请写出关于ros1的程序填空题

好的，下面是五道关于ROS1程序的填空题：

1. 编写一个ROS节点，发布一个名为"/chatter"的字符串消息，其中的数据为"Hello, ROS!"。请填写下列程序的空白部分。

#!/usr/bin/env python
import rospy
from std_msgs.msg import String

def talker():
    pub = rospy.Publisher(_____, String, queue_size=10)
    rospy.init_node(_____, anonymous=True)
    rate = rospy.Rate(10) # 10hz
    while not rospy.is_shutdown():
        hello_str = "Hello, ROS!"
        rospy.loginfo(hello_str)
        pub.publish(hello_str)
        rate.sleep()

if __name__ == '__main__':
    try:
        talker()
    except rospy.ROSInterruptException:
        pass

答案：

pub = rospy.Publisher('/chatter', String, queue_size=10)
rospy.init_node('talker', anonymous=True)

2. 编写一个ROS节点，订阅名为"/chatter"的字符串消息，并将其输出到终端。请填写下列程序的空白部分。

#!/usr/bin/env python
import rospy
from std_msgs.msg import String

def callback(data):
    rospy.loginfo(rospy.get_caller_id() + "I heard %s", data.data)

def listener():
    rospy.init_node(_____, anonymous=True)
    rospy.Subscriber(_____, String, callback)
    rospy.spin()

if __name__ == '__main__':
    listener()

答案：

rospy.init_node('listener', anonymous=True)
rospy.Subscriber('/chatter', String, callback)

3. 编写一个ROS服务，输入两个整数，返回它们的和。请填写下列程序的空白部分。

#!/usr/bin/env python
import rospy
from beginner_tutorials.srv import AddTwoInts, AddTwoIntsResponse

def handle_add_two_ints(req):
    print("Returning [%s + %s = %s]"%(req.a, req.b, (req.a + req.b)))
    return AddTwoIntsResponse(req.a + req.b)

def add_two_ints_server():
    rospy.init_node(_____)
    s = rospy.Service('add_two_ints', AddTwoInts, handle_add_two_ints)
    print("Ready to add two ints.")
    rospy.spin()

if __name__ == "__main__":
    add_two_ints_server()

答案：

rospy.init_node('add_two_ints_server')

4. 编写一个ROS节点，读取名为"/camera/image_raw"的图像消息，将其转换为OpenCV格式并进行处理，最后将处理后的图像发布到名为"/processed_image"的话题上。请填写下列程序的空白部分。

#!/usr/bin/env python
import rospy
import cv2
from sensor_msgs.msg import Image
from cv_bridge import CvBridge, CvBridgeError

def image_callback(data):
    bridge = CvBridge()
    cv_image = bridge.imgmsg_to_cv2(data, "bgr8")
    
    # 处理图像
    # ...

    pub = rospy.Publisher(_____, Image, queue_size=10)
    try:
        pub.publish(bridge.cv2_to_imgmsg(cv_image, "bgr8"))
    except CvBridgeError as e:
        print(e)

def main():
    rospy.init_node(_____)
    rospy.Subscriber(_____, Image, image_callback)
    rospy.spin()

if __name__ == '__main__':
    main()

答案：

pub = rospy.Publisher('/processed_image', Image, queue_size=10)
rospy.init_node('image_processor')
rospy.Subscriber('/camera/image_raw', Image, image_callback)

5. 编写一个ROS节点，使用MoveIt控制机械臂运动到预定位置。请填写下列程序的空白部分。

#!/usr/bin/env python
import rospy
import moveit_commander
from moveit_msgs.msg import RobotTrajectory
from trajectory_msgs.msg import JointTrajectoryPoint

def moveit_move_to_joint_goal(joint_goal):
    moveit_commander.roscpp_initialize(sys.argv)
    robot = moveit_commander.RobotCommander()
    group = moveit_commander.MoveGroupCommander(_____)
    group.set_joint_value_target(joint_goal)
    plan = group.plan()
    traj = RobotTrajectory()
    traj.joint_trajectory = plan.joint_trajectory
    pub = rospy.Publisher(_____, RobotTrajectory, queue_size=10)
    pub.publish(traj)

if __name__ == '__main__':
    try:
        rospy.init_node(_____)
        joint_goal = [0.0, 0.0, 0.0, 0.0, 0.0, 0.0]
        moveit_move_to_joint_goal(joint_goal)
    except rospy.ROSInterruptException:
        pass

答案：

group = moveit_commander.MoveGroupCommander('arm')
pub = rospy.Publisher('/robot_trajectory', RobotTrajectory, queue_size=10)
rospy.init_node('moveit_test')