Basic closed loop example creates runtime error on DSpace DS1202

albert · May 23, 2023, 12:39pm

Hello!

I am trying to run acados on the dspace DS1202 system. I’ve managed to compile it successfully without any errors. However when I want to load and run it on the DS1202 it gives the following errors. I’ve used the basic closed_loop simulink example (pendulum on a cart) in the getting_started folder.

The error message from dspace:
Memory violation exception! Real-time application (ID 0x008796e3) crashed due to an illegal memory access at address 0x00000004. Execution stopped at address 0x48058d5c near symbol ‘test_example_mpc_dspace.ppc@main+0x1115c’.

I will ofc also contact dspace about this, since I don’t know from which side (dspace or acacdos) the problem stems from.

As far as I know DS1202 should work with acados in general? And since I’ve used the most basic example and followed the docs of acados closely, I’m a bit lost.

One more fact: When I do the same, but only with the integrator / model (also an acados-sfunction) (so without the actual mpc / acacdos-solver) it works fine and gives correct results. So there has to be a problem with the other s-function or underlying c-code, but in general, the inclusion of acados c-code works.

Thanks in advance for any help,
Albert

albert · June 16, 2023, 9:58am

An update regarding my situation: I’ve been debugging and got stuck at the following line of code:

github.com

acados/acados/blob/master/acados/ocp_nlp/ocp_nlp_sqp.c#L620


      
                  {
                      char filename[100];
                      sprintf(filename, "qp_in_%d.txt", sqp_iter);
                      FILE *out_file = fopen(filename, "w");
                      print_ocp_qp_in_to_file(out_file, qp_in);
                      fclose(out_file);
                  }
          #endif
                  // solve qp
                  acados_tic(&timer1);
                  qp_status = qp_solver->evaluate(qp_solver, dims->qp_solver, qp_in, qp_out,
                                                  opts->nlp_opts->qp_solver_opts, nlp_mem->qp_solver_mem, nlp_work->qp_work);
                  mem->time_qp_sol += acados_toc(&timer1);
          
          
        qp_solver->memory_get(qp_solver, nlp_mem->qp_solver_mem, "time_qp_solver_call", &tmp_time);
                  mem->time_qp_solver_call += tmp_time;
                  qp_solver->memory_get(qp_solver, nlp_mem->qp_solver_mem, "time_qp_xcond", &tmp_time);
                  mem->time_qp_xcond += tmp_time;
          
          
        // compute correct dual solution in case of Hessian regularization
                  acados_tic(&timer1);

the issue seems to lie here, but I dont really understand the structure of the code well enough to find the definition of the original evaluate function to investigate further. Can you guys help me finding the function?

I’ve also had a look at this: Vxworks 32bit system, PPC, Diab Compiler, Embedded application problems - #5 by FreyJo since it is also QNX and PPC, but I couldn’t replicate the fix unfortunately.

Thanks,
Albert

albert · June 16, 2023, 2:29pm

Update: I fixed the problem by commenting out everything related to the ACADOS_DEBUG_SQP_PRINT_QPS_TO_FILE variable. I couldnt turn it off properly in the installation, but this would be the cleaner solution.
Apparently these code lines did wild things and created NULL pointer in other variables, which was hard to find.