When using [ptCloud,i​sValidTime​,clusters] = lidar(acto​rs,rdMesh,​simTime), clusters is filled with only NaN

I am using the cuboid driving scenario simualtor in MATLAB.

In general, I have no issues with simualting a lidar in a large scenario.

Recently, I've tried to output the class and actor ID for each lidar ray using the clusters from [ptCloud,isValidTime,clusters] = lidar(actors,rdMesh,simTime)

However, this just returns an array of only NaN. I checked the actors list and all actors have an assigned class and actor ID. Any idea why this may happen?

I would like to extract this information to remove certain targets from the point cloud data in post processing for some experiments we are running.

Answer 1

[Shubham]

Hi Paul,

When you're using a lidar simulation in MATLAB, especially with the cuboid driving scenario simulator, and you're encountering an issue where the clusters output from the lidar simulation only contains NaN values despite having actors with assigned class and actor IDs, there are several potential reasons and steps to troubleshoot this issue:

Check Lidar Configuration:

First, ensure your lidar sensor is properly configured to detect the actors in your scenario. The lidar configuration, including its position, field of view, range, and resolution, can significantly impact its ability to detect objects and return meaningful cluster information.

Validate Actor Properties

Double-check that all actors in the scenario are properly configured and their properties are set to values that make them detectable by the lidar. This includes ensuring that the actors have not only IDs and classes assigned but also that their geometrical properties (size, position) are within the lidar's detection capabilities.

Simulation Time and Update Rates:

Ensure that the simulation time (simTime) you're passing to the lidar function aligns with the update intervals of your actors and the lidar sensor itself. If there's a mismatch in timing, it might result in the lidar missing the actors entirely for that time step, leading to NaN values in clusters.

Actor Visibility

Actors must be within the lidar sensor's field of view and range to be detected. If actors are present but not within the detectable area at the time of simulation, they will not contribute to the clusters output. It's also worth checking if any obstructions might be blocking the lidar's line of sight to the actors.

Debugging Steps:

• Temporarily reduce your scenario to a minimal setup where only one actor is present and try to detect it with the lidar. This can help isolate whether the issue is with specific actors or the overall setup.
• Sometimes, MATLAB might provide warnings or errors in the command window that can give clues as to what's going wrong.
• Temporarily place the lidar sensor in a different position or adjust its orientation to ensure it's not a placement issue causing the lack of detection.