Memory alignment error building model on a MicroLabBox DS1202

User Questions
1

Hi :wave:

First of all, thank you for developing and supporting such a useful tool as acados.

I’m working with the latest version of acados using the Matlab interface, and have created an NMPC model that runs fine in Simulink using an acados S-function. Now, I want to test it on an embedded platform.

I’m using a DS1202 MicroLabBox and building the models with the dSPACE RTI for Matlab 2022a. I followed all the steps in Embedded Workflow — acados documentation, so I was able to build acados for the DS1202 without any issues.

However, when I build the model in Simulink after all the steps, I get the following error:

Error occurred in real-time application 'dSPACE_LCL.ppc' (process ID 741383):
In function ocp_qp_xcond_solver_opts_assign -- C:/acados/acados/ocp_qp/ocp_qp_xcond_solver.c:222 (size_t) c_ptr % 8 == 0 && "double not 8-byte aligned!" -- assertion failed [20886,1137866335]

I checked other posts on the forum that had issues with memory alignment, but since acados has been successfully tested on the DS1202, I imagined the issue could be in the settings of the Simulink model. The settings for the hardware implementation are as shown in the following picture:

image
image1174×842 23.3 KB

What could be causing this error? Has someone else encountered it? I will highly appreciate any help that can be provided to solve it.

Many thanks in advance!

Cristóbal

2

Hi Cristóbal,

That seems to be a memory alignment issue in acados.
I would have guessed that it is a 32 bit system, as the error would very likely have shown up otherwise, but it seems that it is a 64 bit system from a brief online search.
Anyway, which version of acados are you on, and what QP solver are you using?
This might help to find the issue.

Best,
Jonathan

3

Hi Jonathan,

Thank you very much for such a fast reply, I really appreciate your help.

The processor is a 64-bit Freescale QorIQ P5020, and the acados version is v.0.5.1 (I didn’t manage to find it explicitly, but I cloned the repository on the 31st of July, so that should be the version). The qp solver is partial condensing HPIPM ('PARTIAL_CONDENSING_HPIPM'), and the NLP solver is SQP with real-time iteration ('SQP_RTI'). Please let me know if there is any additional information or tests that I could provide to find the issue.

Again, thank you very much for all the help.

Kind regards,

Cristóbal

4

Hi,

I looked into the relevant code and made this PR: Fix memory alignment in condensing by FreyJo · Pull Request #1614 · acados/acados · GitHub
Could you test this version of acados in your workflow and let me know if it solves the issue?

Best,
Jonathan

5

It worked, thank you very much!