lerobot/lerobot/common/optim/schedulers.py

57 lines
1.9 KiB
Python

import abc
import math
from dataclasses import asdict, dataclass
import draccus
from torch.optim import Optimizer
from torch.optim.lr_scheduler import LambdaLR, LRScheduler
@dataclass
class LRSchedulerConfig(draccus.ChoiceRegistry, abc.ABC):
num_warmup_steps: int
@property
def type(self) -> str:
return self.get_choice_name(self.__class__)
@abc.abstractmethod
def build(self, optimizer: Optimizer, num_training_steps: int) -> LRScheduler | None:
raise NotImplementedError
@LRSchedulerConfig.register_subclass("diffuser")
@dataclass
class DiffuserSchedulerConfig(LRSchedulerConfig):
name: str = "cosine"
num_warmup_steps: int | None = None
def build(self, optimizer: Optimizer, num_training_steps: int) -> LambdaLR:
from diffusers.optimization import get_scheduler
kwargs = {**asdict(self), "num_training_steps": num_training_steps, "optimizer": optimizer}
return get_scheduler(**kwargs)
@LRSchedulerConfig.register_subclass("vqbet")
@dataclass
class VQBeTSchedulerConfig(LRSchedulerConfig):
num_warmup_steps: int
num_vqvae_training_steps: int
num_cycles: float = 0.5
def build(self, optimizer: Optimizer, num_training_steps: int) -> LambdaLR:
def lr_lambda(current_step):
if current_step < self.num_vqvae_training_steps:
return float(1)
else:
adjusted_step = current_step - self.num_vqvae_training_steps
if adjusted_step < self.num_warmup_steps:
return float(adjusted_step) / float(max(1, self.num_warmup_steps))
progress = float(adjusted_step - self.num_warmup_steps) / float(
max(1, num_training_steps - self.num_warmup_steps)
)
return max(0.0, 0.5 * (1.0 + math.cos(math.pi * float(self.num_cycles) * 2.0 * progress)))
return LambdaLR(optimizer, lr_lambda, -1)