The RealSense SDK provides an API for accessing the camera hardware directly. Accessing the camera via the SDK locks it, until access is released. This tutorial will cover how to use the RealSense SDK for C++ development using the simple example of accessing the camera's intrinsic calibration parameters. Recall that the intrinsic camera matrix for raw…Read more Using the RealSense SDK to access the camera
Working with 3D point clouds in ROS
A point cloud is a set of data points in 3D space. Such data is usually derived from time-of-flight, structured light or stereo reconstruction. Laser scanners such as the Hukuyo or Velodyne provide a planar scan or 3D coloured point cloud respectively. The perception_pcl package is the PCL ROS interface stack. A previous post covered how to integrate the Point…Read more Working with 3D point clouds in ROS
Updating the RealSense nodelet
The ROS Wrapper for Intel RealSense Devices provides a ROS nodelet interface between the camera and the ROS system. Intel updates this ROS package on a fairly regular basis, which could lead to API version mismatch errors. When this happens, the camera (sometimes) works fine on realsense-viewer but any code using the RealSense nodelet fails to compile.…Read more Updating the RealSense nodelet
Setting up CLion for ROS and GitHub
CLion is a cross-platform C/C++ IDE that natively supports CMake (which ROS Catkin is based on), and also supports Python code. Creating or opening ROS projects within CLion makes it easy to debug code, execute nodes, and view packages and classes within a ROS workspace in an intuititve way. More details on the setup can…Read more Setting up CLion for ROS and GitHub
When the RealSense stops connecting
The RealSense D435 RGBD camera is generally very robust and reliable. It can however fail to connect and display the image and depth frames. When this happens, hardware notification errors appear in the realsense-viewer software as shown below. Usually this is caused by a connection issue, such as trying to use USB 2 with the RealSense,…Read more When the RealSense stops connecting
3D Computer Vision in ROS
The RealSense D435 camera can be readily set up to publish all the image and pointcloud streams via ROS topics. For an in-depth setup, read Integrating the Intel RealSense D435 with ROS. Once this data becomes available in ROS, processing it via custom nodes requires a larger ROS ecosystem for perception. Three popular 2D/3D computer…Read more 3D Computer Vision in ROS
Integrating the Hokuyo URG Lidar with ROS
The Hukuyo URG is a lightweight, affordable USB powered lidar sensor. It outputs a single planar scan with 240º scanning range at 0.36º angular resolution and scan rate of 100ms/scan. This sensor can be used for, amongst other things, indoor mapping or collision avoidance. There is presently no pre-compiled driver available for ROS kinetic so…Read more Integrating the Hokuyo URG Lidar with ROS
