chore: 导入gr00t

gr00t/models/gr00t.py

@@ -0,0 +1,124 @@
+
+from .modules import (
+    build_action_decoder,
+    build_action_encoder,
+    build_state_encoder,
+    build_time_sampler,
+    build_noise_scheduler,
+)
+from .backbone import build_backbone
+from .dit import build_dit
+import torch
+import torch.nn as nn
+import torch.nn.functional as F
+
+class gr00t(nn.Module):
+    def __init__(
+            self,
+            backbones,
+            dit,
+            state_encoder,
+            action_encoder,
+            action_decoder,
+            time_sampler,
+            noise_scheduler,
+            num_queries,
+            camera_names,
+    ):
+        super().__init__()
+        self.num_queries = num_queries
+        self.camera_names = camera_names
+        self.dit = dit
+        self.state_encoder = state_encoder
+        self.action_encoder = action_encoder
+        self.action_decoder = action_decoder
+        self.time_sampler = time_sampler
+        self.noise_scheduler = noise_scheduler
+
+        if backbones is not None:
+            self.backbones = nn.ModuleList(backbones)
+        else:
+            raise NotImplementedError
+        
+    def forward(self, qpos, image, actions=None, is_pad=None):
+        is_training = actions is not None # train or val
+        bs, _ = qpos.shape
+
+        all_cam_features = []
+        for cam_id, cam_name in enumerate(self.camera_names):
+            # features, pos = self.backbones[0](image[:, cam_id]) # HARDCODED
+            features, pos = self.backbones[cam_id](image[:, cam_id])
+            features = features[0] # take the last layer feature
+            B, C, H, W = features.shape
+            features_seq = features.permute(0, 2, 3, 1).reshape(B, H * W, C)
+            all_cam_features.append(features_seq)
+        encoder_hidden_states = torch.cat(all_cam_features, dim=1)
+
+        state_features = self.state_encoder(qpos)  # [B, 1, emb_dim]
+
+        if is_training:
+            # training logic
+            
+            timesteps = self.time_sampler(bs, actions.device, actions.dtype)
+            noisy_actions, target_velocity = self.noise_scheduler.add_noise(
+                actions, timesteps
+            )
+            t_discretized = (timesteps[:, 0, 0] * 1000).long()
+            action_features = self.action_encoder(noisy_actions, t_discretized)
+            sa_embs = torch.cat((state_features, action_features), dim=1)
+            model_output = self.dit(sa_embs, t_discretized, encoder_hidden_states)
+            pred = self.action_decoder(model_output)
+            pred_actions = pred[:, -actions.shape[1] :]
+            action_loss = F.mse_loss(pred_actions, target_velocity, reduction='none')
+            return pred_actions, action_loss
+        else:
+            actions = torch.randn(bs, self.num_queries, qpos.shape[-1], device=qpos.device, dtype=qpos.dtype)
+            k = 5
+            dt = 1.0 / k
+            for t in range(k):
+                t_cont = t / float(k)
+                t_discretized = int(t_cont * 1000)
+                timesteps = torch.full((bs,), t_discretized, device=qpos.device, dtype=qpos.dtype)
+                action_features = self.action_encoder(actions, timesteps)
+                sa_embs = torch.cat((state_features, action_features), dim=1)
+                # Create tensor of shape [B] for DiT (consistent with training path)
+                model_output = self.dit(sa_embs, timesteps, encoder_hidden_states)
+                pred = self.action_decoder(model_output)
+                pred_velocity = pred[:, -self.num_queries :]
+                actions = actions + pred_velocity * dt
+            return actions, _
+def build_gr00t_model(args):
+    state_dim = args.state_dim
+    action_dim = args.action_dim
+
+    backbones = []
+    for _ in args.camera_names:
+        backbone = build_backbone(args)
+        backbones.append(backbone)
+
+    cross_attention_dim = backbones[0].num_channels
+
+    dit = build_dit(args, cross_attention_dim)
+
+    state_encoder = build_state_encoder(args)
+    action_encoder = build_action_encoder(args)
+    action_decoder = build_action_decoder(args)
+    time_sampler = build_time_sampler(args)
+    noise_scheduler = build_noise_scheduler(args)
+    model = gr00t(
+        backbones,
+        dit,
+        state_encoder,
+        action_encoder,
+        action_decoder,
+        time_sampler,
+        noise_scheduler,
+        args.num_queries,
+        args.camera_names,
+    )
+
+    n_parameters = sum(p.numel() for p in model.parameters() if p.requires_grad)
+    print("number of parameters: %.2fM" % (n_parameters/1e6,))
+    return model
+
+