Before launch, a vehicle needs to undergo several tests. One of the tests provides the results similar to conducting a four-hour, 1,000 km road test. And, there are several such tests before an automobile is available for you to buy. In every country, vehicles need to comply with local rules and regulations and undergo tests. These tests are aimed at ensuring quality and functionality before they are available in the market.
The performance test is conducted in test tracks to evaluate acceleration, top speed, braking power, high-speed handling etc. The main test tracks in India are at the Vehicles Research and Development Establishment (VRDE) in Ahmednagar and at the National Automotive Test Tracks (NATRAX) in Indore. At the Indore track, vehicles can be tested at 350 kmph, the fastest track in the country. The daily rent for the track begins from Rs 50,000 and goes up to lakhs. Apart from the 0-100 kmph acceleration, tests are also conducted for 0-60, 0-150, 30-80, and 60-100 in different gears according to requirement. Such tests are also conducted whenever a vehicle's engine/motor is upgraded.
Coast down test
Coast down testing is the process of accelerating a vehicle to a high speed (above 100 kmph) and coasting in neutral down to a standstill to understand the time taken and distance covered. It would be done on a flat, straight track. The coast down test aims to find the impact of frictional forces like air resistance, rolling resistance and others while on the move on a road.
Besides this, there are tracks conducting comprehensive testing to evaluate brakes, steering and suspension, among others. Oval tracks are used for high-speed tests. Oval tracks often have banked corners (inclination done on the edges of the road) that prevent skidding at high speeds.
Brakes, steering and suspension are tested on the flat tracks of vehicle dynamics area that is similar to the size of a stadium. Though each manufacturer has its own procedures some companies carry out tests based on the guidelines issued by associations like the Society of Automotive Engineers.
NVH (noise, vibration & harshness) test
The responsibility of NVH engineers of modern day do not end at ensuring a quiet cabin. They fix hundreds of sensors on the chassis and the body of the vehicle, do their frequency mapping and analyse every possible vibration. Through this they understand how vibration and noise from the engine and the road enter the cabin and find necessary solutions. They fix microphones inside the vehicle to assess the level of noise and vibration at different situations and design NVH pads to eliminate them.
To alert pedestrians, electric vehicles need to make some sound as per law in several foreign countries (Hyundai Kona has this warning sound). This artificial sound is provided by NVH engineers. The pass-by test conducted to check vehicle noise emissions by placing microphones a few meters away from the road is also part of this.
Road load data acquisition test
The road load data acquisition (RLDA) test is conducted to analyse the load on components like suspension and chassis. For this, the engineers fix sensors like strain gauges and accelerometers to the above-mentioned components and run the vehicle on good as well as bad roads. These sensors help understand the impact on these components when the vehicle falls in various types of potholes. Through this, the manufacturers can decide to reduce the size of components where the stress is less and thus slash vehicle weight. In the virtual world, the load cycle necessary to carry out simulation of vehicle components is generated through RLDA tests.
Durability tests help manufacturers gauge the lifespan of a vehicle and its components.
a) General durability
Vehicle durability testing involves driving the vehicle subjecting it to inputs similar to those that would normally be encountered during its expected lifespan. It is easy to find photographs and videos of camouflaged vehicles on highways and other roads. They could mostly be vehicles undergoing durability tests. They would be tested on actual roads and could take six months to a year to complete. Most times, these vehicles complete more than a lakh kilometres during the test.
b) Accelerated durability test
Accelerated durability tests are designed to quantify the problems that could come up in 10-15 years of the vehicle by testing at a higher stress level to accelerate the occurrence of failure in just three months. These tests are conducted on specially set up tracks that are designed to contain a variety of surfaces including bumps, cobblestones, resonance and undulating roads, etc. A four-hour drive on these tracks would be equal to driving a 1,000 km on normal roads. This test would help to considerably reduce the time required to develop a vehicle.
C) Rig and lab tests
A vehicle is tested inside a lab using its facilities without even driving it. The vehicle is lifted on a lift similar to that of a workshop. Then, using electromechanical actuators, bounce, roll and pitch motions are generated. The highlight is that tests can be carried out without even taking the vehicle out.
Multi Axis Shaking Table or MAST is a dynamic system designed to perform system level research and development tests. (System level means a group of components that need to function together, for e.g., dashboard, seats). The MAST system moves up, down and sideways in very high frequency. MAST can help avoid testing the whole vehicle for small components. MAST can also analyse the functioning of seat cushions, doors and switches. There are equipment designed to detect the problems that could arise in years in various components. Within days, 10-15 years' use could be simulated.
Fuel efficiency is one of the most appealing part of a vehicle. It is tested in two ways by manufacturers.
Dyno test: This is done by running the vehicle on roller in the lab. During the test the vehicle will be stationary but the tyres will roll. Several road conditions are easily simulated in this method. Vehicles that are of highly secretive nature can be tested on the roads of Mumbai and Chennai without bringing them out of the manufacturing plants with the help of this system. The ARAI mileage usually shown in car advertisements is generated by such dyno tests. These tests are the localised version of the New European Driving Cycle (NEDC). In cycles that last 1,180 seconds, city and highway situations a vehicle has to negotiate will be created in the lab.
These are the tests conducted on the roads. The vehicle is run on city, highway and rural areas. Sometimes, rival companies' vehicles in the same segment are taken along during such tests for comparisons. The fuel tank will be full when the test starts and when it ends, the distance covered and fuel used are measured to arrive at fuel efficiency. The use of fuel flow meter that can accurately monitor the flow of fuel to the engine increases the efficiency of the test.
People of all heights should be able to get in and out of vehicles. Ergonomic tests are conducted to ensure that. Dummies of several sizes and body structure are used for the tests. These dummies are known as mannequins.
Overheating of engine/electric motors could lead to vehicle damage. The tests conducted to study the cooling system in the vehicle are known as cooling trials. They need to ensure that the vehicle won't suffer any damage in the worst of the situations. For that, the vehicle is run for hours in areas that have extremely hot weather, at high speeds, uphill and with excess load. These tests can be conducted on chassis dynos too.
AC/ Demister tests
These tests are carried out to check the functioning of the air conditioner and related components. The tests that include finding the time taken to cool down the cabin after the vehicle is parked under 50 degrees Centigrade in bumper-to-bumper traffic do not necessarily be done on the roads. These tests can be done in modern climatic chambers that can recreate such climatic conditions.
The corrosion test can recreate the rusting that could happen in vehicle in 10 or 15 years. Salt is sprayed in a sweltering room to gauge the lifespan of the vehicle's body.
These tests are held before the vehicle is launched. Indian regulations are known as central motor vehicle rules and are categorised as per the use, size and weight of the vehicle. The rules change as per the category. While two-wheelers and three-wheelers come under the L1 to L5 category, passenger vehicles with four or more tyres are in M1, M2 or M3 categories and commercial vehicles in N1 and N2. The M1 group under which passenger vehicles come has the strictest rules. Here is a look at the main regulatory tests:
This is one of the main regulatory tests. The emission control norms for automobiles came into force in India in 2000. The Bharat Stage or BS emission norms are based on the European emission standards. The tests are conducted by running the vehicle on a dyno meter in a lab. All the fumes produced by the vehicles are collected and the share of carbon monoxide, nitrogen oxide, hydro carbon and particulate matters are measured to arrive at a result. The tests are mainly conducted at the ARAI facility in Pune and VRDE in Ahmednagar. Since the amount of fuel used is also studied, fuel efficiency too can be found in the tests.
A group of extremely important tests comes under this category of tests. Most important among them is the crash test. They include the frontal offset test that simulates a head-on crash with another vehicle at 56 kmph, side impact test at 50 kmph and a pedestrian test that analyses the injuries a person could suffer when the car hits him or her. The crash tests are very expensive; facilities like the ARAI charge around Rs 10 lakh to carry out a frontal offset test. Other safety tests include the seat belt anchorage tests to determine the functionality of seat belts, seat anchorage tests to check how strongly the seats have been fixed to the body, luggage impact test to check if the luggage will enter the cabin from the boot in an accident and tests to assess the functionality of the inside and outside mirrors. Electromagnetic compatibility tests ensure that electromagnetic waves do not affect the functioning of the vehicle. All these tests are conducted inside labs.
Apart from these tests, there are several other major and minor regulatory tests that a vehicle needs to clear in order to be allowed to be sold in the market. And, all these tests have to be carried out in a government-approved facility like the ARAI. The CMVR tests of an M1 category vehicle will alone cost Rs 1.2 crore in fees.
Once production starts, several quality tests are held in the factories. Before they hit the market, most companies make 100-200 vehicles for field evaluation and they are known as field evaluation units. This is aimed at ensuring the functionality of the manufacturing plant. These vehicles are given to company staffers and help detect any deficiencies during the manufacturing process. These vehicles are usually run for 1,000 km to 10,000 km and often sold off to staffers at a reduced price or used for company purpose.
Most manufacturing plants have smaller tracks behind them. The vehicles are run on these tracks to check for any unusual sounds. If any defects are spotted, the examiners have to bring the vehicle to rework areas and ensure that quality standards are maintained. In short, testing is a long-drawn process right from design till the vehicle reaches the customer. Vehicles undergo around 1,000 small or big tests before they hit the market. However, only a few of the important tests have been mentioned above.
About 20 to 30% of costs of developing a vehicle goes into testing its components. Even if issues are spotted during tests, due to time and financial constraints, the company may not be able to fix all the problems. The companies may not be able to examine all the thousands of components that come from hundreds of small manufacturing units individually and ensure that quality standards are met. This is the reason why issues crop up even in modern vehicles.