A novel idea to stop body roll on sharp turns - techies, pl. comment

abhaybakshi · 3rd March 2007, 19:08

Dear All,

Don't know if this idea is plain stupid or hold some sense....

We all see toppling of 4 wheelers due to excessive body roll caused by sharp turns. This idea striked me in sleep yesterday night

(I even saw the system working below the car body ..!!!!!!)

Can we do something like following ...

Request all to give some thought and let me know how feasible is this...

Idea
===
Install pneumatically operated jacks on all of the four wheels. One end of this jack should be attached to the horizontal bar (dont know what it is called) and other end should be fixed to chassis. (Similar to shock absorbers attached to bikes)

Now, design a system which will lift one pair of jacks i.e. left front and left rear or right front and right rear) depending upon some threshold load on them.

How it will work
============
Say your car is taking sharp right turn with high speed. In this case,

1. Left front and left rear jacks will be 'pressed' more as it is connected like shock absorbers and due to body roll on left.

2. This will trigger the sensors on these jacks.

3. System now starts to lift these jacks upwards - arresting body to lean more towards left and hence preventing toppling........
I guess this may put more load on tyres as the jacks will push on the horizontal bar to compensate it's thurst upwards.

4. Now the turn is over and your car body is leaning back towards right.

5. System continues to scan the pressures on these jacks all the time and the moment it feels that pressure is decreasing, it will release the 'lift' and will be back to it's normal setting.

Rudra Sen · 3rd March 2007, 19:52

Basically this is known as Active Suspension. Not exactly the way you're thinking though.

Active suspension is computer-controlled. It raises/lowers the cars body independently at wheel points to match road surface and condition. IT IS EXPENSIVE.

Along with other gizmos, cars like Mercedes CL550 comes with active suspension.

abhaybakshi · 3rd March 2007, 20:05

Rudra Sir,

Can you pl. let me know if this makes any sense practically ?

Vid6639 · 3rd March 2007, 20:11

I think there is a koni shocks which stiffens based on frequency of oscillations. If the frequency is high, than the sensors detect that the car is going over bad roads and softens the shocks.

If the frequency is low then the car is turning hard and the oscillations are due to cornering forces, the sensors detects this and stiffens up the shocks.

abhaybakshi · 3rd March 2007, 20:24

Quote:

Originally Posted by vid6639

I think there is a koni shocks which stiffens based on frequency of oscillations. If the frequency is high, than the sensors detect that the car is going over bad roads and softens the shocks.

If the frequency is low then the car is turning hard and the oscillations are due to cornering forces, the sensors detects this and stiffens up the shocks.

But I am saying diffrent thing...it's not related to suspension

viper · 3rd March 2007, 21:15

Guys,

A simpler and cheaper solution to reduce the same would be to install front and rear strut braces.

Viper

Mpower · 3rd March 2007, 21:20

Pneumatics are not have enough force capability to resist body roll. For that you need Hydraulics.

Like Rudra mentioned, high end Mercs have this feature called ABC, active body control. Do some research on it.

Citroen also has been using a hydraulic suspension to resist body roll.

BMW uses a system called Dynamic drive which uses hydraulics to lock the sway bar during turns to give a similar effect with a much simpler and cheaper system.

revvedup · 4th March 2007, 03:33

Your idea reminds me of the bose suspension system which uses exactly the same technique for countering body roll however it uses electromagnetics instead similar to the tech they use in their speakers.
Bose® Learning Center - Bose Suspension System
What you are talking about was first introduced on the merc pulman limos and was very unreliable back then.

nitroxx · 4th March 2007, 03:55

lets try and listen to what hes saying..its about his thought..yes very well abhay youre right on your part however there are companies that have derived similiar methods of trying to avoid body roll (like the one mentioned above).Your idea is good now to try and make more sense of it...get striked again or struck in my opinion...just kidding,keep thinking dude thats what makes achievements.

z klasse · 4th March 2007, 07:32

This is known as active suspension and it is already present on the New Porsche Cayenne. It keeps the car body roll under control on the turn and almost keeps the car flat throughout the turn.

mithun · 6th March 2007, 05:46

But abhaybakshi your idea seems to be good to some extent. But what about the cost of implementing this ? In India, the first & foremost item is the cost factor !!!

For ex, if we implement this on a vehicle like Omni which is having quite considerable body roll, will anyone buy Omni due to the higher cost.

So let's leave these kind of ideas to luxury/snob cars........BUT they themselves are implementing these kind of features. So why bother ?

PS : Although the idea may sound good to modders.

vabs78 · 6th March 2007, 09:22

@abhaybakshi: the main problem in such a system is identifying the cause of pressure on suspension. How do you know that the pressure on suspensions is due to sharp turn and not due to uneven road surface? if you solve this problem then your system may work.

I think most of the OEMs who have developed such systems have used control software to solve this problem (you can put as many if...else conditions in a software as you like ..lol)

Psycho · 6th March 2007, 12:29

Interesting thoughts but most active suspensions only work on damping and will continue to have some form of body roll, easiest ways to solve the problems to a certain extent:

1) Strut Braces
2) Lowering center of gravity - Most Effective
3) Better Damping

101 RACING · 6th March 2007, 13:55

If price is not a problem , then you can get an Coilover suspension with adjustable camber tops/ride height /correct spring rates& most come with pillowbal upper mounts . companies like Tein/-Cusco/-HKS/-racing logic/-D2 /koni are the few market leaders!
cheers

abhaybakshi · 7th March 2007, 11:31

Quote:

Originally Posted by vabs78

@abhaybakshi: the main problem in such a system is identifying the cause of pressure on suspension. How do you know that the pressure on suspensions is due to sharp turn and not due to uneven road surface? if you solve this problem then your system may work.

I think most of the OEMs who have developed such systems have used control software to solve this problem (you can put as many if...else conditions in a software as you like ..lol)

vabs78, I think uneven road surface shouldn't be a problem becuase even if system malfunctions, it is good that the body will remain flat on tilted surface !

How nice it would be to see that car on a tilted road when these pneumatic jacks are lifting the car from one side to keep it straight !!

3rd March 2007, 19:08	#1
abhaybakshi BHPian Join Date: Jan 2007 Location: Pune Posts: 186 Thanked: 85 Times	A novel idea to stop body roll on sharp turns - techies, pl. comment Dear All, Don't know if this idea is plain stupid or hold some sense.... We all see toppling of 4 wheelers due to excessive body roll caused by sharp turns. This idea striked me in sleep yesterday night (I even saw the system working below the car body ..!!!!!!) Can we do something like following ... Request all to give some thought and let me know how feasible is this... Idea === Install pneumatically operated jacks on all of the four wheels. One end of this jack should be attached to the horizontal bar (dont know what it is called) and other end should be fixed to chassis. (Similar to shock absorbers attached to bikes) Now, design a system which will lift one pair of jacks i.e. left front and left rear or right front and right rear) depending upon some threshold load on them. How it will work ============ Say your car is taking sharp right turn with high speed. In this case, 1. Left front and left rear jacks will be 'pressed' more as it is connected like shock absorbers and due to body roll on left. 2. This will trigger the sensors on these jacks. 3. System now starts to lift these jacks upwards - arresting body to lean more towards left and hence preventing toppling........ I guess this may put more load on tyres as the jacks will push on the horizontal bar to compensate it's thurst upwards. 4. Now the turn is over and your car body is leaning back towards right. 5. System continues to scan the pressures on these jacks all the time and the moment it feels that pressure is decreasing, it will release the 'lift' and will be back to it's normal setting.
	() Thanks

3rd March 2007, 19:52	#2
Rudra Sen Team-BHP Support Join Date: Apr 2004 Location: Bangalore Posts: 11,764 Thanked: 6,885 Times View My Garage	Basically this is known as Active Suspension. Not exactly the way you're thinking though. Active suspension is computer-controlled. It raises/lowers the cars body independently at wheel points to match road surface and condition. IT IS EXPENSIVE. Along with other gizmos, cars like Mercedes CL550 comes with active suspension.
	() Thanks

3rd March 2007, 20:05	#3
abhaybakshi BHPian Join Date: Jan 2007 Location: Pune Posts: 186 Thanked: 85 Times	Rudra Sir, Can you pl. let me know if this makes any sense practically ?
	() Thanks

3rd March 2007, 20:11	#4
Vid6639 Team-BHP Support Join Date: Jul 2006 Location: Bangalore Posts: 17,692 Thanked: 44,182 Times View My Garage	I think there is a koni shocks which stiffens based on frequency of oscillations. If the frequency is high, than the sensors detect that the car is going over bad roads and softens the shocks. If the frequency is low then the car is turning hard and the oscillations are due to cornering forces, the sensors detects this and stiffens up the shocks.
	(1) Thanks

3rd March 2007, 21:15	#6
viper BANNED Join Date: Mar 2005 Location: Mumbai Posts: 1,766 Thanked: 20 Times	Guys, A simpler and cheaper solution to reduce the same would be to install front and rear strut braces. Viper
	() Thanks

3rd March 2007, 21:20	#7
Mpower Senior - BHPian Join Date: Mar 2005 Location: Bangalore Posts: 10,397 Thanked: 1,735 Times View My Garage	Pneumatics are not have enough force capability to resist body roll. For that you need Hydraulics. Like Rudra mentioned, high end Mercs have this feature called ABC, active body control. Do some research on it. Citroen also has been using a hydraulic suspension to resist body roll. BMW uses a system called Dynamic drive which uses hydraulics to lock the sway bar during turns to give a similar effect with a much simpler and cheaper system.
	() Thanks

4th March 2007, 03:33	#8
revvedup BHPian Join Date: Sep 2006 Location: Delhi Posts: 269 Thanked: 24 Times	Your idea reminds me of the bose suspension system which uses exactly the same technique for countering body roll however it uses electromagnetics instead similar to the tech they use in their speakers. Bose® Learning Center - Bose Suspension System What you are talking about was first introduced on the merc pulman limos and was very unreliable back then.
	() Thanks

4th March 2007, 03:55	#9
nitroxx Awaiting Email Confirmation Join Date: Nov 2004 Location: DXB Posts: 815 Thanked: 31 Times View My Garage	lets try and listen to what hes saying..its about his thought..yes very well abhay youre right on your part however there are companies that have derived similiar methods of trying to avoid body roll (like the one mentioned above).Your idea is good now to try and make more sense of it...get striked again or struck in my opinion...just kidding,keep thinking dude thats what makes achievements.
	() Thanks

4th March 2007, 07:32	#10
z klasse BHPian Join Date: Jun 2004 Location: Mumbai Posts: 351 Thanked: 29 Times View My Garage	This is known as active suspension and it is already present on the New Porsche Cayenne. It keeps the car body roll under control on the turn and almost keeps the car flat throughout the turn.
	() Thanks

6th March 2007, 05:46	#11
mithun BANNED Join Date: Jan 2006 Location: Cochin Posts: 2,195 Thanked: 269 Times	But abhaybakshi your idea seems to be good to some extent. But what about the cost of implementing this ? In India, the first & foremost item is the cost factor !!! For ex, if we implement this on a vehicle like Omni which is having quite considerable body roll, will anyone buy Omni due to the higher cost. So let's leave these kind of ideas to luxury/snob cars........BUT they themselves are implementing these kind of features. So why bother ? PS : Although the idea may sound good to modders.
	() Thanks

6th March 2007, 09:22	#12
vabs78 BHPian Join Date: Mar 2007 Location: Pune, India Posts: 552 Thanked: 11 Times View My Garage	@abhaybakshi: the main problem in such a system is identifying the cause of pressure on suspension. How do you know that the pressure on suspensions is due to sharp turn and not due to uneven road surface? if you solve this problem then your system may work. I think most of the OEMs who have developed such systems have used control software to solve this problem (you can put as many if...else conditions in a software as you like ..lol)
	() Thanks

6th March 2007, 12:29	#13
Psycho Senior - BHPian Join Date: Jul 2004 Location: Bangalore Posts: 1,040 Thanked: 111 Times View My Garage	Interesting thoughts but most active suspensions only work on damping and will continue to have some form of body roll, easiest ways to solve the problems to a certain extent: 1) Strut Braces 2) Lowering center of gravity - Most Effective 3) Better Damping
	() Thanks

6th March 2007, 13:55	#14
101 RACING BHPian Join Date: Feb 2007 Location: BRISBANE Posts: 27 Thanked: 0 Times	If price is not a problem , then you can get an Coilover suspension with adjustable camber tops/ride height /correct spring rates& most come with pillowbal upper mounts . companies like Tein/-Cusco/-HKS/-racing logic/-D2 /koni are the few market leaders! cheers
	() Thanks