Arm, Disarm, Prearm Configuration
기체에는 움직이는 부품이 있으며, 그 중에는 특히 모터와 프로펠러는 전원 공급시 위험할 수 있습니다.
사고의 위험을 줄이기 위하여, PX4는 명확한 상태에서만 부품들의 전원을 공급합니다.
- Disarmed: There is no power to motors or actuators.
- Pre-armed: Motors/propellers are locked but actuators for non-dangerous electronics are powered (e.g. ailerons, flaps etc.).
- Armed: Vehicle is fully powered. 모터와 프로펠러가 동작할 수 있음(위험!)
INFO
Ground stations may display disarmed for pre-armed vehicles. 시동전의 기체는 기술적으로 타당하지는 않지만, "안전"한 상태입니다.
Users can control progression though these states using a safety switch on the vehicle (optional) and an arming switch/button, arming gesture, or MAVLink command on the ground controller:
A safety switch is a control on the vehicle that must be engaged before the vehicle can be armed, and which may also prevent pre-arming (depending on the configuration). 보통 안전 스위치는 GPS 장치에 붙어있으나, 별도의 부품으로 공급되기도 합니다.
WARNING
A vehicle that is armed is potentially dangerous. 안전 스위치는 의도하지 않게 갑자기시동이 걸리는 것을 방지합니다.
:::
An arming switch is a switch or button on an RC controller that can be used to arm the vehicle and start motors (provided arming is not prevented by a safety switch).
An arming gesture is a stick movement on an RC controller that can be used as an alternative to an arming switch.
MAVLink commands can also be sent by a ground control station to pre-arm, arm, or disarm a vehicle.
PX4는 시동 후 일정 시간 내에 이륙하지 않고, 착륙 후 수동으로 시동 해제하지 않으면, 기체의 시동은 자동으로 해제됩니다. 이것은 시동이 걸린 기체가 지상에서 안전사고를 유발할 수 있는 시간을 줄입니다.
PX4 allows you to configure how pre-arming, arming and disarming work using parameters (which can be edited in QGroundControl via the parameter editor), as described in the following sections.
TIP
Arming/disarming parameters can be found in Parameter Reference > Commander (search for COM_ARM_* and COM_DISARM_*).
Arming/Disarming Gestures
기본적으로, 기체는 무선조종장치의 추진 제어 스틱과 방위 제어 스틱을 움직인 후 잠깐 동안 또는 1초 동안 상태를 유지하면 시동을 걸거나 시동을 해제할 수 있습니다.
- Arming: Throttle minimum, yaw maximum
- Disarming: Throttle minimum, yaw minimum
RC controllers will use different sticks for throttle and yaw based on their mode, and hence different gestures:
- Mode 2:
- Arm: Left stick to bottom right.
- Disarm: Left stick to the bottom left.
- Mode 1:
- Arm: Left-stick to right, right-stick to bottom.
- Disarm: Left-stick to left, right-stick to the bottom.
Note that disarming in any altitude controlled mode is only possible after landing was detected. In manually piloted modes without altitude control, such as Stabilized, Acro, and Manual, it's always possible to disarm using gestures or buttons — even in flight.
| Parameter | 설명 |
|---|---|
| MAN_ARM_GESTURE | Enable arm/disarm stick guesture. 0: Disabled, 1: Enabled (default). |
Arming Button/Switch
An arming button or "momentary switch" can be configured to trigger arm/disarm instead of gesture-based arming (setting an arming switch disables arming gestures). The button should be held down for one second to arm (when disarmed) or disarm (when armed).
A two-position switch can also be used for arming/disarming, where the respective arm/disarm commands are sent on switch transitions.
TIP
Two-position arming switches are primarily used in/recommended for racing drones.
The switch or button is assigned (and enabled) using RC_MAP_ARM_SW, and the switch "type" is configured using COM_ARM_SWISBTN.
| Parameter | 설명 |
|---|---|
| RC_MAP_ARM_SW | RC arm 스위치 채널 (기본값 : 0 - 할당되지 않음). 정의된 경우 지정된 RC 채널(버튼/스위치)이 스틱 제스처 대신 시동용으로 사용됩니다. Note: - This setting disables the stick gesture! - This setting applies to RC controllers. It does not apply to Joystick controllers that are connected via QGroundControl. |
| COM_ARM_SWISBTN | 시동 스위치는 순간적으로 동작하는 버튼입니다. - 0: Arm switch is a 2-position switch where arm/disarm commands are sent on switch transitions.- 1: Arm switch is a momentary button where the arm/disarm command is sent after holding down the button for one second. |
INFO
The switch can also be set as part of QGroundControl Flight Mode configuration.
자동 시동 끄기
기본적으로, 기체는 착륙시 시동 해제 되며, 시동후 이륙 시간이 너무 오래 걸리면 자동으로 시동 해제됩니다. 이 기능은 다음 시간 제한을 사용하여 설정됩니다.
| Parameter | 설명 |
|---|---|
| COM_DISARM_LAND | 착륙후 자동 시동 해제 대기 시간. 기본값: 2s (-1 비활성화). |
| COM_DISARM_PRFLT | 이륙 속도가 너무 느리면 자동 시동 해제 시간이 초과됩니다. Default: 10s (-1 to disable). |
By default, the vehicle keeps safety off after disarming. If COM_FORCE_SAFETY is set to 1, safety is re-enabled on disarm, so it must be turned off again (by switch or MAVLink command, depending on COM_SAFETY_MODE) before the next arming. In modes that pre-arm when safety is turned off, this also exits the pre-armed state. This parameter has no effect when COM_SAFETY_MODE is set to 0.
| Parameter | 설명 |
|---|---|
| COM_FORCE_SAFETY | Re-enable safety when the vehicle disarms. Default: 0 (Disabled). |
Auto-Arming on Boot
The vehicle can be configured to arm automatically on boot once all preflight checks pass, using the COM_ARM_ON_BOOT parameter. For safety, PX4 enforces a minimum 5-second delay after boot before attempting to arm.
Once armed this way, the vehicle will not re-arm automatically after a manual disarm.
INFO
The parameter value is read once at boot. Changing it while the system is running has no effect until the next reboot.
WARNING
Use with caution. A vehicle that arms automatically can spin up motors and actuators without any operator gesture. Ensure the vehicle is in a safe state before powering on.
| Parameter | 설명 |
|---|---|
| COM_ARM_ON_BOOT | Arm automatically once preflight checks pass after boot. Default: 0 (Disabled). |
Pre-Arm Checks
To reduce accidents, vehicles are only allowed to arm certain conditions are met (some of which are configurable). Arming is prevented if:
- The vehicle is not in a "healthy" state. For example it is not calibrated, or is reporting sensor errors.
- The vehicle still has its safety state set to ON. This could for instance be a safety switch that has not been engaged.
- The vehicle has a remote ID that is unhealthy or otherwise not ready
- A VTOL vehicle is in fixed-wing mode (by default).
- The current mode requires an adequate global position estimate but the vehicle does not have GPS lock.
- Many more (see arming/disarming safety settings for more information).
The current failed checks can be viewed in QGroundControl (v4.2.0 and later) Arming Check Report (see also Fly View > Toolbar > Flight Status).
Note that internally PX4 runs arming checks at 10Hz. A list of the failed checks is kept, and if the list changes PX4 emits the current list using the Events interface. The list is also sent out when the GCS connects. Effectively the GCS knows the status of pre-arm checks immediately, both when disarmed and armed.
Details
Implementation notes for developers The client implementation is in libevents:
QGC implementation: HealthAndArmingCheckReport.cc.
PX4 also emits a subset of the arming check information in the SYS_STATUS message (see MAV_SYS_STATUS_SENSOR).
Arming Sequence: Safety State
The arming sequence depends on whether or not there is a safety switch, and is controlled by the parameter COM_SAFETY_MODE. Changes to the parameter only take effect after a reboot.
When disarmed (or pre-armed), the safety state can either be ON (a.k.a. SAFE), or OFF (a.k.a. DANGEROUS). When it is ON, arming will always be prevented. When it is OFF, the vehicle can be armed for as long as the pre-arm checks have passed.
Additionally, the COM_PREARM_MODE parameter defines when/if pre-arm mode is enabled ("safe"/non-throttling actuators are able to move):
Disabled(Default): Pre-arm mode disabled (there is no stage where only non-throttling actuators are enabled).When safety off: Pre-arm mode is enabled when safety is turned off.Always: Pre-arm mode is enabled from power up.
The sections below detail the startup sequences for the different configurations of COM_SAFETY_MODE and COM_PREARM_MODE.
COM_SAFETY_MODE=Always off (Default) and COM_PREARM_MODE=Disabled (Default)
The default configuration does not impose any additional safety measures. Arming is possible as soon as the rest of the system is ready.
시작 절차는 다음과 같습니다:
- 전원 인가
- 모든 액츄에이터를 시동 해제 상태로 잠금
- System safety is off: Arming possible once the other pre-arm checks pass.
- 시동 명령 인가
- 시스템에 시동이 걸림
- 모든 모터와 액츄에이터를 움직일 수 있음
COM_SAFETY_MODE=Safety switch (physical or virtual via MAVLink) and COM_PREARM_MODE=When safety off
This configuration lets you use either the safety switch or a MAVLink command MAV_CMD_DO_SET_SAFETY_SWITCH_STATE to turn safety off. Note that sending the corresponding MAVLink command with SAFETYSWITCH_STATE_SAFE also lets you turn safety back on, but the physical switch does _not allow to go back to a safe state.
시작 절차는 다음과 같습니다:
- 전원 인가
- 모든 액츄에이터를 시동 해제 상태로 잠금
- 시동 걸기 불가능
- Safety switch is pressed or a MAVLink command is received.
- System now pre-armed: non-throttling actuators can move (e.g. ailerons).
- System safety is off: Arming possible once the other pre-arm checks pass.
- 시동 명령 인가
- 시스템에 시동이 걸림
- 모든 모터와 액츄에이터를 움직일 수 있음
COM_SAFETY_MODE=Physical safety switch only and COM_PREARM_MODE=When safety off
When safety mode is Physical safety switch only, you must press the safety switch to turn safety off. Note that pressing the safety switch again does not allow to go back to a safe state. The MAVLink command is rejected.
시작 절차는 다음과 같습니다:
- 전원 인가
- 모든 액츄에이터를 시동 해제 상태로 잠금
- 시동 걸기 불가능
- 안전 스위치 누름
- System now pre-armed: non-throttling actuators can move (e.g. ailerons).
- System safety is off: Arming possible once the other pre-arm checks pass.
- 시동 명령 인가
- 시스템에 시동이 걸림
- 모든 모터와 액츄에이터를 움직일 수 있음
COM_SAFETY_MODE=MAVLink only and COM_PREARM_MODE=When safety off
When safety mode is MAVLink only, you must send a MAVLink command MAV_CMD_DO_SET_SAFETY_SWITCH_STATE to turn safety off. Note that sending the corresponding MAVLink command with SAFETY_SWITCH_STATE_SAFE also lets you turn safety back on. Any physical safety switch is ignored.
시작 절차는 다음과 같습니다:
- 전원 인가
- 모든 액츄에이터를 시동 해제 상태로 잠금
- 시동 걸기 불가능
- A MAVLink command is received.
- System now pre-armed: non-throttling actuators can move (e.g. ailerons).
- System safety is off: Arming possible once the other pre-arm checks pass.
- 시동 명령 인가
- 시스템에 시동이 걸림
- 모든 모터와 액츄에이터를 움직일 수 있음
매개변수
| Parameter | 설명 |
|---|---|
| COM_SAFETY_MODE | Condition to turn safety off. Vehicle arming is prevented for as long as safety is on. |
| COM_PREARM_MODE | Condition to enter the prearmed state. |