At the start of this week, I was working on integrating the Lidar data with the slam_toolbox algorithm. I was having some difficulty with this since there is no odometry system for our robot, and slam_toolbox requires odometry data as input in addition to Lidar data. I began working on installing Lidar-only odometry, and tried setting up rf20_laser_odometry, but was unable to successfully set it up. Then, on Monday I ran into the problem that the Lidar scanner was no longer detecting any points, and began reporting that all points were infinitely far away with 0 intensity. I tried many things to debug this issue. At first I thought it might be an issue of the Lidar scanner not getting enough power, but after examining and reconfiguring the powering system I decided this was not the problem. I then thought it might be a software issue that could have been created as a result of something I was doing with setting up the laser odometry system. I tried uninstalling and reinstalling all the software on the RPi related to the Lidar scanner, including ROS, but there was still the same problem. I also tried setting up the Lidar scanner with my Windows laptop using Slamtec’s official RoboStudio software, but the Lidar scanner still did not detect any points. This led me to conclude that the issue was a hardware issue with the RPLIDAR A1. I tested connectivity of the wires connecting the Lidar scanner to the MicroUSB converter board, and found that they were all connected correctly. I also tried using a different MicroUSB to USB converter cable. At this point I think that the only possible explanations are that either the Lidar scanner itself or the board that converts its outputs to MicroUSB is broken. I emailed Slamtec’s support staff but have not yet received a response. Since we do not have the budget to buy another RPLIDAR A1, I requested the IntelSense L515 Lidar scanner from the ECE inventory.
My progress at this point is behind schedule as a result of the difficulties with the Lidar scanner. In fact I right now have less accomplished than I did last week since last week the Lidar scanner was working, and now it is broken and I spent most of my time trying to fix it. On Monday I will pick up the new Lidar scanner from ECE inventory and will hopefully be able to catch up on my schedule. Andy and I are also finishing up the motor control system over the weekend, so Andy will be able to help me with the SLAM system next week which should allow me to get back on schedule. By the end of next week I hope to have set up the new Lidar scanner, set up laser odometry, and integrated the results with slam_toolbox and Nav2. If I accomplish those then I will also be able to do the global path planning.
At this point I have not been able to run any tests yet since the SLAM subsystem is not yet at a point where it can be tested. I am planning to test the SLAM subsystem by taking in Lidar data input and examining the generated map to determine its accuracy. I will revise the testing plan further once I am able to get some output from the SLAM subsystem.