toposens_driver Documentation

Overview

ROS packages for working with Toposens 3D Ultrasound sensors: http://toposens.com/

Developed and tested for ROS Melodic on Ubuntu 18.04 (Bionic) and ROS Kinetic on Ubuntu 16.04 (Xenial) using Toposens TS3 ultrasonic sensor.

1. Setup

For Ubuntu 18.04

Follow these guides to install and set up ROS Melodic on your system:

• http://wiki.ros.org/melodic/Installation/Ubuntu
• http://wiki.ros.org/ROS/Tutorials/InstallingandConfiguringROSEnvironment

Install catkin tools:

$ sudo apt install python-catkin-tools

For Ubuntu 16.04

Follow these guides to install and set up ROS Kinetic on your system:

• http://wiki.ros.org/kinetic/Installation/Ubuntu
• http://wiki.ros.org/ROS/Tutorials/InstallingandConfiguringROSEnvironment

Install catkin tools:

$ sudo apt install python-catkin-tools

2. Build Driver

Clone the toposens metapackage into your catkin workspace:

$ cd ~/catkin_ws/src

$ git clone https://gitlab.com/toposens/public/ros-packages.git

Use rosdep to install missing dependencies:

$ rosdep update

$ rosdep install --from-paths ~/catkin_ws/src/ros-packages/ --ignore-src --rosdistro <distro> -y

Build the package by using catkin build:

$ catkin build toposens

3. Enable Serial Port Permissions

Add yourself to the “dialout” group:

$ sudo adduser $USER dialout

Trigger updated group permissions to take effect:

$ newgrp dialout

Re-login or reboot for the updated group permissions to take effect permanently.

4. Connect TS3 Sensor

• Connect your Toposens TS3 sensor via the provided FTDI cable to any available USB port on your computer.
• Obtain the connected terminal ID for the device:

$ dmesg | grep "FTDI USB Serial Device"

In this case the terminal ID would be ttyUSB0.

5. Visualize Data

/ts_scans broadcasts messages of type toposens_msgs/TsScan, which hold the raw data stream parsed as toposens_msgs

View Raw Stream

The ts_driver_node translates the sensor data into custom toposens_msgs/TsScan messages.

Source your ROS setup

$ source devel/setup.bash

Launch the driver node and start accruing data from a TS3 sensor. Set the corresponding serial port as launch argument (here: /dev/ttyUSB0):

$ roslaunch toposens_driver toposens_driver.launch port:=/dev/ttyUSB0

The sensor data is published to the the topic /ts_scans. View the incoming scans with:

$ rostopic echo /ts_scans

6. Manipulate Parameters

To manipulate sensor parameters as well as visualization parameters live in realtime, run in an additional terminal window:

$ rosrun rqt_reconfigure rqt_reconfigure

The ts_driver_node respectively ts_markers_node need to be running for this to work.

Sensor Parameters

There are 6 different parameters that can be changed in the ts_driver_node.

Variable Name	Effect
num_pulse	Number of ultrasonic pulses emitted by the sensors piezo transducer in every transmission cycle. Increasing the value will detect objects that are further away, decreasing it will increase the precision in short range.
peak_detection_window	Kernel size applied on ADC signals for peak detection. Decreasing it will separate multiple objects that are close to each other.
echo_rejection_threshold	Minimum amplitude for an echo to be considered valid. Increasing it will ignore more points of smaller intensity.
use_external_temperature	If checked uses external temperature value to calibrate speed-of-sound, otherwise use value provided by on-board temperature sensor.
external_temperature	Temperature value used to calibrate speed-of-sound. Value is only used if use_external_temperature is checked.
noise_indicator_threshold	Normalized noise level on ADC signals to mark processed points as noisy.