicted action sequence
        '''
        batch_size = image_tokens.shape[0]
        device = image_tokens.device
        dtype = image_tokens.dtype

        img_c = self.img_adapter(image_tokens)

        # Process language features - handle None case
        lang_c = None
        if lang_tokens is not None:
            lang_c = self.lang_adapter(lang_tokens)  # [B, L, D] - keep unpooled for cross attention

        state_traj = self.action_encoder.encode_state(state_tokens)
        noisy_action = torch.randn((batch_size, self.pred_horizon, self.action_dim), dtype=dtype, device=device)
        timestep = torch.tensor([0.0], dtype=dtype, device=device)
        step_size = 1.0 / self.num_inference_timesteps

        for _ in range(self.num_inference_timesteps):
            action_traj = self.action_encoder.encode_action(noisy_action)
            state_action_traj = torch.cat([state_traj, action_traj], dim=1)
            pred = self.model(state_action_traj, timestep, img_c=img_c, lang_c=lang_c, lang_attn_mask=lang_attn_mask)
            noisy_action = pred * step_size + noisy_action
            timestep = timestep + step_size

        return noisy_action

    def forward(self, *args, **kwargs) -> torch.Tensor:
        return self.compute_loss(*args, **kwargs)