Change solver parameters

Antonio · March 15, 2021, 12:28pm

Hi,

I am using the matlab interface.

In this software, once I have generated the c code of the solver, if I want to change parameters such as the weight matrices or the prediction horizon in order to tune the MPC, do I have to change it from the high-level interface and generate c code again?

I think It would take a long time to tune the controller if every time I change something I have to re-regenerate c code.

Thanks in advance!!!

FreyJo · March 22, 2021, 1:00pm

Hi @Antonio,

in Matlab, you can interact with the template based OCP solver, just like you can with the native one.
I.e. using the .set, .get routines.
A lot can be changed after generating the code and creating the solver. For the setter, see e.g. here:

github.com

acados/acados/blob/e6954083fe40a859a0ba47d33c4f163ee5f0e153/interfaces/acados_matlab_octave/ocp_set.c#L633-L638


       MEX_FIELD_NOT_SUPPORTED_SUGGEST(fun_name, field, "p, constr_x0,\
constr_lbx, constr_ubx, constr_C, constr_D, constr_lg, constr_ug, constr_lh, constr_uh\
constr_lbu, constr_ubu, cost_y_ref[_e],\
cost_Vu, cost_Vx, cost_Vz, cost_W, cost_Z, cost_Zl, cost_Zu, cost_z,\
cost_zl, cost_zu, init_x, init_u, init_z, init_xdot, init_gnsf_phi,\
init_pi, nlp_solver_max_iter, qp_warm_start, warm_start_first_qp, print_level");

However, some things (mainly dimensions and the choice of modules) cannot be changed after the creation of the solver, since they are needed in the memory allocation process.

Best,
Jonathan