无人机套件apm2.6 rpi3未接收速度指令

Question

目前有一个raspberry pi通过mavlink连接到运行Arducopter3.2.1的apm2.6。我可以运行一个python脚本，可以武装和起飞无人机没有问题，但当我试图发送速度命令，以移动四方在一个方向，它只是继续在原地徘徊。在发送速度指令时，通过mavlink没有错误，也没有收到ACK，起飞和换模式时收到。降级到dronekit 1.5以确保没有版本问题。代码：

import time
from droneapi.lib import VehicleMode, Location
from pymavlink import mavutil

api = local_connect()
vehicle = api.get_vehicles()[0]

# Demo callback handler for raw MAVLink messages
def mavrx_debug_handler(message):
    print "Received", message

# Set MAVLink callback handler (after getting Vehicle instance)
#vehicle.set_mavlink_callback(mavrx_debug_handler)

def send_ned_velocity(velocity_x, velocity_y, velocity_z, duration):
    """
    Move vehicle in direction based on specified velocity vectors and
    for the specified duration.

    This uses the SET_POSITION_TARGET_LOCAL_NED command with a type mask enabling only 
    velocity components 
    (http://dev.ardupilot.com/wiki/copter-commands-in-guided-mode/#set_position_target_local_ned).

    Note that from AC3.3 the message should be re-sent every second (after about 3 seconds
    with no message the velocity will drop back to zero). In AC3.2.1 and earlier the specified
    velocity persists until it is canceled. The code below should work on either version 
    (sending the message multiple times does not cause problems).

    See the above link for information on the type_mask (0=enable, 1=ignore). 
    At time of writing, acceleration and yaw bits are ignored.
    """
    msg = vehicle.message_factory.set_position_target_local_ned_encode(
        0,       # time_boot_ms (not used)
        0, 0,    # target system, target component
        mavutil.mavlink.MAV_FRAME_LOCAL_NED, # frame
        0b0000111111000111, # type_mask (only speeds enabled)
        0, 0, 0, # x, y, z positions (not used)
        velocity_x, velocity_y, velocity_z, # x, y, z velocity in m/s
        0, 0, 0, # x, y, z acceleration (not supported yet, ignored in GCS_Mavlink)
        0, 0)    # yaw, yaw_rate (not supported yet, ignored in GCS_Mavlink) 

    # send command to vehicle on 1 Hz cycle
    for x in range(0,duration):
        vehicle.send_mavlink(msg)
        time.sleep(1)




def send_global_velocity(velocity_x, velocity_y, velocity_z, duration):
    """
    Move vehicle in direction based on specified velocity vectors.

    This uses the SET_POSITION_TARGET_GLOBAL_INT command with type mask enabling only 
    velocity components 
    (http://dev.ardupilot.com/wiki/copter-commands-in-guided-mode/#set_position_target_global_int).

    Note that from AC3.3 the message should be re-sent every second (after about 3 seconds
    with no message the velocity will drop back to zero). In AC3.2.1 and earlier the specified
    velocity persists until it is canceled. The code below should work on either version 
    (sending the message multiple times does not cause problems).

    See the above link for information on the type_mask (0=enable, 1=ignore). 
    At time of writing, acceleration and yaw bits are ignored.
    """
    msg = vehicle.message_factory.set_position_target_global_int_encode(
        0,       # time_boot_ms (not used)
        0, 0,    # target system, target component
        mavutil.mavlink.MAV_FRAME_GLOBAL_RELATIVE_ALT_INT, # frame
        0b0000111111000111, # type_mask (only speeds enabled)
        0, # lat_int - X Position in WGS84 frame in 1e7 * meters
        0, # lon_int - Y Position in WGS84 frame in 1e7 * meters
        0, # alt - Altitude in meters in AMSL altitude(not WGS84 if absolute or relative)
        # altitude above terrain if GLOBAL_TERRAIN_ALT_INT
        velocity_x, # X velocity in NED frame in m/s
        velocity_y, # Y velocity in NED frame in m/s
        velocity_z, # Z velocity in NED frame in m/s
        0, 0, 0, # afx, afy, afz acceleration (not supported yet, ignored in GCS_Mavlink)
        0, 0)    # yaw, yaw_rate (not supported yet, ignored in GCS_Mavlink) 

    # send command to vehicle on 1 Hz cycle
    for x in range(0,duration):
        vehicle.send_mavlink(msg)
        time.sleep(1)

def arm_and_takeoff(aTargetAltitude):
    """
    Arms vehicle and fly to aTargetAltitude.
    """

    print "Basic pre-arm checks"
    # Don't let the user try to fly autopilot is booting
    if vehicle.mode.name == "INITIALISING":
        print "Waiting for vehicle to initialise"
        time.sleep(1)
    while vehicle.gps_0.fix_type < 2:
        print "Waiting for GPS...:", vehicle.gps_0.fix_type
        time.sleep(1)

    print "Arming motors"
    # Copter should arm in GUIDED mode
    vehicle.mode    = VehicleMode("GUIDED")
    vehicle.armed   = True
    vehicle.flush()

    while not vehicle.armed and not api.exit:
        print " Waiting for arming..."
        time.sleep(1)

    print "Taking off!"
    vehicle.commands.takeoff(aTargetAltitude) # Take off to target altitude
    vehicle.flush()

    # Wait until the vehicle reaches a safe height before processing the goto (otherwise the command 
    #  after Vehicle.commands.takeoff will execute immediately).
    while not api.exit:
        print " Altitude: ", vehicle.location.alt
        if vehicle.location.alt>=aTargetAltitude*0.95: #Just below target, in case of undershoot.
            print "Reached target altitude"
            break;
        time.sleep(1)

arm_and_takeoff(3)


print "Going to first point..."
vehicle.set_mavlink_callback(mavrx_debug_handler)
send_ned_velocity(0,-3,0,3)
vehicle.unset_mavlink_callback(mavrx_debug_handler)
#send_global_velocity(0,-3,0,3)


# sleep so we can see the change in map
time.sleep(5)

print "Landing"
vehicle.mode    = VehicleMode("LAND")
vehicle.flush()

任何帮助都会很棒！ 谢谢