MAVROS 偏航角获取与转换：以东为原点，逆时针为正

以下是一个简单的 Python 代码示例，可以使用 MAVROS 获取飞机的偏航角并将其转换为以东为原点，逆时针为正。

import rospy
from mavros_msgs.msg import State, ExtendedState, PositionTarget
from mavros_msgs.srv import CommandBool, SetMode, CommandTOL
from sensor_msgs.msg import NavSatFix, Imu, MagneticField
from math import degrees, atan2

yaw = 0.0

def imu_callback(data):
    global yaw
    quaternion = (
        data.orientation.x,
        data.orientation.y,
        data.orientation.z,
        data.orientation.w)
    euler = tf.transformations.euler_from_quaternion(quaternion)
    yaw = degrees(euler[2]) % 360.0

def main():
    rospy.init_node('yaw_node', anonymous=True)
    rospy.Subscriber('/mavros/imu/data', Imu, imu_callback)

    while not rospy.is_shutdown():
        # Convert yaw to east as reference, counter-clockwise as positive.
        heading = 90.0 - yaw
        if heading < 0.0:
            heading += 360.0

        rospy.loginfo('Heading: %.2f', heading)
        rospy.sleep(0.1)

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

代码中使用了mavros/imu/data话题来获取IMU数据，然后将四元数转换为欧拉角，最后将偏航角转换为以东为原点，逆时针为正的角度值。可以使用roslaunch启动此节点，并使用rostopic echo命令来查看输出的偏航角。