Sherpa Engine models integrated within CarMaker
Thanks to the close co-operation between Sherpa Engineering and IPG Automotive, the complete Sherpa-Engine model library has been integrated into CarMaker. Sherpa Engine covers detailed motor models, which have - like CarMaker - a modular design and an excellent model performance. The combination of these two leading products offers the users new possibilities using model-based development for the actual generation of motor and vehicle controllers.
Exhaust directives, consumption requirements and at the same time the customer's desire for safety and driving performance demand a great deal from the vehicle and motor development. The response to these requirements is a growing software proportion within the vehicle. Model based methods have established themselves. They allow for efficient development and validation during the whole development process, to control the increasing complexity and the interaction of the software systems.
Easy integration thanks to an open model platform
CarMaker supports the model-based development with its virtual vehicle environment and detailed models, which simulate the complete dynamic behaviour of a vehicle. Ranging from offline simulations, which are realized as Model-in-the-Loop and Software-in-the-Loop during the validation phases, to Hardware-in-the-Loop tests - CarMaker is continuously applicable for the development of controllers in the vehicle. A user-friendly interface, the animation IPG-MOVIE, the signal analysis tool IPG-CONTROL and the ability to automate the tests turn CarMaker into a practical development tool. CarMaker's virtual vehicle environment is both open and modular, accordingly the user can make modifications or extensions on the existing models without any problems. Thanks to this openness, CarMaker has become more and more important as an integration platform and is used by numerous partners of IPG to integrate their own models or tools within an overall CarMaker framework. An outstanding example is the integration of the motor models from the French expert Sherpa Engineering, which opens up new opportunities for model-based vehicle and motor development.
Detailed motor models with modular design
The Sherpa-Engine model library contains models of gasoline, diesel, gas, and electric motors, which offer all physical effects necessary for simulation. Models for different motor configurations are available, for example an induction engine or turbocharger, each with or without AGR. On the basis of the modular and hierarchical design, single motor components can easily be changed without having to engage deeply into the modelling process. To pass from a turbocharger with variable turbine geometry (VTG) to a Waste-Gate controlled turbocharger, you only have to change the respective model component. Further components like drivetrain or air conditioning can also be changed without problems. The models are completely integrated in MATLAB/Simulink. Thanks to their integration in CarMaker, they support the model-based development of control systems from the concept phases to the fuse protection of the control units with Hardware-in-the-Loop testing.
Applications for modern vehicle dynamics and motor development
The combination of Sherpa-Engine and CarMaker is interesting for motor development as well as for vehicle dynamics analysis. With the integration of a complete motor model in CarMaker's full vehicle environment, it is possible to test different motor architectures in the vehicle and to evaluate them considering different factors like consumption, emissions or driving behaviour. Tests on the real combustion engine can be completed by tests in the virtual vehicle with a virtual motor - an advantage for the development of motor control units. Regarding the perspective of vehicle dynamics development, you also have to think about the validation of control systems which interact with the motor management, for example, ESP. It is possible to globally analyse and evaluate the interaction between the control units by simulation.
With Simulink, the user can easily and rapidly integrate a motor model from the Sherpa-Engine library in the simulation environment of CarMaker or CarMaker/HIL. A graphical user interface leads the user step by step through the integration process, beginning with the choice of the motor model through the parameterisation, to the integration within the vehicle model. The parameterisation of the model is based on standard measured data and done automatically using a specially developed tool. The user is able to change the different motor parameters online after the integration within CarMaker.
To cope with the special requirements of the model based motor development, the CarMaker environment has been enlarged with some specific functions. Among these, are the graphical user interface "Instruments", which shows the most important information about the vehicle condition (pedal position, steering angle, selected gear, speed, ...), has been completed with a few displays and controllers. Motor specific data is shown, like the compression at the motor's input and output, also the user can move the sizes "motor rotation", "speed", "gas", "clutch" or "brake" during simulation using slider controls. This feature enables the user to define precise working points for the motor. A further example of the function enlargement is the possibility to influence the signals between the motor and motor control unit during the simulation by direct access to the variables.
Prepared for current challenges
Thanks to the openness of CarMaker and Sherpa-Engine, it is not a problem to integrate more motor specific development tools. The outstanding quality of the models allows testing in areas, where other models have already reach their limit. With the combination of Sherpa-Engine and CarMaker, a unique tool has been developed, which enables the automotive manufacturer and supplier to face up to, self-confidently, the current challenges of motor and vehicle development.
