The problem statement is in simulating both 'car' and a quadcopter in ROS Gazebo SITL as mentioned in this question. Two possibilities have been considered for the same which is as depicted in the image.
(Option 1 uses 6 terminals with independent launch files and MAVproxy initiation terminals)
While trying to search for Option 1, the documentation appeared to be sparse (The idea is to launch the simulation with ErleRover and then spawn ErleCopter on-the-go; I haven't found any official documentation mentioning either the possibility or the impossibility of this option). Can somebody be requested to let me know how option 1 can be achieved or why it is impossible by mentioning corresponding official documentation?
Regarding option 2, additional options have been explored; The problem is apparently with two aspects: param vs rosparam and tf2 vs tf_prefix. Some of the attempts of simulation of multiple turtlebots have used tf_prefix which is deprecated. But, I have been unable to find any example which uses tf2 while simulating multiple (different) robots. But, tf2 works on ROS Hydro (and thus Indigo). Another possible option is the usage of rosparam instead of param (only). But, documentation on that is sparse regarding the usage of same on multi-robot simulation and I have been able to find only one example (for a single robot Husky).
But, one thing is clearer: MAVproxy can support multiple robots through the usage of SYSID and component-ID parameters. (upto 255 robots with 0 being a broadcast ID) Thus, port numbers have to be modified (possibly 14000 and 15000 as each vehicle uses 4 consecutive ports) just like the UCTF simulation. (vehicle_base_port = VEHICLE_BASE_PORT + mav_sys_id*4)
To summarise the question, the main concern is to simulate an independent car moving around and an independent quadcopter flying around in the ROS Gazebo SITL (maybe using Python nodes; C++ is fine too). Can somebody be requested to let me know the answers to the following sub-questions?
Is this kind of simulation possible? (Either by the usage of ROS Indigo, Gazebo 7, MAVproxy 1.5.2 on Ubuntu 14.04 or by modifying UCTF project to spawm a car like ErleRover if there is no other option) (You are kindly requested to let me know the examples if possible and official links if this is impossible)
If on-the-go launch is not possible with two launch files, is it possible to launch two different robots with a single launch file?
This is an optional question: How to modify the listener (subscriber) of the node? (Is it to be done in the Python node?)
This simulation is taking relatively long time with system software crashing for about 3 times (NVIDIA instead of Noveau, broken packages etc) and any help will be whole-heartedly, gratefully and greatly appreciated. Thanks for your time and consideration.
Prasad N R
