Go Back   Team-BHP > Under the Hood > Technical Stuff


Reply
 
Thread Tools Search this Thread
Old 3rd March 2007, 19:08   #1
BHPian
 
abhaybakshi's Avatar
 
Join Date: Jan 2007
Location: Pune
Posts: 177
Thanked: 71 Times
Arrow 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.
abhaybakshi is offline   Reply With Quote
Old 3rd March 2007, 19:52   #2
Team-BHP Support
 
Rudra Sen's Avatar
 
Join Date: Apr 2004
Location: Bangalore
Posts: 10,404
Thanked: 4,092 Times
Default

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.
Rudra Sen is offline   Reply With Quote
Old 3rd March 2007, 20:05   #3
BHPian
 
abhaybakshi's Avatar
 
Join Date: Jan 2007
Location: Pune
Posts: 177
Thanked: 71 Times
Default

Rudra Sir,

Can you pl. let me know if this makes any sense practically ?
abhaybakshi is offline   Reply With Quote
Old 3rd March 2007, 20:11   #4
Team-BHP Support
 
Vid6639's Avatar
 
Join Date: Jul 2006
Location: Bangalore
Posts: 14,465
Thanked: 19,358 Times
Default

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.
Vid6639 is offline   Reply With Quote
Old 3rd March 2007, 20:24   #5
BHPian
 
abhaybakshi's Avatar
 
Join Date: Jan 2007
Location: Pune
Posts: 177
Thanked: 71 Times
Default

Quote:
Originally Posted by vid6639 View Post
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
abhaybakshi is offline   Reply With Quote
Old 3rd March 2007, 21:15   #6
BANNED
 
viper's Avatar
 
Join Date: Mar 2005
Location: Mumbai
Posts: 1,769
Thanked: 8 Times
Default

Guys,

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

Viper
viper is offline   Reply With Quote
Old 3rd March 2007, 21:20   #7
Distinguished - BHPian
 
Mpower's Avatar
 
Join Date: Mar 2005
Location: Bangalore
Posts: 10,432
Thanked: 1,682 Times
Default

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.
Mpower is offline   Reply With Quote
Old 4th March 2007, 03:33   #8
BHPian
 
revvedup's Avatar
 
Join Date: Sep 2006
Location: Delhi
Posts: 251
Thanked: 8 Times
Default

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.
revvedup is offline   Reply With Quote
Old 4th March 2007, 03:55   #9
BHPian
 
nitroxx's Avatar
 
Join Date: Nov 2004
Location: DXB
Posts: 817
Thanked: 26 Times
Default

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.
nitroxx is offline   Reply With Quote
Old 4th March 2007, 07:32   #10
BHPian
 
z klasse's Avatar
 
Join Date: Jun 2004
Location: Mumbai
Posts: 345
Thanked: 2 Times
Default

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.
z klasse is offline   Reply With Quote
Old 6th March 2007, 05:46   #11
Senior - BHPian
 
mithun's Avatar
 
Join Date: Jan 2006
Location: Cochin
Posts: 1,950
Thanked: 49 Times
Default

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.
mithun is offline   Reply With Quote
Old 6th March 2007, 09:22   #12
BHPian
 
vabs78's Avatar
 
Join Date: Mar 2007
Location: Pune, India
Posts: 551
Thanked: 11 Times
Default

@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 is offline   Reply With Quote
Old 6th March 2007, 12:29   #13
Senior - BHPian
 
Psycho's Avatar
 
Join Date: Jul 2004
Location: Bangalore
Posts: 1,042
Thanked: 95 Times
Default

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
Psycho is offline   Reply With Quote
Old 6th March 2007, 13:55   #14
BHPian
 
101 RACING's Avatar
 
Join Date: Feb 2007
Location: BRISBANE
Posts: 27
Thanked: 0 Times
Default

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
101 RACING is offline   Reply With Quote
Old 7th March 2007, 11:31   #15
BHPian
 
abhaybakshi's Avatar
 
Join Date: Jan 2007
Location: Pune
Posts: 177
Thanked: 71 Times
Default

Quote:
Originally Posted by vabs78 View Post
@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 !!
abhaybakshi is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Keep a Family Photo in your car! RTO's novel idea to reduce accidents NPV Street Experiences 46 12th October 2014 23:17
Trivandrum Techies Beware - 18 of 19 food joints at Techno Park fail audit! Scorcher Shifting gears 7 21st October 2011 21:36
What A Novel Idea haryan Shifting gears 2 28th January 2006 18:23
Fiat may roll out ‘Idea’ from Ranjagaon (Near Pune) greatDrive The Indian Car Scene 22 25th July 2005 23:51
Any idea about FIAT Idea? Minardi The Indian Car Scene 13 28th May 2005 12:38


All times are GMT +5.5. The time now is 17:18.

Copyright ©2000 - 2017, Team-BHP.com
Proudly powered by E2E Networks