用ros 实现一个无人机飞点程序

好的，下面是一个简单的基于ROS的无人机飞点程序，它可以让无人机从初始位置飞到目标点并降落。需要注意的是，这个程序只是一个示例，实际应用中需要根据具体的硬件和场景进行适当的修改和调整。

1. 安装ROS和相关依赖

首先需要安装ROS和相关依赖，例如mavros和mavlink等。

2. 连接无人机

将无人机连接到电脑，启动mavros节点，建立与无人机的通信。

3. 编写飞点程序

#!/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 math import sqrt, pow

class Drone:
    def __init__(self):
        rospy.init_node('drone_node')
        self.current_state = State()
        self.target_position = PoseStamped()
        self.local_position = PoseStamped()
        self.current_yaw = 0.0
        self.yaw_tolerance = 0.1
        self.position_tolerance = 0.2
        self.rate = rospy.Rate(10)

        # Subscribe to state and local position topics
        rospy.Subscriber('/mavros/state', State, self.state_callback)
        rospy.Subscriber('/mavros/local_position/pose', PoseStamped, self.local_position_callback)

        # Set up services for arming and setting mode
        self.set_mode_client = rospy.ServiceProxy('/mavros/set_mode', SetMode)
        self.arm_client = rospy.ServiceProxy('/mavros/cmd/arming', CommandBool)

        # Set up publisher for sending target position
        self.target_position_pub = rospy.Publisher('/mavros/setpoint_position/local', PoseStamped, queue_size=10)

    def state_callback(self, msg):
        self.current_state = msg

    def local_position_callback(self, msg):
        self.local_position = msg

    def set_target_position(self, x, y, z, yaw):
        self.target_position.pose.position.x = x
        self.target_position.pose.position.y = y
        self.target_position.pose.position.z = z
        self.current_yaw = yaw

    def distance_to_target(self):
        dx = self.target_position.pose.position.x - self.local_position.pose.position.x
        dy = self.target_position.pose.position.y - self.local_position.pose.position.y
        dz = self.target_position.pose.position.z - self.local_position.pose.position.z
        return sqrt(pow(dx, 2) + pow(dy, 2) + pow(dz, 2))

    def yaw_difference(self):
        dyaw = self.current_yaw - self.get_local_yaw()
        if dyaw > 3.14159:
            dyaw -= 2*3.14159
        elif dyaw < -3.14159:
            dyaw += 2*3.14159
        return dyaw

    def get_local_yaw(self):
        orientation_q = self.local_position.pose.orientation
        orientation_list = [orientation_q.x, orientation_q.y, orientation_q.z, orientation_q.w]
        _, _, yaw = euler_from_quaternion(orientation_list)
        return yaw

    def arm(self):
        self.arm_client(True)

    def disarm(self):
        self.arm_client(False)

    def set_mode(self, mode):
        self.set_mode_client(custom_mode=mode)

    def set_target_yaw(self, yaw):
        self.current_yaw = yaw

    def send_target_position(self):
        self.target_position_pub.publish(self.target_position)

    def move_to_target_position(self):
        # Arm the drone
        self.arm()

        # Wait for connection to be established
        while not self.current_state.connected:
            self.rate.sleep()

        # Set mode to guided
        self.set_mode('GUIDED')

        # Wait for mode to be set
        while not self.current_state.mode == 'GUIDED':
            self.rate.sleep()

        # Move to target position
        self.set_target_yaw(0.0)
        self.set_target_position(0.0, 0.0, 2.0, 0.0)
        while self.distance_to_target() > self.position_tolerance:
            self.send_target_position()
            self.rate.sleep()

        # Rotate to target yaw
        self.set_target_yaw(1.57)
        while abs(self.yaw_difference()) > self.yaw_tolerance:
            self.send_target_position()
            self.rate.sleep()

        # Move to target position
        self.set_target_position(2.0, 0.0, 2.0, 1.57)
        while self.distance_to_target() > self.position_tolerance:
            self.send_target_position()
            self.rate.sleep()

        # Move to ground level
        self.set_target_position(2.0, 0.0, 0.0, 1.57)
        while self.distance_to_target() > self.position_tolerance:
            self.send_target_position()
            self.rate.sleep()

        # Disarm the drone
        self.disarm()

在这个程序中，我们首先定义了一个名为 Drone 的类，用来封装无人机的状态、目标位置和相关操作。在类的初始化函数中，我们初始化了ROS节点，设置了状态和位置的回调函数，以及一些参数和服务。

在类中，我们定义了一些函数来实现无人机的控制。例如，set_target_position() 函数用来设置目标位置，distance_to_target() 函数用来计算当前位置和目标位置之间的距离，yaw_difference() 函数用来计算当前偏航角和目标偏航角之间的差距等。

最后，在 move_to_target_position() 函数中，我们实现了无人机从初始位置飞到目标点并降落的过程。具体来说，我们首先将无人机解锁并设置为 GUIDED 模式，然后将无人机移动到目标位置，旋转到目标偏航角，再次移动到目标位置并降落，最后将无人机锁定。在这个过程中，我们使用了上述函数来控制无人机的位置和姿态，并使用 send_target_position() 函数将目标位置发送到无人机。

4. 运行程序

在完成程序编写后，运行程序并观察无人机的运动。需要注意的是，实际应用中需要根据具体的硬件和场景进行适当的修改和调整。同时，需要注意安全，确保无人机的飞行不会危及人员和财产安全。