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Noise Vibration Harshness (NVH) Test System

The main purpose of NVH testing is the reduction, design and quality assurance of interior and exterior vehicle noise.

AVL Approach

Acoustic treatments like hydraulic bearing, motor enclosures, etc. reduce the acoustic emissions of the chassis dynamometer. Exchangeable roller surfaces allow the simulation of real road textures. Precise road load simulation allows for a highly efficient development and trouble-shooting on the chassis dynamometer.


Benefits at a Glance

  • Extremely low noise characteristic (hydraulic bearings, acoustic insulation, etc.)
  • Simulation of real road textures by exchangeable roller surfaces.
  • Proven record of numerous installations worldwide.
  • Excellent working relationship with all major chamber suppliers.
  • Local service capability with short response time.

Technical Data

Vehicle types supported

Range from light-duty up to medium-duty vehicles 
with front wheel and/or rear wheel driven axle

The following specification shows the typical values of the product AVL ROADSIM NVH 4x4 LIGHT TRUCK and is subject to change. For more detailed information concerning this product or other products in our NVH product range please click here. Alternative technical configurations are available upon request.

 

Nominal power in motor mode (per roller)

135kW @ v≥120km/h

 

Nominal tractive force in motor mode (per roller)

4,054N @ v≤120km/h

 

Max. speed

270km/h

 

Max. axle load

3t
 

Test conditions

Environmental conditions:
Temperature: +5°C … +40°C 
Rel. humidity, not condensed: max. 95%

Noise level w/o vehicle

50dB(A) @ 100km/h(@ 1m height & 1m next to the rollers)

 


System Scope

Optional Robot Driver
The easy to install robot driver, with its control unit which is also part of the central control cabinet, represents an essential part of a vehicle test system. This robot driver makes it possible to operate the accelerator (gas) pedal, the gear shift lever of manual or automatic transmission, the brake and the clutch pedal. The system is designed to be failsafe: in case of emergency the clutch is pressed and the accelerator pedal released. Software is included for closed-loop speed control of the vehicle under test. It can be extended by a human drive style upgrade and/or a keyboy to start/stop of the vehicle.

Chassis Dynamometer
The chassis dynamometer is designed for transient testing requirements. The design has been proven by a lot of installations worldwide. It includes an AC dynamometer specifically designed for vehicle testing. An encoder mounted on the dynamometer shaft provides highly accurate speed measurement. Tractive force is measured using a load cell. It can be upgraded by a second axle for all wheel driven vehicles. The chassis dynamometer controller VECON provides the fundamental control function for transient testing modes and monitors the vehicle. Exchangeable roller surfaces allow for the simulation of real road textures. Therefore a texture copy is made on the test track and transferred to roller shells.

Optional Baseline Measurement
The optional baseline measurement includes thermocouples, temperature sensors, pressure and a speed input as well as digital I/O to cover basic vehicle measuring tasks. Those transducers are connected to AVL I/O modules, which also belong to the module baseline measurement. They are specifically designed for the demanding operating conditions of vehicle outdoor test beds and are housed in a boom box mounted on a movable cable boom, which can be positioned close to the vehicle.

Vehicle Cooling
For repeatable testing conditions, a vehicle cooling fan is used. The rotational speed of the fan is controlled. It is mounted on a support structure with four moveable rollers. This allows the fan to be aligned with the front of the vehicle eg. to cool the engine radiator. The fan control cabinet sets the speed dependent flow rate via a frequency converter.

Test System Mechanics
The test system mechanics include a suitably-sized and robustly designed vehicle restraint systems and an optional vehicle monitoring system. The vehicle position monitoring system alerts the user to any movement of the test vehicle's position. The restraint system on the front and rear of the vehicle allows high dynamic acceleration and deceleration during test runs. On a 2WD layout the wheels of the non-driven axle are firmly fixed on the floor using the wheel holding devices. The driven vehicle axle is fixed with belts as standard. Alternatively, a bar system is available.

System Integration and Start-Up Service
The system integration services contain all services for an efficient project execution from project kick-off until final acceptance. 
In addition, a pre-acceptance on AVL site and FOB packing and transport can be chosen. 
With the 'extended start up services' extension, the user is supported in reaching initial knowledge levels for optimal system operation.