Problem with Using codegen commands to generate C++ code on NLMPC Code Generation Tutorial

I am trying to use the codegen funciton in MATLAB to chagne the code provided in the NLMPC Code Generation Turtorial so that it generates code in C++ instead of MEX files. When I run the tutorial with the original codegen functions it generates the MEX file completely fine but after changing the codegen arguments to generate C++ I continue to get an error. Below is the code I am running (note that my problem is at the very bottom):

nlobj = nlmpc(4,2,1);

Ts = 0.1;

nlobj.Ts = Ts;

nlobj.PredictionHorizon = 10;

nlobj.ControlHorizon = 5;

nlobj.Model.StateFcn = "pendulumDT0";

nlobj.Model.IsContinuousTime = false;

nlobj.Model.NumberOfParameters = 1;

params = {Ts};

nlobj.Model.OutputFcn = "pendulumOutputFcn";

nlobj.Weights.OutputVariables = [3 3];

nlobj.Weights.ManipulatedVariablesRate = 0.1;

nlobj.OV(1).Min = -10;

nlobj.OV(1).Max = 10;

nlobj.MV.Min = -100;

nlobj.MV.Max = 100;

x0 = [0.1;0.2;-pi/2;0.3];

u0 = 0.4;

validateFcns(nlobj,x0,u0,[],params);

EKF = extendedKalmanFilter(@pendulumStateFcn,@pendulumMeasurementFcn);

x0 = [0;0;-pi;0];

y0 = [x0(1);x0(3)];

EKF.State = x0;

mv0 = 0;

[coreData,onlineData] = getCodeGenerationData(nlobj,x0,mv0,params);

onlineData.ref = [0 0];

mv = mv0;

y = y0;

x = x0;

Duration = 10;

xHistory = x0;

for ct = 1:(Duration/Ts)

% Correct previous prediction

xk = correct(EKF,y);

% Compute optimal control move

[mv,onlineData] = nlmpcmoveCodeGeneration(coreData,xk,mv,onlineData);

% Predict prediction model states for the next iteration

predict(EKF,[mv; Ts]);

% Implement first optimal control move

x = pendulumDT0(x,mv,Ts);

% Generate sensor data

y = x([1 3]) + randn(2,1)*0.01;

% Save plant states

xHistory = [xHistory x];

end

%%%%%%This is where I am having problems:%%%%%%

func = 'nlmpcmoveCodeGeneration';

funcOutput = 'testingC';

codegen -config:lib -lang:c++ func;

cfg = coder.config('dll');

cfg.TargetLang = 'C++';

codegen -config cfg func;

Please let me know if there is anyway to format/utilize codegen differnetly to generate this C++ code.

Answer 1

[Emmanouil Tzorakoleftherakis]

You did not specify what kind of error you were seeing? In my case, doing the following worked:

func = 'nlmpcmoveCodeGeneration';
funcOutput = 'nlmpcmoveMEX';
Cfg = coder.config('lib');
Cfg.TargetLang = 'C++';
Cfg.DynamicMemoryAllocation = 'off';
codegen('-config',Cfg,func,'-o',funcOutput,'-args',...
    {coder.Constant(coreData),xk,mv,onlineData});

[Carson Murray]

Hey Emmanouil,

The code you provided did work successfully when I ran it but is there anyway you coould modify it to generate C++ code instead of standard C? That would be very helpful.

[Emmanouil Tzorakoleftherakis]

Edited my answer