Remove EMA model from Diffusion Policy (#134)

lerobot/scripts/eval.py

@@ -121,7 +121,7 @@ def rollout(
     max_steps = env.call("_max_episode_steps")[0]
     progbar = trange(
         max_steps,
-        desc=f"Running rollout with {max_steps} steps (maximum) per rollout",
+        desc=f"Running rollout with at most {max_steps} steps",
         disable=not enable_progbar,
         leave=False,
     )

lerobot/scripts/train.py

@@ -89,9 +89,6 @@ def update_policy(policy, batch, optimizer, grad_clip_norm, lr_scheduler=None):
     if lr_scheduler is not None:
         lr_scheduler.step()
 
-    if hasattr(policy, "ema") and policy.ema is not None:
-        policy.ema.step(policy.diffusion)
-
     if isinstance(policy, PolicyWithUpdate):
         # To possibly update an internal buffer (for instance an Exponential Moving Average like in TDMPC).
         policy.update()