Problems with The LKA System

When it applies torque to make corrections, it won't correct itself the 2nd time when you veer off the other end so it still requires your active input. You're still required to hold the steering wheel as if LKA was off. No torque is applied when in the center of the lane so it being "more difficult to stay in the center of the lane with the LKA active" doesn't really make sense.

 

I have this feeling that when LKA is on, even if I am dead center on smooth straight highway, it 'tests' me a little bit every once and a while by tweaking the wheel to make sure I'm still holding it.

If you think about it, I'm not sure how else it could be sure I am still holding the wheel [which it does say is a requirement].

The wheel does also seem ever so slightly harder to turn when LKA is on.

 

The feeling may indicate that, but it's not trying to "test" you but keep the car in the center of the lane as the steering wheel isn't that precise and needs to be adjusted even on a straight highway.

It detects that you're holding the wheel by your own input, as we don't exactly hold it perfectly static on a straight road.

 

I experience tugs sometimes but it didn't bother me enough to not use it. If you let go the steering wheel, it's gonna veer to either side.

 

This sounds like you are saying that LKA is making corrections even when I am far from either left or right lane markings and LKA is not issuing any warnings. That is not how I read the documentation. Could you please point me to where this is described -- corrections without warnings?

 

Precisely my point -- I seem to need to correct more with it turned on than with it turned off.

 

btw.. all cars are designed to stray away from dead center (at least every toyota). in-case a driver ever does fall asleep, they tend to not want the cars accidentally veering left into oncoming traffic. (so they veer right.. it takes approx. 5 seconds if i remember the documents right). naturally, cars also want to follow the slope of the road. (as said above)

 

Again -- particularly the statement that LKS is keeping the car centered during turns -- suggests you feel it is contributing to steering even when you are not leaving your lane and it is not beeping at you.

Sure, just to know what to expect LKA to do so I can explain it to other family members should one need to take over for part of a long trip, I have experimented. On empty roads with plenty of lanes, I have relaxed my grip on the wheel while approaching a gentle curve [with the car going more or less straight, so it would leave the current lane] and verified that LKA activates when I reach the lane markers, sounds a warning, and steers me back into the lane [sometimes over-correcting, but not the point here].

I have never observed it to 'follow' a curve -- the car goes as straight as it would go on a similar straight section of road -- and when it gets to the point of crossing the lane, then LKA makes it very clear that it is activating and corrects.

Nowhere have I seen it documented that it is designed to do anything to affect steering except during such lane excursions -- during which, it sounds an alarm, flashes the lane display, and applies steering to align more with the lane.

Please, again, is there something documented somewhere otherwise?

 

That's not what I said. I said it's purpose is not to "test" you but keep the car in the center of the lane, which it's designed to do (at least with some input on the driver's part).

 

I guess I am not being clear. Suggesting LKA was testing the driver was just one idea I was floating to explain why there is a different steering response when the system is turned on and is not supposed to be doing anything -- when I am already in the center of the lane.

Are you saying LKA is applying steering corrections even when I am not straying out of the lane and no alarms are sounding? I haven't seen that documented anywhere.

I would appreciate any pointers to documentation indicating that LKA is designed to do any steering correction whatsoever except when system detects I am departing the lane without indicating a lane change. That's all.

 

My experience is that LKA warns you of lane excursion and slightly bumps the steering back into the lane. The bump is not always sufficient to avoid the lane excursion, although, when combined with the beep, it provides an audible and tactile notice of lane excursion. I have experimented, using a gentle grip on the wheel, to determine whether LKA can steer the car down the center of a gently curving highway and determined that it awkwardly bounces you from one side of the road to the other, like a drunk driver reacting too late to lane excursion. LKA was not designed to steer the car, but rather, was intended to provide sensory notice of lane excursion as a reminder to an in attentive driver that they need to pay better attention to driving the car.

 

I have experienced another issue with LKA. Driving straight on a highway and there is a deceleration lane for turning right. Sometimes there are dashed white lines and other times the right hand line just veers to the right with the additional lane width to accomodate a turn. I have experienced the LKA sensing the right turn lane and apply input to keep me centered within the now double lane. Doesn't happen all of the time, only when the lane lines are very pronounced.