Function 'fmincon' not supported for code generation

19 views (last 30 days)
Anuschan Albrecht on 8 May 2021
Commented: Walter Roberson on 12 May 2021
Hello,
im currently trying to implement nonlinear MPC in MATLAB/Simulink using the MATLAB function block.
function u_mpc = MPC(x, u_mpc, u_0, A_ineq, b_ineq, Q_mpc, R_mpc)
costfunc = @(x,u) (x)'*Q_mpc*(x) + (u_mpc)'*R_mpc*(u_mpc);
u_mpc = fmincon(costfunc, u_0, A_ineq, b_ineq);
end
The state x is provided by a plant model, the costfunction is a simple quadratic cost with weight matrices, the matrices are taken from the workspace.
Running the Simulink model results in the error: Function 'fmincon' not supported for code generation.
I'm using the 2018b version normally, tried using 2021a but got the same error.
Is there a mistake in the code or is it simply not possible to use fmincon inside a MATLAB function block?
Thanks in advance for any help.
Anuschan Albrecht on 8 May 2021
On the help page you linked it says to not load options from a file so I added them inside the MATLAB function block:
function u_mpc = MPC(x, u_mpc, u_0, A_ineq, b_ineq, Q_mpc, R_mpc)
costfunc = @(x,u) (x)'*Q_mpc*(x) + (u_mpc)'*R_mpc*(u_mpc);
options = optimoptions('fmincon','Algorithm','sqp');
u_mpc = fmincon(costfunc, u_0, A_ineq, b_ineq,options);
end
This results in the error: Function 'optimoptions' not supported for code generation.

Aditya Patil on 11 May 2021
Edited: Aditya Patil on 12 May 2021
fmincon codegen support was added in R2019b. Also, optimOptions is the last argument for fmincon, you should pass other arguments as empty ([]) if you are not using them. For example,
function u_mpc = MPC(x, u_mpc, u_0, A_ineq, b_ineq, Q_mpc, R_mpc)
costfunc = @(x,u) (x)'*Q_mpc*(x) + (u_mpc)'*R_mpc*(u_mpc);
options = optimoptions('fmincon','Algorithm','sqp');
Aeq = [];
beq = [];
lb = [];
ub = [];
nonlcon = [];
u_mpc = fmincon(costfunc,u_0,A_ineq,b_ineq,Aeq,beq,lb,ub,nonlcon,options);
end
Walter Roberson on 12 May 2021
Good point about needing a later release! I normally think about that kind of issue early on, but I missed it this time!

Categories

Find more on Manual Performance Optimization in Help Center and File Exchange

R2018b

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!