Open dingyifei opened 1 year ago
Within the MQB ACC protocol, openpilot longitudinal always disengages on gas. Even with NDOG toggled on, the temporary disconnect of longitudinal control is handled as ACC disengagement. This is mostly okay while in motion, but disengaging while stopped will set the EPB. If the driver applies gas override input while stopped, depending on timing, the car can end up fighting the driver trying to stop again.
Stock ACC remains engaged during all driver gas input, with a special state meant to indicate gas-override is active. The stock ACC radar even keeps sending desired accel. The ECU/drivetrain coordinator executes something like max(acc_desired_accel, driver_desired_accel)
for a nice smooth handoff experience.
In a perfect world, we'd implement the entire stock ACC protocol including the smooth handoff, but calculating and sending desired accel while longitudinal control is overridden would need changes to safety policy/design as well as higher level controls, and is otherwise a Whole Big Thing that I'm not proposing at this time.
As a more realistic solution, we can implement the gas-override state for the MQB ACC protocol, but just send zero desired acceleration. This is no worse-off than we are today, and should fix the case of standstill departure override. Unfortunately it's still going to break Panda abstractions a little bit, because zero desired acceleration is different from our inactive accel value. I will think about the cleanest way to implement it.
Putting it in the override state and sending 0/inactive accel sounds like the plan.
Currently having some end users test a potential fix.
@jyoung8607 Has the test been working? I'm not sure if its fixed since I never accelerate from stops because now I intervene at every stop to prevent it.
Describe the bug
Sudden braking when the gas pedal is pressed from a stop and OP engaged.
The issue occurred in Segment 26.
Previous conversation for reference
Which car does this affect?
VW Tiguan R-Line 4Motion 2020 (US)
Provide a route where the issue occurs
4e144f64a2535890|2023-03-27--18-14-02--26
openpilot version
master-ci V0.9.1
Additional info
@jyoung8607