Plastic Omnium is a world leader in automotive body components, fuel and energy storage systems and waste management solutions. Founded in 1946, Plastic Omnium has more than 22,000 employees, 111 factories and 22 research and development (R&D) centers in 30 countries, and annual revenues exceeding €5.3 billion. Plastic Omnium is the world leader of blowmolded fuel systems. In 2014, its 33 plants produced 18.4 million plastic fuel tank systems, representing a world market share of 21 percent.
Plastic Omnium is a world-leading tier one automotive supplier. Its core businesses include the Auto Exterior division, which designs and manufactures body components and modules to make vehicles lighter, safer and more aerodynamic; and the Auto Inergy division, which is the global market leader for fuel systems. For the past ten years, the division has developed an onboard AdBlue® storage and delivery system, which enables the use of selective catalytic reduction (SCR), a key technology to reduce nitrogen oxide (NOx) emissions of diesel engines.
In the context of stringent emission and safety regulations, products become increasingly complex: it is now important not only to consider multi-domain aspects of the system, but also to study its interactions with the environment.
Combining integrated safety and emissions control, the fuel systems must serve a number of functions: refueling, storage, ventilation, engine supply and fuel-level gauge systems. The Auto Inergy division applies the requirements management and V-cycle development approach, from the initial control system view to global system validation, to manage the details of active systems for emission control. This includes designing control strategies for the whole perimeter and development of specific actuators, sensors and electronic control units (ECU). Considered the heart of the control system, the ECU is tuned according to the specificities of the system design and interfaces.
The Advanced Innovation and Research department, part of the Auto Inergy division, develops and validates control systems for Auto Inergy products, and uses Simcenter Amesim™ software from product lifecycle management (PLM) specialist Siemens Digital Industries Software.
Plastic Omnium first used the Simcenter Amesim multi-domain systems simulation platform to model its selective catalytic reduction system. SCR is a means of converting NOx with the aid of a catalyst into diatomic nitrogen and water.
The main driver for integrating Simcenter Amesim into the development process was the need to develop control strategies without having to physically test the algorithms. The department uses the Simulink® environment to develop the control strategies, and needed a model representing the physical world. With ready-to-use multi-domain libraries, Simcenter Amesim was an ideal solution for creating the plant model.
“Predefined and validated Simcenter Amesim libraries are particularly useful to reduce our modeling efforts,” says Jurgen Dedeurwaerder, senior expert, control systems architecture at Plastic Omnium. “On top of this, it is easy to execute the simulations without having to worry too much about the solver settings.”
Plastic Omnium also values the documentation included with Simcenter Amesim and the availability of technical support. “What I appreciate in Simcenter Amesim is the enormous amount of well-structured documentation,” says Dedeurwaerder. “Thanks to this, it is perfectly feasible for any engineer to model and simulate systems even if they are not in your domain of competence. Personally I’m an electronics engineer, but the documentation helped me to improve my knowledge in other domains considerably. The technical support is also a key differentiator compared to other tools.”
For the next step, engineers parameterized the system so that all of the components in the model respond as expected, according to test data or their specifications in data sheets. This step involved using Simcenter Amesim batch runs and design exploration tools to determine whether the parameter settings reflect actual behavior.
Once the model is ready, the Plastic Omnium team prepares it for co-simulation with Simulink, and uses the Simcenter Amesim to Simulink interface to couple the Simcenter Amesim plant model with the Simulink control model. “We are using the Simulink interface of Simcenter Amesim in both directions,” explains Dedeurwaerder. “We integrate Simcenter Amesim models in Simulink to develop algorithms and we do the opposite to verify the robustness of the algorithms.”
The co-simulation using Simulink and Simcenter Amesim verifies the performance of the algorithm with respect to critical parameters by taking advantage of Simcenter Amesim batch runs and Monte Carlo analysis functionalities. During this step the team also determines a set of calibration values for the algorithm that results in acceptable performance for all potential configurations.
“By using Simcenter Amesim, we can reduce calibration effort and shorten development cycles since we can start earlier with the development of our control strategies and the strategies are much more mature when entering the test phase,” says Dedeurwaerder. “We can also quickly verify the viability of new ideas, enabling the decision whether to continue or to stop investing in the idea.”
Independent of this typical development process, Plastic Omnium also investigates the system performance using temporal and frequency analysis. The main purpose for these investigations is to better understand physical phenomena observed during testing; for example, the influence of the hydraulic line parameters (connecting the pump with the injector) on the pressure at both sides of the line.
“With Simcenter Amesim, not only can we develop and fine-tune our models more efficiently, we also have gained a better insight into the global performance of our products,” says Dedeurwaerder. “Thanks to this in-depth understanding, we gained our key competitive advantage by offering our customers better flexibility and responsiveness. The reduction of the controls development time by 75 percent compared to our previous way of working was the determining factor in winning multiple contracts.”
One of the next steps Plastic Omnium will undertake involves hardware-in-the-loop (HiL) testing. The model developed with Simcenter Amesim will be used in the HiL real-time test environment.
“Model-based systems engineering will become a necessity in the automotive industry,” Dedeurwaerder asserts. “It offers a systematic design approach that facilitates the analysis of all potential use cases and interactions. This makes analyzing the impact of modifications easier. Previously our technicians and test engineers were overloaded with the execution of experiments, which could be replaced by simulations. Now they have more time available to perform added-value testing and improve testing methodologies. MBSE also facilitates knowledge sharing between different teams – both internal and external, since the models can easily be exchanged and understood.”