Abusing the TJA.

[Bricktop X PWR]

So, some of the regular members will know that I have been having an issue with my car lately.

During the several resets I have carried out, I have had to go into settings to redo all my preferences.

As a rule I have always used ACC as my default setting, and on the whole, it's pretty good.

My only gripe with it is, that I wish its maximum following distance was its minimum. (Edit: update to R46 cures this by increasing the following distance and stops ACC slowing down for bends)

Anyway, yesterday, I had put it into Traffic Jam Assist, and used it on the A40.

My mind was quite literally boggled at how well it did, steering the car.

It was nearly as good as my previous Model3. No, honestly, I was gobsmacked!

I had to intervene just twice in 9 miles of 70 mph driving, so not completely trustworthy!

I know I was asking a lot of it at that speed because

(TO BE CLEAR, I WASN'T USING IT FOR THE PURPOSE THAT IT WAS DESIGNED, NAMELY TRAFFIC JAMS)

but it did extremely well.
I can see this system being excellent at the speeds for which it was designed.

I was messing about with the settings because I read somewhere on here that the car could change direction, autonomously, on the application of an indicator.

It can't.

It does prompt you to hold the wheel if you should let it go completely.

Don't do that. ?

P.S To be absolutely clear.....I WASN'T USING IT FOR THE PURPOSE THAT IT WAS DESIGNED, NAMELY TRAFFIC JAMS!

 

[siteguru]

I just don't trust TJA (at motorway speeds) since the time it tried to steer the car into a lorry (in lane 1) that we were overtaking in lane 2. (All was fine, we were starting to pass the lorry, then the car simply tried to steer left into it. Lane markings were clear and it was a dry, overcast day so no spurious sunshine effects.)

 

[Bricktop X PWR]

I just don't trust TJA (at motorway speeds) since the time it tried to steer the car into a lorry (in lane 1) that we were overtaking in lane 2. (All was fine, we were starting to pass the lorry, then the car simply tried to steer left into it. Lane markings were clear and it was a dry, overcast day so no spurious sunshine effects.)

Sounds like squeaky bum time to me m8!

I will try it again, and reckon it will make the long trip to the MIL's a bit easier.......

Until it tries to kill me of course!?

 

[Rolfe]

So, some of the regular members will know that I have been having an issue with my car lately.

During the several resets I have carried out, I have had to go into settings to redo all my preferences.

As a rule I have always used ACC as my default setting, and on the whole, it's pretty good.

My only gripe with it is, that I wish its maximum following distance was its minimum.

Anyway, yesterday, I had put it into Traffic Jam Assist, and used it on the A40.

My mind was quite literally boggled at how well it did steering the car.

It was nearly as good as my previous Model3. No, honestly, I was gobsmacked!

I had to intervene just twice in 9 miles of 70 mph driving, so not completely trustworthy!

I know I was asking a lot at that speed but it did extremely well.
I can see this system being excellent at the speeds for which it was designed.

I was messing about with the settings because I read somewhere on here that the car could change direction, autonomously, on the application of an indicator.

It can't.

It does prompt you to hold the wheel if you should let it go completely.

Don't do that. ?

That's interesting. I had read of people using TJA at higher speeds but didn't try it myself.

I can't stand LKA, no way. I have used TJA in actual traffic jams (once on the M25) and found it fine below 10 mph, except I got fed up with the continual exhortations to hold the wheel as it was doing fine at that speed without my help. But as soon as the jam speeded up above about 10 mph I found the snatching at the wheel irritating and turned it off.

Do you think I should try again?

 

[Bricktop X PWR]

That's interesting. I had read of people using TJA at higher speeds but didn't try it myself.

I can't stand LKA, no way. I have used TJA in actual traffic jams (once on the M25) and found it fine below 10 mph, except I got fed up with the continual exhortations to hold the wheel as it was doing fine at that speed without my help. But as soon as the jam speeded up above about 10 mph I found the snatching at the wheel irritating and turned it off.

Do you think I should try again?

Absolutely!

My software is R40 at the moment, but due to be updated at the dealer in a couple of weeks, so may bring an improvement with the steering accuracy.

I can see myself using it a lot more in the future, especially at lower speeds (50/60)

The key with it really is, the straighter the road the better and a well marked/lined road will assist even further I would have thought.

I used to use a heavy bean bag on the bottom of the steering wheel in my Tesla to stop it moaning at me to hold the wheel.?

 

[Rolfe]

I took to resting my hand on the bottom of the steering wheel to shut it up. I like the bean-bag idea.

I will try it again some time, probably soon.

 

[DaevM]

I appreciate that this is a part way stop to full autonomous control of the vehicle, getting us used to the idea but I can't see myself wanting to use any of it having had 40+ years of controlling it perfectly well myself. On the other hand I know the lure of using new, previously unexperienced tech will be very great indeed and in no time at all I'll be snoozing on the back seat (maybe that's why it's so dark back there) with a suitably placed beanbag on the steering wheel so as to not disturb me.... Oh dear. ?

 

[Bricktop X PWR]

I took to resting my hand on the bottom of the steering wheel to shut it up. I like the bean-bag idea.

I will try it again some time, probably soon.

It's the type you can heat up in the microwave for your aches and pains.

(Including the pain of your car moaning at you ?)

 

[NLMGSAN]

I do not like it. Although it does a fine job keeping the car up to speed between the lines, it is too nervous and twitchy for me. If the car approaches a line it steers the car back with a short correction to create the standard margin between car and line. Then it releases the wheel. If the road make a left or right bend, particularly in the long bends it constantly repeats these small corrections. This causes a sawtooth like drive. To me this means the system does not look forward far enough to identify the curved lines in front, so allowing for a constant correction.

Btw, there is a same thing is happening with ACC. Given a set distance to the car in front you the car can easily accelerate strongly. Going into the 'danger zone' the system hits the brake without checking if the car in front of you also accelerates. Neither does it reduce acceleration when approaching the zone. It is too much all or nothing. It is poor in anticipating...

 

[fnegroni]

I do not like it. Alrhough it does a fine job keeping the car up to speed between the lines, it is too nervous and twitchy for me. If the car approaches a line it steers the car back with a short correction to create the standard margin between car and line. Then it releases the wheel. If the road make a left or right bend, particularly in the long bends it constantly repeats these small corrections. This causes a sawtooth like drive. To me this means the system does not look forward far enough to identify the curved lines in front, so allowing for a constant correction.

Btw, there is a same thing is happening with ACC. Given a set distance to the car in front you the car can easily accelerate strongly. Going into the 'danger zone' the system hits the brake without checking if the car in front of you also accelerates. Neither does it reduce acceleration when approaching the zone. It is too much all or nothing. It is poor in anticipating...

Do you have the latest updates to the front camera? LKA and TJA are greatly improved recently.

 

[NLMGSAN]

Do you have the latest updates to the front camera? LKA and TJA are greatly improved recently.

To be honest, how can I know? I got my Trophy ER on December 27th last year.

 

[fnegroni]

Chances are you do not have the latest updates. If you complain about the LKA to your dealer they will update it free of charge

 

[NLMGSAN]

Why is ACC related to LKA?
I can understand the LKA modes LDA and ELK could influence TJA. But TJA certainly does not correct the car the same way as LDA or ELK. It looks like TJA uses totally different algorithms.

 

[Jeroen]

I regularly use it at speeds between 100km/h and 130km/h on the highway and overall it performs well. It becomes less useful in dark and rainy conditions

 

[DaevM]

It's the type you can heat up in the microwave for your aches and pains.

(Including the pain of your car moaning at you ?)

Old skool heated steering wheel ??

 

[Ian Key]

I can just see @Bricktop X PWR saying "It wasn't me officer. It was the beanbag that did it"

 

[salty]

LKA, LDA, ELK, TJA. etc etc etc. Jesus!
What happened to just driving the car yourself, managed all these years perfectly ok.

 

[NLMGSAN]

LKA, LDA, ELK, TJA. etc etc etc. Jesus!
What happened to just driving the car yourself, managed all these years perfectly ok.

Same for me. But others decide what's good for you...

 

[JonnyG]

Never used TJA either !! ... will give it a try instead of ACC.

Not keen on ACC particularly, as I find it slows down the car on slight bends even on the A1 !

 

[NLMGSAN]

Never used TJA either !! ... will give it a try instead of ACC.

Not keen on ACC particularly, as I find it slows down the car on slight bends even on the A1 !

Not on slight bends with me, but it does with somewhat tighter ones. The car easily takes them with 80 kmh, yet it always drops to about 75 kmh.
What I find most annoying is the speed drop if I overtake a car ahead of me and I am already in or half way into the next lane. Apparently, once you get a bit too close, the MG drops speed even if there is nobody in front of you anymore. The only effect it has is a cursing driver behind me.....