电机解锁/上锁（Arm/Disarm）源码分析

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一、简介

为了防止设备在未准备好或不安全的情况下意外启动，造成潜在的危险或损坏。电机需要具备上锁解锁功能。常见的方法包括物理开关、软件命令方法。在特定条件下（如失去信号、低电压等）也会自动上锁。

针对软件命令上锁/解锁，可通过地面控制站（QGC）或者RC遥控器操作。

RC遥控器发出各通道控制信号，接收机通过 PPM、PWM、SBUS 等协议直接接收，转化为自驾仪器各通道具体输出。解锁步骤参考这里，乐迪 T8FB 手柄操作方式可参考这里。

地面控制站通过 Mavlink 协议控制解锁。解锁上锁命令如下，详细可以参考【
一、简介 】。

了解上锁/解锁命令使用场景，命令下发方式，接下来我们分析 ArduPilot 源码，对接收到命令后，自驾仪底层控制流程和逻辑做分析。

二、框架和功能接口

首先，来熟悉水下机器人Ardusub 解锁/上锁功能框架和主要接口。

AP_Arming_Sub类继承自库中 AP_Arming类，构造方法也直接继承过来，在此基础上，重写了rc_calibration_checks、pre_arm_checks、disarm等接口。

各接口功能如下：

has_disarm_function 电机解锁前需检测已经指定了解锁按钮；

pre_arm_checks 执行解锁前安全检查；

rc_calibration_checks 检查RC控制4个通道的最小值和最大值是否标定成功；

disarm/arm 电机解锁和上锁接口，传入操作方法，设置是否需要检查。

三、函数调用链

3.1 解锁前检查

void Sub::one_hz_loop() → bool AP_Arming_Sub::pre_arm_checks(bool display_failure) → bool AP_Arming::pre_arm_checks(bool report)

在 Sub类中调用 AP_Arming_Sub 类方法，实例化对象。

1Hz周期调用 AP_Arming_Sub::pre_arm_checks，进行解锁前检查。

AP_Arming_Sub::pre_arm_checks 检测方法首先检测是否解锁，若解锁直接跳出。未解锁则继续运行。判断是否有上锁 disarm 功能，确保解锁后可以上锁。只有存在上锁功能，才执行解锁前检查。

真正解锁前检查功能在AP_Arming库中的pre_arm_checks执行。

3.2 执行解锁/上锁

通过搜索arming.arm，获取具体应用时何处调用解锁方法。ArduSub 中在遥控手柄joystick.cpp中使用，同时我们关注一下多旋翼在motors.cpp和GCS_MAVLINK.cpp中调用。

为啥在 ArduSub 和 ArduCopter下位于不同的函数？

这和通讯控制硬件架构有关。水下机器人通过电力载波有线通讯，通过PC 上地面控制站外接 joystick 进行控制。而多旋翼机器人通过RC遥控器和接收机无线通讯，通过遥控器方向舵Rudder进行控制。

首先分析ArduSub/joystick.cpp源码。transform_manual_control_to_rc_override将人工控制输入转化为rc输出。循环判断是否有按钮按下，不同按钮操作在handle_jsbutton_press中switch:case分支。下面源码列出了解锁/上锁操作，第一种是单个按钮控制解锁/上锁，第二种是单独解锁按钮，第三种是单独上锁按钮。这三种方法都是通过AP_Arming::Method::MAVLINK方法控制。而transform_manual_control_to_rc_override调用过程参考。

总体来说，解锁/上锁整个调用链如下:

GCS::update_receive() → GCS_MAVLINK::update_receive() → void GCS_MAVLINK::packetReceived() → void GCS_MAVLINK_Sub::handle_message() → void Sub::transform_manual_control_to_rc_override() → void Sub::handle_jsbutton_press() → arming.arm()/arming.disarm()

再来分析ArduCopter/motors.cpp，首需要打开方向舵解锁功能，根据偏航角输入，右满舵则解锁，左满舵上锁。为了避免误触发，控制在计数器超过ARM_DELAY 后才执行，防抖动。解锁/上锁调用链如下: SCHED_TASK(arm_motors_check, 10, 50, 21) → arming.arm()/arming.disarm()

四、解锁前检查详细说明

4.1 源码分析

真正的检查工作在AP_Arming库中pre_arm_checks中执行，下面详细分析一下检查项目

ArduPilot includes a suite of Pre-arm Safety Checks which will prevent the vehicle from arming its propulsion system if any of a fairly large number of issues are discovered before movement including missed calibration, configuration or bad sensor data. These checks help prevent crashes or fly-aways but some can also be disabled if necessary.

已经解锁或者解锁无需检测（应该始终不要关闭ARMING_CHECK）；

⚠️

Never disable the arming checks (ie ARMING_CHECK not = “1”, except for bench testing. Always resolve any prearm or arming failures BEFORE attempting to fly. Doing otherwise may result in the loss of the vehicle.

checks_result 检查结果综合不同检查项目结果（逻辑与），不同检查项目检测与否绝对于宏定义是否打开；

检测项目包括气压计、惯导、罗盘、GPS、电池、日志记录功能、遥控器检测、任务检测、板载电压、测距仪等。

4.2 通过QGC识别检测信息

a pre-arm check failure will be unable to arm the vehicle and the notification LED

The first cause of the Pre-Arm Check failure will be displayed in red on the HUD window

Pre-arm checks that are failing will also be sent as messages to the GCS while disarmed, about every 30 seconds. If you wish to disable this and have them sent only when an attempt arm fails, then set the ARMING_OPTIONS bit 1 (value 1).

Pre-Arm Failure Messages (All vehicle types)

Message	Cause	Solution
3D Accel calibration needed	Accelerometer calibration has not been done	Complete the accel calibration
Accels calibrated requires reboot	Autopilot must be rebooted after accel calibration	Reboot autopilot
Accels inconsistent	Two accelerometers are inconsistent by 0.75 m/s/s	Re-do the accel calibration. Allow autopilot to warm-up and reboot. If failure continues replace autopilot
ADSB out of memory	Autopilot has run out of memory	Disable features or replace with a higher powered autopilot
Accels not healthy	At least one accelerometer is not providing data	Reboot autopilot. If failure continues replace autopilot
AHRS: not using configured AHRS type	EKF3 is not ready yet and vehicle is using DCM	If indoors, go outside. Ensure good GPS lock. Check for misconfiguration of EKF (see AHRS_EKF_TYPE)
AHRS: waiting for home	GPS has not gotten a fix	If indoors, go outside. Ensure compass and accelerometer calibrations have been completed. Eliminate radio-frequency sources that could interfere with the GPS
Airspeed 1 not healthy	Autopilot is unable to retrieve data from sensor	Check the physical connection and configuration
AP_Relay not available	Parachute misconfigured	Parachute is controlled via Relay but the relay feature is missing. Custom build server was probably used, rebuild with relay enabled
Auxiliary authorisation refused	External system has disallowed authorisation	Check external authorisation system
Batch sampling requires reboot	Batch sampling feature requires Autopilot reboot	Reboot autopilot or check Batch sampling configuration
Battery below minimum arming capacity	Battery capacity is below BATT_ARM_MAH	Replace battery or adjust BATT_ARM_MAH
Battery below minimum arming voltage	Battery voltage is below BATT_ARM_VOLT	Replace battery or adjust BATT_ARM_VOLT
Battery capacity failsafe critical >= low	Battery failsafe misconfiguration	Check BATT_LOW_MAH is higher than BATT_CRT_MAH
Battery critical capacity failsafe	Battery capacity is below BATT_CRT_MAH	Replace battery or adjust BATT_CRT_MAH
Battery critical voltage failsafe	Battery voltage is below BATT_CRT_VOLT	Replace battery or adjust BATT_CRT_VOLT
Battery low capacity failsafe	Battery capacity is below BATT_LOW_MAH	Replace battery or adjust BATT_LOW_MAH
Battery low voltage failsafe	Battery voltage is below BATT_LOW_VOLT	Replace battery or adjust BATT_LOW_VOLT
Battery unhealthy	Battery is not providing data	Check battery monitors physical connect and configuration
Battery voltage failsafe critical >= low	Battery failsafe misconfiguration	Check BATT_LOW_VOLT is higher than BATT_CRT_VOLT
BendyRuler OA requires reboot	Object avoidance config change requires reboot	Reboot autopilot. See Object Avoidance configuration
Board (Xv) out of range 4.3-5.8v	Board voltage below BRD_VBUS_MIN or too high	Check power supply. If powering via USB plug in a battery or replace USB cable
BTN_PINx=y invalid	Button misconfigured	BTNx_PIN is set to an invalid value. Check Button setup instructions
BTN_PINx=y, set SERVOz_FUNCTION=-1	Button misconfigured	Set SERVOz_FUNCTION to -1
Can’t check rally without position	EKF does not have a position estimate yet	Wait or move to location with better GPS reception
Check fence	Fence feature has failed to be initialised	Reboot autopilot
Check mag field (xy diff:x>875)	Compass horiz field strength is too large or small	Relocate vehicle away from metal in the environment. Move compass away from metal in the frame. repeat compass calibration. Disable internal compass.
Check mag field (z diff:x>875)	Compass vert field strength is too large or small	Relocate vehicle away from metal in the environment. Move compass away from metal in the frame. repeat compass calibration. Disable internal compass.
Check mag field: x, max y, min z	Compass field strength is too large or small	Relocate vehicle away from metal in the environment. Move compass away from metal in the frame. repeat compass calibration. Disable internal compass.
Chute has no channel	Parachute misconfigured	Parachute is controlled using PWM but no servo output function has been configured (e.g. need SERVOx_FUNCTION = 27). see Parachute setup instructions
Chute has no relay	Parachute misconfigured	Parachute is controlled via Relay but no relay output has been configured. see Parachute setup instructions
Chute is released	Parachute has been released	Reboot autopilot
Compass calibrated requires reboot	Autopilot must be rebooted after compass cal	Reboot autopilot
Compass calibration running	Compass calibration is running	Complete or cancel the compass calibration
Compass not healthy	At least one compass is not providing data	Check compass’s connection to autopilot and configuration
Compass offsets too high	Compass offset params are too large	Relocate compass away from metal in the frame and repeat compass calibration. Disable internal compass. Increase COMPASS_OFFS_MAX.
Compasses inconsistent	Two compasses angles or field strength disagree	Check compass orientations (e.g. COMPASS_ORIENT). Move compass away from metal in the frame. repeat compass calibration. Disable internal compass.
Dijkstra OA requires reboot	Object avoidance config change requires reboot	Reboot autopilot. See Object Avoidance configuration
Disarm Switch on	Disarm auxiliary switch is in the high position	Move Disarm switch to the low position or check auxiliary functions setup
Downloading logs	Vehicle cannot be armed while logs are downloading	Wait until logs are downloaded, cancel download or reboot autopilot
DroneCAN: Duplicate Node x../y!	DroneCAN sees same node ids used by two devices	Clear DroneCAN DNS server by setting CAN_D1_UC_OPTION = 1 and reboot
DroneCAN: Failed to access storage!	Possible hardware issue	Reboot autopilot
DroneCAN: Failed to add Node x!	DroneCAN could not init connection to a device	Check sensor’s physical connection and power supply
DroneCAN: Node x unhealthy!	A DroneCAN device is not providing data	Check sensor’s physical connection and power supply
Duplicate Aux Switch Options	Two auxiliary function switches for same feature	Check auxiliary function setup. Check for RCx_OPTION parameters with same values
EKF3 Roll/Pitch inconsistent by x degs	Roll or Pitch lean angle estimates are inconsistent	Normally due to EKF3 not getting good enough GPS accuracy, but could be due to other sensors producing errors. Go outdoors, wait or reboot autopilot.
EKF3 waiting for GPS config data	automatic GPS configuration has not completed	Check GPS connection and configuration especially if using DroneCAN GPS
EKF3 Yaw inconsistent by x degs	Yaw angle estimates are inconsistent	Wait or reboot autopilot
Failed to open mission.stg	Failed to load mission from SD Card	Check SD card. Try to re-save mission to SD card
Fence requires position	If fences are enabled, position estimate required	Wait or move vehicle to a location with a clear view of the sky. Reduce sources of radio-frequency interference
FENCE_ALT_MAX < FENCE_ALT_MIN	FENCE_ALT_MAX must be greater than FENCE_ALT_MIN	Increase FENCE_ALT_MAX or lower FENCE_ALT_MIN
FENCE_MARGIN is less than FENCE_RADIUS	FENCE_MARGIN must be larger than FENCE_RADIUS	Increase FENCE_RADIUS or reduce FENCE_MARGIN
FENCE_MARGIN too big	FENCE_ALT_MAX - FENCE_ALT_MIN < 2x FENCE_MARGIN	Decrease FENCE_MARGIN or increase difference between FENCE_ALT_MAX and FENCE_ALT_MIN
Fences enabled, but none selected	Fences are enabled but none are defined	Disable some or all fences using FENCE_ENABLE or FENCE_TYPE or define the missing fences
Fences invalid	Polygon fence is invalid	Check polygon fence does not have overlapping lines
FETtec: Invalid motor mask	FETtec misconfiguration	See FETtec configuration
FETtec: Invalid pole count x	FETtec misconfiguration	See FETtec configuration
FETtec: No uart	FETtec misconfiguration	See FETtec configuration
FETtec: Not initialised	FETtec ESCs are not communicating with autopilot	See FETtec configuration
FETtec: x of y ESCs are not running	FETtec ESCs are not spinning	See FETtec configuration
FETtec: x of y ESCs are not sending telem	FETtec ESCs are not communicating with autopilot	See FETtec configuration
FFT calibrating noise	FFT Harmonic Notch analysis has not completed	Wait until In-Flight FFT analysis completes
FFT config MAXHZ xHz > yHz	FFT Harmonic Notch misconfiguration	See In-Flight FFT Harmonic Notch Setup completes
FFT self-test failed, max error Hz	FFT Harmonic Notch failed	See In-Flight FFT Harmonic Notch Setup completes
FFT still analyzing	FFT Harmonic Notch analysis has not completed	Wait until In-Flight FFT analysis completes
FFT: calibrated xHz/xHz/xHz	FFT Harmonic Notch issue	See In-Flight FFT Harmonic Notch Setup completes
FFT: resolution is xHz, increase length	FFT Harmonic Notch misconfiguration	See In-Flight FFT Harmonic Notch Setup completes
Generator: Not healthy	Generator is not communicating with autopilot	Check generator configuration
Generator: No backend driver	Firmware does not include seelected generator	Build version of firmware with desired generator using custom.ardupilot.org
GPS and AHRS differ by Xm	GPS and EKF positions differ by at least 10m	Wait until GPS quality improves. Move vehicle to a location with a clear view of the sky. Reduce sources of radio-frequency interference
GPS blending unhealthy	At least one GPS is not providing good data	Move vehicle to a location with a clear view of the sky. Reduce sources of radio-frequency interference. Check GPS blending configuration
GPS Node x not set as instance y	DroneCan GPS configuration error	Check GPS1_CAN_NODEID and GPS2_CAN_NODEID
GPS positions differ by Xm	Two GPSs reported positions differ by 50m or more	Wait until GPS quality improves. Move vehicle to a location with a clear view of the sky. Reduce sources of radio-frequency interference
GPS x still configuring this GPS	Automatic GPS configuration has not completed	Wait until configuration completes. Check GPS connection and configuration especially if using DroneCAN GPS
GPS x: Bad fix	GPS does not have a good lock	Move vehicle to a location with a clear view of the sky. Reduce sources of radio-frequency interference
GPS x: not healthy	GPS is not providing data	Check GPSs physical connection to autopilot and configuration
GPS x: primary but TYPE 0	Primary GPS has not been configured	Check GPS_PRIMARY and confirm corresponding GPS1_TYPE or GPS2_TYPE matches type of GPS used
GPS x: was not found	GPS disconnected or incorrectly configured	Check GPSs physical connection to autopilot and configuration
GPSx yaw not available	GPS-for-yaw configured but not working	Move to location with better GPS reception. Check GPS-for-yaw configuration
Gyros inconsistent	Two gyros are inconsistent by at least 5 deg/sec	Reboot autopilot and hold vehicle still until gyro calibration completes. Allow autopilot to warm-up and reboot. If failure continues replace autopilot
Gyros not calibrated	Gyro calibration normally run at startup failed	Reboot autopilot and hold vehicle still until gyro calibration completes
Gyros not healthy	At least one gyro is not providing data	Reboot autopilot. If failure continues replace autopilot
Hardware safety switch	Hardware safety switch has not been pushed	Push safety switch (normally on top of GPS) or disable by setting BRD_SAFETY_DEFLT to zero and reboot autopilot
heater temp low (x < 45)	Board heater temp is below BRD_HEAT_TARG	Wait for board to heat up. Target temperature can be adjust using BRD_HEAT_TARG
In OSD menu	OSD is being configured	Complete OSD configuration. Check OSD configuration
Internal errors 0x%x l:%u %s	An internal error has occurred	Reboot the autopilot. Report error to the development team
Invalid FENCE_ALT_MAX value	FENCE_ALT_MAX must be positive	Increase FENCE_ALT_MAX
Invalid FENCE_ALT_MIN value	FENCE_ALT_MIN must be higher than -100	Increase FENCE_ALT_MIN
Invalid FENCE_MARGIN value	FENCE_MARGIN must be positive	Increase FENCE_MARGIN
Invalid FENCE_RADIUS value	FENCE_RADIUS must be positive	Increase FENCE_RADIUS
Logging failed	Logs could not be written. Maybe hardware failure	Reboot autopilot. Replace autopilot
Logging not started	Logs could not be written. Maybe hardware failure	Reboot autopilot. Replace autopilot
Main loop slow (xHz < 400Hz)	Autopilot’s CPU is overloaded	Wait to see if the error is temporary. Disable features or replace with a higher powered autopilot. Reduce SCHED_LOOP_RATE
Margin is less than inclusion circle radius	A circular fence has radius below FENCE_MARGIN	Increase the size of the circular fence involved or decrease FENCE_MARGIN
memory low for auxiliary authorisation	Autopilot has run out of memory	Disable features or replace with a higher powered autopilot
Missing mission item: do land start	Auto mission needs a DO_LAND_START command	Add a DO_LAND_START command to the mission or adjust the ARMING_MIS_ITEMS parameter
Missing mission item: land	Auto mission needs a LAND command	Add a LAND command to the mission or adjust the ARMING_MIS_ITEMS parameter
Missing mission item: RTL	Auto mission needs an RTL command	Add an RTL command to the mission or adjust the ARMING_MIS_ITEMS parameter
Missing mission item: takeoff	Auto mission needs a TAKEOFF command	Add a TAKEOFF command to the mission or adjust the ARMING_MIS_ITEMS parameter
Missing mission item: vtol land	Auto mission needs a VTOL_LAND command	Add a VTOL_LAND command to the mission or adjust the ARMING_MIS_ITEMS parameter
Missing mission item: vtol takeoff	Auto mission needs a VTOL_TAKEOFF command	Add a VTOL_TAKEOFF command to the mission or adjust the ARMING_MIS_ITEMS parameter
Mode channel and RCx_OPTION conflict	RC flight mode switch also used for an aux function	Change FLTMODE_CH (or MODE_CH for Rover) or RCx_OPTION to remove conflict
Mode requires mission	Attempting to arm in Auto mode but no mission	Arm in an other mode or create and upload an Auto mission
Motors Emergency Stopped	Motors emergency stopped	Release emergency stop. See auxiliary functions
Mount: check TYPE	Mount (aka camera gimbal) misconfiguration	Check MNT1_TYPE is valid. Check Gimbal configuration
Mount: not healthy	Mount is not communicating with autopilot	Check physical connection between autopilot and gimbal and check Gimbal configuration
Multiple SERIAL ports configured for RC input	RC misconfiguration	see Multiple Radio Control Receivers
No mission library present	Auto mission feature has been disabled	Custom build server was probably used to produce the firmware without auto missions. Rebuild with auto missions enabled
No rally library present	Rally point feature has been disabled	Custom build server was probably used to produce the firmware without rally point. Rebuild with Rally points included
No SD card	SD card is corrupted or missing	Format or replace SD card
No sufficiently close rally point located	Rally points are further than RALLY_LIMIT_KM	Move rally points closer to vehicle’s current location or increase RALLY_LIMIT_KM
OA requires reboot	Object avoidance config change requires reboot	Reboot autopilot. See Object Avoidance configuration
OpenDroneID: ARM_STATUS not available	OpenDroneID misconfiguration	see Remote ID configuration
OpenDroneID: operator location must be set	Operator location is not available	see Remote ID configuration
OpenDroneID: SYSTEM not available	OpenDroneID misconfiguration	see Remote ID configuration
OpenDroneID: UA_TYPE required in BasicID	OpenDroneID misconfiguration	see Remote ID configuration
OSD_TYPE2 not compatible with first OSD	OSD1 and OSD2 configurations are incompatible	Disable 2nd OSD (set OSD_TYPE2 to zero) or check OSD configuration
Param storage failed	Eeprom hardware failure	Check power supply or replace autopilot
parameter storage full	Eeprom storage full	Save params. Reset to defaults. Reload saved parameters.
PiccoloCAN: Servo x not detected	PiccoloCAN misconfiguration or servo issue	Check Currawong Velocity ESC setup instructions
Pin x disabled (ISR flood)	Sensor connected to GPIO pin is rapidly changing	Check sensor attached to specified pin
Pitch (RCx) is not neutral	RC transmitter’s pitch stick is not centered	Move RC pitch stick to center or repeat radio calibration
Pitch radio max too low	RC pitch channel max below 1700	Repeat the radio calibration procedure or increase RC2_MAX above 1700
Pitch radio min too high	RC pitch channel min above 1300	Repeat the radio calibration procedure or reduce RC2_MIN below 1300
PRXx: No Data	Proximity sensor is not providing data	Check proximity sensor physical connection and configuration
PRXx: Not Connected	Proximity sensor is not providing data	Check proximity sensor physical connection and configuration
Radio failsafe on	RC failsafe has triggered	Turn on RC transmitter or check RC failsafe configuration
Rangefinder x: Not Connected	Rangefinder is not providing data	Check rangefinder’s physical connection to autopilot and configuration
Rangefinder x: Not Detected	Rangefinder is not providing data	Check rangefinder’s physical connection to autopilot and configuration
RC calibrating	RC calibration is in progress	Complete the radio calibration procedure
RC not calibrated	RC calibration has not been done	Complete the radio calibration. RC3_MIN and RC3_MAX must have been changed from their default values (1100 and 1900), and for channels 1 to 4, MIN value must be 1300 or less, and MAX value 1700 or more.
RC not found	RC failsafe enabled but no RC signal	Turn on RC transmitter or check RC transmitters connection to autopilot. If operating with only a GCS, see Operation Using Only a Ground Control Station (GCS)
RCx_MAX is less than RCx_TRIM	RC misconfiguration	Adjust RCx_TRIM to be lower than RCx_MAX or repeat radio calibration
RCx_MIN is greater than RCx_TRIM	RC misconfiguration	Adjust RCx_TRIM to be higher than RCx_MIN or repeat radio calibration
RELAYx_PIN=y invalid	Relay misconfigured	RELAYx_PIN is set to an invalid value. Check Relay setup instructions
RELAYx_PIN=y, set SERVx_FUNCTION=-1	Relay misconfigured	Set SERVOx_FUNCTION to -1
RNGFNDx_PIN not set	Rangefinder misconfigured	Set RNGFNDx_PIN to a non-zero value. See rangefinder configuration
RNGFNDx_PIN=y invalid	Rangefinder misconfigured	RNGFNDx_PIN is set to an invalid value. Check rangefinder configuration
RNGFNDx_PIN=y, set SERVOx_FUNCTION=-1	Rangefinder misconfigured	Set SERVOx_FUNCTION to -1
Roll (RCx) is not neutral	RC transmitter’s roll stick is not centered	Move RC roll stick to center or repeat radio calibration
Roll radio max too low	RC roll channel max below 1700	Repeat the radio calibration procedure or increase RC1_MAX above 1700
Roll radio min too high	RC roll channel min above 1300	Repeat the radio calibration procedure or reduce RC1_MIN below 1300
RPMx_PIN not set	RPM sensor misconfigured	Check RPMx_PIN value. Check RPM setup instructions
RPMx_PIN=y invalid	RPM sensor misconfigured	RPMx_PIN is set to an invalid value. Check RPM setup instructions
RPMx_PIN=y, set SERVOx_FUNCTION=-1	RPM sensor misconfigured	Set SERVOz_FUNCTION to -1
Same Node Id x set for multiple GPS	DroneCan GPS configuration error	Check GPS1_CAN_NODEID and GPS2_CAN_NODEID are different. Set one to zero and reboot autopilot
Same rfnd on different CAN ports	Two rangefinders appearing on different CAN ports	Check USD1, TOFSensP, NanoRadar or Benewake setup instructions
Scripting: loaded CRC incorrect want: x	Script has incorrect CRC	Replace Lua script with expected version
Scripting: running CRC incorrect want: x	Script has incorrect CRC	Replace Lua script with expected version
Scripting: xxx failed to start	A Lua script failed to start	Autopilot out of memory or Lua script misconfiguration. See Lua scripts
Scripting: xxx out of memory	A Lua script ran out of memory	Increase SCR_HEAP_SIZE or check Lua script configuration
Servo voltage to low (Xv < 4.3v)	Servo rail voltage below 4.3V	Check power supply to rear servo rail
SERVOx_FUNCTION=y on disabled channel	PWM output misconfigured	SERVOx_FUNCTION is set for a servo output that has been disabled. See BLHeli setup
SERVOx_MAX is less than SERVOx_TRIM	PWM output misconfigured	Set SERVOx_TRIM to be lower than SERVOx_MAX
SERVOx_MIN is greater than SERVOx_TRIM	PWM output misconfigured	Set SERVOx_TRIM to be higher than SERVOx_MIN
temperature cal running	Temperature calibration is running	Wait until temp calibration completes or reboot autopilot
terrain disabled	Auto mission uses terrain but terrain disabled	Enable the terrain database (set TERRAIN_ENABLE = 1) or remove auto mission items that use terrain altitudes. For Copters also check RTL_ALT_TYPE.
Terrain out of memory	Autopilot has run out of memory	Disable features or replace with a higher powered autopilot
Throttle (RCx) is not neutral	RC transmitter’s throttle stick is too high	Lower throttle stick or repeat radio calibration
Throttle radio max too low	RC throttle channel max below 1700	Repeat the radio calibration procedure or increase RC2_MAX above 1700
Throttle radio min too high	RC throttle channel min above 1300	Repeat the radio calibration procedure or reduce RC1_MIN below 1300
Too many auxiliary authorisers	More than 3 external systems controlling arming	Check external authorisation system
vehicle outside fence	Vehicle is outside the fence	Move vehicle within the fence
VisOdom: not healthy	VisualOdometry sensor is not providing data	Check visual odometry physical connection and configuration
VisOdom: out of memory	Autopilot has run out of memory	Disable features or replace with a higher powered autopilot
VTOL Fwd Throttle iz not zero	RC transmitter’s VTOL Fwd throttle stick is high	Lower VTOL Fwd throttle stick or repeat radio calibration
waiting for terrain data	Waiting for GCS to provide required terrain data	Wait or move to location with better GPS reception
Yaw (RCx) is not neutral	RC transmitter’s yaw stick is not centered	Move RC yaw stick to center or repeat radio calibration
Yaw radio max too low	RC yaw channel max below 1700	Repeat the radio calibration procedure or increase RC2_MAX above 1700
Yaw radio min too high	RC yaw channel min above 1300	Repeat the radio calibration procedure or reduce RC1_MIN below 1300

Message	Cause	Solution
ADSB threat detected	ADSB failsafe. Manned vehicles nearby	See ADSB configuration
AHRS not healthy	AHRS/EKF is not yet ready	Wait. Reboot autopilot
Altitude disparity	Barometer and EKF altitudes differ by at least 1m	Wait for EKF altitude to stabilise. Reboot autopilot
Auto mode not armable	Vehicle cannot be armed in Auto mode	Switch to another mode (like Loiter) or set RTL_OPTIONS = 3. See Auto mode
Bad parameter: ATC_ANG_PIT_P must be > 0	Attitude controller misconfiguration	Increase specified parameter value to be above zero. See Tuning Process Instructions
Bad parameter: PSC_POSXY_P must be > 0	Position controller misconfiguration	Increase specified parameter value to be above zero. See Tuning Process Instructions
Battery failsafe	Battery failsafe has triggered	Plug in battery and check its voltage and capacity. See ref:battery failsafe configuration <failsafe-battery>
Check ACRO_BAL_ROLL/PITCH	ACRO_BAL_ROLL or ACRO_BAL_PITCH too high	Reduce ACRO_BAL_ROLL below ATC_ANG_RLL_P and/or ACRO_BAL_PITCH below ATC_ANG_PIT_P. See Acro mode
Check ANGLE_MAX	ANGLE_MAX set too high	Reduce ANGLE_MAX to 8000 (e.g. 80 degrees) or lower
Check FS_THR_VALUE	RC failsafe misconfiguration	Set FS_THR_VALUE between 910 and RC throttle’s min (e.g RC3_MIN. See ref:battery failsafe configuration <failsafe-battery>
Check PILOT_SPEED_UP	PILOT_SPEED_UP set too low	Increase PILOT_SPEED_UP to a positive number (e.g. 100 = 1m/s). See AltHold mode
Collective below failsafe (TradHeli only)	RC collective input is below FS_THR_VALUE	Turn on RC transmitter or check FS_THR_VALUE. Check RC failsafe setup
EKF attitude is bad	EKF does not have a good attitude estimate	Wait for EKF attitude to stabilize. Reboot autopilot. Replace autopilot
EKF compass variance	Compass direction appears incorrect	Relocate vehicle away from metal in the environment. Move compass away from metal in the frame. repeat compass calibration. Disable internal compass.
EKF height variance	Barometer values are unstable or high vibration	Wait. Measure vibration and add vibration isolation
EKF position variance	GPS position is unstable	Wait. If indoors, go outside. Eliminate radio-frequency sources that could interfere with the GPS
EKF velocity variance	GPS or optical flow velocities are unstable	Wait. If indoors, go outside. Eliminate radio-frequency sources that could interfere with the GPS. Check optical flow calibration
Fence enabled, need position estimate	Fence is enabled so need a position estimate	Wait. If indoors, go outside. Ensure compass and accelerometer calibrations have been completed. Eliminate radio-frequency sources that could interfere with the GPS. See Fence configuration
FS_GCS_ENABLE=2 removed, see FS_OPTIONS	GCS failsafe misconfiguration	Set FS_GCS_ENABLE = 1 and check FS_OPTIONS parameter. See ref:GCS Failsafe configuration<gcs-failsafe>
GCS failsafe on	GCS failsafe has triggered	Check telemetry connection. See ref:GCS Failsafe configuration<gcs-failsafe>
GPS glitching	GPS position is unstable	Wait. If indoors, go outside. Eliminate radio-frequency sources that could interfere with the GPS
High GPS HDOP	GPS horizontal quality too low	Wait or move to location with better GPS reception. You may raise GPS_HDOP_GOOD but this is rarely a good idea
Home too far from EKF origin	Home is more than 50km from EKF origin	Reboot autopilot to reset EKF origin to current Location
Interlock/E-Stop Conflict (TradHeli only)	Incompatible auxiliary function switch configured	Remove Interlock, E-Stop or Emergency Stop from auxiliary function setup
Invalid MultiCopter FRAME_CLASS	FRAME_CLASS parameter misconfigured	Multicopter firmware loaded but FRAME_CLASS set to helicopter. Load helicopter firmware or change FRAME_CLASS
Inverted flight option not supported	Inverted flight auxiliary function not supported	Remove auxiliary function switch for inverted flight
Leaning	Vehicle is leaning more than ANGLE_MAX	Level vehicle
Motor Interlock Enabled	Motor Interlock in middle or high position	Move motor interlock auxiliary function switch to low position
Motor Interlock not configured	Helicopters require motor interlock be configured	Enable the motor interlock auxiliary function switch
Motors: Check frame class and type	Unknown or misconfigured frame class or type	Enter valid frame class and/or type
Motors: Check MOT_PWM_MIN and MOT_PWM_MAX	MOT_PWM_MIN or MOT_PWM_MAX misconfigured	Set MOT_PWM_MIN = 1000 and MOT_PWM_MAX = 2000 and repeat the ESC calibration
Motors: MOT_SPIN_ARM > MOT_SPIN_MIN	MOT_SPIN_ARM is too high or MOT_SPIN_MIN is too low	Reducse MOT_SPIN_ARM to below MOT_SPIN_MIN. See Seting motor range
Motors: MOT_SPIN_MIN too high x > 0.3	MOT_SPIN_MIN parameter value is too high	Reduce MOT_SPIN_MIN to below 0.3. See Setting motor range
Motors: no SERVOx_FUNCTION set to MotorX	At least one motor output has not been configured	Check SERVOx_FUNCTION values for “Motor1”, “Motor2”, etc. Check ESC and motor configuration
Need Alt Estimate	EKF has not yet calculated the altitude	Wait. Allow autopilot to heat up. Ensure accelerometer calibration has been done.
Need Position Estimate	EKF does not have a position estimate	Wait. If indoors, go outside. Ensure compass and accelerometer calibrations have been completed. Eliminate radio-frequency sources that could interfere with the GPS
Proximity x deg, ym (want > Zm)	Obstacles too close to vehicle	Move obstacles away from vehicle or check sensor. See proximity sensor configuration
RTL mode not armable	Vehicle cannot be armed in RTL mode	Switch to another flight mode
RTL_ALT_TYPE is above-terrain but no rangefinder	RTL uses rangefinder but rangefinder unavailable	Check rangefinder configuration including RNGFNDx_ORIENT=251
RTL_ALT_TYPE is above-terrain but no terrain data	RTL uses terrain but Terrain database unavailable	Set TERRAIN_ENABLE = 1. See Terrain Following
RTL_ALT_TYPE is above-terrain but RTL_ALT>RNGFND_MAX_CM	RTL return altitude above rangefinder range	Reduce RTL_ALT to less than RNGFNDx_MAX_CM. See Terrain Following
Safety Switch	Hardware safety switch has not been pushed	Push safety switch (normally on top of GPS) or disable by setting BRD_SAFETY_DEFLT to zero and reboot autopilot
Throttle below failsafe	RC throttle input is below FS_THR_VALUE	Turn on RC transmitter or check FS_THR_VALUE. Check RC failsafe setup
Vehicle too far from EKF origin	Vehicle is more than 50km from EKF origin	Reboot autopilot to reset EKF origin to current Location
winch unhealthy	Winch is not communicating with autopilot	Check winch’s physical connection and configuration

Arming the motors — Copter documentation

Arming the vehicle allows the motors to start spinning. Before arming, make sure all people, objects, and any body parts (e.g., hands) are clear of the propellers. Then do the following:

https://ardupilot.org/copter/docs/arming_the_motors.html

举例：PreArm总线电压异常（4.2V，不在4.3-4.8之间）

排查发现，Pixhawk供电电压5.0V时，Vcc采集为4.67V。采集电压不准确。

排查供电若无异常，可以通过修改总线电压报警低限值，取消该报警。

五、解锁/上锁详细说明

5.1 解锁源码分析

由于解锁命令会周期调用，为了防止多次进入，解锁函数被多次执行并发问题。首先在函数开始处，判断是否在此函数中，在此函数中，程序会直接跳出；

调用AP_Arming::arm方法，做解锁检测，若检测不通过，设置标志，直接跳出；

日志记录解锁成功事件（event）；

发出解锁成功提醒；

获取姿态航向参考系统 ahrs 航向作为解锁初始航向；

hal库设置软件解锁功能主要设置解锁时间；

enable_motor_output() 电机输出最小值。

5.2 上锁源码分析

上锁主要保存罗盘偏移、向电机发送上锁命令，重置任务和清除输入保持。