vehicle engineering VARIANT SIMULATION Irrespective of benchmarking, the vehicle has to be represented as a model in the early phase of its development, 1 2 F O C U S so it can be tested in a vehicle simulation model system like AVL VSM with regard to the objectives. The data for this model may stem from various sources: from the manufacturer, from measurements made by AVL or from data provided by a supplier. The process begins by developing a catalog of technical measures together with the customer. This includes a definition of the parameter bandwidth of possible changes made to the vehicle and is usually a combination of suggestions made by AVL experts and supplied by the customer, based on the model policy and technical boundary conditions. This jointly achieved selection results in a set of measures Roll- & Friction resistance concerning the powertrain system, the chassis and the complete vehicle, which are then simulated and assessed in all variants deploying AVL VSM. In the course of the simulation, individual components, e.g. turbochargers, transmission, tires, etc., as well as the final drive ratio or the axle geometry, are varied. With regard to the engine, for example, one might decide to reduce the number of cylinders, apply the Miller cycle or vary the valve train. Even a demand-controlled oil and water pump may offer savings potential. “The electrification of the powertrain can lower CO2 emissions even further. AVL offers a broad scope of systems ranging from 12/48 volt to mild and full-hybrid propulsions and even all-electric drive systems,” Peter Schöggl explains. But it is not only the powertrain components that can be “virtually” replaced. Even the way the transmission is calibrated can be modified in order to change the gear-shifting points and optimize the engine’s load range. Equally, the vehicle’s aerodynamics, which are strongly influenced by factors such as the use of underbody covers or the engine compartment airflow, can be optimized. Further areas are thermal management including heating and cooling and the vehicle mass – from weight reduction at the component level to light-weight material substitutions at the body and doors or closures respectively. Peter Schöggl: “Every single vehicle variant (virtually) completes not only the NEDC/ WLTC cycle, but also, for example, a special ride-comfort test course. This means that we not only get to see which variant delivers the best result in terms of CO2 emissions, but also which variant does best when it comes to dynamics or agility.” Despite powerful cloud computing capabilities and the use of sophisticated algorithms, a simulation of this kind that might involve the Powertrain Vehicle mass Aerodynamic > AVL investigates all CO2 and efficiency relevant technical measures from powertrain to entire vehicle.
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