Introduction
Before any new vehicle – whether a car, race car, tank, ship, or motorcycle, driven by gas, diesel, EV/HEV, or alternative fuels - can be launched to the market, it has to be thoroughly tested. Proving grounds or test tracks serve the automotive industry for on-road and off-road vehicle testing.
In the development process, the performance of a vehicle is put to test in a variety of environments and driving situations. Usually, test cases focus on the dynamic properties of vehicles. Safety is a priority and vehicles are often tested under extreme conditions and speeds.
Until the 1920s, automotive testing was done on city streets and country roads. Proving grounds move vehicle testing from public roads to controlled, secure, and safe testing environments while simulating a wide range of road types and events, all reflecting or relating to the customer's usage of the vehicle.
World map of automotive proving grounds
List of proving grounds by country
What is a proving ground?
Proving ground is an area where the performance of a vehicle is put to the test. Proving grounds are generally spread over large areas and roads (usually several kilometers) and facilities to assess the working of various systems and parts of the vehicle.
Mostly, proving grounds are situated far from populated areas. They maintain the maximum possible diversity in drive conditions.
Big automobile OEMs in the auto industry such as General Motors, FCA, Daimler, and several others usually have their in-house proving grounds and test centers to test their own vehicles. But there are several privately owned proving grounds where everyone can reserve their seat for testing.
Types of proving grounds
There are several different types of proving grounds, depending on the type of vehicle being tested. We can classify proving grounds as:
Aeronautical Applications
Military Applications
Automobile Testing (vehicle testing)
Marine Performance Testing
Aerospace Applications (For test-firing missiles and drones)
This article will focus on Automobile Testing and Proving Grounds.
Vehicle development and testing
Proving grounds enable and support the engineering tasks of validation or verification, inspection, and certification or homologation, and are an efficient means of qualifying the durability of vehicles and their components.
These test facilities are used to expose industry prototypes to the conditions that the final product will experience either in extremes or during its whole lifetime. They achieve this by accelerating damage accumulation rates, so failures are detectable in a short period of time.
Proving grounds are used by manufacturers of the automotive and automotive supplier industry, companies of technical monitoring, providers of engineering services, institutes and universities, as well as providers of driver safety training. Most automakers own and manage one or more proving grounds, but such services are also supplied by independent companies.
Proving grounds often encompass large and remote areas. They have a range of tracks and facilities to assess the functions of various systems of the automobile in the maximum possible diversity in drive conditions, including testing and development in:
Corrosion testing
Functional performance
NVH - Noise, Vibration, and Harshness
All proving grounds uphold a high level of discretion and security due to protect the commercial interests of their customers. Generally, public access is not permitted and the facilities are hidden from outside view.
Autonomous or driverless cars
All modern vehicles are now equipped with Advanced Driver Assistance Systems (ADAS). The development of such systems requires complex testing, including the ability to control and calculate relative positions between multiple vehicles and objects in real-time.
The next step is an autonomous vehicle that can guide itself without any human conduction. Computers take over actual driving, known as driverless cars, driving robots, self-driving cars, ADAS targets, or autonomous vehicles (AV).
Their testing has to ensure that they can drive the roads and keep people inside them as well as that outside safe. The human driver is getting out of the control loop, and new algorithms, e.g. machine learning, are introduced.
The advent of such autonomous vehicles (AVs) or connected and autonomous vehicles (CAVs) requires new proving grounds specially dedicated to self-driving cars. Traditional test tracks are transformed and adopted for highly automated or autonomous vehicle tests.
AD functions require much more intense testing and validation procedure than traditional vehicle functions. This demands a complete and consistent verification of the functional specifications. Simulations are becoming more and more relevant and proving grounds are used for verification of the simulation results.
These new testing and validation methods require redesigned and dedicated proving grounds - proving grounds that are similar enough to the real world to do a satisfactory form of testing. Vehicle dynamics testing in itself is no longer enough. Testing of vehicle environment perception capabilities and of vehicle interaction with other vehicles and the infrastructure is in demand, and communication technologies have to be tested as well.
Proving ground test tracks and facilities
Proving grounds for automobiles most often include:
High-speed tracks are specially made for the performance testing of automobiles at high speeds.
Slow lane tracks are designed to evaluate the performance of the vehicle during city driving and low-traction driving.
Off-road tracks range from second-class roads to wild terrains.
Custom tracks are specially made to impose special conditions for which a vehicle is designed.
However, no proving ground or test track is designed the same way. The most general principle adopted is to design the track to suit specific company demands, fit local conditions, and to conform to national rules.
Handling courses
Providing a variety of different curve radii, curve slopes, climbing gradients, and downhill slopes for testing the vehicle’s handling in extremely curvy situations.
Vehicle behavior
Vehicle maneuverability
Technical settings under controlled no-traffic circumstances
Comfort roads or ride tracks
Comfort road tracks simulate public road surfaces with conditions that may vary from slightly indiscrete to very severe
Comfort and vibration evaluation
Durability verification
Assessment of vehicle suspension
High-speed or highway tracks
These are often long (more than 10 km) and have smooth and banked turns and parabolic curves with an inclination of up to 50 degrees, and installations which can generate side wind. Testing is carried out at speeds of up to above 200 km/h (124 mph) depending on the car. While the vehicle is driving the tracks, these data can be obtained.
Engine performance
Coast down data
Dynamic response
Slow tracks
These may have potholes, pits, speed breakers, water pits, ambient fog, etc., Cars traveling on these tracks travel at about 10-30kmph. Tests on slow tracks yield the following data:
Endurance of body structure
Performance of suspension at low speeds
Vehicle performance in a corrosive environment.
Rough road
Rough road tracks are used to test suspension and electronics providing different road surfaces. Off-road often cross terrain ranging from mud to hill rocks.
Internal noise
Low-speed handling
Endurance of body structure
Steep or uphill tracks
Tracks with different gradients – varying from 5% to up to 30% for the testing of traction control systems and for tests on downhill braking.
Off-road tracks
Tracks are used to test off-road vehicles with all-wheel drive and differential locking.
Traction
High-grade performance
Suspension performance
Steering stability
Noise tracks
Test tracks are used for evaluating the external noise of vehicles. The shape, flatness, and sound absorption properties of the track affect how the sound propagates away from the vehicle. The ISO 10844 standard specifies the design of noise test tracks to minimize the variation of vehicle noise measurements made at different testing locations.
Pass-by noise testing
Braking tracks
Tracks with various road surfaces and friction coefficients for simulating all conceivable road conditions – some are floodable. The coefficient of friction of the track varies with different road paving.
ABS and tires development and homologation
Road driving under low grip conditions
Winter tracks
In some countries, e.g. Sweden and Norway, special tracks or proving grounds are made for testing vehicle prototypes, components, or tires in cold climate conditions.
Performance on snow and ice surfaces
Whirling snow handling
Most often proving grounds will also provide services such as engine dynamometers, low-temperature chambers, kinematics and compliance rigs, or climatic chambers.
Data acquisition and sensors
Vehicle data acquisition (DAQ) systems are used in the vehicle testing environment for measurements of vehicle performance, vehicle dynamics, vehicle durability, combustion, electric and hybrid engine testing, components testing, and more.
Such systems typically measure a wide range of parameters like temperature, pressure, velocity, voltage, current, power, loads and strains, consumption, and emissions, while monitoring the vehicle data bus such as Controller Area Network (CAN, CAN FD) channels.
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During testing, sensors are attached to various critical portions of the vehicle, such as:
Aerodynamic forces and crash forces - capacitive and resistive pressure gauges attached externally on the bonnet and tail.
Dynamic loads – accelerometers and vibrometers at suspension linkage (or) wheel hub.
Engine revolutions - tachos mounted on the crankshaft or camshaft.
Current and power – AC/DC current clamps and transducers on batteries or cabling.
Tire loads – pressure sensors in the tire.
Structural loads – strain gauges on body and frame.
Sounds - microphones mounted onboard or situated along the drive path
Vehicle statistics – onboard sensors.