Consumption & driving performance: Precise predictions and analyses
Consumption and driving performance are crucial target values in vehicle development. Along with the main theme of pollution emissions, the vehicle’s fuel or energy consumption is therefore a key aspect of powertrain development. The tightened standards which impose strict limits on the CO2 emissions of fleet vehicles must be complied with as must the EU directives on emissions. At the same time there are other important factors that need to be considered in addition to reducing the fossil fuels consumed by conventional powertrains. Lowering the energy consumption of new powertrain systems in order to increase the range of electric vehicles, for example, is another key development goal.
Predicting fuel and energy consumption at the start of the development process plays a central role in powertrain development. In later development stages the focus is increasingly on the analysis of the actual consumption values.
As the second essential target value in vehicle development, driving performance has a major effect on the driving experience. It is therefore the key to achieving as high a level of customer acceptance as possible and to sparking driver enthusiasm for the vehicle as inspired by its powertrain. This is an important factor in the commercial success of the vehicle, regardless of the powertrain concept you have selected.
With virtual test driving, we offer you a test method that pays off for you at every stage of the development process, both for the analysis and optimization of consumption and for your vehicle’s driving performance. The CarMaker product family helps you to predict all relevant values at an early development phase through simulation alone as well as analyze these values in a virtual test run on the test bench at a later stage of development.
Realistic consumption forecasts in the early development phases
The energy consumption of vehicles depends not just on the powertrain and its efficiency but on many other factors as well. These factors necessitate an examination of the whole vehicle. All the driving resistances that arise in real test runs in the whole vehicle and the consumption by additional and auxiliary equipment, such as the heating or air conditioning systems, the infotainment systems as well as the propulsion efficiency have a major effect on consumption.
With our simulation solutions, consumption forecasts which take into account the whole vehicle along with all driving resistances, powertrain configurations and the operating strategy can be made in the early development phases.
At the same time tests can be carried out at negligible cost, both in the conventional and new standard driving cycles as well as in real test runs.
How we use virtual test driving to support you in simulation-based consumption tests:
- Use CarMaker, TruckMaker and MotorcycleMaker to calculate your vehicle’s consumption in conventional and new standard driving cycles as well as in real-world driving
- Our simulation solutions can be used to analyze the energy requirements of auxiliary equipment and assess individual modifications in the whole vehicle
- Numerous model interfaces make it possible to incorporate detailed mechanical and thermal models
- Thanks to the environment model, you can simulate all environmental boundary conditions such as temperature, air pressure, wind or sunlight in the virtual test run
- Test predictive systems with the CarMaker product family and use the parameterizable model environment for operating strategy analyses of hybrid and battery electric vehicles
Assess driving performance in real-world driving situations at an early stage
The vehicle’s driving performance defines the level of enthusiasm that can be generated in the client and is therefore always incorporated into assessments – either directly from the clients or in the form of test reports. Impressive driving performance will enable you to create an optimal driving experience, thereby arousing the emotion that is often a decisive factor in the client’s decision to purchase a vehicle.
Factors in driving performance, such as acceleration, responsiveness and maximum speed or the average lap time achievable on test and race tracks, are in fact key elements in the design concept and assessment in the most diverse of driving situations.
With virtual test driving, we offer you the possibility of predicting driving performance at an early stage, enabling you to devise your development processes efficiently.
How we use virtual test driving to support you in reaching your development goals in the field of driving performance:
- CarMaker, TruckMaker and MotorcycleMaker make it possible to effectively test the powertrain or whole vehicle concept, taking into account all relevant boundary conditions
- The longitudinal and lateral dynamics of the vehicle can be assessed at the same time
- Analyze the effects of the control system on the vehicle’s driving performance
- Conventional driving performance specifications and driving performance in real-world driving situations as well as lap times and gradability can be reliably assessed
- The intuitive comparison of vehicle concepts as well as the comparison of the effects of different individual modifications can be carried out easily
Determine real-world consumption and driving performance on the powertrain and whole vehicle test bench
Our simulation solutions and test systems help you carry out real test runs, enabling you to take reproducible, real-world consumption measurements on the powertrain test bench and the whole vehicle test bench. In this process, the entire real powertrain of the vehicle is integrated on the test bench directly into our CarMaker simulation environment and is therefore subjected to the loads that arise during a real test run. To this end we connect individual load machines to the vehicle’s wheel hubs on the powertrain test benches, whereas on roller test benches or flat belt test benches, loads are fed in through the tires of the vehicle, just as they are on the road. The test bench interface which we have developed for the particular requirements of operating on powertrain and whole vehicle test beds is an integrated part of the TestBed product line. Our solution is available for new test beds as well as for an upgrade of your existing test beds.
Benefit from the combined advantages of simulation and test bench tests with our model-based testing approach:
- Thanks to “powertrain-in-the-loop” with CarMaker or TruckMaker, a real powertrain system can be integrated into the simulation environment, enabling reproducible measurements to be made of the consumption of vehicles in real-world driving scenarios and in standard driving cycles on the powertrain and whole vehicle test bench
- Tests can be carried out with a human driver, driving robot or drive-by-wire
- The whole vehicle and scenario can be visualized online on the test bench
- Test the effect of the operating strategy, driver behavior and the impacts of new functions such as predictive systems on consumption in the whole vehicle
- Use standard and special measurement methods on the test bench in reproducible real-world driving situations
- Perform automated engine and gearbox or powertrain system applications flexibly under transient, real-world operating conditions in all kinds of scenarios
Determine real-world consumption and driving performance on the engine test bench
As with emissions, the question of selecting a suitable measuring method in the context of lower CO2 limits is increasingly central. There is as yet often a wide discrepancy between a vehicle’s actual consumption and the values measured on the test bench.
Our simulation solutions and test systems enable us to carry out real test runs on the engine test bench and thus to record reproducible real-world consumption measurements. In this process, the internal combustion engine is integrated into the CarMaker simulation environment directly on the test bench and is this way operated in the virtual whole vehicle with a virtual powertrain.
The test bench control system enables the engine to be run dynamically under all the loads that the vehicle would be subject to during a real test run. It is possible to run the engine dynamically under all the loads that the vehicle would be subject to during a real test drive. By using the online calculation and overlaying all driving resistances, we bring real driving to the engine dynamometer with virtual test driving. The closed-loop test bed integration is achieved via a test bed interface, which we have specially developed for the particular requirements of testing on the engine dynamometer. Our solution is available for new test beds as well as for an upgrade of your existing test beds.
Use our model-based testing approach and benefit from the advantages of integrated simulation on the engine test bench in the following ways:
- Thanks to “engine-in-the-loop” with CarMaker or TruckMaker, a real engine can be integrated into the simulation environment, enabling reproducible measurements to be made of the consumption of vehicles in real-world driving scenarios and in standard driving cycles on the engine test bench
- The whole vehicle and scenario can be visualized online on the test bench
- You can assess the effect of individual modifications and subsystem changes as well as driver behavior reproducibly under real-world operating conditions, using standard and special measuring methods
- By running the real engine with a virtual powertrain and whole vehicle, we make it possible to carry out rapid and early analyses of the influences that electrification, gearboxes and other changes to the whole vehicle, for instance, have on consumption
- Perform engine calibration flexibly under transient real-world operating conditions in different powertrain configurations, vehicle variants and model ranges