mirror of
https://gitee.com/mirrors_PX4/PX4-Autopilot.git
synced 2026-04-14 10:07:39 +08:00
401 lines
16 KiB
Markdown
401 lines
16 KiB
Markdown
# jMAVSim with SITL
|
|
|
|
:::warning
|
|
This simulator is [community supported and maintained](../simulation/community_supported_simulators.md).
|
|
It may or may not work with current versions of PX4 and may be removed in future releases.
|
|
|
|
See [Toolchain Installation](../dev_setup/dev_env.md) for information about the environments and tools supported by the core development team.
|
|
:::
|
|
|
|
jMAVSim is a simple multirotor/Quad simulator that allows you to fly _copter_ type vehicles running PX4 around a simulated world.
|
|
It is easy to set up and can be used to test that your vehicle can take off, fly, land, and responds appropriately to various fail conditions (e.g. GPS failure).
|
|
|
|
<strong>Supported Vehicles:</strong>
|
|
|
|
- Quad
|
|
|
|
This topic shows how to set up jMAVSim to connect with a SITL version of PX4.
|
|
|
|
:::tip
|
|
jMAVSim can also be used for HITL Simulation ([as shown here](../simulation/hitl.md#jmavsim-quadrotor-only)).
|
|
:::
|
|
|
|
## 설치
|
|
|
|
jMAVSim requires JDK 17 or later.
|
|
On Ubuntu and Windows, the [standard development environment setup](../dev_setup/dev_env.md) scripts install all required dependencies including Java.
|
|
On macOS, you need to install Java manually as shown below.
|
|
|
|
### macOS
|
|
|
|
jMAVSim requires OpenJDK 17 or later.
|
|
Install it via Homebrew:
|
|
|
|
```sh
|
|
brew install openjdk@17
|
|
```
|
|
|
|
Homebrew installs OpenJDK but does not link it into your `PATH`, so you need to set `JAVA_HOME` for jMAVSim to find it.
|
|
Add this to your shell profile (e.g. `~/.zshrc`):
|
|
|
|
```sh
|
|
export JAVA_HOME=$(/usr/libexec/java_home -v 17)
|
|
```
|
|
|
|
## Simulation Environment
|
|
|
|
Software in the Loop Simulation runs the complete system on the host machine and simulates the autopilot.
|
|
It connects via local network to the simulator.
|
|
The setup looks like this:
|
|
|
|
[](https://mermaid-js.github.io/mermaid-live-editor/#/edit/eyJjb2RlIjoiZ3JhcGggTFI7XG4gIFNpbXVsYXRvci0tPk1BVkxpbms7XG4gIE1BVkxpbmstLT5TSVRMOyIsIm1lcm1haWQiOnsidGhlbWUiOiJkZWZhdWx0In0sInVwZGF0ZUVkaXRvciI6ZmFsc2V9)
|
|
|
|
<!-- original graph
|
|
graph LR;
|
|
Simulator-- >MAVLink;
|
|
MAVLink-- >SITL;
|
|
-->
|
|
|
|
## Running SITL
|
|
|
|
After ensuring that the [simulation prerequisites](../dev_setup/dev_env.md) are installed on the system, just launch: The convenience make target will compile the POSIX host build and run the simulation.
|
|
|
|
```sh
|
|
make px4_sitl_default jmavsim
|
|
```
|
|
|
|
This will bring up the PX4 shell:
|
|
|
|
```sh
|
|
[init] shell id: 140735313310464
|
|
[init] task name: px4
|
|
|
|
______ __ __ ___
|
|
| ___ \ \ \ / / / |
|
|
| |_/ / \ V / / /| |
|
|
| __/ / \ / /_| |
|
|
| | / /^\ \ \___ |
|
|
\_| \/ \/ |_/
|
|
|
|
Ready to fly.
|
|
|
|
|
|
pxh>
|
|
```
|
|
|
|
It will also bring up a window showing a 3D view of the [jMAVSim](https://github.com/PX4/jMAVSim) simulator:
|
|
|
|
|
|
|
|
## Taking it to the Sky
|
|
|
|
The system will start printing status information.
|
|
You will be able to start flying once you have a position lock (shortly after the console displays the message: _EKF commencing GPS fusion_).
|
|
|
|
To takeoff enter the following into the console:
|
|
|
|
```sh
|
|
pxh> commander takeoff
|
|
```
|
|
|
|
You can use _QGroundControl_ to fly a mission or to connect to a [joystick](#using-a-joystick).
|
|
|
|
## Usage/Configuration Options
|
|
|
|
Options that apply to all simulators are covered in the top level [Simulation](../simulation/index.md#sitl-simulation-environment) topic (some of these may be duplicated below).
|
|
|
|
### Simulating Sensor/Hardware Failure
|
|
|
|
[Simulate Failsafes](../simulation/failsafes.md) explains how to trigger safety failsafes like GPS failure and battery drain.
|
|
|
|
### Set Custom Takeoff Location
|
|
|
|
The default takeoff location in can be overridden using the environment variables: `PX4_HOME_LAT`, `PX4_HOME_LON`, and `PX4_HOME_ALT`.
|
|
|
|
For example, to set the latitude, longitude and altitude:
|
|
|
|
```sh
|
|
export PX4_HOME_LAT=28.452386
|
|
export PX4_HOME_LON=-13.867138
|
|
export PX4_HOME_ALT=28.5
|
|
make px4_sitl_default jmavsim
|
|
```
|
|
|
|
### Change Simulation Speed
|
|
|
|
The simulation speed can be increased or decreased with respect to realtime using the environment variable `PX4_SIM_SPEED_FACTOR`.
|
|
|
|
To run at double real-time:
|
|
|
|
```sh
|
|
PX4_SIM_SPEED_FACTOR=2 make px4_sitl_default jmavsim
|
|
```
|
|
|
|
To run at half real-time:
|
|
|
|
```sh
|
|
PX4_SIM_SPEED_FACTOR=0.5 make px4_sitl_default jmavsim
|
|
```
|
|
|
|
To apply a factor to all SITL runs in the current session, use `EXPORT`:
|
|
|
|
```sh
|
|
export PX4_SIM_SPEED_FACTOR=2
|
|
make px4_sitl_default jmavsim
|
|
```
|
|
|
|
### Using a Joystick
|
|
|
|
Joystick and thumb-joystick support are supported through _QGroundControl_ ([setup instructions here](../simulation/index.md#joystick-gamepad-integration)).
|
|
|
|
### Simulating a Wifi Drone
|
|
|
|
There is a special target to simulate a drone connected via Wifi on the local network:
|
|
|
|
```sh
|
|
make broadcast jmavsim
|
|
```
|
|
|
|
The simulator broadcasts its address on the local network as a real drone would do.
|
|
|
|
### Start JMAVSim and PX4 Separately
|
|
|
|
You can start JMAVSim and PX4 separately:
|
|
|
|
```sh
|
|
./Tools/simulation/jmavsim/jmavsim_run.sh -l
|
|
make px4_sitl none
|
|
```
|
|
|
|
This allows a faster testing cycle (restarting jMAVSim takes significantly more time).
|
|
|
|
### Headless Mode
|
|
|
|
To start jMAVSim without the GUI, set the env variable `HEADLESS=1` as shown:
|
|
|
|
```sh
|
|
HEADLESS=1 make px4_sitl jmavsim
|
|
```
|
|
|
|
## 다중 차량 시뮬레이션
|
|
|
|
JMAVSim can be used for multi-vehicle simulation: [Multi-Vehicle Sim with JMAVSim](../sim_jmavsim/multi_vehicle.md).
|
|
|
|
## Lockstep
|
|
|
|
PX4 SITL and jMAVSim have been set up to run in _lockstep_.
|
|
What this means is that PX4 and the simulator run at the same speed, and therefore can react appropriately to sensor and actuator messages.
|
|
Lockstep makes it possible to [change the simulation speed](#change-simulation-speed), and also to pause it in order to step through code.
|
|
|
|
#### Lockstep Sequence
|
|
|
|
The sequence of steps for lockstep are:
|
|
|
|
1. The simulation sends a sensor message [HIL_SENSOR](https://mavlink.io/en/messages/common.html#HIL_SENSOR) including a timestamp `time_usec` to update the sensor state and time of PX4.
|
|
2. PX4 receives this and does one iteration of state estimation, controls, etc. and eventually sends an actuator message [HIL_ACTUATOR_CONTROLS](https://mavlink.io/en/messages/common.html#HIL_ACTUATOR_CONTROLS).
|
|
3. The simulation waits until it receives the actuator/motor message, then simulates the physics and calculates the next sensor message to send to PX4 again.
|
|
|
|
The system starts with a "freewheeling" period where the simulation sends sensor messages including time and therefore runs PX4 until it has initialized and responds with an actuator message.
|
|
|
|
#### Disabling Lockstep
|
|
|
|
The lockstep simulation can be disabled if, for example, SITL is to be used with a simulator that does not support this feature.
|
|
In this case the simulator and PX4 use the host system time and do not wait on each other.
|
|
|
|
To disable lockstep in:
|
|
|
|
- PX4, run `make px4_sitl_default boardconfig` and set the `BOARD_NOLOCKSTEP` "Force disable lockstep" symbol which is located under toolchain.
|
|
- jMAVSim, remove `-l` in [sitl_run.sh](https://github.com/PX4/PX4-Autopilot/blob/main/Tools/simulation/jsbsim/sitl_run.sh#L40), or make sure otherwise that the java binary is started without the `-lockstep` flag.
|
|
|
|
<!-- Relevant lines in sitl_run.sh are: -->
|
|
|
|
<!-- # Start Java simulator -->
|
|
|
|
<!-- "$src_path"/Tools/simulation/jmavsim/jmavsim_run.sh -r 250 -l & SIM_PID=$! -->
|
|
|
|
## Extending and Customizing
|
|
|
|
To extend or customize the simulation interface, edit the files in the **Tools/jMAVSim** folder.
|
|
The code can be accessed through the[jMAVSim repository](https://github.com/px4/jMAVSim) on Github.
|
|
|
|
:::info
|
|
The build system enforces the correct submodule to be checked out for all dependencies, including the simulator.
|
|
It will not overwrite changes in files in the directory, however, when these changes are committed the submodule needs to be registered in the Firmware repo with the new commit hash.
|
|
To do so, `git add Tools/jMAVSim` and commit the change.
|
|
This will update the GIT hash of the simulator.
|
|
:::
|
|
|
|
## Interfacing to ROS
|
|
|
|
The simulation can be [interfaced to ROS](../simulation/ros_interface.md) the same way as onboard a real vehicle.
|
|
|
|
## Important Files
|
|
|
|
- The startup scripts are discussed in [System Startup](../concept/system_startup.md).
|
|
- The simulated root file system ("`/`" directory) is created inside the build directory here: `build/px4_sitl_default/rootfs`.
|
|
|
|
## Display-Only Mode
|
|
|
|
jMAVSim can run as a display-only renderer for other simulators (like [SIH](../sim_sih/index.md)), with its internal physics disabled.
|
|
In this mode, jMAVSim receives vehicle position via MAVLink and only renders the 3D view.
|
|
|
|
To use jMAVSim as a display for SIH running in SITL:
|
|
|
|
```sh
|
|
# Start SIH first
|
|
make px4_sitl_sih sihsim_quadx
|
|
|
|
# In another terminal, start jMAVSim in display-only mode
|
|
./Tools/simulation/jmavsim/jmavsim_run.sh -p 19410 -u -q -o # 19410 is the default SIH display port
|
|
```
|
|
|
|
For SIH running on flight controller hardware:
|
|
|
|
```sh
|
|
./Tools/simulation/jmavsim/jmavsim_run.sh -q -d /dev/ttyACM0 -b 2000000 -o
|
|
```
|
|
|
|
Use `-a` for airplane display or `-t` for tailsitter display.
|
|
|
|
## Command-Line Reference
|
|
|
|
The `jmavsim_run.sh` launch script accepts the following flags:
|
|
|
|
| Flag | 설명 |
|
|
| ------------- | -------------------------------------------------------------------------------------------- |
|
|
| `-b <rate>` | Serial baud rate (default: 921600) |
|
|
| `-d <device>` | Serial device path (e.g., `/dev/ttyACM0`) |
|
|
| `-u` | Use UDP connection instead of serial |
|
|
| `-i <id>` | Simulated MAVLink system ID |
|
|
| `-p <port>` | UDP port (default: 14560) |
|
|
| `-q` | No interactive console |
|
|
| `-s <port>` | TCP serial port |
|
|
| `-r <rate>` | Render rate in Hz |
|
|
| `-l` | Enable lockstep |
|
|
| `-o` | Display-only mode (disable physics, render only) |
|
|
| `-a` | Use airplane model |
|
|
| `-t` | Use tailsitter model |
|
|
| `HEADLESS=1` | Environment variable: run without GUI window |
|
|
|
|
## How jMAVSim Works
|
|
|
|
jMAVSim is a Java-based lightweight simulator that communicates with PX4 via MAVLink HIL (Hardware-In-the-Loop) messages.
|
|
|
|
In normal mode:
|
|
|
|
1. PX4 sends actuator commands via [HIL_ACTUATOR_CONTROLS](https://mavlink.io/en/messages/common.html#HIL_ACTUATOR_CONTROLS).
|
|
2. jMAVSim runs its physics engine to compute the vehicle state.
|
|
3. jMAVSim sends sensor data back via [HIL_SENSOR](https://mavlink.io/en/messages/common.html#HIL_SENSOR) and [HIL_GPS](https://mavlink.io/en/messages/common.html#HIL_GPS).
|
|
|
|
In **display-only mode** (`-o` flag), jMAVSim disables its physics engine and only reads [HIL_STATE_QUATERNION](https://mavlink.io/en/messages/common.html#HIL_STATE_QUATERNION) messages to render the vehicle position.
|
|
This allows it to visualize vehicles from other simulators like SIH.
|
|
|
|
jMAVSim supports [lockstep synchronization](#lockstep) with PX4 (enabled with `-l` flag), ensuring deterministic simulation results.
|
|
|
|
## Keyboard Shortcuts
|
|
|
|
Camera modes in the jMAVSim 3D view:
|
|
|
|
| Key | Camera Mode |
|
|
| -------------------------------- | ------------------------------------------------------- |
|
|
| **F** | First person (attached to vehicle) |
|
|
| **S** | Stationary (fixed position) |
|
|
| **G** | Gimbal (follows vehicle orientation) |
|
|
| **(default)** | Third person follow |
|
|
|
|
## 문제 해결
|
|
|
|
### java.long.NoClassDefFoundError
|
|
|
|
```sh
|
|
Exception in thread "main" java.lang.NoClassDefFoundError: javax/vecmath/Tuple3d
|
|
at java.base/java.lang.Class.forName0(Native Method)
|
|
at java.base/java.lang.Class.forName(Class.java:374)
|
|
at org.eclipse.jdt.internal.jarinjarloader.JarRsrcLoader.main(JarRsrcLoader.java:56)
|
|
Caused by: java.lang.ClassNotFoundException: javax.vecmath.Tuple3d
|
|
at java.base/java.net.URLClassLoader.findClass(URLClassLoader.java:466)
|
|
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:566)
|
|
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:499)
|
|
... 3 more
|
|
Exception in thread "main" java.lang.NoClassDefFoundError: javax/vecmath/Tuple3d
|
|
at java.base/java.lang.Class.forName0(Native Method)
|
|
at java.base/java.lang.Class.forName(Class.java:374)
|
|
at org.eclipse.jdt.internal.jarinjarloader.JarRsrcLoader.main(JarRsrcLoader.java:56)
|
|
Caused by: java.lang.ClassNotFoundException: javax.vecmath.Tuple3d
|
|
at java.base/java.net.URLClassLoader.findClass(URLClassLoader.java:466)
|
|
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:566)
|
|
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:499)
|
|
```
|
|
|
|
This error should no longer occur once the jMAVSim submodule is [updated to newer jar libs](https://github.com/PX4/jMAVSim/pull/119) and Java 11 or Java 14 should work fine.
|
|
|
|
### An illegal reflective access operation has occurred
|
|
|
|
This warning can be ignored (it will probably be displayed but the simulation will still work correctly).
|
|
|
|
```sh
|
|
WARNING: An illegal reflective access operation has occurred
|
|
WARNING: Illegal reflective access by javax.media.j3d.JoglPipeline (rsrc:j3dcore.jar) to method sun.awt.AppContext.getAppContext()
|
|
WARNING: Please consider reporting this to the maintainers of javax.media.j3d.JoglPipeline
|
|
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
|
|
WARNING: All illegal access operations will be denied in a future release
|
|
Inconsistency detected by ld.so: dl-lookup.c: 112: check_match: Assertion version->filename == NULL || ! _dl_name_match_p (version->filename, map)' failed!
|
|
```
|
|
|
|
### java.awt.AWTError: Assistive Technology not found: org.GNOME.Accessibility.AtkWrapper
|
|
|
|
```sh
|
|
Exception in thread "main" java.lang.reflect.InvocationTargetException
|
|
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
|
|
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
|
|
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
|
|
at java.lang.reflect.Method.invoke(Method.java:498)
|
|
at org.eclipse.jdt.internal.jarinjarloader.JarRsrcLoader.main(JarRsrcLoader.java:58)
|
|
Caused by: java.awt.AWTError: Assistive Technology not found: org.GNOME.Accessibility.AtkWrapper
|
|
at java.awt.Toolkit.loadAssistiveTechnologies(Toolkit.java:807)
|
|
at java.awt.Toolkit.getDefaultToolkit(Toolkit.java:886)
|
|
at java.awt.Window.getToolkit(Window.java:1358)
|
|
at java.awt.Window.init(Window.java:506)
|
|
at java.awt.Window.(Window.java:537)
|
|
at java.awt.Frame.(Frame.java:420)
|
|
at java.awt.Frame.(Frame.java:385)
|
|
at javax.swing.JFrame.(JFrame.java:189)
|
|
at me.drton.jmavsim.Visualizer3D.(Visualizer3D.java:104)
|
|
at me.drton.jmavsim.Simulator.(Simulator.java:157)
|
|
at me.drton.jmavsim.Simulator.main(Simulator.java:678)
|
|
```
|
|
|
|
If you see this error, try this workaround:
|
|
|
|
Edit the **accessibility.properties** file:
|
|
|
|
```sh
|
|
sudo gedit /etc/java-8-openjdk/accessibility.properties
|
|
```
|
|
|
|
and comment out the line indicated below:
|
|
|
|
```sh
|
|
#assistive_technologies=org.GNOME.Accessibility.AtkWrapper
|
|
```
|
|
|
|
For more info, check [this GitHub issue](https://github.com/PX4/PX4-Autopilot/issues/9557).
|
|
A contributor found the fix in [askubuntu.com](https://askubuntu.com/questions/695560/assistive-technology-not-found-awterror).
|
|
|
|
### Exception in thread "main" java.lang.UnsupportedClassVersionError
|
|
|
|
When compiling jMAVsim, you might encounter the following error:
|
|
|
|
```sh
|
|
Exception in thread "main" java.lang.UnsupportedClassVersionError: me/drton/jmavsim/Simulator has been compiled by a more recent version of the Java Runtime (class file version 59.0), this version of the Java Runtime only recognizes class file versions up to 58.0
|
|
```
|
|
|
|
This error is telling you, you need a more recent version of Java in your environment.
|
|
Class file version 58 corresponds to jdk14, version 59 to jdk15, version 60 to jdk 16 etc.
|
|
|
|
To fix it under macOS, install a newer OpenJDK via Homebrew:
|
|
|
|
```sh
|
|
brew install openjdk@17
|
|
```
|