if AEB is activated in the tow vehicle, is braking also automatically applied to the caravan brakes in the same proportional manner? Or should I turn off AEB when towing? Thoughts please.
Whenarewethere said
09:12 PM Oct 15, 2020
What does the car's manual say.
Rusty W said
10:04 PM Oct 15, 2020
When the AEB is actuated the stop lights come on, so the trailer brakes would also come on.
regards Russell
erad said
08:59 AM Oct 16, 2020
There is no simple answer to this question. AEB senses the fact that you are braking heavily in an emergency situation. This means that should it apply with a caravan on the back, the van will push the tug quite heavily. Now, if your brake controller is a g sensitive unit, theoretically it should apply the van brakes strongly and therefore hopefully not load up the tug too much and certainly try to stop it in a straight line. If, however, your brake controller is not a proportional unit (sadly like mine), the caravan braking will only be as strong as the setting that it currently set at. This means that the caravan will probably be pushing the rig harder than it should.
AEB also will act as a stabilising influence on the tug under braking. Should the tug try to go off course, the vehicle's braking system should try to correct the deviation and therefore I think it is essential to keep AEB activated at all times. Without the AEB, the van could push the tug well off course so that a jackknife would almost certainly ensue.
Bobdown said
12:01 PM Oct 16, 2020
erad wrote:
AEB also will act as a stabilising influence on the tug under braking. Should the tug try to go off course, the vehicle's braking system should try to correct the deviation and therefore I think it is essential to keep AEB activated at all times. Without the AEB, the van could push the tug well off course so that a jackknife would almost certainly ensue.
Hey Erad, I think you might be thinking of ABS........anti-skid braking, rather than the sensor activated braking.
Not sure if van brakes would be activated if the tug braked by its own means, but you would hope so.
'Just as ABS uses sensors at each wheel to determine if and how quickly each wheel is turning, autonomous braking uses sensors to detect hazards in front of the car. Generally, an autonomous braking system will use a radar or laser that projects forward to see pedestrians, animals, or rapidly approaching rear bumpers.'
Cheers Bob
Jaahn said
03:15 PM Oct 16, 2020
Bobdown wrote:
erad wrote:
AEB also will act as a stabilising influence on the tug under braking. Should the tug try to go off course, the vehicle's braking system should try to correct the deviation and therefore I think it is essential to keep AEB activated at all times. Without the AEB, the van could push the tug well off course so that a jackknife would almost certainly ensue.
Hey Erad, I think you might be thinking of ABS........anti-skid braking, rather than the sensor activated braking.
Not sure if van brakes would be activated if the tug braked by its own means, but you would hope so.
'Just as ABS uses sensors at each wheel to determine if and how quickly each wheel is turning, autonomous braking uses sensors to detect hazards in front of the car. Generally, an autonomous braking system will use a radar or laser that projects forward to see pedestrians, animals, or rapidly approaching rear bumpers.'
Cheers Bob
Hi
In our modern world things change as we sleep !! It is not simple and I have not kept up with it at all. Try this article for a quick look ! Which type do you have ?
-- Edited by Jaahn on Friday 16th of October 2020 03:16:17 PM
erad said
07:28 PM Oct 16, 2020
No- AEB is when the OH Sh1t moment occurs and you apply the brakes very hard. In fact the system will apply the brakes by itself if it thinks you are going to have a crash. The system thinks that you want to stop very quickly so it takes over and applies the maximum braking effort on the wheels. This is when the ABS would certainly be working. The brake lights will be on so the caravan braking unit will therefore be activated as well. If the caravan braking system is an accelerometric unit, it should also apply maximum braking to the caravan, and depending on the van setup, it may even lock up the caravan wheels. If this is the case you can almost guarantee that the van is not going to stay behind the tug. The tug will then be thrown off at an angle and the tug's ASC will then cut in and using the ABS as well, will try to keep the tug straight - but the van will still be sliding sideways and jack knifing. Is this situation any worse if you turn off the AEB? I don't think so - the AEB will try to stop the rig as quickly as possible and at the least will minimise damage and injury, and hopefully it will totally stop the rig before it hits anything. I would definitely keep AEB active.
The only downer I can see with the AEB is that it probably will not allow you to accelerate out of the situation, should the opportunity be available. It is a case of the electronics working much quicker than the human brain can respond, hence I still like the idea of using AEB if it is available.
If the van has stability control, hopefully it will be working to keep the rig in a straight line and therefore will minimise any jackknifing tendencies.
Whenarewethere said
08:04 PM Oct 16, 2020
If you turn off the car's Stability Control then AEB will be off, ie for off-road.
So if the car if finding itself a bit unstable during AEB it will reduce the braking to maintain control of the car. If the car is not stable it won't brake safety.
If the car has AEB there is going to be a bit more going on than the car simply turning off rear distance parking sensors when you attach a trailer.
Contact the manufacturer of your car & ask them. As said above there are a lot of different systems.
Greg 1 said
02:06 PM Oct 17, 2020
Please keep in mind that these systems are no substitute for safe and attentive driver practice's.
Mamil said
05:01 PM Oct 17, 2020
An interesting topic, and made me realise I didn't know exactly how my car's electronic systems reacted in an emergency, so I did a bit of digging through the manuals.
This is what I found, but stress it's only applicable to MY car, although I believe other systems with other manufacturers work similarly, but I'd echo Whenarewethere by advising you check out how YOUR car operates.
The Autonomous Emergency Braking (AEB) system uses forward-facing cameras, located above the rear-view mirror, to help identify if you are at an imminent risk of colliding with a vehicle travelling in front of you. The AEB system only operates when the vehicle is travelling between 5 km/h (3 mph) and 80 km/h (50 mph). It will detect real vehicles, plus other certified Euro NCAP target objects. It is not designed to detect any other objects, including non-industry approved targets. In order for it to operate, it must be able to detect a clear image of the object and be able to determine its movement. If either of these does not occur, the AEB system may not operate. If the AEB system starts to engage, the driver can override its operation using steering wheel or accelerator inputs. This causes the AEB system to disengage. This is to make sure that the driver remains in full control of the vehicle. There are two distinct stages of AEB system operation:-
1. A forward collision warning informs the driver of a collision risk concerning the vehicle ahead. The warning provides the driver with an opportunity to avoid the situation by braking or steering.
2. If the driver does not react, and the Intelligent Emergency Braking (IEB) system determines that a collision is unavoidable, even with driver intervention, it signals the Anti-lock Brake System (ABS) control module to apply emergency brake pressure to all of the brakes. Intelligent Emergency Braking (IEB) reduces the impact velocity if a collision is unavoidable, it is not designed to prevent accidents from occurring. Typical activation of IEB is approximately 0.8 second before impact, during which the speed of the sensing vehicle is reduced, thus reducing the impact energy.
There is no mention of what happens to attached trailers during an AEB event, though I assume that when the ABS control module applies emergency braking that the brake lights will be activated, in turn triggering the brake control module to operate the trailer brakes. But in order for this to happen it is important that the electronic brake controller gets it's activation signal from the correct source. Redarc have a technical bulletin about this on their website https://www.redarc.com.au/how-to-fit-a-towpro-in-a-high-spec-vehicle but the gist of it is that you need to source the electric brake controller trigger signal from the brake light circuit, not the brake pedal switch, or the trailer brakes will not operate in an AEB event!
However, it may be a moot point anyway, as all this happens only 0.8 seconds before impact, and with the inherent delays in each stage of the chain of operations I highly doubt that trailer braking will have a chance to play any meaningful part.
-- Edited by Mamil on Saturday 17th of October 2020 07:02:19 PM
hufnpuf said
07:02 PM Oct 17, 2020
erad wrote:
The system thinks that you want to stop very quickly so it takes over and applies the maximum braking effort on the wheels. This is when the ABS would certainly be working.
My car doesn't have the AEB thing, but one day somebody turned in front of me as I was coming up a main road at around 70 km/h and I found out what the ABS is like. I stomped on the brakes hard and the ABS did its thing. I could feel the brakes coming on each tire in turn, it was clunk clunk clunk clunk, it wasn't even braking like when you brake normally, I could feel that it was working each tire in turn (I don't know what it was really doing, but that's how it felt). The car kept straight (I didn't swerve, but it didn't skid or do anything like that) and stopped straight. Luckily I saw the turning driver in time for the brakes to do their thing and we didn't collide. It was interesting to find out that the system works and how, but I'd rather not have found out, it was pretty nervewracking thinking I was going to be in a collision.
Mamil said
07:23 PM Oct 17, 2020
hufnpuf wrote:
My car doesn't have the AEB thing, but one day somebody turned in front of me as I was coming up a main road at around 70 km/h and I found out what the ABS is like. I stomped on the brakes hard and the ABS did its thing. I could feel the brakes coming on each tire in turn, it was clunk clunk clunk clunk, it wasn't even braking like when you brake normally, I could feel that it was working each tire in turn (I don't know what it was really doing, but that's how it felt). The car kept straight (I didn't swerve, but it didn't skid or do anything like that) and stopped straight. Luckily I saw the turning driver in time for the brakes to do their thing and we didn't collide. It was interesting to find out that the system works and how, but I'd rather not have found out, it was pretty nervewracking thinking I was going to be in a collision.
A good point Hufnpuf. I remember way back when ABS was pretty new there was an incident where an experienced traffic cop was killed because during a high speed pursuit his ABS operated for the first time and he was so shocked by the unfamiliar behaviour of the car that he took his foot off the brake and crashed. So, it's a good idea for us all to get familiar with our car's ABS and how it feels in a controlled and safe environment, before we experience it for real! When I bought my LandRover they give you a free "Experience" day out in the countryside on a 4WD track with instructors who take you through all the car's features, including an emergency stop on gravel so you know how the ABS operates. I was quite impressed how quickly it brought the car to a stop and in a straight line. They also showed us a nice feature where the passenger can independently operate the ABS from their seat if the driver has a seizure or something, to bring the car safely to a stop.
-- Edited by Mamil on Saturday 17th of October 2020 07:30:58 PM
landy said
10:27 PM Oct 17, 2020
ConsumerMan wrote:
if AEB is activated in the tow vehicle, is braking also automatically applied to the caravan brakes in the same proportional manner? Or should I turn off AEB when towing? Thoughts please.
AEB is just one of many braking assistance packages used on modern cars . and the conditions under which it operates change from brand to brand, on my Hyundai Santa Fe it definitely shows the brake lights and would apply the trailer brakes. I think what could be more of a problem is the ability of some cars mine included to also swerve to avoid an accident if necessary,( I must remember to turn that off if I'm going to tow with it) in my case this can be activated or disabled in the cars driver assist menu. Automatic Emergency Braking - Home | Safercar [Search domain www.safercar.gov/Vehicle+Shoppers/Safety+Technology/aeb-1] https://www.safercar.gov/Vehicle+Shoppers/Safety+Technology/aeb-1 Automatic emergency braking (AEB) systems detect an impending forward crash with another vehicle in time to avoid or mitigate the crash. These systems first alert the driver to take corrective action to avoid the crash. If the driver s response is not sufficient to avoid the crash, the AEB system may automatically apply the brakes to assist in preventing or reducing the severity of a crash . AEB should not be confused with ABS Anti lock braking, EBD Electronic brake distribution or EBA Electronic brake assist.
Jaahn said
10:40 AM Oct 18, 2020
Hi
I agree that people should tryout the systems in their vehicle to see what they do. Use a gravel surface so the grip is less and at a modest speed and see what happens. Certainly you should know that the pulsing in the brake pedal is normal and just the ABS working as it should. AND you should be confident to keep your foot pressure on to keep it working. Actually just stand on the brakes and hold them on. I have done that with a couple of learner drivers to show them what to do.
Just the other night coming back from a farm after dark I avoided a roo at modest speed with the assistance of the ABS and EBA. Jumped out of nowhere as they do halfway round a corner on a narrow dirt road. No worries, magic, modern magic. But of course keeping the speed modest was a good factor also. In the old days I might have managed to brake enough but would have slid off the road backwards doing it.
Jaahn
Whenarewethere said
11:56 AM Oct 18, 2020
Years ago I tried out the ABS on a quiet safe bit of road. Stood on the brakes as hard as I could. It is staggering how short the distance the car stops in. I was a bit surprised at first at all the noises.
One should test the ABS out so you know what to expect. Like any new device for that matter!
StewG said
03:42 PM Oct 19, 2020
20 years ago I bought a new car and ABS was an optional, expensive addition. I said no to that because I did not understand how good ABS really is. I later did an ABS training course and after that experience, regretted not paying the extra money. Most if not all cars now have that as standard equipment. AEB is a different matter. Only the car manufacturer or the installer of trailer braking system can tell if AEB will activate the trailer brakes too. Fortunately I have a driver alertness mechanism to wake me up if any collision is imminent. She sits in the seat beside me.
if AEB is activated in the tow vehicle, is braking also automatically applied to the caravan brakes in the same proportional manner? Or should I turn off AEB when towing? Thoughts please.
What does the car's manual say.
When the AEB is actuated the stop lights come on, so the trailer brakes would also come on.
regards Russell
AEB also will act as a stabilising influence on the tug under braking. Should the tug try to go off course, the vehicle's braking system should try to correct the deviation and therefore I think it is essential to keep AEB activated at all times. Without the AEB, the van could push the tug well off course so that a jackknife would almost certainly ensue.
Hey Erad, I think you might be thinking of ABS........anti-skid braking, rather than the sensor activated braking.
Not sure if van brakes would be activated if the tug braked by its own means, but you would hope so.
'Just as ABS uses sensors at each wheel to determine if and how quickly each wheel is turning, autonomous braking uses sensors to detect hazards in front of the car. Generally, an autonomous braking system will use a radar or laser that projects forward to see pedestrians, animals, or rapidly approaching rear bumpers.'
Cheers Bob
Hi
In our modern world things change as we sleep !! It is not simple and I have not kept up with it at all. Try this article for a quick look ! Which type do you have ?
https://www.whichcar.com.au/car-advice/autonomous-emergency-braking-explained
Jaahn
-- Edited by Jaahn on Friday 16th of October 2020 03:16:17 PM
The only downer I can see with the AEB is that it probably will not allow you to accelerate out of the situation, should the opportunity be available. It is a case of the electronics working much quicker than the human brain can respond, hence I still like the idea of using AEB if it is available.
If the van has stability control, hopefully it will be working to keep the rig in a straight line and therefore will minimise any jackknifing tendencies.
If you turn off the car's Stability Control then AEB will be off, ie for off-road.
So if the car if finding itself a bit unstable during AEB it will reduce the braking to maintain control of the car. If the car is not stable it won't brake safety.
If the car has AEB there is going to be a bit more going on than the car simply turning off rear distance parking sensors when you attach a trailer.
Contact the manufacturer of your car & ask them. As said above there are a lot of different systems.
An interesting topic, and made me realise I didn't know exactly how my car's electronic systems reacted in an emergency, so I did a bit of digging through the manuals.
This is what I found, but stress it's only applicable to MY car, although I believe other systems with other manufacturers work similarly, but I'd echo Whenarewethere by advising you check out how YOUR car operates.
There is no mention of what happens to attached trailers during an AEB event, though I assume that when the ABS control module applies emergency braking that the brake lights will be activated, in turn triggering the brake control module to operate the trailer brakes. But in order for this to happen it is important that the electronic brake controller gets it's activation signal from the correct source. Redarc have a technical bulletin about this on their website https://www.redarc.com.au/how-to-fit-a-towpro-in-a-high-spec-vehicle but the gist of it is that you need to source the electric brake controller trigger signal from the brake light circuit, not the brake pedal switch, or the trailer brakes will not operate in an AEB event!
However, it may be a moot point anyway, as all this happens only 0.8 seconds before impact, and with the inherent delays in each stage of the chain of operations I highly doubt that trailer braking will have a chance to play any meaningful part.
-- Edited by Mamil on Saturday 17th of October 2020 07:02:19 PM
A good point Hufnpuf. I remember way back when ABS was pretty new there was an incident where an experienced traffic cop was killed because during a high speed pursuit his ABS operated for the first time and he was so shocked by the unfamiliar behaviour of the car that he took his foot off the brake and crashed. So, it's a good idea for us all to get familiar with our car's ABS and how it feels in a controlled and safe environment, before we experience it for real! When I bought my LandRover they give you a free "Experience" day out in the countryside on a 4WD track with instructors who take you through all the car's features, including an emergency stop on gravel so you know how the ABS operates. I was quite impressed how quickly it brought the car to a stop and in a straight line. They also showed us a nice feature where the passenger can independently operate the ABS from their seat if the driver has a seizure or something, to bring the car safely to a stop.
-- Edited by Mamil on Saturday 17th of October 2020 07:30:58 PM
AEB is just one of many braking assistance packages used on modern cars . and the conditions under which it operates change from brand to brand, on my Hyundai Santa Fe it definitely shows the brake lights and would apply the trailer brakes. I think what could be more of a problem is the ability of some cars mine included to also swerve to avoid an accident if necessary,( I must remember to turn that off if I'm going to tow with it) in my case this can be activated or disabled in the cars driver assist menu. Automatic Emergency Braking - Home | Safercar
[Search domain www.safercar.gov/Vehicle+Shoppers/Safety+Technology/aeb-1] https://www.safercar.gov/Vehicle+Shoppers/Safety+Technology/aeb-1
Automatic emergency braking (AEB) systems detect an impending forward crash with another vehicle in time to avoid or mitigate the crash. These systems first alert the driver to take corrective action to avoid the crash. If the driver s response is not sufficient to avoid the crash, the AEB system may automatically apply the brakes to assist in preventing or reducing the severity of a crash . AEB should not be confused with ABS Anti lock braking, EBD Electronic brake distribution or EBA Electronic brake assist.
Hi
I agree that people should tryout the systems in their vehicle to see what they do. Use a gravel surface so the grip is less and at a modest speed and see what happens. Certainly you should know that the pulsing in the brake pedal is normal and just the ABS working as it should. AND you should be confident to keep your foot pressure on to keep it working. Actually just stand on the brakes and hold them on.
I have done that with a couple of learner drivers to show them what to do.
Just the other night coming back from a farm after dark I avoided a roo at modest speed with the assistance of the ABS and EBA. Jumped out of nowhere as they do halfway round a corner on a narrow dirt road. No worries, magic, modern magic.
But of course keeping the speed modest was a good factor also. In the old days I might have managed to brake enough but would have slid off the road backwards doing it.
Jaahn
Years ago I tried out the ABS on a quiet safe bit of road. Stood on the brakes as hard as I could. It is staggering how short the distance the car stops in. I was a bit surprised at first at all the noises.
One should test the ABS out so you know what to expect. Like any new device for that matter!