For testing the complete vehicle, ATESTEO uses a dynamometer and our own proving grounds, where driving dynamics, noise tests, and fuel consumption tests are conducted. Tests of individual assemblies such as transmissions or axle drives are possible without separating them from the rest of the vehicle. Vehicles are subjected to loads on the dynamometer with street loads or constant loads, over a longer period of time as well. This enables endurance and durability testing. Noise testing is conducted on both the dynamometer and the test track. The test track is certified in accordance with DIN ISO 362 und ECE R 51 for PBN testing. Fuel consumption and fuel economy tests take place on the dynamometer.
Acoustics measurements, vehicle interior noise, torsion vibrations
An essential criterion during evaluation of a vehicle is vibration and noise behaviour. The effects of vibrational behaviour of individual drivetrain components on interior noise can only be assessed in the complete vehicle. This is accomplished by various airborne noise measurements in the passenger compartment; for example, with arrays of microphones. Comparative airborne and structure-borne sound measurements between the passenger and engine compartments offer the precondition for determining how sound is transferred. To do this, we employ measurement and analyse tools from HEAD acoustics. The torsional behaviour of the drivetrain; such as, for example, stiffness, play, and resonance, is investigated with the help of a system from the company Rotec which has been designed especially for this purpose. A test track and an acoustic dynamometer (roller test bench) (certified in accordance with DIN 45635 class 1) are available at ATESTEO for this longitudinal dynamics investigation.
Driving dynamics testing
Driving dynamics investigations into the longitudinal dynamics of a vehicle are carried out at ATESTEO on a dynamometer. During testing, a load test program is implemented as a test bench control program. Typical load test programs are testing programs of the automotive and automotive supply manufacturers that are exactly simulated at ATESTEO. The dynamometer is set up for the load with the rolling resistance characteristic curve for the vehicle to be tested and a total weight specified for the testing run. The vehicle may be operated by any actuator, or driving robot. The process implemented in the test bench control program regulates the speed at which the vehicle is to travel over time and, in the case of manual transmission vehicles, also controls the stipulated shifting points based on the engine speed. For guaranteed reliability of the test run, motor oil checks and visible inspection of the transmission, axle differential, and tires are carried out. The stipulated measurement values are displayed during the test run on the screen of the measurement data monitoring system and are monitored during the entire run time of the vehicle by a test bench computer. In addition, the test bench is monitored by operating personnel.
Fuel consumption and fuel economy measurements
ATESTEO measures fuel consumption on the dynamometer. This assures constant investigations under the same conditions. The dynamometer is adjusted to the load with the rolling resistance characteristic curve for the vehicle to be tested and a total weight stipulated for the test run. The dynamometer is subsequently corrected to the data required for the vehicle’s rolling load by an adjustment run. All usual drive cycles used worldwide can be simulated as a test program. The cycle program is shown during the test on a computer monitor. This monitor displays the speed to be driven by the vehicle over time. The driver reconstructs this speed profile. Consumption within the speed profile is recorded using a flow meter DFL 2 to measure fuel consumption. The measured data is analysed for the European drive cycle (NEDC, New European Driving Cycle) for three areas of consumption: urban traffic, extra-urban traffic, and combined consumption.
Pass-by noise measurements in accordance with DIN ISO 362
On our own in-house test track at the ATESTEO corporate proving grounds in Alsdorf, Germany, which is protected from view, we conduct pass-by noise (PBN) measurements while the vehicle is driving past under acceleration similarly to DIN ISO 362 in accordance with the new guideline R 51. During measurements for vehicles from passenger cars to heavy-duty vehicles, noise levels are measured at both sides at the track while the vehicle drives by.