Is there any way to enable keyboard control while using the ROS wrapper? (Car mode)

[Mohammed Almatar (matar251)]

Hi, just trying to use the ROS wrapper to monitor vehicle data (speed, position, etc.). But once I enable the ROS wrapper, Control Mode is set to API and I can no longer manually control the car.

I tried to set RemoteControlID = -1 in settings.json but that doesnt seem to work. Is there any way to use ROS just to monitor and not control the vehicle? I've seen some scripts where users (e.g. Ahmed Elsaharti (@ahmed-elsaharti) ) input commands through an API but I want to expand this to steering wheels later.

[Ahmed Elsaharti (ahmed-elsaharti)]

Hi Mohammed Almatar (@matar251), my understanding is that the ROS wrapper uses the C++ APIs to monitor sensors and control the vehicles (through movebyvelocity I think). Since enabling API control automatically disables manual control (atleast on the drone side of things), the more elegant way of doing what you want to do is to modify the wrapper's code and get rid of the bits that perform the motion control leaving only the monitoring sections (AFAIK sensor monitoring doesnt require API control to be enabled).

An easier approach is, as you mentioned, to write a python (or C++) program that translates keyboard key-presses to setCarControls calls (for example). Something like:

import airsim
import keyboard  # using module keyboard (install using pip3 install keyboard)

client = airsim.CarClient()
car_controls = airsim.CarControls()
client.confirmConnection()
client.enableApiControl(True)
 
 
while True:  # making a loop
    try:  # used try so that if user pressed other than the given key error will not be shown
        if keyboard.is_pressed('w'):
            car_controls.throttle = 1
        elif keyboard.is_pressed('s'):
            car_controls.throttle = -1
        else:
            car_controls.throttle = 0
        if keyboard.is_pressed('d'):
            car_controls.steering = 1
        elif keyboard.is_pressed('a'):
            car_controls.steering = -1
        else:
            car_controls.steering = 0
        if keyboard.is_pressed('space'):
            car_controls.brake = 1
        else:
            car_controls.brake = 0           
        print(car_controls)
        client.setCarControls(car_controls)
    except:
        break  # if user pressed a key other than the given key the loop will break

should do the trick

[Mohammed Almatar (matar251)]

Ahmed Elsaharti (@ahmed-elsaharti) thanks for your response. Am I correct in saying that every time I modify airsim_node I need to rebuild the entire ros package to test the change?

[Mohammed Almatar (matar251)]

I've also found that python uses enableApiControl function to turn off API mode, which does not interfere with ROS sensors. Just need to find where that is enabled in the ROS package

[Leandro Borgnino (leoborgnino)]

Ahmed Elsaharti (@ahmed-elsaharti) thanks for your response. Am I correct in saying that every time I modify airsim_node I need to rebuild the entire ros package to test the change?

Yes, but catkin_make/catkin build should compile only the files with changes.

I've also found that python uses enableApiControl function to turn off API mode, which does not interfere with ROS sensors. Just need to find where that is enabled in the ROS package

You can also use ros packages for keyboard control (key_teleop, teleop_twist_keyboard). These packages have as output a twist msg that can be used instead the msg generated from pd_position_controller to airsim_ros_wrapper.