1. introduction
One of the most important functions of a UAS/UAV is its fully functional autopilot system. Ultimately, an autopilot system is a system that can control the trajectory or the flight path and procedures during a flight autonomously by analysing the data autonomously without any human interaction.
normally we see drone operations controlled by human operators, using the Remote control method. But by using an autopilot system, most or all of the procedures such as take-off and landing can be done by the UAV itself. some of these main/basic functions controlled by autopilot are stabilization in mid-air, VTOL, altitude hold, waypoint navigation, obstacle detection & avoidance etc.
In this blog series, I am going to cover the basics of creating an autopilot system from scratch.
2. Autopilot system
An aerial vehicle system needs a proper control strategy system for stable flight and performing designed tasks in the real world.
An average autopilot system depends on two main factors. they are hardware and software. Hardware includes microcontrollers/flight controllers, sensors, flight computers, actuators etc and software components include computer programs that have programmed commands for the control functions based on receiving data to the flight computer.
The diagram on the top demonstrates a simple and basic autopilot system for an Unmanned Aerial vehicle.
3. commands
The flight management system contains multiple commands to perform functions after analysing the data. these commands can be implemented before the flight or reprogrammed during the flight. the diagram below shows the structure of an FMS update algorithm.
main command types :
- direct to waypoint command
- track to waypoint command
- jump command
- CIRCLE command
- lift-off command
- landing command
1. track to waypoint command
in this command function, an aircraft is being directed to follow and maintain a specific course or path towards a desired waypoint.
A waypoint is a specific geographical location defined by coordinates(latitude and longitude).
2. Jump command
jump command Is a feature that allows the autopilot system to skip ahead to a specific waypoint in their flight plan. This command can be used in occasions/scenarios such as when air traffic control directs an aircraft to bypass certain waypoints.
3. CIRCLE command
in an autopilot FMS system, the circle command function instructs the aerial vehicle to move in a circular formation. the aerial vehicle will maintain a racetrack or circular pattern around a specific waypoint within a given radius.
4. Take-off command
basic functional structure for this function is to provide commands to perform an autonomous take-off. this command will be engaged during the takeoff phase of a flight.
5. landing command
this is the opposite of the take-off command. This command is used during the landing phase. autonomous or semi-automated procedures and a command list is being used to perform a safe and comfortable landing procedure.