开源桌面机器鸭 Open Duck Mini 复现指南: 硬件选型、舵机接线与 LeRobot 步态训练

[DC 稳压电源 6V-7.4V 5A]
       |
       +----> 舵机群 VCC (并联至各总线舵机电源脚)
       |
       +----> URT-1 / 舵机驱动板 VIN
       |
       +----> [DC-DC 降压至 5V] ---> ESP32-S3 5V 引脚
       |
       +----> 共地 GND ------------------------+
                                              |
[PC / 树莓派]                                  |
     |                                        |
 (USB-C 数据线)                               |
     |                                        |
     v                                        v
[ESP32-S3] --(TX1/RX1 TTL 半双工)--> [URT-1] --(总线串联信号线)--> [舵机 1~8]

conda create -y -n lerobot python=3.10
conda activate lerobot

# 安装核心依赖与 LeRobot
git clone https://github.com/huggingface/lerobot.git
cd lerobot
pip install -e .
pip install pyserial feetech-servo-sdk

import time
import serial
from dataclasses import dataclass

# 假设使用基础串口协议与 ESP32 或驱动板通信
class OpenDuckMotors:
    def __init__(self, port: str = "/dev/ttyUSB0", baudrate: int = 1000000):
        self.ser = serial.Serial(port, baudrate, timeout=0.05)
        # 初始化舵机 ID 列表：左髋、左膝、右髋、右膝
        self.servo_ids = [1, 2, 3, 4]

    def read_positions(self) -> list[float]:
        """
        读取当前所有关节角度（归一化到 -1.0 至 1.0 之间）
        LeRobot 的策略网络输入要求特征范围规整
        """
        raw_positions = []
        for sid in self.servo_ids:
            # 伪代码：向舵机发送读取位置指令
            self.ser.write(bytearray([0xFF, 0xFF, sid, 0x04, 0x02, 0x38, 0x02]))
            response = self.ser.read(8)
            if len(response) >= 8:
                pos = (response[5] << 8) | response[6]
                # 将 0-4096 映射到 -1.0 到 1.0
                norm_pos = (pos - 2048) / 2048.0
                raw_positions.append(norm_pos)
            else:
                raw_positions.append(0.0)
        return raw_positions

    def write_positions(self, target_positions: list[float]):
        """
        下发控制指令
        """
        assert len(target_positions) == len(self.servo_ids)
        for sid, norm_pos in zip(self.servo_ids, target_positions):
            # 将 -1.0 到 1.0 还原为原始刻度
            raw_pos = int(norm_pos * 2048 + 2048)
            raw_pos = max(0, min(4095, raw_pos))
            # 发送同步写或单写指令
            low_byte = raw_pos & 0xFF
            high_byte = (raw_pos >> 8) & 0xFF
            packet = bytearray([0xFF, 0xFF, sid, 0x05, 0x03, 0x2A, low_byte, high_byte])
            self.ser.write(packet)

    def close(self):
        self.ser.close()

import numpy as np

def generate_duck_gait_step(t: float, freq: float = 1.5) -> list[float]:
    """
    极简的开环对侧摆动步态
    t: 时间戳 (秒)
    """
    phase = 2 * np.pi * freq * t
    # 髋关节负责前倾推进，膝关节负责抬腿离地
    left_hip = 0.3 * np.sin(phase)
    left_knee = 0.4 * np.maximum(0, np.cos(phase))
    right_hip = 0.3 * np.sin(phase + np.pi)
    right_knee = 0.4 * np.maximum(0, np.cos(phase + np.pi))
    return [left_hip, left_knee, right_hip, right_knee]

# 录制 50 组演示片段至本地数据集
python lerobot/scripts/record.py \
    --robot-path lerobot.common.robot_devices.robots.open_duck \
    --fps 30 \
    --num-episodes 50 \
    --run-compute-stats 1 \
    --out-dir data/duck_walking_dataset