Interview with SIEMENS
With PANDA being 18 months underway, Siemens Industry Software Romania has completed the first major step in the project. Dr. Cristi Irimia, research manager: “We have just integrated a
new library in Simcenter Amesim, our simulation platform. It is a library that is based on the energetic macroscopic representation (EMR) approach. This will be a big help to bring electrical vehicles to the market sooner and to significantly lower the development costs.”
The new addition to Simcenter Amesim allows a mechanical engineer to start playing with different strategies or scenarios. Irimia: “Let’s say you want to build an electrical car that can go from A to B on a hot day, and you want to be sure you have enough charge. Our simulation allows you to see if you can go 300 km with the air-conditioning running. The important thing is that we can easily change the level of detail of our models, or define the so-called n-level of the simulation. You can start with a simple model to get a very general answer, and once you get closer to the behaviour that you want you can proceed to a more detailed and more accurate model. So, you can start with finding the global optimum, and find the local optimum you want from there. You can do that in existing simulations, but you cannot combine it with the controlling part.”
It was challenging to add EMR to the simulation platform. Irimia: “First of all, we needed to understand EMR. What does it mean exactly?” In EMR an electrical motor is represented as a component that has for instance two inputs (voltage and speed) and two outputs (force and current). For the simulation the actual design of the component is irrelevant. The e-motor can have a very simple structure or a very complex one, but for the simulation only the function in the whole system is relevant. By taking into account only the inputs and the outputs, the program needs to consider little amount of data. As a consequence, all inputs and outputs are strictly defined, so any model should be developed within these rules. Irimia: “The calculations are very fast, even if we model an entire electrical car. On top of that, in EMR you also have the feedback integrated in the simulation. You can link the output back to the input: how does the road affect the response of the e-motor to the voltage and current? You cannot do that controlling part, applying different controlling strategies, in existing structural simulations.”
Traditionally, automotive companies have different departments for structure and control. Irimia: “The people in the structural team are mechanical engineers, they always take the physical design as a starting point. The people in the control team have a background in automation. They don’t see a structure, they see boxes with input and output, and limits for the vehicle behaviour. These people have different skills and use different pieces of software. For the first time, we combined these abilities in a single platform. It was very exciting for us to include that and have everything together in one place.”
The PANDA project is now ready for the next step. Irimia: “The next phase is to put all these simulations at work with our partners in PANDA, and demonstrate that we can reduce the time to market for electrical vehicles by 20%.”
Cristi Irimia, Manager Siemens Industry Software SRL
