用python写一个mavros的offboard节点脚本

下面是一个使用Python编写的mavros offboard节点脚本示例：

#!/usr/bin/env python

import rospy
from mavros_msgs.msg import State
from mavros_msgs.srv import SetMode, CommandBool
from geometry_msgs.msg import PoseStamped
from std_msgs.msg import Float64

current_state = State()
current_pose = PoseStamped()

def state_cb(msg):
    global current_state
    current_state = msg

def pose_cb(msg):
    global current_pose
    current_pose = msg

def offboard_node():
    rospy.init_node('offboard_node', anonymous=True)

    state_sub = rospy.Subscriber('/mavros/state', State, state_cb)
    pose_sub = rospy.Subscriber('/mavros/local_position/pose', PoseStamped, pose_cb)

    local_pos_pub = rospy.Publisher('/mavros/setpoint_position/local', PoseStamped, queue_size=10)
    arming_client = rospy.ServiceProxy('/mavros/cmd/arming', CommandBool)
    set_mode_client = rospy.ServiceProxy('/mavros/set_mode', SetMode)

    rate = rospy.Rate(20)  # 20hz

    # 等待与飞控建立连接
    while not rospy.is_shutdown() and not current_state.connected:
        rate.sleep()

    # 发送位置控制指令进行起飞
    takeoff_pose = PoseStamped()
    takeoff_pose.pose.position.z = 2.0  # 设置起飞高度
    takeoff_pose.pose.orientation.w = 1.0
    for _ in range(100):  # 发送100次指令以确保起飞
        local_pos_pub.publish(takeoff_pose)
        rate.sleep()

    # 切换到OFFBOARD模式
    offboard_mode = "OFFBOARD"
    while not rospy.is_shutdown() and current_state.mode != offboard_mode:
        set_mode_client(base_mode=0, custom_mode=offboard_mode)
        rate.sleep()

    # 解锁
    arm_cmd = CommandBool()
    arm_cmd.value = True
    while not rospy.is_shutdown() and not current_state.armed:
        arming_client(arm_cmd)
        rate.sleep()

    # 在空中保持悬停
    hover_pose = PoseStamped()
    hover_pose.pose.position.z = 2.0  # 设置悬停高度
    hover_pose.pose.orientation.w = 1.0
    for _ in range(200):  # 悬停10秒钟
        local_pos_pub.publish(hover_pose)
        rate.sleep()

    # 发送位置控制指令进行降落
    land_pose = PoseStamped()
    land_pose.pose.position.z = 0.0  # 设置降落高度
    land_pose.pose.orientation.w = 1.0
    for _ in range(100):  # 发送100次指令以确保降落
        local_pos_pub.publish(land_pose)
        rate.sleep()

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

这个脚本实现了一个简单的mavros offboard节点，用于控制无人机起飞、悬停和降落。你可以根据需要进行修改和扩展。

请确保你已安装ROS、mavros以及相关的依赖包，并且已连接到正确的飞控硬件。在运行脚本之前，你可能还需要修改一些参数，例如起飞高度、悬停高度和降落高度，以适应你的无人机和应用场景。

运行脚本时，使用以下命令：

rosrun <your_package_name> offboard_node.py

请注意，在操作无人机之前，确保你已经熟悉并了解无人机的飞行控制原理和相关安全事项。