[dhanushs]

Originally Posted by Mpower

What if you are standing in a signal (or parked) and get hit from the front (head on) by a car that has lost control. Thats clearly a grey area..

Even then Airbags deploy. As DerAlte suggested, the deployment does not depend on the speed of the vehicle, but on the impact sensors.

[DerAlte]

Originally Posted by Mpower

... hit from the front (head on) by a car that has lost control. Thats clearly a grey area ...

No, that's not grey area at all. Airbags sensor senses G slope (magnitude v/s time graph; slope during rapid braking or acceleration is 30deg or less; impact slope is > 45deg), and it is not necessary that the vehicle has to be moving.

Originally Posted by sagarpadaki

... Passenger Airbag switch on the dashboard is on(Passenger airbag active) but there is no passenger in the seat.Car gets involved in head on collision at reasonable speed high enough to deploy airbags.Do the passenger airbags deploy?

Yes, unless there is a weight sensor signal preventing the firing.

Originally Posted by sagarpadaki

... Only he was in the car when he met with the collision.And all the 6(8??) airbags-front,side,curtain deployed... I repeat it was a straight head on collision. ...

No fault. Can happen if the impact direction, even though in simple language "head on", is diagonal (draw a line from center of bonnet to rear headlamp; can happen when on of the cars is taking evasive action) - tending to spin the car. If the impact is hard enough, all airbags will deploy, and the car would have most likely spun.

[drsnt]

Originally Posted by supremeBaleno

How old is your kid? My 3-yr old son also would not agree to sit in the rear which was an issue with our Swift-Zxi having airbags - we are to blame since we should have inculcated the habit from when he was small.

Anyway, one day I decided to have a father-to-son talk with him while driving home and told him about how it is dangerous for him to be seated in the front. Since he wont understand airbags, I told him that in case of an accident, the front glass would break and injure him. He was silent and seemed to digest this information.

I had almost thought I succeeded in convincing him, when he pipes up, "But won't the glass pieces hit you, Daddy, since you are also seated in the front ?"

Logical, right ? I am asking him to be seated in the rear, while I sit in the front exposed to dangerous shrapnel. Unsure how to counter this logic, I tell him that I have no option but to sit in front since I have to drive the car.

Anyway, that worked and today when we go out, he insists on sitting in the rear. The problem now is wifey, who feels sad that kiddo is alone/ignored in the backseat while we sit in the front. I tell her that she can join him in the rear - problem solved.

My daughter is also 31/2 yrs old. the problem is that her mother is not there 90% of times and it's her and me alone in car and the kid does not go in back. but I never drive on highways with her in front. most of the time her mother would be there and they both would sit in back and I drive sitting alone in front and I have made this compulsory from day one that they both sit in back on highways.

I also drive very very slow approx 30-40 kmph max when she is standing in front and as I live in Bokaro Steel City the traffic is very less and roads good, travel is normally short distance of 1-2 km.

I was planning a upgrade and so I have thought of this few times as to Airbag causing injury to child so I put forth the question to forum.

I see that the discussion has shifted to general procedures for airbag operation. I request if anyone could give me exact details of models below 8 lacs how their airbags are activated/deactivated. People from Industry can help in this aspect.

i20 Asta
Punto/Linea Em Pk
Figo Titanium
dezire ZDi

[carboy]

Originally Posted by drsnt

thankx everyone, now my next question is what should I do if my child only travels in front seat?

Get a babysitter & let her be at home.

[DerAlte]

@drsnt, as long as you drive carefully and control speed so as not to reach a situation of frontal impact, it is OK if the child is in the front seat in a child seat sometimes. I admit this is technically wrong advice, but perhaps in the towns where you drive it is easier to drive slow and count on providence to avoid accidents.

Does not obviate the fact that you have to develop nerves of steel to overcome your emotions at seeing the child throwing tantrums (get angry at the situation and make mistakes in controlling the car). There have been times when I have had to allow my infant daughter to cry herself hoarse and learn that she cannot get what she wants always. Constantly talking to her (and sometimes the promise of goodies) used to calm her down gradually. Never used a DVD player for her, but I believe that can provide a diversion.

Airbags are activated in the same way in all cars - whether less than or more than 8lacs. As we have discussed in this thread, the passenger side airbag can be disabled, whether by a key (watch out for those times when your wife is in the passenger seat and the key is set to Passenger Airbag = OFF), or by virtue of weight sensor.

[Mpower]

OK guys. What if

1. Ignition is OFF with people seated in car (either parked or waiting at signal)
2. Like someone said Vento bags wont fire below x kmph (even though actual trigger is from g sensor). At the end of the day each vehicle can be calibrated differently even though they are using identical hardware and software. Thats what I meant by grey area

Originally Posted by dhanushs

Even then Airbags deploy. As DerAlte suggested, the deployment does not depend on the speed of the vehicle, but on the impact sensors.

Originally Posted by DerAlte

No, that's not grey area at all. Airbags sensor senses G slope (magnitude v/s time graph; slope during rapid braking or acceleration is 30deg or less; impact slope is > 45deg), and it is not necessary that the vehicle has to be moving.

[jigbarai]

Ok, not all cars have passenger side deactivation built in. By 'default' it is set to deploy both in any eventuality.

Does it make sense to 'add' a manual switch for controlling the passenger side airbag here when cars dont come with them by default ?

[supremeBaleno]

Does the Swift-Zxi have this airbags-deactivation switch ? I don't remember reading about one in the manual - so believe it is not there. Not that I want to deactivate it in our car, but just curious.

[DerAlte]

Originally Posted by Mpower

... What if

1. Ignition is OFF with people seated in car (either parked or waiting at signal)
2. Like someone said Vento bags wont fire below x kmph (even though actual trigger is from g sensor). At the end of the day each vehicle can be calibrated differently even though they are using identical hardware and software. Thats what I meant by grey area

1. No it won't deploy if key is in 1st position (Ignition Off). With engine off but key ON (2nd position; Ignition On) it will. Always better to keep the key in Ignition On position while waiting at signal with engine off.

2. Vento airbags (Bosch) will deploy even at vehicle speed = 0 (I am sure whoever said that has never tested it), and I think it is the same with airbags of any make. Safety outweighs any other consideration, and airbag manufacturers don't keep a minimum speed consideration just so that replacement cost is avoided.

Originally Posted by jigbarai

... Does it make sense to 'add' a manual switch for controlling the passenger side airbag here when cars dont come with them by default ?

No, it doesn't make sense at all. What will happen if you have a passenger and have forgotten to flip the switch you added? In developed countries, in accident cases Insurance checks if the owner of the vehicle has in any way tampered with / disabled the (OE) Safety equipment; if true, the owner is held responsible and has to pay.

[Udayrg]

An air bag is inflated when the inflater triggers and the inflater triger signal is controlled by the ECU The ECU needs to get minimum two and now days numerous inputs in the form of signals for the sources like

1) Accelerometer - Which detect the deaccelartion rate..

2) Inpact sensors ( Frontal collision, Side Impact & Roll over.......)

3) Occupant in position ( Detections of occupant by various sensors)

4) Vehical engine input

Now many complex inputs are being coded to make the air bag deployment foolproof

However there might be chance of missing firing because again all these signal inputs

are compared to a algorithm which sits in ECU now every manufacturer has his own

Setups in the algorithm which cannot be 100% true for every probability. But

Companies are trying to make the best they can do.....

Air bag can avert fatal injuries to Head Chest ( Thoraic Cavity) when used in proper

restrained System viz Seat belts ( SRS Air bags (Suplimentary restraint System))


Uday

[harikr]

Hello All,
Being working with Airbag systems for quite some time, i think i can throw some light on to this subject. The airbag system ideally consists of the following components:

1. Airbags (Driver, Passenger, Side, Curtain, Knee etc...)
2. ACU (Airbag control Unit, or Airbag ECU)
3. Seat Belt Pretensioners
4. Impact Sensors
5. Seat Position sensors
6. Weight Sensors
7. Buckle sensors

PS: This is a sort of theroetical explanation. So Sorry for writing long paragraphs.

Airbags can be single stage or dual stage. The low end vehicles are normally having the single stage. That means, what ever be the level of impact or whoever be the person sitting in the vehicle, it will deploy to its full. (Level of impact should be above the threshold of the impact, which varies from vehicle to vehicle). The dual stage airbag fires in two stages depending on the impact level as well as the condition of the passenger inside. The airbag module consists of the nylon bag, then an igniter and the chemicals which react to give the gas. Normally Sodium Acetate and Pottassium Nitrate (which is a class II explosive) are used to give nitrogen gas which fills the bag in case of a deployment. Presence of Pottassium nitrate makes the module a dangerous thing to handle unless trained. That is why it is always recommended not to repair or handle airbag modules by youreself.

Seat belt pretensioners are used to pull you back and hold you to the seat to a certain extend in case of an impact. It removes the slackness of the seat belt. And as per my knowledge, it is system requirement that all air bag equipped vehicles will have a pretensioner also. In case of an impact, the pretensioner is activated first.

ACU controls the whole airbag system. In low end models, the impact sensor will be located only inside the ACU. There need not be dedicated sensors in the front or side of the vehicle. The sensor inside is basically an accelerometer which detects the impact and if the impact passes a certain threshold value, it will send the deploy signal to the seat belt pretensioner followed by the airbag module.

Impact sensors are normally not provided on low end models with airbag as it increases cost. These are located on the front side of the vehicle and side of the vehicle if it has a curtain or side airbag. Again these are accelerometers which are impact rated.

Seat position sensors and weight sensors combined will give the system an idea about the person sitting on the seat. Position and weight sensors together will identify if a child is sitting on the seat or if an adult is sitting.
These sensors are calibrated for the standard average weights of persons around the world and it varies from market to market.

Buckle sensors are small switches inside the seat belt buckle which will sense the condition of the seat belt. As already mentioned in the discussion, previously the idea was that the airbag should not be deployed in case the seat belt is not worn as it can be disastrous. But now with the introduction of multi stage airbags, the airbags will fire even if the seat belt is not worn, but with a lesser deployment force.


Now coming to the topic, in most vehicles coming in India at the entry level are having only the ACU, Driver and passenger airbags (Single stage) and seat belt pretensioner. As such in India, there are no regulations which mandates the use of seat position, weight sensors, and bucle swithes. But these are mandatory in US market. In India some vehicle are providing the switch for passenger airbag which facilitates manually turning off that particular airbag. So if the vehicle doesnt have a switch and it doesnt have a buckle switch or seat position sensor or seat weight sensor, all the airbags will deploy in case of an impact.

Now coming to child seats, and seating of children in vehicle which doesnt have any such disabling options, it is always recommended to have the children sitting on the rear seats. This is because in case of an impact, if the airbag is deployed, the airbag will hit the child directly on the head and mostly due to the small height of the child, will press him down to the seat. The force with which the airbag opens is too high and if it doesnt hit you in a proper intended way, it will prove disastrous.

Finally all of you should have seen the words SRS written over the airbag modules in the vehicles. It means Supplimentary Restrain System (sometimes referred as Secondary Restrain System) and the primary restrain system is the seat belt. So the SRS will not help you if you have not using the PRS ideally.


Thanks and regards,

Harikrishnan.

[harikr]

Hi, Sorry, i left one point. Regarding addition of a switch for turning off the airbag.
You cannot just cut the wire and add a switch as we do in case of normal electric circuits. The ACU is continuosly checking for the presence of an airbag module in the circuit and if at an point we remove it from circuit, it will give you an error (normally the tell-tale lamp on the cluster will turn on) and you will have to reflash the ACU to remove the error. Then the question is How do the companies add a switch? So basically the ACU looks for the resistance of the airbag module connected. In case of company provided switches, the circuit is remapped when we switch off the airbag module which replaces the airbag module with an electrical resistor having the same resistance as the airbag module. So the ACU thinks that airbag module is there and in case of an impact, it gives the deployment signal to the resistor also.

Now, is it possible to add the resistor as a DIY? I will say no as the resistance of airbag modules varies from model to model and it is difficult to get that value, unless given by the company. We cannot measure it using a normal multimeter because the multimeters usually pass some electric current through the circuit to calculate the resistance. Even though this is a small current it can initiate the spark in the igniter and can deploy the airbag. Hope this clarifies the last query also.

Thanks and Regards,
Harikrishnan

[Mpower]

Originally Posted by DerAlte

Safety outweighs any other consideration, and airbag manufacturers don't keep a minimum speed consideration just so that replacement cost is avoided.

I agree and wonder if there is a Govt mandate (Euro NCAP?) that requires and enforces the same.

Originally Posted by DerAlte

No, it doesn't make sense at all. What will happen if you have a passenger and have forgotten to flip the switch you added?

Seen some single cab pickup trucks with key operated switch to turn off the pass airbag in case you had to put an infant in that seat.

[DerAlte]

Originally Posted by Mpower

... Govt mandate (Euro NCAP?) that requires and enforces the same. ...

By and large it is self-regulated by the manufacturers. Internal Design review by multi-functional teams review this.

Originally Posted by Mpower

Seen some single cab pickup trucks with key operated switch to turn off the pass airbag in case you had to put an infant in that seat.

Sure, even Volvo cars have the same - the switch being cheaper than weight sensor. Problem is, onus is on the driver to keep it in the correct position depending on whether there is a front-seat passenger or not.

[saurabhdadhichi]

Is there a way to switch off the passenger side Airbag of new Maruti Swift? I am buying ZDI and have a kiddo just 1.5 years old, so would like to look at the possibility of switching off the passenger side airbag.