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Old 26th March 2010, 13:53   #1
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Default How is vehicle testing done?

Hi All,
Most of us at TBHP come to know about, discuss and at times, see new vehicles/launches being tested on the road and a few of us do it in the factory as well.
I think it would be good if the gurus could share their knowledge and the procedures about the methodologies of vehicle testing in India and abroad. This could also generate feedback, process improvement, CMVR rules etc. The list is endless. I understand that some information is confidential and we could avoid posting that here.

Mods, in case a similar thread exists somewhere, please merge this there or cancel this thread. Thank you.
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Old 26th March 2010, 16:07   #2
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Most of the test procedurs are all over the world the same because all manufacturers work on more markets than just the home market.

Before the testing can commence certain regulations have to be fulfilled.

For example, you can't make the front of the car lower than a certain amount because of pedestrian safety issues and there is ever changing shapes.

A lot of testin is done by computer simulation. The simulation is useful, but by far not the answer to everything.

Certain components can be tested on the bench and will be fitted to test cars when a level of satisfaction is reeached.

All components that are of structural importance will go through test and partly endurance testing.

Many materials are bing banned for different uses. For example it is not allowed to have wind screens without glass unless the screen is not a full screen impairing visibility.

Once the first prototypes are built by hand they go through all sorts of test on the manufacturers test tracks, which simulate all situations to an extreme.

Also they will be treated in the wind tunnel (not only for aerodynamic reasons) and climate chambers, where a variety of tests are condcted.

Closer to production many manufacturers take a number of cars to extreme locations suc as places in Africa, where it is extremely hot and dusty and to freezing cold Siberia to run fleets of cars with accumulated miles that often exceed one million miles in a matter of weeks. Engineers examine the cars and collected data on a daily basis.

One important test, which I think deserves mentioning is tyre testing, where the manufacturer tests the different behaviour caused ba different makes (Porsche is one company that does not take reponsibility for tyres on their cars, which they didn't approve and in Germany the law punishes drivers of Porsches that got involved in accidents not using approved tyres. Porsche approves tyres on the cars on a tyre by tyre basis).

Other than the initial crash test simulations real crash test will take place, which is usually the NCAP test. On defined impacts from the front (at currently 65kph) and sides dirver, passenger, rear passenger and pedestrian safety is determined with dummies that are packed with sensors. Each sensor gives information to determine whether it is head, chest or lower body parts injuries and the strength of those. Also the g-force deceleration is monitored, which can be deadly without hitting any solid object.

In the NCAP it is also evaluated what the problems straight after the impact mean. It must be possible to open the doors to recover occupants etc.

Cars are also being tested by daily users, but these test are more practicality tests.

This doesn't cover all tests conducted but the main safety issues. Some of these test will not be conducted everywhere and in some places other additional safety test are being conducted.

Material safety tests and a lot of the component endurance tests are usually done by component suppliers unless their is specific reasons for the manufacturer to do so.
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Old 26th March 2010, 17:40   #3
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Default What about the different categories of vehicles?

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This doesn't cover all tests conducted but the main safety issues. Some of these test will not be conducted everywhere and in some places other additional safety test are being conducted.

Material safety tests and a lot of the component endurance tests are usually done by component suppliers unless their is specific reasons for the manufacturer to do so.
Thank you for your detailed reply. So, does that mean that testing standards are more or less the same across the world? And does that apply to all types of vehicles being tested? What percentage of testing do you think these days is based on simulation and what percentage on actual on road testing??

Also waiting for inputs from Behram Dhabhar Sir and SPIKE on the discussion.
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Old 26th March 2010, 18:04   #4
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Originally Posted by n.devdath View Post
Also waiting for inputs from Behram Dhabhar Sir and SPIKE on the discussion.
This is one of the most interesting topics that both of us like discussing on, BD Sir being a professional test engineer is a sea of wealth as far as vehicle testing is concerned, I am amazed every time I go for Vehicle Testing with him, the kind of feedback/input he comes out with is truly amazing. It would be better if we categorize "Vehicle Testing" into various sub groups like Subsystems (Engine, Transmission and so on) . CMVR is also likely to yield a fruitful discussion.

Spike
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Old 26th March 2010, 18:06   #5
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Originally Posted by n.devdath View Post
Thank you for your detailed reply. So, does that mean that testing standards are more or less the same across the world? And does that apply to all types of vehicles being tested? What percentage of testing do you think these days is based on simulation and what percentage on actual on road testing??

Also waiting for inputs from Behram Dhabhar Sir and SPIKE on the discussion.
The testing standards vary and it is dependent on the market they are being sold. If you take a car like the Nano, that is not only intended to be sold on the Indian market, but all over the world, the car has to be designed to at least scrape through all test in the parts of th world they are sold at. It would be too costly to do otherwise.

If Maruti, Mahindra or anyone else does built cars with other manufacturers is because the design is tried and tested and accepted by most of the approving agencies.

One big problem market is the USA. They have many different standards in the different states.

Another scenario is cars like the Mini. The original Mini was built up to 2005. After that it was not in line with the homologation requirements for safety issues. BMW would have like to continue building the icon, but it was to expensive to re-work it. Therefore it decided on the new Mini.

Not all types of vehicles are tested to the same standards.

Till in date many places seat belts in buses and coaches aren't a requirement. The maximumum force applie to tilt a buse or coach before it exceeds a certain angle is not regulated uniformly.

Trucks in Europe have to be fitted with ABS brakes for many years even retro fitting was imposed. ABS was introduced compulsary in those countries much later. In othe countries it still is different.

Certain applications have excemptions, which sometimes makes sense in other areas it doesn't.

Cars are by far the most regulated vehicles at the moment when it comes to mass productions. Small runs of cars are excempt from the NCAP testing and the regulations are much less.
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Old 27th March 2010, 23:28   #6
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Originally Posted by SPIKE ARRESTOR View Post
This is one of the most interesting topics that both of us like discussing on, BD Sir being a professional test engineer is a sea of wealth as far as vehicle testing is concerned,Spike
All right then, lets begin with the first step. How is the Test Plan formulated for a vehicle and at what stage?? Eagerly waiting for BD sir and other Gurus.

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The testing standards vary and it is dependent on the market they are being sold.
So CPH, what are the current standards of different vehicles that are followed, say in the U.K.?
And yes, thank you for all your contribution so far. You the only one apart from SPIKE who seems to be interested. Is this topic so boring?
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Old 28th March 2010, 09:00   #7
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Dear Devdath - thank you for starting this discussion. There is so much information, I don't know where to start.

I must mention this today. Let the world know - I worked with engineers of a world class automobile manufacturing company during one of my assignments in India. The chief vehicle test engineer of the overseas company made this comment - "Mr.So and so (to my boss's boss), please send this boy to us. We will make him one of the best test engineers". Return comment? No comment. Return body language? Negative. Return action? Harassment and no promotion for 7 years. Says it all, does'nt it? This is the "kamnaseebi" of India. So, there is no point breaking your head against a wall. It is like an irrestible force striking an immovable object. The result will be destruction only. This makes me sad. As I was an employee and could do precious little about it, I learnt, quietly, quietly, quietly. All the learning is helping me today. Therefore, within the constraints of working in the automobile industry, I will try and explain whatever is possible.

The first step - a test engineer can be a good test engineer only if he works in other related departments also, the most important one being vehicle engineering. Then you look at the problem from both ends of the scale, which results in better work output. Exchanging engineers between vehicle testing and vehicle engineering is a good practice and must be adopted to get good results.

Best regards,

Behram Dhabhar
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Old 28th March 2010, 11:01   #8
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Default How are the test engineers chosen or trained?

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The first step - a test engineer can be a good test engineer only if he works in other....
Thank you Sir for your inputs. I must say, that was an act of killing youngster's potential which is dastardly to say the least. But with your determination and patience you have come a long way.

So, how are test engineers chosen? I mean are they recruited as freshers and then trained? What are they trained on and what parameters do they measure initially on those camouflaged test mules that we see running on the road?
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Old 29th March 2010, 15:26   #9
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HI, I am the organiser of an International Exhibition called Automotive Testing Expo Europe, We make manufacturers of Automotive Testing Equipments participate and showcase the latest products in the very area and I keep on seeing the best of latest technologies used to test and validate engines,suspension,gearbox,exhaust systems, vehicle dynamics etc. Although I am not an engineer but by virtue of being a car enthusiast and ofcourse a bhpian I love talking to my exhibitors about what's happening in this arm of the automotive industry which is much more essential than any other thing. You guys can log on to my website and know more about these companies. www.testing-expo.com

Mods, please do not consider this post as a spam as I am not selling or marketing anything out here.

Last edited by Berry : 29th March 2010 at 15:28. Reason: mentioned the web address.
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Old 29th March 2010, 16:08   #10
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Originally Posted by DHABHAR.BEHRAM View Post
Dear Devdath - thank you for starting this discussion. There is so much information, I don't know where to start.

I must mention this today. Let the world know - I worked with engineers of a world class automobile manufacturing company during one of my assignments in India. The chief vehicle test engineer of the overseas company made this comment - "Mr.So and so (to my boss's boss), please send this boy to us. We will make him one of the best test engineers". Return comment? No comment. Return body language? Negative. Return action? Harassment and no promotion for 7 years. Says it all, does'nt it? This is the "kamnaseebi" of India. So, there is no point breaking your head against a wall. It is like an irrestible force striking an immovable object. The result will be destruction only. This makes me sad. As I was an employee and could do precious little about it, I learnt, quietly, quietly, quietly. All the learning is helping me today. Therefore, within the constraints of working in the automobile industry, I will try and explain whatever is possible.

The first step - a test engineer can be a good test engineer only if he works in other related departments also, the most important one being vehicle engineering. Then you look at the problem from both ends of the scale, which results in better work output. Exchanging engineers between vehicle testing and vehicle engineering is a good practice and must be adopted to get good results.

Best regards,

Behram Dhabhar
Unfortunately I have to agree that your experience is neither far fetched nor unique.

It is happening all over the world. I have been subject to a similar treatment and have seen some of my friends being treated the same, which made me in this respect very tough.
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Old 29th March 2010, 16:28   #11
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Default Is this such a coveted field/job?

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It is happening all over the world. I have been subject to a similar treatment and have seen some of my friends being treated the same, which made me in this respect very tough.
Thats surprising CPH. What do you think are the reasons? Usual office politics or does this profile hold some special significance?
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Old 29th March 2010, 17:26   #12
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Thats surprising CPH. What do you think are the reasons? Usual office politics or does this profile hold some special significance?
It is partly envy, partly hatred, partly arrogance and partly selfishness.

A lot of people don't like change. It is rather comfortable not to change things even if it makes life easier and products safer.

I have this in my own work. People whome I have to deal with often hold on to old technologies that have been superceeded by new developments.

I was yesterday on a Rolling road day, where a product of mine produced 9.5% more peak power and over 14% more toque then before.

We have measured similar improvements on different rolling roads all over Britain. Most people don't understand the signifcance of air intake design calling the modifications just a piece of pipe.

They can't see the possibility of improvements.

When you show them the figures from the rolling road with graphs from brfore and after, they claim the rr is not calibrated.

If you show them rr graphs from the same cars from different rrs all over the country, they claim that I faked the figures.

You can go on and they are right.

Why? Because they want to be the ones in the lime light and be the daddies. They can't cope with it that anyone culd be promoted because they do a better job.

It is sad, but true.

Sorry, if I have burst your bubble when you think this is only happening in a few companies.

Believe me saying this: There is some bad Indians in such positions, but there is as many bad Germans, British, Americans...in other companies in the very same positions. Don't think that this is only a problem in India.

Unfortunately the good Indians, Germans, British, Americans... have to suffer because of those.

The test procedures are in place, but also envy, hatred, complacency, arrogance and self importance are in place too.
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Old 29th March 2010, 17:32   #13
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Default What about in-lab dyno figures?

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The test procedures are in place, but also envy, hatred, complacency, arrogance and self importance are in place too.
Thats bad news man, but like you said, thats probably the way it is everywhere, across industries, across countries.

On a positive note, your air intake modification resulted in the increased power and torque figures right? But prior to the rr test, you would have also tested it on an engine dyno, and that would have been done in the lab if I m not wrong. How could those figures be faked according to them?
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Old 10th April 2010, 18:38   #14
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Post Slalom and Elk Test

Slalom and Elks/Moose/Double Lane change test are all transient state handling tests, which aim to determine the transient handling response due to steering and suspension. These are definitely two of the most glamorous tests in Vehicle Testing.

Purpose-
Elk test determines the vehicle handling during fast continuous lane change maneuvers. This is a step further to single lane change maneuvers.

Slalom test aims to study Vehicle dynamics as well as the wheel packaging calculations like camber, toe changes etc. Parameters measured over here are speed, steering wheel angle, steering wheel torque, roll angle, lateral acceleration, Yaw etc.

Procedure-

Slalom Test- The vehicle is run through the designated track in a sinusoidal way in a suitable gear. Test is started with a minimum speed to get a feel of the vehicle behavior through the test track. The speed is then gradually increased in steps until maximum controllable speed is achieved. Test criteria varies for vehicles with different applications. Maximum controllable speed is measured at the end of this test.

Elk Test- Here the section width (as shown in pics) is different when compared to a Slalom test. The dimensions of the test track with lane offset are as per ISO standards. The test driver gets the vehicle to a minimum specified speed before he enters the course. Test speed can then be incremenally increased upto the maximum test speed. Maximum test speed shall be 10-30% lower than the maximum speed the vehicle can obtain. The car must be driven into the track at the maximum test speed (estimated) and the exit speed is noted at the end of the track. Over the test course the throttle position must be held as steady as possible and the gear position engaged during the test is stated in the final test report.
A successful pass through the lane-change track requires that none of the cones is displaced during the test.

Points to be noted during the tests-

1. Both these tests can be conducted in Kerb weight or GVW conditions.
2. Track surface must be dry and as hard as possible.
3. Longitudinal deviation of track shall not be more than 1 degree and Transverse deviation not more than 2 degrees
4. Wind speed must be noted and shall not exceed the specified limit.
5. Vehicle must have 'Test Tare Mass' ,this means vehicle must be equipped with all optional equipments that is likely to increase the mass of the vehicle like lubricants, coolant, fluids, fuel(90%) etc. Spare wheel, wheel chokes, tool kits if offered as a standard equipment must be included in the vehicle.
6. Before beginning the tests, vehicle dress level is thoroughly checked this includes Wheel alignment parameters, Tire Pressures, Steering angle correction (steering angle set at zero in straight ahead position) etc.

Members are requested to chip in with their comments/experiences if any with similar tests and please do correct me if I am wrong.

Spike

P.S. There are tests which also determine the steady state handling characteristics of a vehicle, namely- Constant radius test, Constant Forward speed test, Constant steer angle test.
Attached Thumbnails
How is vehicle testing done?-1.jpg  

How is vehicle testing done?-2.jpg  

How is vehicle testing done?-slalom.jpg  


Last edited by SPIKE ARRESTOR : 10th April 2010 at 18:40.
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Old 11th April 2010, 09:03   #15
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Spike: good report.

How about weaving a car and what is the max speed at which one can do it without the tyres screeching?

IMO, learning to weave a car lets one understand the behaviour of the car from handling to steering response to road grip and driver confidence.

And a slalom is done once, a lane change is half a slalom and a multiple slalom is ???
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