neetche/ats-pilot

A controller prototype for Unmanned Aerial Vehicles (UAV) in ATS.

ATS Pilot

A prototype for building a Flight Management System in ATS. We wish to make convincing use of the ATS2 template system and abstract types as a method to write embedded software.

Running

1. Install the FlightGear Simulator for your platform. On Windows and Mac there are installers you can use but on Linux you should look for it on your distribution's package manager.

2. FlightGear supports controlling the simulation through external programs over sockets. The state of a flight at any point is controlled through a Property Tree in FlightGear. In order to receive these properties at some rate, we outline a protocol in an XML file that describes which properties we want and in what format FlightGear should send them. Refer to input_protocol.xml for this example. We can read this information as text over a UDP socket across a network or even on the same machine. In this system, we receive sensor readings from the aircraft 40 times per second. To send control data back to FlightGear, we outline a protocol as we did for input in an XML file. The file, output_protocol.xml, serves this purpose. In order for the simulator to read these files, copy them to your FlightGear protocol directory. This is located in

   /path/to/flightgear/data/Protocol/

If you would like to see a full list of properties available, go to the following page with a web browser after you start FlightGear with the included shell script.

http://localhost:5500

This will display the whole property tree. Any property listed here may be specified in either the input or output protocol you provide to FlightGear.

3. Compile the control program with make. Note, a working ATS2 compiler is required.

4. Run the simulator with

   ./fgfs.sh

and then when you want the control software to take over, run

./control

The shell script starts the aircraft at a few thousand feet so you don't have to worry about lift off. Just start the engine by pressing "s" and then adjusting the throttle with Page Up/Page Down. You can press "Tab" to adjust the controls so that your mouse will control the elevators, ailerons, and rudders.

Control Laws

What makes a control law?

• A target value
• A transfer function : (input, parameters) -> output
• A model for each plant or process we wish to control

The template system allows us to define a typekind which can identify each plant that is controlled.

abst@ype pcontrol (tk:tkind)

fun{tk:tkind} make_pcontrol (target: double, p: double): pcontrol (tk)

fun{tk:tkind} update: (pcontrol(tk), reference: double): double

In this example we only wish to control the roll and pitch of the aircraft.

Demo

As the project continues, we'll have some videos to post to demonstrate our system.

http://www.youtube.com/embed/1qbjSViBSco