Question on Generating Gazebo World File
Hi Dr. Sprinkle,
It says in Task 3 description that "within 60 seconds of stopping at the end of the trajectory, should generate a Gazebo world file centered at the origin point of the trajectory".
I am not sure whether this Gazebo world file 1. is generated by the car itself by using some machine techniques or 2. is generated by us (developers) manually through recognizing the shape of a bunch of coordinates published by the car and decide what object may be there.
According to "within 60 seconds", it seems like that the world file should be generated automatically at the end of car's movement. Not sure...
Thanks in advance,
Ju
This Gazebo world file is generated by you. Lots of teams may take different approaches, but if you aren't sure what a good approach is I suggest the following:
- Create a node that listens to /catvehicle/vel
- Inside that node, generate your Gazebo file if the following two cases are satisfied:
- The vehicle has moved more than X meters, AND
- The vehicle's velocity has been < 0.1 m/s for more then Y seconds
We're working on identifying in the launch file where to generate your Gazebo file so that you can have your system be simulated on the CPS-VO, so I suggest having the location of the output file be a parameter that can be set when you start up that node.
I think we recently put up a Simulink model that shows how to make the car stop, so if you run the Task 3 seed, you will already have an example where the car follows some trajectory and then stops after some time. You can use this as the initial idea for how to make your system behave like the car will on "race day" :)
Please let me know if this seems to have answered the question.
That's a valid interpretation of what I suggested above but teams are not required to do it this way: they can use any means they like to transform a collection of detections into a gazebo world file. The chief goal is that when the car stops, a worldfile is generated within 60 seconds after.
Just want to make sure if I am undertaning rightly.
We are supposed to create a ROS node listening to /catvehicle/vel, while the car is running, this node may store the information (ie. location) of objects detected by the car, and once some contditions related to distance and velocity are met, we use those objects' information to create a gazebo world file and finally output this file to a specific directiory.