Dr. Mark Nan Tu 涂南博士

这是网上找到的拍摄小车的设计, 小车上有智能控制系统，应该可以沿着设置的轨迹移动，也可以遥控，云台主要负责保持相机的稳定性，应该还有图传等辅助设备。

?MAVLink????????

MAVLINK Common Message Set MAVLink ????
These messages define the common message set, which is the reference message set implemented by most ground control stations and autopilots.
????????????,??????????????????????????
??:??? 2012/12/22 ??:V1.0
?????:https://pixhawk.ethz.ch/mavlink/
MAVLink Protocol Version ?? This file has protocol version: 3. The version numbers range from 1-255.
?????:3,???????:1~255
MAVLink Type Enumerations ???
MAV_AUTOPILOT ????
Micro air vehicle / autopilot classes. This identifies the individual model.?????????
?????CMD ID
???Field Name
????Descriptio
????0 MAV_AUTOPILOT_GENERIC
1 MAV_AUTOPILOT_PIXHAWK
2 MAV_AUTOPILOT_SLUGS
3 MAV_AUTOPILOT_ARDUPILOTMEGA
4 MAV_AUTOPILOT_OPENPILOT
5 MAV_AUTOPILOT_GENERIC_WAYP
OINTS_ONL Y
6 MAV_AUTOPILOT_GENERIC_WAYP OINTS_AND_SIMPLE_NAVIGATION_ ONLY
7 MAV_AUTOPILOT_GENERIC_MISSIO N_FULL
Generic autopilot, full support for everything ????,??????
PIXHAWK autopilot, http://pixhawk.ethz.ch
SLUGS autopilot, http://slugsuav.soe.ucsc.edu
ArduPilotMega / ArduCopter, http://diydrones.com
OpenPilot, http://openpilot.org
Generic autopilot only supporting simple waypoints
Generic autopilot supporting waypoints and other simple navigation commands ????,????????????
Generic autopilot supporting the full mission command set
???????????????????????????????????
?????CMD ID
???Field Name
????Descriptio
????????8 MAV_AUTOPILOT_INVALID
9 MAV_AUTOPILOT_PPZ
10 MAV_AUTOPILOT_UDB
11 MAV_AUTOPILOT_FP
12 MAV_AUTOPILOT_PX4
????,??????
No valid autopilot, e.g. a GCS or other MAVLink component ????
PPZ UAV – http://nongnu.org/paparazzi UAV Dev Board
FlexiPilot
PX4 Autopilot – http://pixhawk.ethz.ch/px4/
???????????????????????
MAV_TYPE ?????
?????CMD
????Field Name
????Description
0 1 2 3 4 5 6
7
8
9
10
11
12
13
14
15
16
17
MAV_TYPE_GENERIC MAV_TYPE_FIXED_WING MAV_TYPE_QUADROTOR MAV_TYPE_COAXIAL MAV_TYPE_HELICOPTER MAV_TYPE_ANTENNA_TRACKER MAV_TYPE_GCS
MAV_TYPE_AIRSHIP MAV_TYPE_FREE_BALLOON MAV_TYPE_ROCKET MAV_TYPE_GROUND_ROVER MAV_TYPE_SURFACE_BOAT MAV_TYPE_SUBMARINE MAV_TYPE_HEXAROTOR MAV_TYPE_OCTOROTOR MAV_TYPE_TRICOPTER MAV_TYPE_FLAPPING_WING MAV_TYPE_KITE
ID
Generic micro air vehicle. ??
Fixed wing aircraft. ???
Quadrotor ??
Coaxial helicopter ??
Normal helicopter with tail rotor. ??
Ground installation ??????
Operator control unit / ground control station ???
Airship, controlled ????
Free balloon, uncontrolled ????? Rocket ??
Ground rover ????
Surface vessel, boat, ship ???? Submarine ??
Hexarotor ??
Octorotor ??
Octorotor??:?? Triroter? ?? Flapping wing ???
Flapping wing??:?? Kite???
???????????????????????????????????????????????????????????????????????????????
MAV_MODE_FLAG ?????
These flags encode the MAV mode. ? MAVLink ???,??????????????? ???(Mode)???? 8 ???????????????????,????

MAVLink通讯协议全文副本

MAVLINK Common Message Set MAVLink 消息设置
These messages define the common message set, which is the reference message set implemented by most ground control stations and autopilots.
下列消息是通常的消息设置,这些设置已

1 Flight Modes
2 Major Flight Modes
3 MANUAL
4 STABILIZE
5 FLY BY WIRE_A (FBWA)
6 FLY BY WIRE_B (FBWB)
7 AUTOTUNE
8 TRAINING
9 ACRO
10 CRUISE
11 AUTO
12 Return To Launch (RTL)
13 LOITER
14 CIRCLE
15 GUIDED
16 Mission Specific Modes
17 TAKEOFF
18 LAND

ArduPlane has a wide range of built in flight modes. ArduPlane can act as a simple flight stabilization system, a sophisticated autopilot, a training system or a flight safety system depending on what flight mode and options you choose. Flight modes are controlled through the radio (via a transmitter switch) via mission commands or via ground station (GCS) commands.

To setup your radio to control APM’s Flight Modes use your ground station flight mode setup screen. In the Mission Planner use the Configuration -> Flight Modes screenArduPlane-flightmodes

The above setup shows a configuration for a RC transmitter with a 6 position switch (or a combination of a 3 position switch with a 2 position switch). Each switch position corresponds to a PWM (pulse width modulation) range shown on the right. Each of those switch positions is mapped to one of the available flight modes. In the above example, when the switch is in a position that generates a PWM value of between 1491 and 1620 then ArduPlane will enter Training mode.
上面的这张图展示了6个开关位置（或者一个3档位的开关和一个2档位的开关），每一个档位对应一个PWM数值。

Major Flight Modes (主要飞行模式）
All of the flight modes below have optional additional controls that may be used to change the behaviour to suit particular flying needs. After you have read the introductory material below it is highly recommended that you look through the complete set of ArduPlane parameters so you can explore the full range of functionality available.

MANUAL （手动，没有自稳定）
Regular RC control, no stabilization. All RC inputs are passed through to the outputs. The only ways in which the RC output may be different from inputs are as follows:

if a configured failsafe or geofence triggers, and ArduPlane takes control
if the VTAIL_OUTPUT option is enabled, then a software VTAIL mixer is applied on the output
if the ELEVON_OUTPUT option is enabled, then a software Elevon mixer is applied on the output

STABILIZE （自稳定）（通常用在室内或者起飞，降落时），没有GPS定位，只能保持水平方向平稳。高度，和位置完全靠手动。初学者必须练习和掌握的模式。
RC control with simple stabilization. If you let go of the sticks then ArduPlane will level the plane. This is a bit like flying a plane with a lot of dihedral. You will find that while it is possible to do maneuvers like rolls and loops in stabilize mode, the tendency of the plane to right itself will make these maneuvers difficult. For people wanting the plane to mostly fly itself, with the pilot just telling it where to fly, you are better off using the FlyByWireA mode.

In stabilize mode the throttle is limited by the THR_MIN and THR_MAX settings.

Note that STABILIZE mode is not a good mode to use for tuning the control loops. You are far better off using FBWA for that.

FLY BY WIRE_A (FBWA) （电控飞A），对于大多数新手来说，这是最常用的飞行模式，但事实上，基本没人飞这个模式。
This is the most popular mode for assisted flying in ArduPlane, and is the best mode for inexperienced flyers. In this mode ArduPlane will hold the roll and pitch specified by the control sticks. So if you hold the aileron stick hard right then the plane will hold it’s pitch level and will bank right by the angle specified in the LIM_ROLL_CD option (in centidegrees). It is not possible to roll the plane past the roll limit specified in LIM_ROLL_CD, and it is not possible to pitch the plane beyond the LIM_PITCH_MAX/LIM_PITCH_MIN settings.

Note that holding level pitch does not mean the plane will hold altitude. How much altitude a plane gains or loses at a particular pitch depends on its airspeed, which is primarily controlled by throttle. So to gain altitude you should raise the throttle, and to lose altitude you should lower the throttle. If you want ArduPlane to take care of holding altitude then you should look at the FlyByWireB mode.

In FBWA mode throttle is manually controlled, but is constrained by the THR_MIN and THR_MAX settings.

In FBWA mode the rudder is under both manual control, plus whatever rudder mixing for roll you have configured. Thus you can use the rudder for ground steering, and still have it used for automatically coordinating turns.

FLY BY WIRE_B (FBWB) （电控飞B） 和电控飞A一样，但是有能自动控制高度
The FBWB mode is similar to FBWA, but ArduPlane will try to hold altitude as well. The roll and pitch control is the same as FBWA,and altitude is controlled using the elevator. The target airspeed is controlled using the throttle.

To control your altitude in FBWB mode you use the elevator to ask for a change in altitude. If you leave the elevator centered then ArduPlane will try to hold the current altitude. As you move the elevator ArduPlane will try to gain or lose altitude in proportion to how far you move the elevator. How much altitude it tries to gain for full elevator deflection depends on the FBWB_CLIMB_RATE parameter, which defaults to 2 meters/second.

Whether you need to pull back on the elevator stick or push forward to climb depends on the setting of the FBWB_ELEV_REV parameter. The default is for pulling back on the elevator to cause the plane to climb. This corresponds to the normal response direction for a RC model. If you are more comfortable with the reverse you can set FBWB_ELEV_REV to 1 and the elevator will be reversed in FBWB mode.

If you have an airspeed sensor then the throttle will control the target airspeed in the range ARSPD_FBW_MIN to ARSPD_FBW_MAX. If throttle is mimimum then the plane will try to fly at ARSPD_FBW_MIN. If it is maximum it will try to fly at ARSPD_FBW_MAX.

If you don’t have an airspeed sensor then the throttle will set the target throttle of the plane, and ArduPlane will adjust the throttle around that setting to achieve the desired altitude hold. The throttle stick can be used to push the target throttle up beyond what it calculates is needed, to fly faster.

As with FBWA, the rudder is under a combination of manual control and auto control for turn coordination.

AUTOTUNE 自动调参是pixhawk一个比较牛逼的功能，再也不需要调节飞控的PID值，只要在空中开启自动调参，pixhawk自动设置PID值。不过实际上，飞机的高度是自动控制的，飞机会在空中来回摇晃几分钟，幅度越来越小。
The AUTOTUNE mode flies in the same way as FBWA, but it does automatic tuning of roll and pitch control gains. Please read the full documentation on AUTOTUNE for more details.

TRAINING 培训
This mode is like training wheels on a bicycle and is ideal for teaching students manual R/C control. If the roll is less the the LIM_ROLL_CD parameter than the pilot has manual roll control. If the plane tries to roll past that limit then the roll will be held at that limit. The plane will not automatically roll back to level flight, but it will prevent the pilot from rolling past the limit. The same applies to pitch – the pilot has manual pitch control until the LIM_PITCH_MIN or LIM_PITCH_MAX limits are reached, at which point the plane won’t allow the pitch to go past those limits.

In training mode the rudder and throttle are both completely under manual control.

ACRO （杂技）高级应用，主要用户是想玩电控飞A或者自平衡但是又不想全手动。
ACRO (for acrobatic) is a mode for advanced users that provides rate based stabilization with attitude lock. It is a good choice for people who want to push their plane harder than you can in FBWA or STABILIZE mode without flying in MANUAL. This is the mode to use for rolls, loops and other basic aerobatic maneuvers, or if you just want an “on rails” manual flying mode.

To setup this mode you need to set ACRO_ROLL_RATE and ACRO_PITCH_RATE. These default to 180 degrees/second, and control how responsive your plane will be about each axis.

When flying in ACRO the aircraft will try to hold it’s existing attitude if you have no stick input. So if you roll the plane to a 30 degree bank angle with 10 degrees pitch and then let go of the sticks, the plane should hold that attitude. This applies upside down as well, so if you roll the plane upside down and let go of the sticks the plane will try to hold the inverted attitude until you move the sticks again.

When you apply aileron or elevator stick the plane will rotate about that axis (in body frame) at a rate proportional to the amount of stick movement. So if you apply half deflection on the aileron stick then the plane will start rolling at half of ACRO_ROLL_RATE.

So to perform a simple horizontal roll, just start in level flight then hold the aileron stick hard over while leaving the elevator stick alone. The plane will apply elevator correction to try to hold your pitch while rolling, including applying inverse elevator while inverted.

In the current implementation the controller won’t use rudder while the plane is on it’s side to hold pitch, which means horizontal rolls won’t be as smooth as a good manual pilot, but that should be fixed in a future release. This also means that it won’t hold knife-edge flight.

Performing a loop is just as simple – just start with wings level then pull back on the elevator stick while leaving the aileron alone. The controller will try to hold your roll attitude through the loop. You can stop the loop upside down if you like as part of maneuvers such as Immelman turns or cuban eights.

Note that if you are using ACRO mode to try and teach yourself aerobatic flying then it is highly recommended that you setup a geo-fence in case you get disoriented.

Warning: It is very easy to stall your plane in ACRO mode, and if you stall you should change to MANUAL mode to recover

make sure you know the limitations of your airframe, and what the correct stall recovery procedure is. This varies a lot between airframes. Search for stall recovery tutorials for R/C aircraft and read them
don’t overload your airframe, only fly ACRO mode with a lightly loaded plane
make sure you have enough airspeed for whatever maneuver you are attempting. Throttle and speed control is completely under manual pilot control in ACRO mode
practice stall recovery before trying anything too fancy. Make sure you practice when you have plenty of altitude to give you time to try different recovery strategies
It can be a lot of fun flying ACRO mode, but you can also easily stall and crash hard. Automatic stall detection and recovery in autopilots is an area of research, and is not yet implemented in APM:Plane, so if you do stall then recovery is up to you. The best mode for recovery is MANUAL.

CRUISE （自动巡航）类似电控飞B，但是有机头锁定，较多用于长距离第一视角的飞行
Cruise mode is a bit like FBWB, but it has “heading lock”. It is the ideal mode for longer distance FPV flight, as you can point the plane at a distant object and it will accurately track to that object, automatically controlling altitude, airspeed and heading.

The way it works is this:

if you have any aileron or rudder input then it flies just like FBWB. So it holds altitude until you use the elevator to change the target altitude (at the FBWB_CLIMB_RATE rate) and it adjusts airspeed based on throttle
when you let go of the aileron and rudder sticks for more than 0.5 seconds it sets an internal waypoint at your current location, and projects a target waypoint one kilometre ahead (note that heading lock will only activate if you have GPS lock, and have a ground speed of at least 3 m/s)
as it flies along it heads for the target waypoint, and constantly updates that target to always be one kilometre ahead, leaving the previous waypoint as the position that you centred the aileron and rudder sticks
as long as you don’t touch the aileron or rudder, it will run the same navigation system it uses for waypoints, including crabbing, cross-track etc, so it will very accurately hold that ground course even in the face of changing wind conditions
One of the nicer aspects of CRUISE mode is how it handles rudder. If you give it some rudder then the roll controller will keep the wings level, but the plane will yaw with the rudder. So you get a “wings level” turn, allowing you to rotate your flight to point at whatever geographic feature you want to head towards. Then when you let go of the rudder it will head straight for that point.

Note that CRUISE mode does not currently have the ability to do terrain following. The ability to follow an altitude above ground level over variable terrain is planned for a future release of APM on the PX4 controller board.注意：目前还不能在飞机的高度方面自动跟随地面的高差改变

Warning: Make sure you only fly FPV if it is allowed by your countries flight and airspace control rules. Many countries do not allow non line of sight flight without a special operating license.

AUTO 自动，用在地面站控制，航点（按照GPS坐标）飞行。
In AUTO mode the follow a mission (a set of GPS waypoints and other commands) set by your ground station configuration. When entering AUTO mode ArduPlane will continue from whatever mission item it was last doing, unless you have reset the mission.

When in AUTO ArduPlane will by default allow the pilot to influence the flight of the plane by using “stick mixing”, which allows for aileron, elevator and rudder input to steer the plane in a way that can override the autopilot control. Whether this is enabled is determined by the STICK_MIXING option. By default stick mixing behaves the same as FBWA mode.

Warning: “Home” position is always supposed to be your Planes actual GPS takeoff location:
It is very important to acquire GPS lock before arming in order for RTL, Loiter, Auto or any GPS dependent mode to work properly.
For APM:Plane the home position is the postion of the Plane when you first get GPS lock whether it was armed or not.
This means if you execute an RTL in APM:Plane, it will return to the location where it was when it first acquired GPS lock.
For APM:Plane: Plug in the battery and let it acquire GPS lock where you want it to return to: (Not the Pits).
Return To Launch (RTL)
In RTL mode the plane will return to launch point (the point where the plane first got a GPS lock) and loiter there until manual control is regained (or it runs out of fuel!). As with AUTO mode you can also “nudge” the aircraft manually in this mode using stick mixing. The target altitude for RTL mode is set using the ALT_HOLD_RTL parameter in centimeters.

Alternatively, you may configure the plane to return to a Rally Point, rather than the launch point.

Warning: “Home” position is always supposed to be your Planes actual GPS takeoff location:
It is very important to acquire GPS lock before arming in order for RTL, Loiter, Auto or any GPS dependent mode to work properly.
For APM:Plane the home position is the postion of the Plane when you first get GPS lock whether it was armed or not.
This means if you execute an RTL in APM:Plane, it will return to the location where it was when it first acquired GPS lock.
For APM:Plane: Plug in the battery and let it acquire GPS lock where you want it to return to: (Not the Pits).
LOITER （GPS控制飞行），航拍最常用的模式。可以完全脱控，悬停。飞机移动比较慢，好比用GPS位置控制了飞机在3维空中的位置。
In LOITER mode the plane will circle around the point where you started the loiter, holding altitude at the altitude that you entered loiter in. The radius of the circle is controlled by the WP_LOITER_RAD parameter, but is also limited by your NAV_ROLL_CD limit, and your NAVL1_PERIOD navigation tuning.

As with RTL （自动返航，只要起飞的时候已经定位，那么切这个模式，飞机可以制动返航，并在20米的高度，慢慢降落到起飞的位置）and AUTO mode you can “nudge” the plane while in LOITER using stick mixing, if enabled.

Warning: “Home” position is always supposed to be your Planes actual GPS takeoff location: 自动返航点就是你的飞机上电以后找到的第一个的GPS地点（不管你开没开动马达），所以在以下飞行模式必须在GPS定位以后才能进行，比如RTL，定点定高，自动等
It is very important to acquire GPS lock before arming in order for RTL, Loiter, Auto or any GPS dependent mode to work properly.
For APM:Plane the home position is the postion of the Plane when you first get GPS lock whether it was armed or not.
This means if you execute an RTL in APM:Plane, it will return to the location where it was when it first acquired GPS lock.
For APM:Plane: Plug in the battery and let it acquire GPS lock where you want it to return to: (Not the Pits).

CIRCLE 画圆（类似定点定高，但是不需要GPS定位）（这个模式比较好玩，主要用在航拍一个点，比如宝塔，飞机围绕宝塔转圈，机头永远对着宝塔，半径可调，初设20米）
Circle mode is similar to loiter, but doesn’t attempt to hold position. This is primarily meant as a failsafe mode and is the mode that the aircraft will enter by default for 20 seconds when a failsafe event occurs, before switching to RTL （一键返航）.

Circle mode is deliberately a very conservative mode, and doesn’t rely on GPS positioning as it is used when GPS fails. It will do a large circle, The bank angle is set to the LIM_ROLL_CD divided by 3, to try to ensure the plane remains stable even without GPS velocity data for accelerometer correction. That is why the circle radius is so large.

Circle mode uses throttle and pitch control to maintain altitude at the altitude where it started circling.

GUIDED （导航）主要用于在地面站的数字地图上点击某个位置，然后飞机自动飞过去，另外一个用处，就是地理限围，飞机飞过边界以后，自动进入导航模式，会自动飞到一个返航地点并定点定高，等待下一个操作指令
The GUIDED mode is used when you want the aircraft to fly to a specific point on the map without setting up a mission. Most ground control stations support a “click to fly to” feature where you can click a point on the map and the aircraft will fly to that location when loiter.

The other major use for GUIDED mode is in geo-fencing. When the geo-fence is breached the aircraft will enter GUIDED mode, and head to the predefined geo-fence return point, where it will loiter until the operator takes over.

Mission Specific Modes
When flying an AUTO mission ArduPlane has some sub-modes that are set using mission items. The two main sub-modes are TAKEOFF and LAND.

TAKEOFF 起飞，通常用在使用地面站或者手机控制，自动起飞，到20米高度，然后自动悬停。
Auto takeoff is set by the mission control scripting only. The takeoff mission specifies a takeoff pitch and a target altitude. During takeoff ArduPlane will use the maximum throttle set by the THR_MAX parameter. The takeoff mission item is considered complete when the plane has reached the target altitude specified in the mission.

Before takeoff it is important that the plane be pointing into the wind, and be aligned with the runway (if a wheeled takeoff is used). The plane will try to hold its heading during takeoff, with the initial heading set by the direction the plane is facing when the takeoff starts. It is highly recommended that a compass be enabled and properly configured for auto takeoff, as takeoff with a GPS heading can lead to poor heading control.

If you are using a wheeled aircraft then you should look at the WHEELSTEER_* PID settings for controlling ground steering. If you are hand launching or using a catapult you should look at the TKOFF_THR_MINACC and TKOFF_THR_MINSPD parameters.

LAND 降落
Auto Land is set by the mission control scripting only. Throttle and altitude is controlled by the autopilot. After getting closer LAND_FLARE_ALT meters from the target altitude or LAND_FLARE_SEC seconds from the target landing point the plane will “flare” to the LAND_PITCH_CD pitch (in centidegrees) and will hold heading for the final approach.

Setting up ArduPlane for reliable auto-takeoff and landing is very airframe dependent, and it is recommended that you first get some experience flying your aircraft in FBWA mode, and be ready to take over control in manual or FBWA mode the first few times you use an automatic takeoff or landing.

You should also look through the complete list of parameters, as there are a lot of parameters that help control takeoff and landing for different situations.

1、稳定模式Stabilize
稳定模式是使用得最多的飞行模式，也是最基本的飞行模式，起飞和降落都应该使用此模式。
此模式下，飞控会让飞行器保持稳定，是初学者进行一般飞行的首选，也是FPV第一视角飞行的最佳模式。
一定要确保遥控器上的开关能很方便无误地拨到该模式，这对抢救紧急情况十分重要！

2、定高模式ALT_HOLD
初次试飞之后就可以尝试定高模式，此模式不需要GPS支持，APM会根据气压传感器的数据保持当前高度。
定高时如果不会定点，因此飞行器依然会漂移。可以遥控来移动或保持位置。
定高时就是APM控制油门来保持高度。但仍然可以用遥控油门来调整高度，不可以用来降落，因为油门不会降到0。
稳定模式和定高模式之间切换时，要让遥控发射机的油门在同一位置，避免因模式切换、油门控制方式发生变化造成飞行器突然上升或者下降。

3、悬停模式Loiter
悬停模式就是GPS定点模式。应该在起飞前先让GPS定点，避免在空中突然定位发生问题。其他方面跟定高模式基本相同。

4、简单模式Simple Mode
设置过APM飞行模式的朋友都会注意到，软件界面的各个模式旁边，都有个“Simple Mode”简单模式的勾选框。勾了这个框之后的模式，飞行中会更加简单：
不用再管飞行器机头的朝向，可以将飞行器看成一个点，如果升降舵给出俯冲指令，飞行器就会飞得远离操作者；反之如果给出拉杆指令，飞行器会飞回操作者；给出向左滚转的指令，飞行器会向左飞，反之亦然。。。注意，这些前后左右的飞行，是不管当时的机头指向的！

5、返航模式RTL
返航模式需要GPS定位。GPS在每次ARM前的定位点，就是当前的“家”的位置；GPS如果在起飞前没有定位，在空中首次定位的那个点，就会成为“家”。
进入返航模式后，飞行器会升高到15米，或者如果已经高于15米，就保持当前高度，然后飞回“家”。
还可以设置高级参数选择到“家”后是否自主降落，和悬停多少秒之后自动降落。

6、绕圈模式Circle
当切入绕圈模式时，飞行器会以当前位置为圆心绕圈飞行。而且此时机头会不受遥控器方向舵的控制，始终指向圆心。
如果遥控器给出横滚和俯仰方向上的指令，将会移动圆心。
与定高模式相同，可以通过油门来调整飞行器高度，但是不能降落。
圆的半径可以通过高级参数设置调整。

7、指导模式Guided
此模式需要地面站软件和飞行器之间通信。连接后，在任务规划器Mission Planner软件地图界面上，在地图上任意位置点鼠标右键，选弹出菜单中的“Fly to here”（飞到这里），软件会让你输入一个高度，然后飞行器会飞到指定位置和高度并保持悬停。

8、跟随模式FollowMe
跟随模式基本原理是：操作者手中的笔记本电脑带有GPS，此GPS会将位置信息通过地面站和数传电台随时发给飞行器，飞行器实际执行的是“飞到这里”的指令。其结果就是飞行器跟随操作者移动。
由于此模式需要额外的设备，暂时不讨论。

9、自动模式Auto
此模式下飞行器会自动执行地面站Mission Planner设定好的任务，例如起飞、按顺序飞向多个航点、旋转、拍照等。
此模式内容丰富，会另行详细介绍。

10: 手动：MANUAL （完全手动，没有自稳定）

11: 自动起飞，TAKEOFF 通常用在使用地面站或者手机控制，自动起飞，到20米高度，然后自动悬停。

12: 自动降落 LAND，顾名思义，就是用手机或者地面站控制，自动降落。要保证地面水平哦，否则。。。

13:自动调参AUTOTUNE 是pixhawk一个比较牛逼的功能，再也不需要调节飞控的PID值，只要在空中开启自动调参，pixhawk自动设置PID值。不过实际上，飞机的高度是自动控制的，飞机会在空中来回摇晃几分钟，幅度越来越小。

1、四轴需要准备什么零件
无刷电机（4个）
电子调速器（简称电调，4个，常见有好盈、中特威、新西达等品牌）
螺旋桨（4个，需要2个正浆，2个反浆）
飞行控制板（常见有KK、FF、玉兔等品牌）
电池（11.1v航模动力电池）
遥控器（最低四通道遥控器）
机架（非必选）
充电器(尽量选择平衡充电器)

2、四轴零件之间的接线与简单说明

4个电调的正负极需要并联（红色连一起，黑色连1一起），并接到电池的正负极上；
电调3根黑色的电机控制线，连接电机；
电调有个BEC输出，用于输出5v的电压，给飞行控制板供电，和接收飞行控制板的控制信号；
遥控接收器连接在飞行控制器上，输出遥控信号，并同时从飞行控制板上得到5v供电；

【基本原理与名词解释】
1、遥控器篇
什么是通道？
通道就是可以遥控器控制的动作路数，比如遥控器只能控制四轴上下飞，那么就是1个通道。但四轴在控制过程中需要控制的动作路数有：上下、左右、前后、旋转
所以最低得4通道遥控器。如果想以后玩航拍这些就需要更多通道的遥控器了。

什么是日本手、美国手？
遥控器上油门的位置在右边是日本手、在左边是美国手，所谓遥控器油门，在四轴飞行器当中控制供电电流大小，电流大，电动机转得快，飞得高、力量大。反之同理。判断遥控器的油门很简单，遥控器2个摇杆当中，上下板动后不自动回到中间的那个就是油门摇杆。

2、飞行控制板篇
一般简称飞控就是这个东西了。
飞控的用途？
如果没有飞控板，四轴飞行器就会因为安装、外界干扰、零件之间的不一致型等原因形成飞行力量不平衡，后果就是左右、上下的胡乱翻滚，根本无法飞行，飞控板的作用就是通过飞控板上的陀螺仪，对四轴飞行状态进行快速调整（都是瞬间的事，不要妄想用人肉完成），如发现右边力量大，向左倾斜，那么就减弱右边电流输出，电机变慢，升力变小，自然就不再向左倾斜。

什么是x模式和+模式？

购买飞控的时候老板都要问这个问题，刷买什么模式的，以上就是区别。
X模式要难飞一点，但动作更灵活。+模式要好飞一点，动作灵活差一点，所以适合初学者。
特别注意，x模式和+模式的飞控安装是不同的（我只有kk飞控板，所以只能讲kk飞控）。
如果飞控板安装错误，会剧烈的晃动，根本无法飞。
四轴3.jpg
四轴2.jpg

选什么飞控好？
个人意见初学的先来个kk飞控吧，最便宜，尝个鲜够用了。

电调篇
为什么需要电调？
电调的作用就是将飞控板的控制信号，转变为电流的大小，以控制电机的转速。
因为电机的电流是很大的，通常每个电机正常工作时，平均有3a左右的电流，如果没有电调的存在，飞控板根本无法承受这样大的电流（另外也没驱动无刷电机的功能）。
同时电调在四轴当中还充当了电压变化器的作用，将11.1v的电压变为5v为飞控板和遥控器供电。

买多大的电调？
电调都会标上多少A，如20a，40a 这个数字就是电调能够提供的电流。大电流的电调可以兼容用在小电流的地方。小电流电调不能超标使用。
根据我简单测试，常见新西达2212加1045浆最大电机电流有可能达到了5a，为了保险起见，建议这样配置用30a 或 40a电调（大家用20a电调的也多），说买大一点，以后还可以用到其他地方去。

四轴专用电调是什么意思？
因为四轴飞行要求，电调快速响应，而电调有快速响应和慢速响应的区别，所以四轴需要快速响应的电调。
其实大多数常见电调是可以编程的，能通过编程来设置响应速度。所以其实并没有什么专用一说。

电调编程什么意思？
首先要说明电调是有很多功能模式的，选择这个功能就是对电调编程。
编程的途径可以直接将电调连接至遥控接收机的油门输出通道（通常是3通道），按说明书，在遥控器上通过搬动摇杆进行设置，这个方法比较麻烦，但节约。另外，还可以通过厂家的编程卡来进行设置（需要单独购买），方法简单，无需接遥控器。
为了保险，一定要将购买的电调设置一致，否则容易难于控制。如：电调的启动模式不一样，那么有些都转很快了，有些还很慢，这就有问题了。
注：通过遥控器进行设置电调，一定要接上电机，因为说明书上说的“滴滴”类的声音，是通过电机发出来的。我开始就是因为没有接电机，还疑惑怎么没声音，以为坏了。

无刷电机与螺旋桨篇
电机分为有刷电机和无刷电机，不要买错了，无刷是四轴的主流。它力气大，耐用。
电机的型号含义？
经常看人说什么2212电机，2018电机等等，到底是什么意思呢？这其实电机的尺寸。
不管什么牌子的电机，具体都要对应4位这类数字，其中前面2位是电机转子的直径，后面2位是电机转子的高度。注意，不是外壳哦。
简单来说，前面2位越大，电机越肥，后面2位越大，电机越高。 又高又大的电机，功率就更大，适合做大四轴。 通常2212电机是最常见的配置了。
四轴5.jpg

什么是电机kv值？
每个无刷电机都会标准多少kv值，这个kv是外加1v电压对应的每分钟空转转速，例如：1000kv电机，外加1v电压，电机空转时每分钟转1000转，外加2v电压，电机空转就2000转了。

桨的型号含义？
同电机类似，桨也有啥1045,7040这些4位数字，前面2位代表桨的直径（单位：英寸 1英寸=254毫米）后面2位是桨的角度。

什么是正反桨，为什么需要它？
四轴飞行为了抵消螺旋桨的自旋，相隔的桨旋转方向是不一样的，所以需要正反桨。正反桨的风都向下吹。适合顺时针旋转的叫正浆、适合逆时针旋转的是反浆。安装的时候，一定记得无论正反桨，有字的一面是向上的（桨叶圆润的一面要和电机旋转方向一致）。

电机与螺旋桨的搭配
这是非常复杂的问题，我自己也在研究当中，所以建议采用大家常见的配置吧，但原理这里可以阐述一下。
螺旋桨越大，升力就越大，但对应需要更大的力量来驱动；
螺旋桨转速越高，升力越大；
电机的kv越小，转动力量就越大；
综上所述，大螺旋桨就需要用低kv电机，小螺旋桨就需要高kv电机（因为需要用转速来弥补升力不足）
如果高kv带大桨，力量不够，那么就很困难，实际还是低俗运转，电机和电调很容易烧掉。
如果低kv带小桨，完全没有问题，但升力不够，可能造成无法起飞。
例如：常用1000kv电机，配10寸左右的桨。

电池和充电器篇
为什么要选锂电池？
同样电池容量锂电最轻，起飞效率最高。

电池的多少mah时什么意思？
表示电池容量，如1000mah电池，如果以1000ma放电，可持续放电1小时。如果以500mh放电，可以持续放电2小时。

电池后面的2s，3s，4s什么意思？
代表锂电池的节数，锂电池1节标准电压为3.7v，那么2s电池，就是代表有2个3.7v电池在里面，电压为7.4v。

电池后面多少c是什么意思？
代表电池放电能力，这是普通锂电池和动力锂电池最重要区别，动力锂电池需要很大电流放电，这个放电能力就是C来表示的。如1000mah电池 标准为5c，那么用5x1000mah，得出电池可以以5000mh的电流强度放电。
这很重要，如果用低c的电池，大电流放电，电池会迅速损坏，甚至自燃。

多少c快充是什么意思？
这个与上面的c一样，只是将放电变成了充电，如1000mah电池，2c快充，就代表可以用2000ma的电流来充电。所以千万不要图快冒然用大电流，超过规定参数充电，电池很容易损坏。

怎么配电池？
这与选择的电机、螺旋桨，想要的飞行时间相关。
容量越大，c越高，s越多，电池越重；
基本原理是用大桨，因为整体搭配下来功率高，自身升力大，为了保证可玩时间，可选高容量，高c，3s以上电池。最低建议1500mah，20c，3s。
小四轴，因为自身升力有限，整体功率也不高，就可以考虑小容量，小c，3s以下电池。（没玩过，不做建议）

平衡充电什么意思
如3s电池，内部是3个锂电池，因为制造工艺原因，没办法保证每个电池完全一致，充电放电特性都有差异，电池串联的情况下，就容易照常某些放电过度或充电过度，充电不饱满等，所以解决办法是分别对内部单节电池充电。动力锂电都有2组线，1组是输出线（2根），1组是单节锂电引出线（与s数有关），充电时按说明书，都插入充电器内，就可以进行平衡充电了。

机架篇
机架的轴长短有没有规定？
理论上讲，只要4个螺旋桨不打架就可以了，但要考虑到，螺旋桨之间因为旋转产生的乱流互相影响，建议还是不要太近，否则影响效率。 这也是为什么四轴用2叶螺旋桨比用3叶螺旋桨多的原因之一（3叶的还有个缺点，平衡不好做）

【实战调试】
安装好四轴以后是需要做一些准备工作的，这里以我用过的kk飞控为例
Kk飞控的连接
四轴7.jpg

飞控解锁
飞控接上电不是马上可以起飞的，这是安全设计，所以需要解锁。（飞控设置略，很多攻略了）
通上电，飞控板上的灯是不亮的，只有电调发出的滴滴声，将油门打到最低（注意油门方向，需要实现确定是设置的向上为最低，还是向下为最低），然后方向舵向右板到底，飞控板的灯就会亮，电调也不会再继续发声，说明准备好起飞了。

螺旋桨的安装
调试完毕，最后安装螺旋桨，安装好后，第一件事是拿手上，轻加油门，看看是否风都往下吹，电机的旋转是否是 正转和反转间隔的。如果剧烈抖动，并且升力很小，就应该是正反浆没有安装对。交换一下。 如果旋转方向不是间隔的，就需要将电调和电机的连接线1和3，交换一下，进行旋转方向校正。 次序为，先方向，后螺旋桨。

注意电池过放
电调是可以设置电池低压保护的，但尽量不要等电调保护的时候才充电，这样可以延长使用寿命。

我怎么知道能正常起飞？
一切准备完毕，怎么知道可以试飞了呢，我个人建议为了避免匆忙上马，秒炸。先拿手上试飞比较好，但要注意离身体距离。
拿手上通电，加油门，如果一切正常，四轴是 不会大幅度的晃动的，而是比较平稳。还可以故意左右晃动一下，会感觉到四轴保持平衡的反力量，只要达到这个效果，就基本达到了试飞的条件。kk飞控我复位了好几次，只要没有意外，是基本都能成功的。
试飞场地建议选草坪，这样的不容甩坏。

It can sometimes be difficult to know which battery is best for your application.
For R/C aircraft there is a huge variety of batteries available and while many may suit your application your ultimate goal is to purchase a battery pack that will;
-be within your budget 预算之内
-have a long cycle life 使用寿命长
-have the correct size and weight 大小，重量合适
-give you the longest flight times 以上满足的前提下，最长的飞行时间
-be able to deliver the correct voltage/amp (Power) 输出的电流和电压正确
We hope this simple guide helps you understand the different types of LiPoly (Lithium Polymer) batteries and which is right for your model.

You may have noticed by now that batteries have different ratings, sizes, plugs, wire, charge rates and chemical makeup. Lets decipher;

Capacity (mAh). 容量
This is usually the biggest number shown on the pack and is measured in mAh (Milliamp/hour) or Ah (Amp/hour). The capacity is the first indicator of the batteries size. To keep things simple, think of capacity (mAh) as the amount of fuel in your cars gas tank. A higher capacity tank will run your car for longer. A 4,000mAh battery will run for twice as long as a 2,000mAh battery.
A 2,000mah battery will (in theory) run for 1hr if drained at a constant 2,000 Milliamps.
原则上（没有虚标的话），2000mah的电池以2000milliamps放电的话可以用1小时。

Discharge (C) 放电
Discharge is the amount of power the battery can ‘push’ out and the number shown ’20C’ is an multiplication of the capacity. For example; A 20C battery can discharge at 20 x 2,000mAh which is 40,000mAh or 40Amps.
20C就是20倍电池容量，比如20C的2000mah放电是20*2000 或者40Amps

瞬时放电就是电池瞬时（10－20秒）可以达到的最高电量
This is an important number if you know your motor requires a certain power level.
In addition to this, batteries have a ‘Burst’ rate, which is the amount of power the battery can discharge for a short period, usually 10-20 seconds. A typical battery label may show 20-30C, this would mean a 1,000mAh battery can discharge 20,000mAh constantly or give a sudden and short 10-20 second 30,000mAh (30A) burst of power.
比如：一块1000mah电池写20－30C，可以按照20amps长期放电或者可以按照30amps短时放电。
Tip: A higher ‘C’ rated battery will last longer if run at a lower ‘C’ rate. Example: a 30C battery run at 20C maximum will have a longer cycle life than a 20C run at 20C each flight.

Voltage (S)电压
All lithium Polymer cells in any industry have a nominal voltage of 3.7v per cell. When fully charged a LiPoly cell should be 4.2v and when discharged it should never be below 3v.
You will notice that LiPoly RC packs are made up of layers of multiple cells. If the battery’s rating is 3S this means it is 3 x 3.7v which is 11.1v. It has 3 layers of 3.7v each. In other words, its a ‘3 cell pack’.
Lipo电池的通用标准是3.7v每一个单元，4.2v(满电）或者3V(放完），一个3单元的电池，就是3*3.7v或者11.1v。
Weight/Size
For a battery to be right for your model it must fit within the models battery compartment and also balance the plane correctly.
It’s temping to choose the biggest and most powerful battery your model can handle, but this will sacrafice flight performance and if your packs voltage is too high; destroy the ESC or Motor.
Check with your ESC and Motor specification to ensure you have the right voltage pack then check the models CG (Center of Gravity) to decide on the right battery weight.
电池的电压要与电机匹配而且要考虑平衡等因素

LiPoly Charging
Always use a lithium Polymer battery charger and never charge the battery above 4.2v per cell. (example: 2S, never above 8.4v)
Never leave a charging battery unattended.
Never allow the battery’s voltage to fall below 3.2v per cell. (example: 3S, never below 9.6v)
充电时，不要充过每个单元4.2V或者3个单元12.6v，
放电时，不要低于3每个单元3.2V或者3个单元9.6v.

只要是串口透传（透明传输，不管什么协议，一个只管发，一个只管接），就支持apm数传， 注意要设置默认波特率57600。3DR 和其它433Mhz数传， 基本上是Si1000芯片（带MCU)，也可以预设912Mhz频段。其它433芯片也可以使用，理论最距离一般在1000M以内ZigBee/XBee 是基于2.4G频段的，3DR没有使用可能会和2.4G遥控器有干扰，当然贵也是一个原因。我自己先用蓝牙HC-06接APM, 手机就连接DroidPlanner和Ardupilot，电脑有蓝牙的话可以，当然距离很短。后来自己diy了si4463透传模块(mcu用stm8)，接收使用si4463+蓝牙，也可以正常接收。

注：跟随飞行功能将给无人机非常多的用途，最近在kickstarter上成功融资百万美元的几个项目都是使用这个功能，从这个开发者的原话来看，只要有开源的pixhawk飞控，加上配套的数字传输，加上任何一个安卓手机上安装上免费的，就可以实现跟随飞行，而且从原文下面的讨论来看，跟随功能不仅能在头顶跟踪，而且能够赋予一定的余量，比如在身后10米，高10米的地方跟随。
使用的场景有：摩托车，高山滑雪，滑水，翼装飞行，田径，自行车等运动的跟踪拍摄，小孩上学的护送，高尔夫球包车，仓库管理与行李运输等。可以说是无人机领域的一个killerapp。
当然这里面的水还是非常深的，比如躲避使用者头上的树枝障碍，准确的高度跟踪，等。
目前看到的技术基本都是不能自己计算轨迹的，关键是无人机本身不能产生地图，所以无法自动计算轨迹。

这是原文：
3D Robotics is thrilled to introduce the Follow Me feature, the latest adventure in autonomous flight. Follow Me mode allows you to be your own one-man aerial film crew: Capture yourself in action, with all the freedom of spontaneity and zero pre-planning, even when there’s no one around to helm the sticks for you. Just select “Follow” in DroidPlanner, strap on your Android phone or throw your tablet in your backpack, and your drone will follow wherever you go—and keep the camera trained on you the whole time! Place your Android device on another vehicle—say a car, boat, or rover—and Follow Me tracks that for you, too.
Best of all, it’s totally free from 3D Robotics, and it’s available today. You just need the beta of the new DroidPlanner 2.0 (free here) and the latest release candidate (3.2 RC 2) version of Arducopter (free here).*

To get the beta of DroidPlanner, please follow these instructions:
1) Join the Google+ community
2) Become a beta tester
3) Download the app from the Play Store (this may take 30 mins or so to go live for you after you become a beta tester)
To get the latest release candidate of Arducopter, select “Beta software” from the firmware upload screen of Mission Planner or APM Planner.
Both of these will be coming out of beta in a few weeks (after the Sparkfun AVC), so if you’d rather not be using beta software, just sit tight and it will automatically come to you with the next public update.
Follow Me frees you to be yourself, by yourself. Happy flying!
*Please note that as advised in the warning notice in Mission Planner and APM-Planner 2, Beta versions and release candidates are by definition unstable and should only be used by expert operators and only to help the developers test the code during the pre-release test cycle in direct coordination with the developers. In those versions, bugs are very likely to be present and the operator should be aware of a significantly higher operational risk and choose location and operation modes for flights accordingly, as well as be prepared for the possibility of undesired behavior of the aircraft and even a catastrophic failure.

Friendly drones are innovative, cutting edge and afforded with life changing technology.
Just to give you an idea of how they can be of assistance to us, we have listed 22 of their most compelling applications:
1. News Gathering.
Imagine photo-journalists being able to capture bird’s-eye views of breaking news such as national elections, disaster zones and war zones. Aerial coverage of events like these are set to revolutionise news gathering. Example: UK company Aerialvue

2. Energy Conservation.
Drones fitted with infrared sensors are able to scan buildings to detect heat losses. The reported data can then be used to implement energy and money saving building enhancements.

3. Protecting Endangered Wildlife.
Poaching of endangered wildlife such as rhinos and tigers is a major concern. Park Rangers around the world have already begun to successfully use drones to help monitor wildlife habitats. This is proving to be effective at deterring poachers.

4. Aerial Photography.
This is already a booming sector. We all love to see aerial images, and many companies are willing to pay generously for the privilege of having aerial footage of their products and buildings. Aerial photography is also the number one reason why people buy their first drone. It is a great hobby! Example: Award-Winning Aerial Photographer Brent Foster

5. Search and Rescue Assistance.
A drone really could save your life. Search and Rescue teams around the globe are starting to discover how helpful drones can be. Search and rescue times can be massively reduced, and difficult ground conditions can be circumvented. Example: A pioneering search and rescue drone trial by research staff at the University of Central Lancashire (UCLan)

6. Wildfire Mapping.
Forest fires can be catastrophic. Anything that can help reduce their spread is sure to be readily accepted. Drones fit this category. They are able to fly over wildfires and provide real-time mapping that can allow firefighters to make critical decisions.

7. Providing Internet Access.
Google and Facebook are already moving into this space. Using giant solar-powered drones it appears that in the near future isolated areas will have high-speed internet coverage for the first time. A very promising technology. Example: Solar drone Titan Aerospace Solara 50

8. Relieving Traffic Congestion.
Roads in towns and cities become more crowded and perilous every day. Picture a team of lightweight camera drones that fly high above the congested areas at peak times and relay what they see back to traffic controllers. Faster flowing and safer roads are the likely outcome.

9. Humanitarian Assistance in Disaster Zones.
We’ve all seen how nature can suddenly wreak havoc on a towns, villages and cities. Tsunamis, storms and earthquakes are often devastating and deadly. Drones could be used to fly into the affected areas to provide mapping, to deliver food and aid, and to go where roads may no longer exist. Example: company Matternet

10. Measuring Environmental Pollutants.
Are you really sure what toxins and fumes factories, farms and other industrial sites are releasing into the atmosphere? Drones are designed to measure environmental pollutants could tell you exactly this information. They could also help ensure that companies are not breaching environmental regulations.

11. Tracking Hurricanes and Tropical Storms.
To be forewarned of when and where a storm or hurricane is likely to hit can be a major advantage. Buildings can be protected and people moved out of harm’s way. Unmanned aerial vehicles can fly safely near and above storms to provide vital tracking and monitoring. Example: NASA ERAST Program on Wikipedia

12. Air Delivery.
Yes, Amazon and Jeff Bezos have made delivery by drones a very well known and highly-anticipated development. But it not just Amazon who want to fly things to you. Other companies already experimenting with this new technology include Dominos and DHL. Expect many more. Example: Amazon Prime Air

13. Geophysical Surveys for Oil, Gas and Minerals.
These commodities are becoming increasingly harder to find. Drones make it cheaper and easier for exploration companies to assess suitable areas for test drilling.

14. Aerial Footage in Filmmaking.
What used to be the domain of big-budget Hollywood blockbusters is now within range of even the smallest film production. Drones are rapidly replacing manned planes and helicopters to provide cheap, safe and stunning aerial footage.

15. Livestock Monitoring.
Farmers often leave their livestock unattended for long periods of time. Animals can be stolen, injured or lost without warning. A video drone can provide constant monitoring of livestock, and even track wandering animals.

16. Pipeline Security.
Much of the world’s oil and gas is located in politically unstable and often dangerous regions. Attacks on pipelines are common. Drones can help monitor pipelines and help deter attackers. They can also be used to pinpoint maintenance issues.

17. Delivering Medical Supplies to Hard-to-Reach Areas.
There are many places in the world where roads are either in disrepair or don’t exist at all. People living in remote villages are often cut-off from access to emergency medical care. Drones could prove to be lifesavers. They are able to fly essential medical aid direct to communities who otherwise would be unreachable by land.

18. Event Coverage.
The Sochi 2014 Winter Olympics gave us a glimpse into the near future. Video drones were skillfully deployed to capture unique and breathtaking footage of various Olympic events. Other sporting and cultural events are also likely to soon see the benefits of drones and aerial photography. The viewer is the real winner.

19. Urban Planning.
Property developers and planning approvers have a new tool. Drones can take detailed images, surveys and maps of prospective sites. Significant time and effort can be saved by capturing aerial imagery of areas marked for development.

20. Exploring the Undersea World.
Humans are restricted in the depth they can travel in the seas and oceans. Drones are not. Detailed 3D imaging of the ocean depths for monitoring and research are possible with undersea drones. Sea-life can also be safely studied with drones, as in the recent example of Great White Sharks being filmed by scientists off the western coast of Mexico

21. Surveying and Spraying of Crops.
Farmers and drones are already proving to be a winning combination. Using drones over their agricultural land, farmers are able to assess the condition and development of their crops. They can also use the drones for safe and cost-saving crop spraying.

22. Selling Homes.
An aerial video of a home can be both beautiful and a very effective sales tool. The last few years have seen Real Estate agents begin to utilise the power of this new perspective. Buyers love it too, as they can see clearly what is on offer.