Toyota: Prolonged low speed lateral oscillation

[ntegan1]

Describe the bug

This is an instance of steering oscillation commonly experienced when driving tssp corolla at low speeds (20->35mph).

https://user-images.githubusercontent.com/3820605/186998526-4404dbbe-1ecd-45ef-bbab-e99b05373967.mp4

(segment 9)

segments 10 and 11 also display oscillating torque output/steering angle.

Which car does this affect?

Toyota Corolla 2017

Provide a route where the issue occurs

a152dad3c3368320|2022-08-26--15-36-30--9

openpilot version

38eb19bf04a5b6498cc38377796134205f0ee725

Additional info

latcontrol torque error equations

setpoint = desired_curvature * vego^2 + desired_curvature * low_speed_factor
setpoint = desired_curvature * (vego^2 + low_speed_factor)
measurement = actual_curvature * (vego^2 + low_speed_factor)

==>

error = (desired_curvature - actual_curvature) * (vego^2 + low_speed_factor)

error is difference in curvature multiplied by vego^2 + low_speed_factor

graph of vego^2 + low_speed_factor

https://www.wolframalpha.com/input?i=y+%3D+piecewise%5B%7B%7B500%2C+x+%3C+10%7D%2C+%7B800+-+30x%2C+x+%3C+20%7D%2C+%7B200%2C+x+%3E+20%7D%7D%5D+%2B+x%5E2

y = piecewise[{{500, x < 10}, {800 - 30x, x < 20}, {200, x > 20}}] + x^2

[sshane]

Loving the use of the clipping feature!

[ntegan1]

discord user sunny68 seems to be experiencing something similar (HKG i think) https://1drv.ms/v/s!AunEjGlrWjRakCQ8T0fshxa3KtSn

#tuning https://discord.com/channels/469524606043160576/574796986822295569/1014285718073380926

[ntegan1]

friction / 3.

some drives on a152dad3c3368320|2022-09-01 with ~1/3 friction code here seem to have less oscillation. feels smoother but doesn't want to turn as hard into sharper low speed curves as it needs to, so car ends up floating toward the double yellow lines/other lane and goes over occasionally (controller accuracy issue?).

-TOYOTA COROLLA 2017: [3.117154369115421, 1.8438132575043773, 0.12289685869250652]
+TOYOTA COROLLA 2017: [3.117154369115421, 1.8438132575043773, 0.04289685869250652]

Discord user suggests

In my 2010 Corolla, which has a similar steering setup to the 2017. I use MAX_LAT=3.6 FRICTION=0.032 and steer_actuator_delay=0.3875

will try out soon

edit: a152dad3c3368320|2022-09-02--11-53-20 code here

these values are too extreme

less drastic tuning changes

many good routes after that one with friction .052 and steerActuatorDelay 0.24

e.g. a152dad3c3368320|2022-09-02--13-05-45 code here ==>

~ 1/2 friction reduces oscillation

[adeebshihadeh]

Is this still an issue?

[sshane]

@ntegan1 any updates?

[ntegan1]

Is this still an issue?

Missed this. Much better!

Torque control is so good