如何使用 ROS 导入自定义 python 模块？

Question

在 side simulator.py 中，我从 Control 导入了 PID.py，根据 PyCharm IDE 有效。

程序结构：

src
├── quantum_drone
│   ├── CMakeLists.txt
│   ├── Control
│   │   ├── __init__.py
│   │   ├── Keys.py
│   │   ├── MonotonicTime.py
│   │   └── PID.py
│   ├── package.xml
│   └── scripts
│       ├── __init__.py
│       └── simulator.py

我意识到我的根目录 (quantum_drone) 中没有 setup.py 设置，所以我什么时候设置它：

#!/usr/bin/env python
# noinspection PyUnresolvedReferences
from distutils.core import setup
from catkin_pkg.python_setup import generate_distutils_setup
   
# fetch values from package.xml
setup_args = generate_distutils_setup(
     packages=['quantum_drone'],
     scripts=['Control', 'scripts'],
     package_dir={'': 'src'},
 )
 
setup(**setup_args)

在我的 CMakeLists.txt 中，我取消了对 catkin_python_setup() 的注释，并在 catkin_install_python 中写道：

catkin_install_python(PROGRAMS
   scripts/simulator.py
   Control/PID.py
   DESTINATION ${CATKIN_PACKAGE_BIN_DESTINATION}
)

最后，我跑了：

catkin_make 
source devel/setup.bash

我尝试运行： rosrun quantum_drone simulator.py

但我不断收到这条消息：

Traceback (most recent call last):
  Traceback (most recent call last):
  File "/home/kannachan/drone/src/quantum_drone/scripts/simulator.py", line 3, in <module>
    from Control import PID
ImportError: No module named Control

我可以发誓我做了我需要做的一切，所以我不确定我哪里错了以至于我无法导入我的文件/目录。

PID.py 的内容（我可以导入 MonotonicTime.py 就好了）：

#!/usr/bin/env python

from pymavlink import mavutil
from MonotonicTime import monotonic_time
import numpy as np

current_time = monotonic_time


class PID:

    def __init__(self, vehicle, kp=0, ki=0, kd=0, velocity=(0, 0, 0)):
        self.kp = kp  # Constants (kp, ki, kd)
        self.ki = ki
        self.kd = kd
        self.drone = vehicle
        self.p_terms = np.array([0, 0, 0], dtype=float)  # 3-axis
        self.i_terms = np.array([0, 0, 0], dtype=float)
        self.d_terms = np.array([0, 0, 0], dtype=float)
        self.velocity = np.asarray(velocity)  # Desired Velocity
        self.current_velocity = np.array(self.drone.velocity)  # Current Velocity
        self.errors = np.array([0, 0, 0], dtype=float)  # Previous Error
        self.time = current_time()  # Current Time
        self.__max__ = 40  # Max Speed
        self.__min__ = 0  # Min Speed

    def reset(self):
        #  Resetting terms
        self.p_terms = np.array([0, 0, 0], dtype=float)
        self.i_terms = np.array([0, 0, 0], dtype=float)
        self.d_terms = np.array([0, 0, 0], dtype=float)
        self.errors = np.array([0, 0, 0], dtype=float)

    def calculate_change(self):
        now = current_time()
        delta_error = self.velocity - self.current_velocity  # Change in error
        delta_time = now - self.time if now - self.time else 1e-16  # Change in time
        self.time = now
        return delta_error, delta_time

    def pid_calculation(self):
        delta_error, delta_time = self.calculate_change()
        # PID controller formula
        self.p_terms = delta_error * self.kp
        self.i_terms += self.errors * delta_time
        self.d_terms = (delta_error - self.errors) / delta_time
        self.errors = delta_error
        outputs = self.kp * self.p_terms + self.ki * self.i_terms + self.kd * self.d_terms
        outputs = np.where(outputs > self.__max__, self.__max__, outputs)  # Replacing terms too big
        outputs = np.where(outputs < self.__min__, self.__min__, outputs)  # Replacing terms too small
        return outputs

    def send_command(self):
        vx, vy, vz = self.pid_calculation()
        msg = self.drone.message_factory.set_position_target_location_ned_encode(
            0,
            0, 0,
            mavutil.mavlink.MAV_FRAME_BODY_NED,
            0b0000111111000111,
            0, 0, 0,
            vx, vy, vz,
            0, 0
        )
        self.drone.send_mavlink(msg)
        self.drone.flush()

Answer 1

你的导入是错误的。 它应该从 PID 而不是 Control 导入。 同样，在 ROS1 中，您不需要 Python package 的 setup.py 文件。