ping360_sonar

Overview

A python ROS package for the BlueRobotics Ping360 Sonar. The package has been tested under ROS melodic and Ubuntu 16.04. This code is mostly experimental, expect that it changes often.

Keywords: ROS, package, ping360, ping360 emulator

License

The source code is released under a MIT license.

Installation

Download the latest release

Get the latest stable release here.

Building from Source

Dependencies

Robot Operating System (ROS) (middleware for robotics),
OpenCV
cv_bridge

Building

Before building from source, install ping-protocol python lib:

pip install bluerobotics-ping

To build from source, clone the latest version from this repository into your catkin workspace and compile the package using

cd catkin_workspace/src
git clone https://github.com/CentraleNantesRobotics/ping360_sonar.git
cd ../
catkin build

Unit Tests

TODO

Usage

An example launch file has been provided example.launch:

Run the main node with:

roslaunch ping360_sonar example.launch

Launch files

example.launch: contains the default parameteres to run the Ping360 Sonar, including the serial port and the baudrate to interface with the sonar. The rest of the parameters are documented here: Ping360 Documentation. The same parameters can also be reconfigured using the dynamic_reconfigure.

An emulated mode was added to test the package when you don't have the sonar. To run the emulated sonar, set the env variable to "true":
```
  <env name="emulated_sonar" value="true" />
```
The results from the emulation should be:

Three extra parameters can be set to toggle specific topics, they are set to true by default.

    <param name="enableImageTopic" value="True"/> 
    <param name="enableScanTopic" value="True"/> 
    <param name="enableDataTopic" value="True"/>

Nodes

ping360_node

While continuously rotating the sonar, it publishes two types of messages:

The sonar's response data (the echo intensities for a given angle & range)
A black and white image using the date received from the sonar. Same as the one generated by the ping viewer.

Published Topics

/ping360_node/sonar/images (sensor_msgs/Image)

The generated sonar image. This topic can be toggled using the enableImageTopic parameter.

/ping360_node/sonar/data (msg/SonarEcho)

Publishes the raw sonar data in a custom message:

  Header header            #header info
  float32 angle               # the measurement angle [rad]
  uint8 gain  # Sonar Gain
  uint16 number_of_samples 
  uint16 transmit_frequency # [kHz]
  uint16 speed_of_sound # [m/s]
  uint8 range      #  range value [m]
  uint8[] intensities    # intensity data [0-255].  This is the actual data received from the sonar

This topic can be toggled using the enableDataTopic parameter.

/ping360_node/sonar/scan (sensor_msgs/LaserScan)

Publishes a LaserScan msg with ranges detected with a certain intensity threshold:

  float32 angle_min = 0     # start angle of the scan [rad]
  float32 angle_max = 2*pi  # end angle of the scan [rad]
  float32 angle_increment   # angular distance between measurements, calculated using the configured Step  [rad]

  float32 range_min = .75   # minimum range value [m]
  float32 range_max = sonarRange # maximum range value, it's set to the configured sonarRange [m]

  float32[] ranges         # calculated ranges that correspond to an intensity > threshold [m] 
  float32[] intensities    # sensor intensity data [0-255]

This topic can be toggled using the enableScanTopic parameter.

Note: