Drivetrain Design Space

OpenMETA Design Space Exploration demonstration

Variability Model

Our sample project is based on component selection for the drivetrain of a heavy vehicle. We want to consider a number of diesel engines and transmissions, as well as options for a hybrid drivetrain.

image of system variability architecture

In this architecture, we always have a Diesel Engine and a Transmission, and we have several alternatives for each. They are joined by a driveshaft. We will always have a Drivetrain Control Unit that controls these via the CAN bus.

Optionally, we can turn this into a hybrid drivetrain by adding an Integrated Starter-Generator (ISG) and supporting Hybrid System Elements. The Integrated Starter-Generator sits between the engine and transmission and is connected to each by a driveshaft. The Hybrid System Elements include the Battery, for which we have several alternatives, the High-Voltage Battery Power Converter, the Hybrid Control Unit, and the Generator Control Unit. The other Hybrid System Elements are joined to the Drivetrain Control Unit via the CAN bus.

This varability model provides us with 200 distinct drivetrain configurations. We can then use Constraints to reduce the number of configuration instances under consideration. After applying all of the constraints, only 14 of the original 200 possibilities remain.


With constraints, we can express the criteria that each configuration must meet in order to be valid. There are two types of constraints that we will consider here: property and implication.

Constraint Name Concept Type
MustHaveTransmissionOverhead The combined power of the engine and ISG cannot exceed the power-handling capacity of the transmission. property
HybridSystemElementConsistency If the ISG is selected for inclusion, then the other Hybrid System Elements must also be selected, and vice-versa. implication
MassLimit The total mass of all components must not exceed 2,000 kg. property
MustBeAbleToHandleEnginePower If an ISG is selected, it must be capable of handling the power output of the engine. property
MinimumPower The drivetrain must be capable of producing at least 500 hp. property

For more information, see the README on Github.