UWE Bristol Engineering showcase 2015

Thomas Moran
BEng Robotics (Hons)
Project Supervisor
Dr Alexander Lenz
An Investigation into Automotive Electronic Communication Systems
towards creating a demonstration platform to be used in an educational
environment.
Introduction
As automotive systems have become more
complex, combinations of different sensor
information is required to come to an effective
decision. This leads to a problem of several
Electronic Control Units (ECUs) that need to send
information to each other over a network
protocol. The automotive industry created CAN
bus to allow these systems to talk to each other.
With the increasing number of systems and a large
contingent of automotive students at the
University of the West of England. A need was
identified for a demonstration system to be
produced for the teaching labs.
System Design
A scaffolding approach was selected for the
project. This is introducing the concepts in a
simplified way with lots of explanation and
support, this is then gradually removed. Figure 1
shows the scaffolding approach of the project.
Figure 1 – Scaffolding Approach
CAN Bus Poster
A Poster was produced in an attempt to explain
CAN Bus in simple terms. The poster gives a brief
introduction to CAN bus and lists its key features
and uses. It gives an example of a standard
message frame format and discusses the
important feature of bus arbitration, when several
messages try to send at the same time. Several
disadvantages of the protocol are also included for
completeness.
Instructional Booklet
An instructional booklet or user guide for the
demonstration board was also produced. This
discusses the features of the demonstration board,
giving a diagram explaining the location of the
important parts of functionality. The instructional
booklet includes several both simple and
advanced exercises; these help develop the
knowledge of the user.
Demonstration board
A demonstration system was created consisting of
two CAN Node Printed Circuit Boards . These
replicate the electronic systems behind a
commonly used Anti Lock Braking System (ABS).
One node monitors the speed of a spinning wheel
through an encoder as would happen in a real
vehicle. This transmits the actual speed of this
wheel onto a CAN Bus network.
A second node receives and checks this value
against an expected value of the wheel also on the
network. If the actual speed is less than the
expected speed, an ABS activation condition
occurs lighting an indicator and modulating a
linear actuator which would be controlling a
braking line in a real system. The demonstration
board is shown within Figure 2.
Figure 2 – Demonstration Board
Exercises
Several exercises were created and included within
the instructional booklet. Some exercises were
simple testing the basic functionality whilst some
were more advanced. The more advanced
exercises made use of a Kvaser Semi Leaf Pro
analyzer to monitor the labels. A configuration
label was provided to allow modification of the
demand speed.
Project Verification
The project was verified through two forms of
testing to ensure it met the project objectives and
satisfied the overall aim.
Unit testing ensured that the individual PCB
functionality was correct. Unit testing also
included testing of the system as a whole, along
with the CAN labels to ensure that they were
correctly functioning.
Requirements based testing was conducted to
ensure that the project met the requirements, that
were developed from stakeholder expectations to
express the aims and objects of the project in a
testable form.
Project summary
The purpose of this study was to develop a CAN bus
educational platform for the teaching labs at the
University of the West of England. A demonstration
system was developed that was intended to be used
by engineers from a mainly mechanical background.
Project Objectives
• Create a system to demonstrate how Electronic
Control Units (ECUs) communicate within a
vehicle.
• Use a real world example such as Anti-Lock Braking
so the system can be related to automotive
teaching.
• Develop supporting educational material to help
support students experience.
Project Conclusion
Too much focus was placed on the demonstration
board which was only a part of the entire system. This
was due to a overestimate of experience and ability
in developing electronic hardware. Debugging a
system is a challenging task and it can be difficult to
know if the problem lies in hardware or software.
A large portion of the verification was focused on the
demonstration board. However in the requirements
based testing it was found that only 5 of the 14
requirements could be claimed as fully achieved. 7 of
the requirements can be said as partially achieved in
that they have been achieved however not explicitly
tested. This was due to not enough testing being
conducted on the entire system. Testing of the
educational material with the intended audience of
automotive students needs to be conducted to claim
full achievement of these requirements.