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Acquisition of distributed CAN traffic for centralized analysis at functional and electrical levels

Mellström, Sebastian LU (2015) EEM820 20151
Department of Biomedical Engineering
Abstract
This thesis covers specification and development of a distributed measurement system intended for CAN bus. It was completed at Scania CV, Södertälje in collaboration with Lund University. The goal of the thesis is to specifiy and develop a distributed measurement system that helps Scania with acquisition of functional and electrical data. Several topics are adressed such as filtering, at what speed the system shall run at and much more. By a thorough pre-study that began with reading of specifications and continuing into measurements of the bus, a number of requirements was produced to reach a specification to be able to begin development.

Development was done by producing a custom hardware controller that handles the incoming data and... (More)
This thesis covers specification and development of a distributed measurement system intended for CAN bus. It was completed at Scania CV, Södertälje in collaboration with Lund University. The goal of the thesis is to specifiy and develop a distributed measurement system that helps Scania with acquisition of functional and electrical data. Several topics are adressed such as filtering, at what speed the system shall run at and much more. By a thorough pre-study that began with reading of specifications and continuing into measurements of the bus, a number of requirements was produced to reach a specification to be able to begin development.

Development was done by producing a custom hardware controller that handles the incoming data and performs a conversion to logical data. This controller is in turn connected to a system bus on the evaluation board that makes it possible to write directly into the CPU's RAM. Due to this, valuable CPU time that would be spent fetching data is saved and the CPU can be used for signal processing and handling the upstream connection to a server instead. In addition to this, an input stage that handles interaction with the CAN bus was produced. It is essential that the bus is not affected by the measurement system. Furthermore this stage filters the signal to minimize aliasing from the ADCs.

The developed system aims to increase knowledge of the electrical behaviour of the bus as well as a new method to acquire logical information from the bus. With more development, a custom PCB could be manufactured that could be placed on-board for increased vehicle diagnostics. Finally, tips and ideas for further development are suggested. (Less)
Popular Abstract
Acquisition of distributed CAN traffic for centralized analysis of functional and electrical levels

When specifying and building a distributed measurement system there are many, many, aspects to address. This article aims to summarise the variables that are of highest importance to the subject, without getting too far into the technical details of how this is done and how the physical models behind work.

With that being said, it's about time to get into details. A measurement system is a system that measures something, an \textit{object}, and delivers quantified values from that said \textit{object}. The problem is that as soon as something is measured, it will affect the system measured. Intentially or unintentionally. Therefore the... (More)
Acquisition of distributed CAN traffic for centralized analysis of functional and electrical levels

When specifying and building a distributed measurement system there are many, many, aspects to address. This article aims to summarise the variables that are of highest importance to the subject, without getting too far into the technical details of how this is done and how the physical models behind work.

With that being said, it's about time to get into details. A measurement system is a system that measures something, an \textit{object}, and delivers quantified values from that said \textit{object}. The problem is that as soon as something is measured, it will affect the system measured. Intentially or unintentionally. Therefore the method used when measuring must be with as little affection as possible, or atleast at an acceptible level. With that being said, how do we know that the measured values represent what we want them to represent? This in combination with a desired frequency of measurements and a resolution that provides enough information to be able to act upon are by far the biggest problems encountered when designing measurement systems. (Less)
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author
Mellström, Sebastian LU
supervisor
organization
course
EEM820 20151
year
type
H2 - Master's Degree (Two Years)
subject
keywords
CAN, FPGA, DAQ, Distributed, Measurement, System
language
English
additional info
2015-09
id
7370385
date added to LUP
2015-06-22 13:44:41
date last changed
2015-06-22 13:44:41
@misc{7370385,
  abstract     = {This thesis covers specification and development of a distributed measurement system intended for CAN bus. It was completed at Scania CV, Södertälje in collaboration with Lund University. The goal of the thesis is to specifiy and develop a distributed measurement system that helps Scania with acquisition of functional and electrical data. Several topics are adressed such as filtering, at what speed the system shall run at and much more. By a thorough pre-study that began with reading of specifications and continuing into measurements of the bus, a number of requirements was produced to reach a specification to be able to begin development. 

Development was done by producing a custom hardware controller that handles the incoming data and performs a conversion to logical data. This controller is in turn connected to a system bus on the evaluation board that makes it possible to write directly into the CPU's RAM. Due to this, valuable CPU time that would be spent fetching data is saved and the CPU can be used for signal processing and handling the upstream connection to a server instead. In addition to this, an input stage that handles interaction with the CAN bus was produced. It is essential that the bus is not affected by the measurement system. Furthermore this stage filters the signal to minimize aliasing from the ADCs.

The developed system aims to increase knowledge of the electrical behaviour of the bus as well as a new method to acquire logical information from the bus. With more development, a custom PCB could be manufactured that could be placed on-board for increased vehicle diagnostics. Finally, tips and ideas for further development are suggested.},
  author       = {Mellström, Sebastian},
  keyword      = {CAN,FPGA,DAQ,Distributed,Measurement,System},
  language     = {eng},
  note         = {Student Paper},
  title        = {Acquisition of distributed CAN traffic for centralized analysis at functional and electrical levels},
  year         = {2015},
}