OSQP makes Matlab crash for some problems

tgybel · August 4, 2022, 11:22am

Hi,
I am experiencing an issue when trying to switch to OSQP for my particular problem. The problem is running fine with
qp_solver = ‘partial_condensing_hpipm’;
but setting
qp_solver = ‘partial_condensing_osqp’;
causes Matlab to crash when the generated solver is called. Code generation and compiling seem to run as it should.

I have tried with a couple of the examples:

“acados\examples\acados_matlab_octave\masses_chain_model\example_closed_loop.m” runs perfectly fine with either hpipm or OSQP.
“\acados\examples\acados_matlab_octave\wind_turbine_nx6\example_ocp.m” seems to have the same problem as I am experiencing with the setup I have defined; with partial_condensing_hpipm, the solver is running fine, but changing to partial_condensing_osqp makes my Matlab crash on solver execution.

My Acados is on commit 459a8b8dbd4de1cb384123e4e9fe941d807e3c3b.
I have experienced the same with Matlab R2020a and R2021b.

Thanks for the good work!

FreyJo · August 5, 2022, 3:48pm

Hi,

I just tried this on Linux, there you get errors printed to your terminal.
In this case, I get:

OSQP interface can not handle ns>0 yet: what about implementing it?

So, the current OSQP acados interface does not support soft constraints.
I just added a check, such that there is a Matlab error, for Windows users

Cheers!
Jonathan

tgybel · August 8, 2022, 8:58am

Hi Jonathan,
Thanks a lot for your fast response. That explains it

imcinerney · August 8, 2022, 10:37am

@FreyJo did the crash happen in the acados mex file or in the OSQP library code?

FreyJo · August 8, 2022, 11:38am

@imcinerney The crash happened in the acados interface to OSQP, specifically here:

github.com

acados/acados/blob/cb7c5a1d9331b69b61b47c14bd04e37daa1a2803/acados/ocp_qp/ocp_qp_osqp.c#L1325


      
          
          
int N = qp_in->dim->N;
          int *ns = qp_in->dim->ns;
          
          
// print_ocp_qp_dims(qp_in->dim);
          
          
for (int ii = 0; ii <= N; ii++)
          {
              if (ns[ii] > 0)
              {
                  printf("\nOSQP interface can not handle ns>0 yet: what about implementing it? :)\n");
                  exit(1);
              }
          }
          
          
// print_ocp_qp_in(qp_in);
          
          
qp_info *info = (qp_info *) qp_out->misc;
          acados_timer tot_timer, qp_timer, interface_timer, solver_call_timer;
          acados_tic(&tot_timer);

imcinerney · August 8, 2022, 3:23pm

Thanks. I was worried we had an issue in OSQP somewhere that caused a segfault.