feat(trajectory_follower): add min_prediction_length to mpc

[kosuke55]

Description

• When stopped and given a curve trajectory, the steer command value of mpc can not be large enough.
  • This is because precition_length is obtained from the distance traveled in a certain time with the speeds.
• Therefore, min_prediction_length was added to look some distance ahead even when stopped.

example where the steer command is not large enough and the vehicle cannot follow the trajectory

pull_over_steer-2022-05-26_18.03.43_cut.mp4

Related links

Tests performed

checked that the vehicle can follow curve trajectory(like video above) with psim and real vehicle.

Notes for reviewers

Pre-review checklist for the PR author

The PR author must check the checkboxes below when creating the PR.

• I've confirmed the contribution guidelines.
• The PR follows the pull request guidelines.

In-review checklist for the PR reviewers

The PR reviewers must check the checkboxes below before approval.

• The PR follows the pull request guidelines.
• The PR has been properly tested.
• The PR has been reviewed by the code owners.

Post-review checklist for the PR author

The PR author must check the checkboxes below before merging.

• There are no open discussions or they are tracked via tickets.
• The PR is ready for merge.

After all checkboxes are checked, anyone who has write access can merge the PR.

[codecov]

Codecov Report

Attention: Patch coverage is 58.18182% with 23 lines in your changes missing coverage. Please review.

Project coverage is 9.93%. Comparing base (54eca59) to head (d1eea82).
Report is 5753 commits behind head on main.

Files	Patch %	Lines
control/trajectory_follower/src/mpc.cpp	58.82%	4 Missing and 17 partials ⚠️
...trajectory_follower/src/mpc_lateral_controller.cpp	33.33%	0 Missing and 2 partials ⚠️

Additional details and impacted files

@@           Coverage Diff            @@
##            main   #1171      +/-   ##
========================================
+ Coverage   9.64%   9.93%   +0.28%     
========================================
  Files       1056    1054       -2     
  Lines      72744   72960     +216     
  Branches   15819   16048     +229     
========================================
+ Hits        7019    7246     +227     
+ Misses     59404   59319      -85     
- Partials    6321    6395      +74     

Flag	Coverage Δ		*Carryforward flag
differential	43.03% <63.41%> (?)
total	9.64% <29.62%> (+0.01%)	⬆️	Carriedforward from b190ea7

*This pull request uses carry forward flags. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[rej55]

I have some minor comments.
Could you check it?

[rej55]

@kosuke55
In my environment, with this change, trajectory follower nodes does not run in the planning_simulator.
How about your environment?

[kosuke55]

@rej55
yes, It can run(I will check again). Could your share error message?
How about adding min_prediction_length your config or rebuild with upto options..?
(sorry for no launch PR, I will send it)

typo
mpc_min_prediction_length

[rej55]

It runs with mpc_min_prediction_length.
Thank you for your comment!

[rej55]

LGTM