Function development & application

Development, validation and application of thermal management and climate control functions

In modern thermal management architectures, function control software becomes an independent component within the overall system. It must be developed and validated in conjunction with the specific hardware system. The ‘function’ refers to the interaction between the physical components of the refrigerant and coolant circuits, as well as the HVAC unit. The development of these control functions is carried out using model-based development tools such as MATLAB Simulink. Function implementation takes place through rapid prototyping systems, either on real test setups at the test bench or directly within the target system in the vehicle. The application of these control algorithms is a key part of system integration into the vehicle, including fine-tuning functional behavior to align with partner systems and customer expectations. During global test drives, we ensure that the thermal management system operates optimally under all environmental conditions.

As part of function development, we breathe intelligence into thermal management and climate control systems. With the electrification of powertrains, components in the refrigerant and coolant circuits have also become electrified. Today’s systems typically include electric refrigerant compressors, electric expansion, shut-off and switching valves, as well as electric water pumps. As a result, the actual functionality no longer resides inherently within the components themselves, but must be externally imposed via electrical control. This is precisely the role of the function control software. Thanks to our in-depth system expertise in both refrigerant and coolant circuits on one hand, and modern HVAC systems on the other, we are able to define system-level functionality – as perceived by the customer – and translate it into control algorithms, even in the absence of detailed customer specifications. The verification, validation, and initial baseline calibration of this function control software takes place using the complete system setup at our thermal management test benches.

Development of control algorithms in the actual active system

When developing control functions for thermal and climate systems, a deep understanding of the physical and thermodynamic interrelationships within these complex systems is essential to ensure reliable and robust functional implementation.

Physical system understanding

It must be ensured that the system response generated by the control does not lead to any direct or indirect damage to the components of the thermal management or HVAC system.

Modular functional approaches

Our function control models are modular and scalable, and can therefore be adapted to the complexity of the hardware systems to be operated. The control parameters are all freely configurable.

Documentation of the function implementation

The functional implementation is documented in the functional specification. The associated Matlab model supplements this textual description to create an ‘executable specification’ or an ‘executable specification’.

Application and operation of the function control software in the vehicle

The application of the function control software for the thermal and air conditioning system is an elementary component of the overall system integration into the vehicle. The desired functional characteristics in the respective target system are coordinated on the basis of the relevant project objectives.

Control parameter data

Such complex control functions have a large number of parameters and characteristic curves that must be individually adapted to the respective system variant and the desired system behaviour.

Extension of control functions

Particularly in the case of cross-series platform solutions, brand-specific functional enhancements or additions are often necessary, which have to be implemented and tested as part of the application runs.

Incorporate change requirements into the project

After functional confirmation in the target system, the respective change requirements must now be documented and fed back into the project. This is followed by implementation in the series software.