线程问题以及何时停止

Question

import time
import threading
import qi
import balldetection
import common
import cv2
import vision_definitions
import math 

lock = threading.Lock()

ball_detected = False
ip = "10.42.0.98"
port = 9559
session = qi.Session()
session.connect("tcp://" + ip + ":" + str(port))
motion_service = session.service("ALMotion")
posture_service = session.service("ALRobotPosture")
video_service = session.service("ALVideoDevice")
speak_service = session.service("ALTextToSpeech")

def detect_ball_and_act():
    global ball_detected
    print("In detect_ball_and_act")
    videoClient = video_service.subscribeCamera("nao_opencv", 0, vision_definitions.kQVGA, vision_definitions.kBGRColorSpace, 5)
while not ball_detected:
    print("Not ball detected")
    try:
        print("In try")
        frame = common.readImage(video_service, videoClient)
        if frame is not None:
            print("in none")
            hsv = cv2.cvtColor(frame, cv2.COLOR_BGR2HSV)
            img, (ret, x, y, radius, distance) = balldetection.detect_ball(hsv)
            if ret:
                print("Ball in sight at ({}, {}) with radius {} and distance {}".format(x, y, radius, distance))
                print("Performing action...")
                speak_service.say("Ball is in sight!")
                with lock:
                    ball_detected = True
            else:
                time.sleep(1.0)
    except Exception as e:
        print("An error occurred:", e)

def keep_walking_and_looking():
    while not ball_detected:
        print("Walking and looking around...")
        walk_and_look()

 def walk_and_look():
    print("In walk_and_look")
    motion_service.moveToward(0.5, 0, 0)
    time.sleep(3.0)
    motion_service.moveToward(0, 0, 0)
    time.sleep(1.0)
    motion_service.angleInterpolationWithSpeed(["HeadYaw", "HeadPitch"],     [0.5, 1.0], 0.2)
    time.sleep(1.0)
    motion_service.angleInterpolationWithSpeed(["HeadYaw", "HeadPitch"], [-0.5, 1.0], 0.2)
    time.sleep(1.0)
    motion_service.angleInterpolationWithSpeed(["HeadYaw", "HeadPitch"], [0.0, 0.0], 0.2)

walking_thread = threading.Thread(target=keep_walking_and_looking)
ball_detection_thread = threading.Thread(target=detect_ball_and_act)

motion_service.setStiffnesses("Body", 1.0)
posture_service.goToPosture("StandInit", 1.0)

walking_thread.start()
ball_detection_thread.start()

ball_detection_thread.join()
walking_thread.join()

代码做了我想要的，但我想知道是否有更好的方法来处理这个问题。这是 Nao 机器人的任务，他现在的任务是在房间里走动并寻找球。截至目前，他确实在寻找球并在房间里走来走去，但在他看到球后，他继续走动，这是我想阻止的事情。我知道这是因为线程仍在运行并在他完成步行后停止，但我希望他在看到球后完全停止，因为下一步是他走向球。它应该像一个状态机。

Answer 1

naoqi API 的目的是简化多线程。 因此，要移动和查看，您可以例如执行 Motion_service.post.angleInterpolationWithSpeed 头部会移动，但你的线程不会被阻塞，所以你可以同时继续做某事。

据说，当机器人看到球时，您可以使用运动命令来停止您的移动，例如：motion_service.stopWalk 或motion_service.stopMove。 另请查看 post 方法返回的 id。

idToKillTaskLater = motion_service.post.angleInterpolationWithSpeed

不要犹豫，查看 NAOqi 的文档以及您可以在其中找到的一些示例...