I am wondering whenever I should use set_attitude_target message available in GUIDED_NO_GPS mode vs manual_control_send (or rc_override) available in not AUTO modes (such as ALT_HOLD) for controlling my vehicle from companion computer outdoors (so I am able to rely on ALT_HOLD working properly)?
As far as I can see, both messages allow you to achieve the same result and make the copter to fly in the way and direction you want. So why should I use GUIDED_NO_GPS and operate on quarternions if instead I can use manual_control_send, which seems to me to be more intuitive since it can be interpreted as commands from joystick?
Nevertheless, I’ve already seen multiple posts on the forum asking for help where authors wanted to fly in GUIDED_NO_GPS mode and use set_attitude_target to control their vehicles.
For example this one Indoor Autonomous Flight Without GPS: GUIDED_NOGPS Mode Settings and PID Gains (there were more, but can’t find them in the moment).
I have a Computer Science major, so, if attitude based control being easier for such applications, is some concept from robotics, avionics, mechanics, etc. and I am missing it, I would be grateful for pointing it out and sharing the link to the resources.
This blog post mostly answers my question, so sharing it in a reply in case someone needs it.
As stated:
In vision based systems, there are many types of hardware/software configuration tailored for specific applications: Visual Servoing, Visual Odometry and Visual Simultaneous Localization And Mapping (SLAM). In this project we are using the former type of system: Visual Servoing that is designed to:
• Take off and Landing
• Obstacle Avoidance/Tracking
• Position and Attitude control
• Stabilization over a target
The main idea of Visual Servoing is to regulate the pose {Cξ,T } (position and orientation) of a robotic platform relative to a target, using a set of visual features {f } extracted from the sensors.
GUIDED and GUIDED No-GPS is the only mode I am aware of, where we can set the attitude of the object, so we are using it.