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python - 如何从 Python 3 中的无限循环线程获取实时返回值

问题描述

我正在尝试创建一个不断从我的机器人传感器读取的线程，因此我可以在电机的不同运行情况下使用输出的“转向”值，以便能够在旋转、准时等情况下运行电机。我发现了类似的东西（Python从无限循环线程返回值），但这没有帮助，因为它只在我打破循环时打印值（即：断开传感器）。这是我的代码：

from sensor_and_motor_startup import *
import threading
import queue

DEFAULT_SPEED = 60

# PID Values --These are subjective and need to be tuned to the robot and mat
# Kp must be augmented or decreased until the robot follows the line smoothly --Higher Kp = Stronger corrections
# Same with Ki, after Kp is done --- note, Ki is not used in this case (error accumulation)
# Kd to 1, and move up or done until smooth, after Kp and Ki
# This process can take a VERY long time to fine-tune
K_PROPORTIONAL = 0.2
K_INTEGRAL = 0
K_DERIVATIVE = 0


class OneSensorLineFollower:
    target = 24
    error = 0
    last_error = 0
    derivative = 0
    integral = 0

    def __init__(self, color_sensor):
        self.__color_sensor = color_sensor

    def follower(self, side_of_line=None, kp=K_PROPORTIONAL):
        if side_of_line is None:
            side_of_line = self.SideOfLine.left
        else:
            side_of_line = self.SideOfLine.right
        self.error = self.target - (self.__color_sensor.value(3) / 2)
        self.integral = self.error + self.integral
        self.derivative = self.error - self.last_error
        motor_steering = ((self.error * kp) + (self.integral * K_INTEGRAL) + (self.derivative * K_DERIVATIVE
                                                                                          )) * float(side_of_line)
        self.last_error = self.error
        return motor_steering

    class SideOfLine:
        left = 1
        right = -1


def hisp_center_corrector(out_que):
    while True:
        follow = OneSensorLineFollower(left_side_sensor)
        steering = follow.follower(kp=0.15)
        out_que.put(steering)
        sleep(0.1)


def low_speed_follower(speed=DEFAULT_SPEED, rotations=5):
    follower = OneSensorLineFollower(center_sensor)
    steer_pair.on_for_rotations(follower.follower(kp=0.3), speed, rotations)


que = queue.Queue()
t = threading.Thread(target=hisp_center_corrector, args=(que,))
t.start()
t.join()
while True:
    value = que.get()
    print(value)

标签： pythonpython-3.xloopsinfinite-looppython-multithreading

解决方案

您正在调用.join()这使您的主线程等待该线程完成。

将您的线程作为一个守护进程启动并且不要加入它：

threading.Thread(target=hisp_center_corrector, args=(que,), daemon=True).start()

否则您的value = que.get()代码将无法运行。

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