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Eventtjänst för diagnos av tunga fordon

Winér, Johan LU and Birksjö, Marcus (2016) In LU-CS-EX 2016-44 EDA920 20161
Department of Computer Science
Abstract
The integration of small computer units in vehicles has made more complex in-vehicle functionality possible. To troubleshoot these more advanced functions, the diagnostic services need to read out more data from the integrated computer units, causing an increased network load. This has caused a demand on more efficient ways of performing vehicle
diagnostics.

One possible way to decrease the network load is to use an event based service. The aim of this thesis was to investigate the benefit of an event based service within the domain of vehicle diagnostics as well as to present a recommendation of how such a service should be designed. The thesis also aimed at eliciting obstacles and pitfalls connected
with the implementation of the... (More)
The integration of small computer units in vehicles has made more complex in-vehicle functionality possible. To troubleshoot these more advanced functions, the diagnostic services need to read out more data from the integrated computer units, causing an increased network load. This has caused a demand on more efficient ways of performing vehicle
diagnostics.

One possible way to decrease the network load is to use an event based service. The aim of this thesis was to investigate the benefit of an event based service within the domain of vehicle diagnostics as well as to present a recommendation of how such a service should be designed. The thesis also aimed at eliciting obstacles and pitfalls connected
with the implementation of the service in the current software architecture in heavy duty vehicles.

An industrial case study was performed at the Swedish company Scania to elicit the advantages, problems and limitations with an event based service for vehicle diagnostics. First a set of experts representing different domains within vehicle diagnostics were interviewed
to investigate the need for an event based service. Requirements were elicited and compared with the event based service ResponseOnEvent defined in the ISO standard 14229-1:2013. A decision was then made to diverge from the standard in order to increase the number of fulfilled requirements and flexibility of the service. A new proprietary service was thus created and evaluated through a proof of concept implementation where a prototype of the service was implemented in two control unit. The prototype implementation of the proprietary service highlighted multiple difficulties
connected with the realization of an event based service in the current software architecture.

One of the biggest problems was the fact that diagnostic services was assumed to always have a one-to-one relation between request and response, which an event based service would not have. Different workarounds were discovered and assessed. Another problem was the linking between an event triggered response message and the trigger condition. It was concluded that some restrictions would have to be made to facilitate the process of linking a response to its trigger condition. Non-determinism was another
problem, since there were no guarantees that an event would not occur too often causing a network overload. In the final recommendation there are suggestions of how to solve these problems and some suggested areas for further research.

The thesis argues that there is a need for a new way to diagnose vehicle functionality due to their increased complexity and the limited bandwidth of today’s in-vehicle networks. The event based service ResponseOnEvent offers a good alternative but might lack some key functionality required by an event based service. Therefore it is valuable to consider a proprietary service instead to maximize the benefits of an event based service.

Due to its nature, an event based service might require a restructuring of the system architecture and limitations in the hardware might limit the usability and flexibility of the service. (Less)
Popular Abstract (Swedish)
Integrationen av datorenheter i dagens fordon har gjort nya och mer avancerade funktioner
möjliga. För att kunna verifiera att dessa funktioner fungerar och för att felsöka
dem så används så kallade diagnostjänster. Allt eftersom funktionerna i fordon blir mer
avancerade och beroende på data från flera olika sensorer och datorenheter så ställs nya
krav på diagnostjänsterna att kunna läsa ut mer data ur datorenheterna. Detta orsakar
en ökad nätverkslast och eftersom bandbredden på nätverket är begränsad ser man idag
ett behov av nya diagnostjänster som kan utföra diagnos på ett sätt som ger upphov till
mindre nätverkslast.
Målet med denna studie var att undersöka om en eventtjänst kan underlätta diagnostiken
av fordonsfunktioner... (More)
Integrationen av datorenheter i dagens fordon har gjort nya och mer avancerade funktioner
möjliga. För att kunna verifiera att dessa funktioner fungerar och för att felsöka
dem så används så kallade diagnostjänster. Allt eftersom funktionerna i fordon blir mer
avancerade och beroende på data från flera olika sensorer och datorenheter så ställs nya
krav på diagnostjänsterna att kunna läsa ut mer data ur datorenheterna. Detta orsakar
en ökad nätverkslast och eftersom bandbredden på nätverket är begränsad ser man idag
ett behov av nya diagnostjänster som kan utföra diagnos på ett sätt som ger upphov till
mindre nätverkslast.
Målet med denna studie var att undersöka om en eventtjänst kan underlätta diagnostiken
av fordonsfunktioner inom olika områden och vilka problem och begränsningar som
finns. En fallstudie gjordes på den svenska motor och fordonstillverkaren Scania för att
undersöka vilka områden som skulle kunna tänkas ha nytta av en eventtjänst och vilka
krav de ställde på tjänsten.
Kraven som erhölls jämfördes med eventtjänsten ResponseOnEvent som är definierad
i ISO standard 14229-1:2013. ResponseOnEvent visade sig inte kunna uppfylla alla de krav
som ställdes på en eventtjänst och därför designades en proprietär tjänst som ett alternativ.
En prototyp av den proprietära tjänsten implementerades i två av Scanias styrenheter för
att undersöka problem och begränsningar i samband med en realisering av tjänsten. Ett av
de största problemen som sågs var det faktum att den befintliga arkitekturen inte hade stöd
för att skicka diagnosmeddelanden per event, något som en eventtjänst skulle kräva. En
omstrukturering av den befintliga mjukvaruarkitekturen skulle krävas. Ett annat problem
var kopplingen mellan ett eventtriggat meddelande och själva eventet. Icke-determinism
var ett annat fundamentalt problem med en eventtjänst. Ett event skulle kunna ge upphov
till skickandet av flera meddelanden vilket momentant skulle kunna överbelasta nätverket,
det är därför viktigt att vidta åtgärder för att hindra ett sådant beteende.
Uppsatsen bekräftar ett behov av ett nytt sätt att diagnostisera funktioner i fordon och
att en eventtjänst kan bidra till att minska nätverkslasten och erbjuda nya sätt att utföra
diagnos på. ResponseOnEvent är ett bra alternativ men kan sakna några efterfrågade funktionaliteter
som gör det värt att överväga andra alternativ. På grund av sin utformning kan
en eventtjänst komma att kräva en omstrukturering av den befintliga mjukvaruarkitekturen
och begränsningar i form av lagringsutrymme och beräkningskraft kan begränsa
tjänstens tillgänglighet. (Less)
Please use this url to cite or link to this publication:
author
Winér, Johan LU and Birksjö, Marcus
supervisor
organization
alternative title
Event based diagnostic on heavy duty vehicles
course
EDA920 20161
year
type
H3 - Professional qualifications (4 Years - )
subject
keywords
Event based service, Response on Event, ECU, Vehicle Diagnostics, UDS, KWP.
publication/series
LU-CS-EX 2016-44
report number
LU-CS-EX 2016-44
ISSN
1650-2884
language
English
id
8894837
date added to LUP
2016-11-11 10:39:51
date last changed
2016-11-11 10:39:51
@misc{8894837,
  abstract     = {The integration of small computer units in vehicles has made more complex in-vehicle functionality possible. To troubleshoot these more advanced functions, the diagnostic services need to read out more data from the integrated computer units, causing an increased network load. This has caused a demand on more efficient ways of performing vehicle
diagnostics.

One possible way to decrease the network load is to use an event based service. The aim of this thesis was to investigate the benefit of an event based service within the domain of vehicle diagnostics as well as to present a recommendation of how such a service should be designed. The thesis also aimed at eliciting obstacles and pitfalls connected
with the implementation of the service in the current software architecture in heavy duty vehicles.

An industrial case study was performed at the Swedish company Scania to elicit the advantages, problems and limitations with an event based service for vehicle diagnostics. First a set of experts representing different domains within vehicle diagnostics were interviewed
to investigate the need for an event based service. Requirements were elicited and compared with the event based service ResponseOnEvent defined in the ISO standard 14229-1:2013. A decision was then made to diverge from the standard in order to increase the number of fulfilled requirements and flexibility of the service. A new proprietary service was thus created and evaluated through a proof of concept implementation where a prototype of the service was implemented in two control unit. The prototype implementation of the proprietary service highlighted multiple difficulties
connected with the realization of an event based service in the current software architecture.

One of the biggest problems was the fact that diagnostic services was assumed to always have a one-to-one relation between request and response, which an event based service would not have. Different workarounds were discovered and assessed. Another problem was the linking between an event triggered response message and the trigger condition. It was concluded that some restrictions would have to be made to facilitate the process of linking a response to its trigger condition. Non-determinism was another
problem, since there were no guarantees that an event would not occur too often causing a network overload. In the final recommendation there are suggestions of how to solve these problems and some suggested areas for further research.

The thesis argues that there is a need for a new way to diagnose vehicle functionality due to their increased complexity and the limited bandwidth of today’s in-vehicle networks. The event based service ResponseOnEvent offers a good alternative but might lack some key functionality required by an event based service. Therefore it is valuable to consider a proprietary service instead to maximize the benefits of an event based service.

Due to its nature, an event based service might require a restructuring of the system architecture and limitations in the hardware might limit the usability and flexibility of the service.},
  author       = {Winér, Johan and Birksjö, Marcus},
  issn         = {1650-2884},
  keyword      = {Event based service,Response on Event,ECU,Vehicle Diagnostics,UDS,KWP.},
  language     = {eng},
  note         = {Student Paper},
  series       = {LU-CS-EX 2016-44},
  title        = {Eventtjänst för diagnos av tunga fordon},
  year         = {2016},
}