Velodyne Simulator

URDF description and Gazebo plugins to simulate Velodyne laser scanners

Features

• URDF with colored meshes
• Gazebo plugin based on gazebo_plugins/gazebo_ros_block_laser
• Publishes PointCloud2 with same structure (x, y, z, intensity, ring, time)
• Simulated Gaussian noise
• GPU acceleration (with a modern Gazebo build)
• Supported models:
  • VLP-16
  • HDL-32E
  • Pull requests for other models are welcome
• Experimental support for clipping low-intensity returns

Parameters

• *origin URDF transform from parent link.

• ``` URDF parent link name. Default 
  ```base_link
  

• ``` URDF model name. Also used as tf frame_id for PointCloud2 output. Default 
  ```velodyne
  

• ``` PointCloud2 output topic name. Default 
  ```/velodyne_points
  

• ``` Update rate in hz. Default 
  ```10
  

• ``` Number of vertical spinning lasers. Default 
  ```VLP-16: 16, HDL-32E: 32
  

• ``` Nuber of horizontal rotating samples. Default 
  ```VLP-16: 1875, HDL-32E: 2187
  

• ``` Organize PointCloud2 into 2D array with NaN placeholders, otherwise 1D array and leave out invlaid points. Default 
  ```false
  

• ``` Minimum range value in meters. Default 
  ```0.9
  

• ``` Maximum range value in meters. Default 
  ```130.0
  

• ``` Gausian noise value in meters. Default 
  ```0.008
  

• ``` Minimum horizontal angle in radians. Default 
  ```-3.14
  

• ``` Maximum horizontal angle in radians. Default 
  ```3.14
  

• ``` Use gpu_ray sensor instead of the standard ray sensor. Default 
  ```false
  

• min_intensity The minimum intensity beneath which returns will be clipped. Can be used to remove low-intensity objects.

Known Issues

• At full sample resolution, Gazebo can take up to 30 seconds to load the VLP-16 pluggin, 60 seconds for the HDL-32E
• With the default Gazebo version shipped with ROS, ranges are incorrect when accelerated with the GPU option (issue,image)
  • Solution: Upgrade to a modern Gazebo version
• Gazebo cannot maintain 10Hz with large pointclouds
  • Solution: User can reduce number of points (samples) or frequency (hz) in the urdf parameters, see example.urdf.xacro
• Gazebo crashes when updating HDL-32E sensors with default number of points. “Took over 1.0 seconds to update a sensor.”
  • Solution: User can reduce number of points in urdf (same as above)

Example Gazebo Robot

```roslaunch velodyne_description example.launch

# Example Gazebo Robot (with GPU)

```roslaunch velodyne_description example.launch gpu:=true