How to create a "realistic" UAV flight dynamic model of a popular UAV airframe (such as MutiplexEasyStar ) for simulation?
Is it possible to create a generic model such a way that the model can later be re-configured for different UAV airframes?
The model should be able to accurately approximate the next state (position, attitude, velocities and accelerations) of the UAV given its current state and control inputs (throttle, ailerons, rudder, elevator control values). That is, the model should tell me what will happen in dt (delta t, i.e. short time interval) time in the future if I apply a know set of control inputs.
Plenty has been written about this. Essentially what you want is a 6DOF aerodynamic model of the aircraft. There are a couple of things you need. First I would highly recommend, as Tom Yochum suggests, to use Simulink as your simulation engine.
The equations of motion are well known and you can find them in either Steven & Lewis' Aircraft Control and Simulation or in Blakelock's Automatic Control of Aircraft and Missiles. Both have excellent discussions on deriving this equations (although I tend to prefer the Steven and Lewis).
These equations are essentially the same for all aircraft. Thus this would be what you call a "generic model". The complicated part is deriving the aerodynamic coefficients that characterize each aircraft. These can be obtained by system identification methods or using a panel method to obtain a good approximation based on the geometry of the aircraft. LinAir is for instance a simple to use panel method tool.
Another option, although I am not familiar with the source code of FlightGear I am sure you can make use of plenty of code there. Since they have an excellent simulation engine and have implemented a simple way for you to choose different aircraft you could also make use of that.
Comments
The equations of motion are well known and you can find them in either Steven & Lewis' Aircraft Control and Simulation or in Blakelock's Automatic Control of Aircraft and Missiles. Both have excellent discussions on deriving this equations (although I tend to prefer the Steven and Lewis).
These equations are essentially the same for all aircraft. Thus this would be what you call a "generic model". The complicated part is deriving the aerodynamic coefficients that characterize each aircraft. These can be obtained by system identification methods or using a panel method to obtain a good approximation based on the geometry of the aircraft. LinAir is for instance a simple to use panel method tool.
Another option, although I am not familiar with the source code of FlightGear I am sure you can make use of plenty of code there. Since they have an excellent simulation engine and have implemented a simple way for you to choose different aircraft you could also make use of that.
Hope this helps.
Also, you may have a look at this software package of mine that implements a flight model: http://lis.epfl.ch/enlil