Usable, interpretable, developable
Our goal is to assist Turku AMK’s electric rally cross vehicle project, eRallyCross, through the investigation, development, and utilisation of vehicle powertrain simulations. The models provided and outlined by the team aim to create a foundation for future work that is usable, interpretable, and developable.
developing new models
The team has created custom models from the ground up using a fundamentals-based approach. These have been developed using MATLAB code and Simlink models.
Race velocity model
This model estimates a vehicles velocity over any given route from GPS data. This can then be fed into other powertrain models to build an image of vehicle behaviour over a race. As the eRallyCross car is still in development, this model provides the initial platform to begin simulating the vehicle performance before it is race ready.
battery power model
This model takes race velocity and slope data and produces estimations of battery heat load and temperature increase. This is done through determining the power consumed by the vehicle, then applying constant efficiency factors to estimate the power lost from the battery as heat. This can be used to initial create estimates of battery heat loads by using race data from similar vehicles or race routes.
model research
The team has proposed additional future models that could be implemented within the eRallyCross project, similar university based projects or external client based projects. These models would further enhance the clients ability to accurately conduct powertrain simulations and analyse specific parameters related to electric vehicle simulation and cooling system design. This section aims to provide a brief overview of the models which were researched for use in the eRallyCross project.
Equivalent circuit battery model
The Equivalent Circuit approach for modelling Li-ion batteries provides a simple but effective estimation of a battery cell’s performance characteristics. The model had immediate applications to the eRallyCross project due to its easy integration with currently used models and focus on variables of key interest, such as a non-constant battery efficiency.
Alternative battery models
Model based State of Charge estimation methods have been considered as these have superior performance over alternative cell estimation methods, providing robustness; a vital characteristic due to the varied operating conditions of electric vehicles. Additional models are suggested, each providing a unique set benefits, to outline the several possible directions for future development.
Powertrain Modelling
Through the implementation of more advanced powertrain modelling, the eRallyCross team would be able to make key vehicle design choices based off the information provided by the powertrain simulations. The team has provided an overview of powertrain modelling in terms of the approach for developing the system and how it could be used to benefit the eRallyCross project.