Drive by Wire Technology

ajaysurfs · 12th August 2009, 16:07

Have been hearing about this phrase for a long time now. Basically it replaces mechanical systems by electronic systems for wider applications in a vehicle. Like a hydraulic clutch/brake assist (power brake/power clutch) replaced by an electro-mechanical actuator.

I saw this practically being used in one of the latest KSRTC buses - Volvo 9400's. I happened to look at the footwell of the bus, having accelerator/clutch/brake assembly. There were no mechanical linkages to any of the pedals, but just some kind of sensors mounted on the lower part.

I suppose that some of the cars also use this technology, but dont know the extent to which it is being used (given that it adds costs).

Which cars sold in India and to what extent is this technology being used here?

gpa · 12th August 2009, 16:15

Drive-by-wire technology is in a very nascent stage here in India. Will take a while before it evolves and becomes common.

Word has it that MUL will be introducing this technology on one of their new upcoming models with the new Euro 4 all aluminium 16v DOHC KB series engine.

R_R · 12th August 2009, 16:45

The Grand Vitara has drive-by-wire technology, but am not sure if its for all controls or just accelerator.

jav · 12th August 2009, 17:04

Most of the new cars available now have drive by wire for accelerator

im_srini · 12th August 2009, 17:06

The Swift diesel comes with an electronic throttle, by extension, cars from other stables that use the multi-jet-diesel engine should come with electronic throttles too. The M16A engine, i.e. SX4, is also controlled by an electronic throttle.

ImmortalZ · 12th August 2009, 17:27

All Hondas currently for sale except the ANHC have DBW throttles. I remember a generation of Mercs were extremely criticized for their DBW braking systems which failed often. I think there is some sort of law now in the EU saying that certain systems on a car MUST have mechanical links.

hellstar · 12th August 2009, 18:13

Verna CRDis are Drive by wire so does Getz CRDi , I20, Swift DDSi :-)

KSM-Vtec · 12th August 2009, 18:24

Well it gets only more and more unreliable & complicated to maintain this way....but i guess thats not a good enough excuse to avoid change and upgrade.

ImmortalZ · 12th August 2009, 18:26

The excuse is emissions, like every other change that is going on.

chaxy · 12th August 2009, 19:02

the safari's too has it for the accelerator. In UV's Scorpio and Innvova too have this.

Trust_In_Thrust · 12th August 2009, 22:32

The palio also has DBW since its launch in india if i recall correctly which makes it the earliest in India .Also with DBW the ECU is able to get better/faster readings from the potentiometer vs the older mechanical linkage system.

profold · 13th August 2009, 01:48

Thanks ajaysurfs for starting this thread. I had been looking forward to it.
Just jotting down some random thoughts.
Thus spake wikipedia:

"Drive-by-wire, DbW, by-wire, or x-by-wire technology in the automotive industry replaces the traditional mechanical and hydraulic control systems with electronic control systems using electro-mechannical actuators and human-machine interfaces such as pedal and steering feel emulators."

Is the rubber-bulb honker, standard in pre-war cars which got replaced almost overnight without a whimper by electric horns, the first X-by wire victim :-)? Or the honour of the the first X-by wire should go to the "self" starter, replacing the sturdy and macho crank?

Jokes aside, electronic throttle which does away with direct mechanical linkage from the accelerator pedal is a commonplace. It seems to jell well with the ECU.
If we permit substitution of "replaces" by "partially replaces" in the above wikipedia definition, bits and pieces of x-by-wire is available in many modern cars, even in India . We have central locking, power windows (trivial), power steering, ABS (Brake-by-wire assist), electronic stability control.
In the automotive sector, the motivation for X-by-wire appears to be flexibility in positioning the controls and better performance.
In the downside, electrical systems, unlike mechanical and hydraulic systems do not degrade gracefully and have a tendency to fail without warning.
A complete X-by-wire can create a very unsafe situation. Safety issues may be minor in electronic throttle as one can kill the ignition if misbehavior is suspected. But consider a full steer-by-wire. If it conks out in a highway, the lives of occupants of the concerned and other cars are in jeopardy.
Cost of course is another but less grave downside.

We would like to know (i) the experience of using and maintaining the various X-by-wire components in Indian cars (ii) evolution of X-by-wire application in our home-grown auto industry (iii) world-wide laws, regulations and practices which allows or disallows complete (no mechanical backup) X-by-wire features.

Senior and knowledgeable TBHPians please contribute and keep this thread alive.

Cheers

P.S.
A bit of history, possibly known by many. The term "by-wire" appears to be used first in aeroplane context as "fly-by-wire" where the mechanical or hydraulic connection between pilot joystick and the controlled surfaces were replaced by electrical connection from stick position sensors. Airbus A320 has it. our very own LCA/Tejas has it. Fly-by-wire allows reduction of weight (hence endurance with same amount of fuel) and better handling qualities. To ensure safety ALL sensor and Electronics are copied 4-times, in a fail-safe configuration so that up to two failures can be safely tolerated. We cannot possibly afford the 4-fold cost in a down-to-earth automobile.
Apologies for the longish post.

neoonwheels · 13th August 2009, 10:09

Quote:

Originally Posted by Trust_In_Thrust

The palio also has DBW since its launch in india if i recall correctly which makes it the earliest in India .Also with DBW the ECU is able to get better/faster readings from the potentiometer vs the older mechanical linkage system.

Yes, I remember reading about Petra in the broacher that the car is equipped with drive by wire. Not sure about Palio though.

esteem_lover · 13th August 2009, 11:33

I have literally rode my Yezdi by wire many times when the accelerator cable gets cut. Have to hold the wire & pull to accelerate and push to decelerate.

ajaysurfs · 13th August 2009, 12:09

Thanks Profold.

Imagine an automobile being driven by a joystick, if the DBW proponents have their way! If any system goes for a toss, god can only save.

Which brings me to another observation. When i was Germany few years back, one of my colleagues (who was physically challenged) used to drive a retrofitted Golf (Automatic). Steering was as usual as with other cars (with a kind of blob for easy maneuverability), however there was a kind of joystick in pace of gear lever - when pushed forward the car used to accelerate and when pulled back it used to brake. There were no pedals to be seen.

So i think in similar circumstances DBW becomes indespensable.

12th August 2009, 16:07	#1
ajaysurfs BHPian Join Date: Sep 2006 Location: Bangalore Posts: 52 Thanked: Once	Drive by Wire Technology Have been hearing about this phrase for a long time now. Basically it replaces mechanical systems by electronic systems for wider applications in a vehicle. Like a hydraulic clutch/brake assist (power brake/power clutch) replaced by an electro-mechanical actuator. I saw this practically being used in one of the latest KSRTC buses - Volvo 9400's. I happened to look at the footwell of the bus, having accelerator/clutch/brake assembly. There were no mechanical linkages to any of the pedals, but just some kind of sensors mounted on the lower part. I suppose that some of the cars also use this technology, but dont know the extent to which it is being used (given that it adds costs). Which cars sold in India and to what extent is this technology being used here?
	() Thanks

12th August 2009, 16:15	#2
gpa Senior - BHPian Join Date: Aug 2008 Location: Bangalore Posts: 1,790 Thanked: 345 Times	Drive-by-wire technology is in a very nascent stage here in India. Will take a while before it evolves and becomes common. Word has it that MUL will be introducing this technology on one of their new upcoming models with the new Euro 4 all aluminium 16v DOHC KB series engine.
	() Thanks

12th August 2009, 16:45	#3
R_R BHPian Join Date: Apr 2009 Location: NCR Posts: 318 Thanked: 294 Times	The Grand Vitara has drive-by-wire technology, but am not sure if its for all controls or just accelerator.
	() Thanks

12th August 2009, 17:04	#4
jav BHPian Join Date: Apr 2007 Location: Bangalore Posts: 225 Thanked: 66 Times	Most of the new cars available now have drive by wire for accelerator
	() Thanks

12th August 2009, 17:06	#5
im_srini BHPian Join Date: Sep 2006 Location: Portland Posts: 1,010 Thanked: 491 Times View My Garage	The Swift diesel comes with an electronic throttle, by extension, cars from other stables that use the multi-jet-diesel engine should come with electronic throttles too. The M16A engine, i.e. SX4, is also controlled by an electronic throttle.
	() Thanks

12th August 2009, 17:27	#6
ImmortalZ Senior - BHPian Join Date: Jan 2008 Location: Trivandrum Posts: 2,195 Thanked: 601 Times View My Garage	All Hondas currently for sale except the ANHC have DBW throttles. I remember a generation of Mercs were extremely criticized for their DBW braking systems which failed often. I think there is some sort of law now in the EU saying that certain systems on a car MUST have mechanical links. Last edited by ImmortalZ : 12th August 2009 at 17:28.
	() Thanks

12th August 2009, 18:13	#7
hellstar Senior - BHPian Join Date: Dec 2006 Location: Bangalore Posts: 1,073 Thanked: 44 Times	Verna CRDis are Drive by wire so does Getz CRDi , I20, Swift DDSi :-)
	() Thanks

12th August 2009, 18:24	#8
KSM-Vtec Senior - BHPian Join Date: Jun 2008 Location: MH-02-India-Bombay-Bandra Posts: 1,561 Thanked: 447 Times View My Garage	Well it gets only more and more unreliable & complicated to maintain this way....but i guess thats not a good enough excuse to avoid change and upgrade.
	() Thanks

12th August 2009, 18:26	#9
ImmortalZ Senior - BHPian Join Date: Jan 2008 Location: Trivandrum Posts: 2,195 Thanked: 601 Times View My Garage	The excuse is emissions, like every other change that is going on.
	() Thanks

12th August 2009, 19:02	#10
chaxy BHPian Join Date: Apr 2004 Location: hyderabad Posts: 388 Thanked: 18 Times View My Garage	the safari's too has it for the accelerator. In UV's Scorpio and Innvova too have this.
	() Thanks

12th August 2009, 22:32	#11
Trust_In_Thrust BHPian Join Date: Nov 2008 Location: New Delhi Posts: 768 Thanked: 350 Times	The palio also has DBW since its launch in india if i recall correctly which makes it the earliest in India .Also with DBW the ECU is able to get better/faster readings from the potentiometer vs the older mechanical linkage system. Last edited by Trust_In_Thrust : 12th August 2009 at 22:40.
	(1) Thanks

13th August 2009, 01:48	#12
profold BHPian Join Date: May 2009 Location: Kolkata Posts: 44 Thanked: 0 Times	Thanks for starting this thread Thanks ajaysurfs for starting this thread. I had been looking forward to it. Just jotting down some random thoughts. Thus spake wikipedia: "Drive-by-wire, DbW, by-wire, or x-by-wire technology in the automotive industry replaces the traditional mechanical and hydraulic control systems with electronic control systems using electro-mechannical actuators and human-machine interfaces such as pedal and steering feel emulators." Is the rubber-bulb honker, standard in pre-war cars which got replaced almost overnight without a whimper by electric horns, the first X-by wire victim :-)? Or the honour of the the first X-by wire should go to the "self" starter, replacing the sturdy and macho crank? Jokes aside, electronic throttle which does away with direct mechanical linkage from the accelerator pedal is a commonplace. It seems to jell well with the ECU. If we permit substitution of "replaces" by "partially replaces" in the above wikipedia definition, bits and pieces of x-by-wire is available in many modern cars, even in India . We have central locking, power windows (trivial), power steering, ABS (Brake-by-wire assist), electronic stability control. In the automotive sector, the motivation for X-by-wire appears to be flexibility in positioning the controls and better performance. In the downside, electrical systems, unlike mechanical and hydraulic systems do not degrade gracefully and have a tendency to fail without warning. A complete X-by-wire can create a very unsafe situation. Safety issues may be minor in electronic throttle as one can kill the ignition if misbehavior is suspected. But consider a full steer-by-wire. If it conks out in a highway, the lives of occupants of the concerned and other cars are in jeopardy. Cost of course is another but less grave downside. We would like to know (i) the experience of using and maintaining the various X-by-wire components in Indian cars (ii) evolution of X-by-wire application in our home-grown auto industry (iii) world-wide laws, regulations and practices which allows or disallows complete (no mechanical backup) X-by-wire features. Senior and knowledgeable TBHPians please contribute and keep this thread alive. Cheers P.S. A bit of history, possibly known by many. The term "by-wire" appears to be used first in aeroplane context as "fly-by-wire" where the mechanical or hydraulic connection between pilot joystick and the controlled surfaces were replaced by electrical connection from stick position sensors. Airbus A320 has it. our very own LCA/Tejas has it. Fly-by-wire allows reduction of weight (hence endurance with same amount of fuel) and better handling qualities. To ensure safety ALL sensor and Electronics are copied 4-times, in a fail-safe configuration so that up to two failures can be safely tolerated. We cannot possibly afford the 4-fold cost in a down-to-earth automobile. Apologies for the longish post.
	() Thanks

13th August 2009, 11:33	#14
esteem_lover Senior - BHPian Join Date: Jul 2006 Location: Madras/Py Posts: 7,556 Thanked: 513 Times View My Garage	I have literally rode my Yezdi by wire many times when the accelerator cable gets cut. Have to hold the wire & pull to accelerate and push to decelerate.
	() Thanks

13th August 2009, 12:09	#15
ajaysurfs BHPian Join Date: Sep 2006 Location: Bangalore Posts: 52 Thanked: Once	Thanks Profold. Imagine an automobile being driven by a joystick, if the DBW proponents have their way! If any system goes for a toss, god can only save. Which brings me to another observation. When i was Germany few years back, one of my colleagues (who was physically challenged) used to drive a retrofitted Golf (Automatic). Steering was as usual as with other cars (with a kind of blob for easy maneuverability), however there was a kind of joystick in pace of gear lever - when pushed forward the car used to accelerate and when pulled back it used to brake. There were no pedals to be seen. So i think in similar circumstances DBW becomes indespensable.
	() Thanks