The modern automotive product is a complex system consisting of many different interconnected subsystems spanning multiple engineering domains. These subsystems need to work together seamlessly and efficiently to deliver the experience demanded by the customer. This means the engineers developing the product need to understand how the mechanical, electrical, thermal, fluid and control systems interact. Dymola and Modelica application libraries provide a solution to address this.
Traditional CAE processes such as FEA and CFD can help with the detailed understanding and optimisation of the component parts. A systems engineering approach is also needed to look at the overall behaviour of the complete vehicle and allow optimisation at the system level.
For example, it might be necessary to operate a subsystem in what would be considered a sub-optimal way if we just analysed that subsystem to enable the whole vehicle system to reach its optimal operating condition.
This analysis can start in the concept phase where predictive models can be used to assess the vehicle performance based on the program assumptions. We can also test that the program assumptions are compatible and make informed decisions based on predictive simulation results very early in the project enabling changes to be made at minimal cost. Techniques such as design of experiments and optimisation can then be used to explore the design space and determine the appropriate system architecture, component sizes and their interactions spanning the multiple domains involved in the complete vehicle.
As the project then progresses, application specific Modelica libraries enable the model to be extended in many different directions to explore the system behaviour.
- The core VeSyMA library support the concept stage evaluation of vehicle performance, fuel economy and energy usage and provides the framework to integrate all other application libraries in to a complete vehicle system model
- Explore the behaviour of the internal combustion engine with the VeSyMA – Engines Library
- Integrate the electric and hybrid drivetrain using the Electrified Powertrains and Battery Libraries.
- Understand the interaction of the gearbox and driveline with the VeSyMA – Powertrain Library
- Assess the vehicle ride and handling with the VeSyMA – Suspensions Library
- Optimise the HVAC system performance and operation with the Thermal Systems and Human Comfort Libraries
- Investigate thermal management using any of the VeSyMA – Engines, Cooling or Thermal Systems library depending on the system configuration.
Having developed a comprehensive set of vehicle models we then need to use them effectively across the organisation and there are many different needs and requirements that can be fulfilled.
- Deploy models to non-simulation experts by providing controlled access to a simulation using the FMI Blockset for Microsoft Excel®
- Compile the models to run on Hardware-in-the-Loop (HiL) simulators to support the development, verification and validation of the vehicle control systems
- Experience the virtual vehicle in Driver-in-the-Loop simulators with systems ranging from simple desk-based static simulators to engineering-class motion platforms
- Provide black-boxed and license controlled models to customers and suppliers to help them integrate their subsystems in to the whole vehicle environment
- Utilise the FMI standard to combine and reuse models from many different sources to build the complete vehicle system model
- Export the model as c-code for integration into bespoke analysis tools