Implement custom Gazebo sensors at ease

The current structure of the Gazebo simulator doesn’t allow implementation of custom <sensor>s in the form of externally loaded plugins. To add a new sensor implementation, you officially need to fork Gazebo and add the sensor to its source code.

This doesn’t sound really great, does it?

This Gazebo system plugin allows you to write custom Gazebo sensors as ROS packages (so it depends on gazebo_ros, and adding them to Gazebo is then a matter of a few configuration lines in your sensor code. Theoretically, the mechanism this plugin uses could work completely without ROS, but hey, who uses Gazebo without ROS? :)

This plugin is only tested to work with Gazebo 9. If you successfully use it with a different version, please let me know in the issues.

Known custom sensors

Here’s a (noncomprehensive) list of known custom sensor implementations that work with this plugin. Feel free to open a pull request to add your own implementation here.

• gazebo_rotating_lidar: A sensor for more realistic simulation of lidars based on a rotating mirror where each laser beam has a different timestamp.

How to do it

There is an example custom sensor in this package: ExampleCustomSensor.cpp, ExampleCustomSensor.h and example_custom_sensor.xml. The most important things will be described further in this document.

⚠ In this guide, we use the names ExampleCustomSensor and example_custom_sensor, which you have to change, because a custom sensor with this class/name is already built in this package.

Create a ROS/catkin package for your sensor

E.g. by calling

catkin_create_pkg ... example_custom_sensor ...

A pretty normal Sensor implementation …

ExampleCustomSensor.h

Here, it is important to note that your custom sensor has to reside inside the gazebo::sensors namespace.

#include <gazebo/sensors/Sensor.hh>

namespace gazebo
{
namespace sensors
{

class ExampleCustomSensor : public Sensor
{

// your code

}
}
}

ExampleCustomSensor.cpp

In the implementation file, you have to register your sensor via the following block of code. The first argument is the Gazebo sensor type, which is how you reference the custom sensor in SDF. It should also match the name attribute in XML plugin definition (prefixed with sensors/).

#include <gazebo/sensors/SensorFactory.hh>

using gazebo::sensors::Sensor;
using gazebo::sensors::SensorFactory;
extern "C"
{
GZ_REGISTER_STATIC_SENSOR("example_custom_sensor", ExampleCustomSensor)
}

// your sensor implementation

… a few configuration lines …

example_custom_sensor.xml

This is a configuration file you may know if you’ve ever used ROS pluginlib, e.g. when implementing a nodelet. The library path is relative to the devel space of your sensor’s workspace, and contains the name of the shared object containing the sensor, excluding the

File truncated at 100 lines see the full file