Testing of an automobile vehicle is much needed for the passage safety and for the better condition of the vehicle. A vehicle has a lot of complex equipment to run and function on the road. So, each of these equipment needs to be cleaned and maintained from time to time. In this article, I will discuss the factors one should keep for laboratory and road testing of an automobile vehicle.
Testing of an Automobile Vehicle
Testing an automobile vehicle is a crucial step in ensuring its safety, performance, and compliance with regulatory standards. The testing process typically involves a combination of laboratory tests, simulations, and on-road evaluations.
The motor vehicles are tested both in the laboratory on the bed test as well as on the road in the actual conditions of running. In this article, I will discuss these two factors.
Laboratory Testing of an Automobile Vehicle
In the laboratory, the motor vehicles and the engines are not only checked for their rated power outputs but final adjustments are also made in different components as well and tests are carried out to check up fuel consumption, acceleration, freedom from vibration, leaks, and other items necessary for the acceptable running of an automobile and engine.
In the laboratory, in any road testing of automobiles and engines, a large number of testing instruments and components are used. Tachometer, cylinder compression, and leakage testers, engine vacuum gauge, exhaust gas analyzer, fuel mileage, and fuel pump testers, flexiscope, ignition timing, electric checks, chassis dynamometer, etc.
A laboratory test bed consists of :
- A dynamometer testing equipment coupled to the engine is driven by it. It absorbs and measures the engine output.
- A carbon shaft or a flexible drive to connect the dynamometer to the engine.
- An adjustable engine stand or cradle.
- Running in equipment usually as separate motor
- A control station for providing necessary control levers and instruments for the engine as well as test data record or writing space.
- Fuel supply equipment includes a device for measuring the fuel consumption of the engine.
- Equipment for exhaust gas disposal, water piping to and from the engine and dynamometer, engine lifting blocks accessories.
Tests carried out in a laboratory include speed testing, cylinder compression, leakage test, engine vacuum test, exhaust gas analysis, flexiscope tests, ignition timing test, and electrical checks like testing of the battery, generator, regulator, cranking motor, and igniting system, engine tune-up.
These tests record the power given off by the road wheels as well as provide a true indication of the ultimate performance. By providing a rocking motion to the whole structure by a cam-roller rig, body creaks are diagnosed and rectified statically.
Road Testing of an Automobile Vehicle
A new vehicle is tested on the road in the actual running conditions and environments. Road testing consists of two types of tests, i.e. production and development tests which are complementary to each other. The main purpose of a production test is to maintain a good standard of the automobile and take care to ensure that the finished products leave the factory in good standard conditions.
For this purpose, a test route adjacent to the factory is mapped. The distance run varies considerably to the type of the vehicle under test. The road testing which is, in general, an inspection procedure should be as simple as possible.
A report sheet in the form of a questionnaire is provided for each component from the radiator to the rear axle. There are, in general, two tests first run performed by rough testers and the final run performed by experienced and technically capable persons after proper rectification.
The development tests carried out by the research and development department are necessitated to put the ideas of the designer into practice for producing a vehicle to provides trouble-free service in different environments. These tests include a wide range of exhaustive tri a ls carried out over a prolonged period. The development tests are generally performed on the prototype of certain vehicles. There are, in general, the following types of tests performed in this category :
- Performance test- Preliminary tests, air resistance, maximum speed, acceleration tests, etc.
- Fuel consumption test- Constant speed consumption, overall consumption, mixture strength, cold start tests, etc.
- Cooling system tests- Radiator, cooling design, correct speed for fan and water pump, thermostatic control, fan design, and ventilation.
- Brake test- Brake performance tests, fade test, recovery test, racing conditions tests, brake drum temperature recording, drum ventilation, and lining wear.
- Steering and suspension tests- Roll and altitude angles, turning effort, shock absorber settings, tests on rough surfaces, and stresses in the structure.
- Noise problem test.
- Dust sealing.
- Final tests.
Accessory testing- lighting equipment, radio, heater, screen wipers, etc.
Road Test for Steering
Road testing is carried out to find the following factors-
- Tire pressure.
- Conditions of Tires.
- Wheel lock.
- Castor, right or left.
- Camber, left or right.
- Toe in.
- Worn joints in the steering linkage.
- Brake adjustment.
- Brake drag.
- Spring clips.
- Shackles in good order.
- The spring chamber is correct.
- Steering gear mounting light.
- Steering gear in mid-position when wheels are straight ahead.
- Out of round brake drums.
- Wheel balance, run out, and bearing adjustment correct.
- Axle location correct, front or rear.
- Distorted rear axle housing, right or left.
- Bent frame.
It’s important to note that testing is an iterative process, and manufacturers often go through multiple rounds of testing to identify and address any issues that may arise. Additionally, testing procedures may vary depending on the type of vehicle (e.g., conventional, electric, autonomous) and regional regulations.
Frequently Asked Questions(FAQ’S)
How are emissions tested in automobiles?
Emissions testing involves measuring exhaust emissions to ensure compliance with environmental standards and regulations.
How are manufacturing defects addressed during testing?
Quality control checks are conducted to identify and rectify manufacturing defects, ensuring that vehicles meet high-quality standards.
Are there specific tests for electric vehicles (EVs)?
Yes, EVs undergo tests specific to electric propulsion systems, battery management, and charging systems to ensure their reliability and performance.