Inconsistency between centerline and PDM-Closed trajectory about tuplan_garage

[DanielDauner]

Hi @CristianGariboldi,

The trajectory proposals of PDM-Closed are a pairwise combination of 3 lateral centerline offsets and 5 IDM policies. For the centerline offsets we have ±1m and 0m. Therefore, it’s perfectly normal that the trajectory of PDM-Closed is not consistent with the centerline and runs parallel to the centerline (also see here in code). There might also be inconsistencies due to precision or interpolation errors, which should be negligible.

Note that PDM-Hybrid does use PDM-Offset for long-term correction. PDM-Offset follows the architecture and input of PDM-Open but additionally receives the output trajectory of PDM-Closed as input that includes the centerline offset (see here in code).

The PDM-Hybrid output often looks disturbed, especially if PDM-Offset is out-of-distribution during closed-loop simulation. Could you share the scenario token of the third image? I might have a look.

[CristianGariboldi]

@DanielDauner thanks for your quick reply! The scenario token is '1e77a04e93c75ba5', but in lots of cases you can notice a distortion in the fusion point of the 2 trajectories.
Since PDM-offset takes as input PDM-Closed trajectory together with the centerline, what could be the reason for this distortion?

[DanielDauner]

I checked the scenario. The distortion on the cutting point is nothing unusual. When PDM-Offset predicts large offsets to the PDM-Closed trajectory, the waypoints on the cutting point are far apart. The nuBoard connects the waypoints with a linear spline, making the output look distorted.

Note that the concept of PDM-Hybrid purely serves to have a high OLS and CLS simultaneously. The underlying core for planning all comes from PDM-Closed.

I hope that helps. Let me know if you have further questions!

[CristianGariboldi]

@DanielDauner thanks for your clarification! I'll close the issue.