The dynamics of a wheel loader handling unbound granular material: FMI-based co-simulation with Simulink and Demify Master’s thesis
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Typ
Examensarbete för masterexamen
Program
Automotive engineering (MPAUT), MSc
Publicerad
2021
Författare
Balla, Marsel
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
A wheel loader is a heavy equipment used to perform granular material handling
operations. The complete machine model is developed in Matlab/Simulink®, meanwhile
a discrete element method (DEM) solver, modelling unbound granular materials
is developed in Demify®. Virtual development technologies allow for more
efficient testing of the machine and its sub-systems. Therefore, the implementation
of models between different software is required, though there is a lack of standardized
interfaces. At this step, FMUs are the leading component making up for a
possible integration between different working environments. The work focuses in
creating an interface between the two software so the sharing of information is possible.
The granular material was previously modelled with the DEM solver GRAPE,
which is based on a spherical shaped particle representation to model soil material.
On the other hand, crushed rock aggregates which we are working with, require a
well-resolved rock particles’ representation of the irregular and angular shape.
A new GPU solver for complex particle shape based on non-convex polyhedral triangulation
has been implemented, allowing for high fidelity rock shape representation.
In this project, the created FMU files contain the information needed to relief the
communication issue between the software and make the co-simulation possible. The
DEM solver Demify® provides high fidelity results in terms of material contact force
detection, while Multi-Body Dynamics (MBD) Simulink® integrates the equations
of motion. The computational performance, involving the computational cost and
the physical fidelity, is a pivotal factor used to evaluate and optimise the design
of a new level machine-particle interaction. Reliable and computationally effective
results are obtained in the interaction between machine and non-convex shaped rock
particles. In addition, a realistic and an efficient communication between the two
software is reached.
Beskrivning
Ämne/nyckelord
FMU , Wheel loader , Demify® , Matlab/Simulink®