BAT Script Usage Reference¶

The RflySim toolchain has developed numerous batch scripts based on batch processing technology, enabling users to quickly and effortlessly launch multi-vehicle, multi-type, and diverse unmanned system combination simulations—significantly accelerating unmanned system development and simulation workflows.

Common scripts:

SITLRun.bat — Launch multi-vehicle Software-in-the-Loop (SITL) simulation
HITLRun.bat — Launch multi-vehicle Hardware-in-the-Loop (HITL) simulation (enter the COM port number as prompted after connecting the flight controller)

For more scripts, refer to the *\PX4PSP\RflySimAPIs\BatScripts directory.

Simulation Parameter Configuration¶

CopterSim Simulation Function Area Parameters¶

CopterSim Parameter Mapping

The following parameters are configured in BAT scripts via the SET command and correspond one-to-one with the CopterSim GUI interface:

Parameter 1 · CopterID / `START_INDEX`¶

Sets the vehicle ID; used to specify the starting vehicle ID in multi-vehicle simulations.

SET /a START_INDEX=1

Parameter 2 · 3DClassID / `CLASS_3D_ID`¶

Sets the 3D model style of the vehicle displayed in RflySim3D.

Value	Meaning
`-1`	Use the default 3D model (specified by the DLL file)
`ClassID`	Specify vehicle configuration (e.g., quadcopter, fixed-wing), using the default style for that configuration
`Unique3DClassID`	Specify a unique 3D style for a particular configuration

For 3D style parameter reference, see Platform 3D Model Resource Index

Parameter 3 · Use DLL Model File / `DLLModel`¶

Select different DLL dynamic model files (located in *PX4PSP\CopterSim\external\model).

Value	Meaning
`0`	Do not use a DLL; use the model built on the CopterSim interface
`≥1 (index or name)`	Use the specified DLL model

Parameter 4 · Simulation Mode / `SimMode`¶

Simulation Mode Values

Value	Mode Name	Description
`0`	PX4_HITL	PX4 official Hardware-in-the-Loop simulation
`1`	PX4_SITL	PX4 official Software-in-the-Loop simulation
`2`	PX4_SITL_RFLY	RflySim-customized SITL, supporting hundreds of vehicles in swarm simulation
`3`	Simulink&DLL_SIL	Simulink-generated DLL simulation (integrated model)
`4`	PX4_HITL_NET	Ethernet-based flight controller HIL (Full version only)
`5`	EXT_HITL_COM	Serial connection to third-party flight controllers (Full version only)
`6`	EXT_SIM_NET	Network connection to third-party flight controllers (Full version only)
`7`	APM_SITL_COM	APM (Ardupilot) SITL (Full version only)
`8`	PX4_SIH_COM	SIH mode via USB connection (Full version only)
`9`	PX4_SIH_NET	SIH mode via LAN connection (Full version only)
`10`	PX4_SIH_SITL	SIH Software-in-the-Loop (Full version only)
`11`	PX4_SIH_FLY	SIH Hardware-in-the-Loop (Full version only)

Parameter 5 · 3D Display Map / `UE4_MAP`¶

Select the 3D scene (located in *PX4PSP\CopterSim\external\map); supports both numeric indices and names.

SET UE4_MAP=Grasslands

Parameter 6 · Networked Simulation / `IS_BROADCAST`¶

Enable LAN-based networked simulation (also requires pressing the I key in RflySim3D).

Value	Meaning
`0`	Local machine only
`1`	Broadcast to the entire network
`IP address`	Specify a single IP (`0`=`127.0.0.1`, `1`=`255.255.255.255`)
`IP1,IP2,...`	Send to multiple IPs
`json`	Configure communication IPs and ports via a JSON file

Parameter 7 · GPS Coordinates / `isPosGps` (Full version only)¶

Value	Meaning
`0`	Cartesian coordinate system (default)
`1`	GPS/LLA coordinate system

Parameter 8 · Initial Position¶

SET /a ORIGIN_POS_X=0    :: Initial X position (m)
SET /a ORIGIN_POS_Y=0    :: Initial Y position (m)
SET LatLongAlt=116.3,39.9,50  :: LLA coordinates (Full version only)

Parameter 9 · Yaw / `ORIGIN_YAW`¶

Initial heading angle (degrees), relative to true north.

SET /a ORIGIN_YAW=0

Parameter 10 · Flight Controller Selection¶

After launching the BAT script, enter the recommended COM port number in the command line.

Parameter 11 · Baud Rate / `BaudRate`¶

Serial communication baud rate; default is 921600.

Parameter 12 · Communication Mode / `UDPSIMMODE`¶

UDPSIMMODE Communication Mode Values

Value	Mode	Applicable Scale	Description
`0`	UDP_Full	<10 vehicles	Most complete data flow: Python → CopterSim → PX4
`1`	UDP_Simple	<100 vehicles	Simplified structure, suitable for large-scale swarms
`2`	Mavlink_Full	<4 vehicles	Python directly sends MAVLink messages; high data volume but closest to real hardware
`3`	Mavlink_Simple	<8 vehicles	Filters out some message packets to reduce frequency
`4`	Mavlink_NoSend	Unlimited	CopterSim does not send MAVLink; requires pairing with telemetry serial port
`5`	Mavlink_NoGPS	—	Does not send GPS data; suitable for indoor SLAM simulation
`6`	Mavlink_Vision	—	NoGPS mode + automatically sends EKF2_AID_MASK parameter
`7`	Redis_Full	—	Full Redis mode (available only in full version)
`8`	Redis_Simple	—	Simplified Redis mode (available only in full version)

Other Key Parameters¶

Frame Configuration¶

Parameter	Values	Description
`PX4SitlFrame`	Frame name	Corresponds to frame files under `Firmware\ROMFS\px4fmu_common\init.d-posix`

Swarm Configuration¶

Parameter	Values	Description
`TOTOAL_COPTER`	Integer	Total number of vehicles
`IsSysID`	`0`/`1`	Whether to assign CopterID based on flight controller SysID
`VEHICLE_INTERVAL`	Integer	Inter-vehicle spacing (m)

GPS Origin Mode¶

Parameter	Values	Description
`isBatLLAOrin`	`0`	Use default GPS origin from DLL/terrain file
	`1`	Set GPS origin via BAT script

Vehicle Initial Pose¶

Parameter	Description
`PosXStr`	When `isPosGps=0`: X position list; when `isPosGps=1`: latitude list
`PosYStr`	When `isPosGps=0`: Y position list; when `isPosGps=1`: longitude list
`YawStr`	Yaw angle list (deg)

RflySim3D Initialization and Startup Configuration¶

BAT script shortcut key configuration:

start %PSP_PATH%\RflySimUE5\RflySim3D.exe -key=S,N1

BAT script console command configuration:

start %PSP_PATH%\RflySim3D\RflySim3D.exe -cmd=RflyChangeMapbyID-15

Main Program and Startup Parameter Configuration¶

Setting Simulation Scale¶

REM Max vehicle number 50
SET /a MAX_VEHICLE=50
SET /P VehicleNum=Please input UAV swarm number:
SET /A Evaluated=VehicleNum

if %Evaluated% EQU %VehicleNum% (
  IF %VehicleNum% GTR 0 (
    IF %VehicleNum% GTR %MAX_VEHICLE% (
      ECHO The vehicle number is too large, which may cause a crash
      pause
    )
    GOTO StartSim
  )
  ECHO Not a positive integer
  GOTO Top
) ELSE (
  ECHO Not a integer
  GOTO Top
)

Limits the maximum simulation count (default 50, adjustable). After entering the vehicle count, validation is performed and simulation begins.

Starting the Simulation¶

:StartSim
SET /A VehicleTotalNum=%VehicleNum% + %START_INDEX% - 1
if not defined TOTOAL_COPTER (
  SET /A TOTOAL_COPTER=%VehicleTotalNum%
)

set /a sqrtNum=1
set /a squareNum=1
:loopSqrt
set /a squareNum=%sqrtNum% * %sqrtNum%
if %squareNum% EQU %TOTOAL_COPTER% ( goto loopSqrtEnd )
if %squareNum% GTR %TOTOAL_COPTER% ( goto loopSqrtEnd )
set /a sqrtNum=%sqrtNum%+1
goto loopSqrt
:loopSqrtEnd

Calculates the total number of vehicles in the swarm and assigns IDs using a recursive algorithm.

REM Start QGC and RflySim3D
tasklist|find /i "QGroundControl.exe" || start %PSP_PATH%\QGroundControl\QGroundControl.exe
tasklist|find /i "RflySim3D.exe" || start %PSP_PATH%\RflySim3D\RflySim3D.exe
choice /t 5 /d y /n >nul
tasklist|find /i "CopterSim.exe" && taskkill /im "CopterSim.exe"
cd %PSP_PATH%\CopterSim

REM Loop to start CopterSim
set /a cntr=%START_INDEX%
set /a endNum=%VehicleTotalNum%+1
set /a portNum=%UDP_START_PORT%+((%START_INDEX%-1)*2)

:loopBegin
set /a PosXX=((%cntr%-1) / %sqrtNum%)*%VEHICLE_INTERVAL% + %ORIGIN_POS_X%
set /a PosYY=((%cntr%-1) %% %sqrtNum%)*%VEHICLE_INTERVAL% + %ORIGIN_POS_Y%
start /realtime CopterSim.exe 1 %cntr% %portNum% %DLLModel% %SimMode% %UE4_MAP% %IS_BROADCAST% %PosXX% %PosYY% %ORIGIN_YAW% 1 %UDPSIMMODE%
choice /t 1 /d y /n >nul
set /a cntr=%cntr%+1
set /a portNum=%portNum%+2
if %cntr% EQU %endNum% goto loopEnd
goto loopBegin
:loopEnd

In the loop, the initial position is calculated for each vehicle and a CopterSim instance is launched.

REM Compile and start PX4 SITL
SET /a ToolChainType=1
SET WINDOWSPATH=%PATH%
if %ToolChainType% EQU 1 (
  wsl echo Starting PX4 Build; cd %PSP_PATH_LINUX%/Firmware; ...
) else (
  cd %PSP_PATH%\CygwinToolchain
  CALL setPX4Env.bat
  bash -l -i -c '...'
)
SET PATH=%WINDOWSPATH%

Ending the Simulation¶

tasklist|find /i "CopterSim.exe" && taskkill /im "CopterSim.exe"
tasklist|find /i "QGroundControl.exe" && taskkill /f /im "QGroundControl.exe"
tasklist|find /i "RflySim3D.exe" && taskkill /f /im "RflySim3D.exe"
ECHO Start End.

Differences Between HITLRun and SITLRun¶

HITLRun.bat is largely identical to SITLRun.bat, with the following key differences:

Difference	HITLRun	SITLRun
Port Configuration	Requires user input of COM serial port number	Automatically assigns UDP ports
QGC Startup Order	Starts after CopterSim (to avoid COM port conflicts)	Starts before CopterSim
Firmware Compilation	Not performed	Compiles PX4 in WSL

Port Configuration (HITLRun-Specific)¶

1. Retrieve COM Port Information¶

for /f "delims=" %%t in ('%PSP_PATH%\CopterSim\GetComList.exe 3 %BaudRate%') do set ComInfoStr=%%t

2. Parse COM Port Information¶

for /f "tokens=1,2,3 delims=#" %%a in ("%ComInfoStr%") do (
    set ComNumExe=%%a
    set ComNameList=%%b
    set ComInfoList=%%c
)

3. Display Available COM Ports¶

set remain=%ComInfoList%
echo All COM ports on this computer are:
:loopInfo
for /f "tokens=1* delims=;" %%a in ("%remain%") do (
    echo %%a
    set remain=%%b
)
if defined remain goto :loopInfo

4. Output Recommended Port List¶

if %ComNumExe% EQU 0 (
    echo Warning: there is no available COM port
) else (
    echo Recommended COM list input is: %ComNameList%
)

5. Input COM Port List¶

SET /P ComNum=My COM list for HITL simulation is:

COM Port Input Interface

6. Parse and Validate Input¶

SET string=%ComNum%
set /a VehicleNum=0
:split
    for /f "tokens=1,* delims=," %%i in ("%string%") do (
    set subStr=%%i
    set string=%%j
    )
    set /a eValue=subStr
    if not %eValue% EQU %subStr% (
        echo Error: Input '%subStr%' is not a integer!
        goto EOF
    )
    set /a VehicleNum = VehicleNum +1
if not "%string%"=="" goto split

QGC Startup Order (HITLRun)¶

QGC is started after CopterSim parameters are configured, to prevent QGC from occupying the COM port.

start /realtime CopterSim.exe 1 %cntr% %CLASS_3D_ID% ... %subStr%:%BaudRate% %UDPSIMMODE% %IsSysID%
...
tasklist|find /i "QGroundControl.exe" || start %PSP_PATH%\QGroundControl\QGroundControl.exe -noComPix

BAT Script Quick Reference Index¶

The table below lists all available BAT scripts and their key features:

Basic Simulation Scripts¶

Script Name	Simulation Type	Feature Description
HITLRun.bat	HIL	Conventional hardware-in-the-loop; manual COM port input required
SITLRun.bat	SIL	Conventional software-in-the-loop; automatically starts based on aircraft count input
HITLRunAuto.bat	HIL	Automatically assigns COM ports; no manual input needed
SITLRunDebug.bat	SIL	PX4 official single-vehicle SITL debugging

Position Initialization Scripts¶

Script Name	Simulation Type	Feature Description
HITLPos.bat	HIL	Manual input of PosX/PosY/Yaw
SITLPos.bat	SIL	Manual input of PosX/PosY/Yaw
HITLPosAlt.bat	HIL	Supports initialization in air or underwater
SITLPosAlt.bat	SIL	Supports initialization in air or underwater
HITLPosStr.bat	HIL	Position specified as string within script
SITLPosStr.bat	SIL	Position specified as string within script
HITLPosAltStr.bat	HIL	Automatic input; supports air/underwater initialization
SITLPosAltStr.bat	SIL	Automatic input; supports air/underwater initialization
SITLPosStrSel.bat	SIL	String-based position + selective subset enabling

GPS Coordinate Scripts (Full Version Only)¶

Script Name	Simulation Type	Feature Description
HITLPosStrGPS.bat	HIL	Global GPS coordinate initialization
SITLPosStrGPS.bat	SIL	Global GPS coordinate initialization

Key settings: SET isPosGps=1 + SET isBatLLAOrin=1

SysID Binding Scripts¶

Script Name	Simulation Type	Feature Description
HITLRunSysID.bat	HIL	CopterID automatically determined by flight controller SysID
HITLPosSysID.bat	HIL	SysID + manual position input
HITLPosSysIDStr.bat	HIL	SysID + string-based position

Key setting: SET /a IsSysID=1

Networked & Swarm Scripts¶

Script Name	Simulation Type	Feature Description
HITLRunLANSwarm.bat	HIL	LAN-based networked swarm flight (`IS_BROADCAST=1`)
SITLRunLANSwarm.bat	SIL	LAN-based networked swarm flight

Special Mode Scripts¶

Script Name	Simulation Type	Feature Description
HITLRunFw.bat	HIL	Fixed-wing mode (`DLLModel=FixWingModel`)
SITLRunFw.bat	SIL	Fixed-wing SITL
HITLRunChange3D.bat	HIL	Switch 3D vehicle model style
SITLRunChange3D.bat	SIL	Switch 3D vehicle model style
HITLRunMAVLinkNoGPS.bat	HIL	No-GPS mode (SLAM)
SITLRunMAVLinkNoGPS.bat	SIL	No-GPS mode (SLAM)
HITLRunPX4Net.bat	HIL	Network-connected flight controller (`PX4_HITL_NET`)
HITLRunExtNet.bat	HIL	Third-party flight controller (`EXT_SIM_NET`)
HITLRunLowGPU.bat	HIL	Low GPU mode (`UE4_MAP=LowGPU`)
SITLRunLowGPU.bat	SIL	Low GPU mode
HITLRunNoUI.bat	HIL	Headless background execution
SITLRunNoUI.bat	SIL	Headless background execution
HITLRunUE5.bat	HIL	Uses UE5-based 3D program
SITLRunUE5.bat	SIL	Uses UE5-based 3D program

ROS Integration Scripts¶

Script Name	Simulation Type	Feature Description
HITLRunROS.bat	HIL	HIL + automatic MAVROS startup
SITLRunROS.bat	SIL	SIL + automatic MAVROS startup

Utility & Environment Scripts¶

Script Name	Function
CloseALL.bat	One-click cleanup of all simulation processes + WSL
StopBuild.bat	Terminate WSL-related processes
DistSim.bat	Launch distributed simulation manager
UdpPortFree.bat	Port conflict detection and resolution
Python38Env.bat	Open command line with preconfigured Python 3.8 environment
Python38Run.bat	Open Python 3.8 environment in current directory
StartCFclient.bat	Launch cfclient
WinWSL.bat	Open WSL console + VcXsrv
WslGUI.bat	One-click enable WSL GUI support
WslSwith2.bat	WSL1/WSL2 switching and network configuration
gpedit.bat	Install Group Policy Editor on Windows Home edition

Common Script Parameter Differences¶

The main flow of different scripts is the same; differences are mainly in simulation mode, position input method, communication link, and background program selection. When modifying a script, first confirm the key variables in the table below, then check ports, maps, and vehicle count.

| Script | Key Variables or Commands | Usage Notes | | --- | --- | --- | --- | | HITLRun.bat | SimMode=0 or PX4_HITL, UDPSIMMODE=0, user inputs COM serial port list | Conventional hardware-in-the-loop; vehicle IDs increment sequentially based on user-input serial port order | | SITLRun.bat | SimMode=2, PX4SitlFrame=iris | Conventional software-in-the-loop; after inputting the number of vehicles, automatically starts PX4 SITL and CopterSim | | HITLPos.bat / SITLPos.bat | SET /P PosXStr, SET /P PosYStr, SET /P YawStr | Manually input initial position and yaw angle list at runtime | | HITLPosStr.bat / SITLPosStr.bat | SET PosXStr=..., SET PosYStr=..., SET YawStr=... | Position and yaw written directly in the script, suitable for repeated experiments with fixed formations | | HITLPosAlt.bat / SITLPosAlt.bat | Position, yaw, and altitude-related variables | Supports initial state in air or underwater, suitable for in-flight takeover, landing, or water/underwater scenarios | | HITLRunSysID.bat | SET /a IsSysID=1 | CopterID automatically determined by flight controller SysID, suitable for fixed hardware numbering and fault localization | | HITLPosSysIDStr.bat | IsSysID=1, START_INDEX, position string | Indexes the position list using SysID - START_INDEX, suitable for binding fixed hardware to fixed formations | | HITLPosStrGPS.bat / SITLPosStrGPS.bat | SET isPosGps=1, SET isBatLLAOrin=1, LatLongAlt | Initializes position using latitude/longitude; the free version does not support configuring GPS initial position | | HITLRunExtNet.bat | SimMode=EXT_SIM_NET | Connects to third-party flight controllers or external flight controller simulators via network | | HITLRunPX4Net.bat | SimMode=PX4_HITL_NET | Ethernet-based PX4 hardware-in-the-loop, suitable for flight controller links that do not use serial ports | | HITLRunMAVLinkNoGPS.bat / SITLRunMAVLinkNoGPS.bat | SET UDPSIMMODE=Mavlink_NoGPS | Disables GPS-related MAVLink data, suitable for indoor positioning, SLAM, or motion capture scenarios | | HITLRunAuto.bat | GetComList.exe, 0:%BaudRate% | After inputting the number of vehicles, automatically matches Pixhawk serial ports, reducing manual COM list input | | HITLRunFw.bat / SITLRunFw.bat | DLLModel=FixWingModel, PX4SitlFrame=standard_plane | Fixed-wing simulation scripts, typically use the OldFactory map and Mavlink_Full communication mode | | HITLRunLANSwarm.bat / SITLRunLANSwarm.bat | IS_BROADCAST=1, RflySim3D -key=I1 | LAN-based networked swarm flight, requires synchronized configuration of firewall and target host network | | HITLRunLowGPU.bat / SITLRunLowGPU.bat | UE4_MAP=LowGPU | Low GPU or remote desktop scenarios, reduces 3D rendering load | | HITLRunNoUI.bat / SITLRunNoUI.bat | CopterSimNoUI.exe | Headless background execution, suitable for servers, batch testing, and automated regression | | HITLRunROS.bat / SITLRunROS.bat | mavros_run.sh %START_INDEX%,%VehicleNum% | Automatically starts the MAVROS link after simulation launch, typically executes wsl --shutdown at the end | | HITLRunUE5.bat / SITLRunUE5.bat | %PSP_PATH%\RflySimUE5\RflySim3D.exe | Uses UE5 version of the 3D program and UE5 scene resources | | UdpPortFree.bat | netstat -ano, :check_and_kill, :check_and_kill_tcp | Calculates port ranges based on fixed ports and vehicle numbers, releases residual simulation processes |

Position strings typically use English commas to separate values for multiple vehicles in the same dimension:

SET PosXStr=1,2,3,4,5,6,7,8,9,10
SET PosYStr=0,0,0,0,0,0,0,0,0,0
SET YawStr=0,0,0,0,0,0,0,0,0,0

For SysID binding scripts, START_INDEX also affects the position list index. For example, when SysID=15 and START_INDEX=11, the 4th offset position in the position list (i.e., 15-11=4) is read, which is the 4th item counting from 0.

Appendix: Common Batch Script Code Snippet Descriptions¶

1) Self-Elevation to Administrator Privileges¶

NET SESSION >nul 2>&1 || powershell -Command "Start-Process cmd -ArgumentList '/c, ""%~f0""' -Verb RunAs" && exit /b

NET SESSION can only be executed successfully by an administrator; if it fails, it self-elevates and re-runs the current script.

2) Silent Output and Error Redirection¶

someCommand >nul 2>&1

Suppresses standard output and error output. Common combination: cmd1 || cmd2 (executes the latter only if the former fails).

3) Process Query and Safe Termination¶

tasklist | find /i "CopterSim.exe" && taskkill /im "CopterSim.exe"
tasklist | find /i "QGroundControl.exe" && taskkill /f /im "QGroundControl.exe"

Check first, then kill, to avoid "process not found" errors. /f forces termination.

4) WSL Environment Management¶

wsl --shutdown          :: Shuts down all WSL distributions
wsl -d RflySim-20.04    :: Executes in the specified distribution

5) X Server and GUI Launch¶

cd /d %PSP_PATH%\VcXsrv
tasklist|find /i "vcxsrv.exe" >nul || Xlaunch.exe -run config.xlaunch

6) Path and Working Directory¶

cd /d %PSP_PATH%\CopterSim     :: Cross-drive switching
pushd "%~dp0"                   :: Enter the script's directory

7) Program Launch and Console Session¶

start /realtime CopterSim.exe ...
start cmd.exe /k "SET PATH=...;%PATH% & someCommand"

/min minimizes the window, /realtime sets high priority, /k keeps the window open, /c exits after execution.

8) Delay and Throttling¶

choice /t 2 /d y /n >nul

Non-interactive wait for 2 seconds to allow processes time to start.

9) Environment Variables and Arithmetic¶

set /a VEHICLE_INTERVAL=2
setlocal enabledelayedexpansion
echo !var!   :: Delayed expansion, used within loops

%var% expands at parse time, !var! expands at execution time.

10) String and List Parsing¶

for /f "tokens=1,2,3 delims=#" %%a in ("%ComInfoStr%") do (
  set ComNumExe=%%a
  set ComNameList=%%b
  set ComInfoList=%%c
)

11) Labels and Subroutines¶

call :check_and_kill 20010
goto :eof

:check_and_kill
REM ...implementation...
exit /b 0

12) Temporary PATH Injection¶

SET WINDOWSPATH=%PATH%
SET PATH=%PSP_PATH%\Python38;%PATH%
...
SET PATH=%WINDOWSPATH%

13) Pipelines and Conditional Execution¶

tasklist | find /i "RflySim3D.exe" || start %PSP_PATH%\RflySim3D\RflySim3D.exe

Starts a new instance only if the process is not found.

Typical Script Families and Usage Differences¶

RflySim's BAT scripts are typically organized around simulation mode, initial pose, network environment, 3D engine, and toolchain environment. In addition to the parameters listed earlier, the following table can be used to quickly distinguish common script families.

Script Family	Typical Scripts	Main Purpose	Common Differences
HITL Launch	`HITLRun.bat`, `HITLPos.bat`, `HITLRunFw.bat`	Start hardware-in-the-loop simulation workflow	Connects to real flight controllers or external PX4 instances, often includes serial port, network port, or position initialization parameters
SITL Launch	`SITLRun.bat`, `SITLPos.bat`, `SITLRunFw.bat`	Start software-in-the-loop simulation workflow	Automatically starts PX4 SITL and assigns TCP/UDP ports based on vehicle number
Pose Initialization	`HITLPos.bat`, `SITLPos.bat`, `HITLPosAlt.bat`, `SITLPosAlt.bat`	Set vehicle initial position, attitude, and altitude	`Pos` focuses on position, `Alt` additionally specifies altitude, `Str` supports batch configuration via string format
GPS Origin	`HITLPosStrGPS.bat`, `SITLPosStrGPS.bat`	Set GPS origin and multi-vehicle initial pose	Commonly used to replicate real-world latitude/longitude, group takeoff positions, or cross-map scenarios
System Identification	`HITLRunSysID.bat`, `HITLPosSysID.bat`, `HITLPosSysIDStr.bat`	Start data collection simulation suitable for model identification	Typically fixes map, weather, vehicle initial state, and log directory
Network Extension	`HITLRunExtNet.bat`, `HITLRunPX4Net.bat`, `HITLRunLANSwarm.bat`, `SITLRunLANSwarm.bat`	Cross-host or LAN cluster simulation	Requires configuration of target IP, multicast/unicast strategy, and firewall
No GPS / MAVLink	`HITLRunMAVLinkNoGPS.bat`, `SITLRunMAVLinkNoGPS.bat`	MAVLink control or indoor positioning scenarios without GPS	Suitable for external positioning, visual positioning, motion capture input
Performance/UI	`HITLRunLowGPU.bat`, `SITLRunLowGPU.bat`, `HITLRunNoUI.bat`, `SITLRunNoUI.bat`	Reduce GPU usage or run without UI	Suitable for batch testing, server deployment, remote automation
ROS/UE5	`HITLRunROS.bat`, `SITLRunROS.bat`, `HITLRunUE5.bat`, `SITLRunUE5.bat`	Start ROS bridge or UE5 scene	Requires synchronized configuration of ROS, WSL, UE5 project paths

Choosing Between HITLRun and SITLRun¶

Use HITL when a real flight controller or external flight controller hardware is present.
Use SITL when running only PX4 and the simulator on the computer.
The port, process, and troubleshooting methods for the two script types differ; mixing them is not recommended.

Main Program Startup Sequence¶

A typical startup script organizes the main programs in the following order. The actual order can be adjusted based on whether QGC, ROS, UE5, or distributed deployment is used.

Phase	Typical Action	Description
1	Set `PSP_PATH`, `START_INDEX`, `TOTOAL_COPTER`, `SimMode`	Determine toolchain path, starting vehicle number, total vehicle count, and simulation mode
2	Check serial ports or network ports	HITL checks `COMn` or `/dev/ttyUSBn`; SITL checks TCP/UDP ports
3	Start PX4 SITL or connect to hardware flight controller	SITL scripts start PX4, HITL scripts wait for user to select flight controller port
4	Start CopterSim	Create motion simulation instances based on `CopterID`, model, map, and communication mode
5	Start RflySim3D / UE5	Load map, objects, and visual sensor configuration
6	Start QGroundControl, ROS, Python, or other external programs	Connect ground station, algorithm nodes, and control scripts as needed by the task

COM Port Selection Process¶

HITL scripts typically first obtain the system's available COM ports, then prompt the user to input the port list for flight controller connection. In multi-flight controller scenarios, the user input order should match the CopterID order.

Step	Description
Get Port String	Read the system serial port list, forming intermediate variables such as `ComInfoStr`
Parse Ports	Use `for /f` to split port numbers, names, and descriptions by delimiter
Display Available Ports	List all candidate COM ports in the command line
Check Quantity	If the number of available flight controllers is less than the number of simulated aircraft, prompt to reconnect or reduce the number of aircraft
User Input	Input a port list such as `3,4,5`, corresponding to `COM3`, `COM4`, `COM5`
Validate Ports	Check whether the input ports exist, are duplicated, and whether the quantity matches

QGroundControl Startup Order¶

In multi-vehicle or multi-port simulations, it is recommended to start the PX4/CopterSim communication link first, then start QGroundControl. If QGC occupies port 14550 or related TCP ports first, it may cause CopterSim or the MAVLink forwarding link to fail to connect.

Multi-Vehicle Pose String¶

Batch position scripts often use strings to describe the initial positions of multiple vehicles:

set POS_STR=0,0,0;5,0,0;10,0,0
set YAW_STR=0;90;180

Here, ; separates different vehicles, and , separates the position components of a single vehicle. Internally, the script typically uses for /f or delayed variable expansion to parse the string.

Troubleshooting Points¶

If a port is occupied, first run UdpPortFree.bat or manually check ports in the 14550, 20100, 30100, 40100 series.
In multi-vehicle scripts, CopterID, PX4 instance number, CopterSim number, and RflySim3D object number must be consistent.
For WSL-related scripts, confirm the distribution, PX4 path, VcXsrv/graphics forwarding, and firewall rules.
When starting in batch, it is recommended to keep a 1 to 3 second delay between PX4, CopterSim, RflySim3D, and QGroundControl.