ETD system

Electronic theses and dissertations repository


Tesi etd-09082018-103755

Thesis type
Tesi di laurea magistrale
email address
Modelling and co-simulation of advanced control techniques for electric engines with real-time constraints
Corso di studi
relatore Prof. Buttazzo, Giorgio C.
controrelatore Prof. Landi, Alberto
relatore Prof. Di Natale, Marco
relatore Ing. Pazzaglia, Paolo
Parole chiave
  • PETC
  • LET
  • control
  • motor
  • engine
  • electric
  • real-time
Data inizio appello
Secretata d'ufficio
Riassunto analitico
The increasing complexity of embedded software in modern cars, the transition
to multi-core platforms and the introduction of safety-critical functions
in automotive systems, are posing new problems to both control and software
engineers. Developers need high levels of predictability, testability, and ultimately
determinism in the execution of their code, while control engineers
must be aware of possible delays and scheduling issues due to real-time events
or sporadic overload conditions on undersized CPUs. Thus, the development
of the control part of such applications cannot be separated from the timing
analysis of the scheduling effects introduced by the computing platform in
the execution of the code. Although classical control design methods and offline
studies can help, they cannot be used to describe complex interactions
between control and software timing in the design control phase.
In order to fill this gap, this thesis presents a co-simulation environment
aimed to take into account, simultaneously, the scheduling part, the control
part and the physical components of an Internal Permanent Magnet Synchronous
Motor (IPMSM) for an Electric Vehicle (EV). The co-simulation
tool, entirely based on Simulink, comprehends a behavioural model of a CPU
in order to manage, with a high timing precision, the entire task control chain
for an IPMSM. In addition, also mechanical and electrical components of the
system (e.g., IPMSM and the EV itself) have been included in the model.
In this context, we address the control problem of an IPMSM for EVs, carry
out a deep analysis of field weakening technique for IPMSM and present the
development of an enhanced control scheme in order to improve the performance
of the system.
The model allows also a designer to test different intra-core communication
and control paradigms, and see how they interact with the entire
system. More in details, in this thesis we tested how the Logical Execution
Time (LET) paradigm, which is used to increase predictability in multicores
by trading jitter for latency, impacts the performance of control. On the other
hand, we also tested the system performance when using the Periodic Event
Triggered Control (PETC) paradigm, which can selectively “switch off” the
control execution when its is not needed, in order to save computational and
communication resources.
Finally, an extensive set of experiments for a case study built with realistic
data given by BOSCH is presented, in order to show the interactions
presented in our work and prove the effectiveness of this approach. The performance
of the system has been tested also in CPU overload conditions,
looking for the sequence of scheduling delays that leads to the worst-case