[Jsbsim-matlab] Mex-Function to run JSBSim from Matlab command line

[Agostino De M. <ago...@un...>]

Hi all,
I've been working at the Matlab mex-function "MexJSBSim".
You'll find all the archived stuff here:
http://www.dias.unina.it/demarco/Work/JSBSim_Matlab/JSBSim_Matlab.zip

or you can browse the sources here:
http://www.dias.unina.it/demarco/Work/JSBSim_Matlab/

I was able to compile and debug the mex-function with
Visual Studio 2008.
To compile, just use the solution file MexJSBSim.sln,
adjusting the include and lib directories as necessary.
For example, I use Matlab 2008b installed in N:\MATLAB\R2008b\
so, in the MexJSBSim project I need to set the dirs:
N:\MATLAB\R2008b\extern\include\
and N:\MATLAB\R2008b\extern\lib\win32\microsoft\
to link the Matlab libs: libmx.lib libmex.lib libmat.lib

The mex-function is also linked to the static library
"JSBSimLib.lib", which I made out of the latest JSBSim
distribution (this project is also included in the solution).

The mex-function MexJSBSim is an attempt to establish a sort of
standardized way of using a JSBSim::FGFDMExec object from Matlab
command line.
Every suggestion or criticism is welcomed.

-----------------------------------------------------------------
This is an example of output of the command: MexJSBSim('help')
-----------------------------------------------------------------
>> MexJSBSim('help')
function usage:
result = MexJSBSim( string_directive [, string, value] )

Examples:
     res = MexJSBSim('help');
        Prints this help text. returns 1 (always)

     res = MexJSBSim('open','c172r');
        returns 1 if success, 0 otherwise

     res = MexJSBSim('get','fcs/elevator-cmd-norm')
        returns the value of the property,
        or -9999 if property not found

     res = MexJSBSim('set','fcs/elevator-cmd-norm',-0.5)
        returns 1 if success, 0 otherwise

     res = MexJSBSim('set','elevator-cmd-norm',-0.5)
     res = MexJSBSim('set','u-fps',80.5)
        same as above, but it scans a set of predefined,
        and commonly used variable names:
             'u-fps', 'v-fps', 'w-fps'
             'p-rad_sec', 'q-rad_sec', 'r-rad_sec'
             'h-sl-ft'
             'long-gc-deg'
             'lat-gc-deg'
             'phi-rad', 'theta-rad', 'psi-rad'
             'elevator-cmd-norm'
             'aileron-cmd-norm'
             'rudder-cmd-norm'

     res = MexJSBSim('init',ic)
        initializes the JSBSim::FGFDMExec by means of the
        matlab structure ic.
        The structure ic must have the two fields: name and value.
        The Matlab user is forced to build such a structure first,
        then to pass it to the mex-file. Example:
        >> ic(1).name = 'u-fps'; ic(1).value = 80;
        >> ic(2).name = 'v-fps'; ic(2).value =  0;
        >> ic(3).name = 'w-fps'; ic(3).value =  0;
        >> ic(4).name = 'p-rad_sec'; ic(4).value =  0;
        >> MexJSBSim('init', ic);
>>

-----------------------------------------------------------------
This is the output of the Matlab script: test_1.m
-----------------------------------------------------------------
	Setting up JSBSim with standard 'aircraft', 'engine', and 'system' paths.
	Loading aircraft 'c172r' ...
	Model c172r loaded.

ans =

      1

Property name: 'u-fps'; Property value: 80.000000
	Easy-set: true flight speed (ft/s) = 80.000000
Property name: 'v-fps'; Property value: 20.000000
	Easy-set: true flight speed (ft/s) = 82.462113
Property name: 'w-fps'; Property value: 10.000000
	Easy-set: true flight speed (ft/s) = 83.066239
Property name: 'p-rad_sec'; Property value: 0.100000
	Easy-set: roll rate (rad/s) = 0.100000
Property name: 'q-rad_sec'; Property value: 0.200000
	Easy-set: pitch rate (rad/s) = 0.200000
Property name: 'r-rad_sec'; Property value: 0.300000
	Easy-set: yaw rate (rad/s) = 0.300000
Property name: 'h-sl-ft'; Property value: 3000.000000
	Easy-set: altitude over sea level (mt) = 914.400000
Property name: 'long-gc-deg'; Property value: 122.000000
	Easy-set: geocentric longitude (deg) = 121.999983
Property name: 'lat-gc-deg'; Property value: 47.000000
	Easy-set: geocentric latitude (deg) = 46.999994
Property name: 'phi-rad'; Property value: 0.000000
	Easy-set: phi -> quaternion = (1.000000,0.000000,0.000000,0.000000)
	Easy-set: alpha (deg) = 7.125016,
	beta (deg) = 13.932092,
	gamma (deg) = -6.914372
Property name: 'theta-rad'; Property value: 0.034907
	Easy-set: phi -> quaternion = (0.999848,0.000000,0.017452,0.000000)
	Easy-set: alpha (deg) = 7.125016,
	beta (deg) = 13.932092,
	gamma (deg) = -4.973862
Property name: 'psi-rad'; Property value: 0.000000
	Easy-set: phi -> quaternion = (0.999848,0.000000,0.017452,0.000000)
	Easy-set: alpha (deg) = 7.125016,
	beta (deg) = 13.932092,
	gamma (deg) = -4.973862
Property name: 'aileron-cmd-norm'; Property value: 1.000000
	Easy-set: right aileron pos (deg) = -14.997170
Property name: 'elevator-cmd-norm'; Property value: -0.400000
	Easy-set: elevator pos (deg) = -11.197887
Property name: 'rudder-cmd-norm'; Property value: 1.000000
	Easy-set: rudder pos (deg) = 15.996982
Property name: 'fcs/throttle-cmd-norm'; Property value: 1.000000
Property name: 'fcs/mixture-cmd-norm'; Property value: 0.700000
Property name: 'set-running'; Property value: 1.000000
	Easy-set: engine(s) running = 1
Vt = 83.066239
	State derivatives calculated.
	V true 83.066239 (ft/s)
	[u_dot, v_dot, w_dot] = [2.450673,-24.558555,28.438848] (ft/s/s)
	[p_dot, q_dot, r_dot] = [1.037838,0.046871,-0.037094] (ft/s/s)
	[x_dot,y_dot,z_dot] = [16.762871,-64.567836,49.497482] (ft/s/s)
	[phi_dot,theta_dot,psi_dot] = [0.110476,0.200000,0.300183] (ft/s/s)

ans =

      1
-----------------------------------------------------------------


Agostino



-------------------------------------------------------
Agostino De Marco, PhD
Assistant Professor
Università degli Studi di Napoli Federico II
/ University of Naples Federico II /
Dipartimento di Ingegneria Aerospaziale
/ Department of Aerospace Engineering /
Web: www.dpa.unina.it/demarco
-------------------------------------------------------