Special Issue

Automobile Electronics

RelatedRelated productproduct

Upgrading Plan for Utilizing of MBD

1.

INTRODUCTION

The recent trend in the development for the ElectricControl Unit (ECU) of the automotive is in response to the
Functional Safety Standard of ISO26262 and is introducing the Model Based Development (MBD). The standard
takes the MBD up with a good verifiable development
method and many car manufacturers and suppliers areadopting it in their research and development.
The Automotive System & Device Laboratories ofFurukawa Electric has been using the MBD for theresearch area; however has less experience in the software development area. The laboratory is beginning toexpand the MBD in more applicable scope.
This topic shows examples of the introduction of theMBD and its difference and its effectiveness when compared to the conventional development method.

2.

2.2

Difference From the Conventional Development
MethodSince MBD simulates the controller model in the earlier
development stage shown in Figure 2, the development
efficiency is expected to improve.

DesignTest

Front Loading
Requirement analysis

Base Design

System Test
Joint Test
Joint Test

Functional Design
Detail Design

CHARACTERISTICS

The MBD is a development method using simulation andit has been introduced in the automotive industry recently.
The method has been recognized as the technology that
contributes to the decrease in the man-hour requirementfor developing and to the enhancement of quality.
2.1 Model
The MBD generates a relevant model to combine with theexisting functional block and checks its operation on themicrocomputer through the simulation. The model isdivided into the following two components.
· A Plant model	It is the model for the controlled side which is simulated on the physical property and the mechanical property.
· A Controller model	It is the model for the controller side which is simulated on the program operated on the microcomputer.

Qualification

System Test

Unit Test

Programming

Achieve High Quality

Quality Verification

Figure 2 V-model for developing.

2.3 Merit to Introduce the MBD
The MBD has the following advantages.
·	Review of the development specification by thesimulation	The cost reduction and the speeding up the processof the development, because of the decreasing of thenumbers of the trial in manufacturing.
·	Front loading	Since checking of the operation (requirement checkand mounting mistake) is achieved in the early stageof development, the hours of production rework will beexpected to decrease.
·	Auto code generation of the program	C-language program is generated automatically fromthe controller model and the code quality is evenbetween programs.
·	Availability of interactive development of the hardware	The operation check of the model (program) can beachieved before finalizing the hardware.
·	Communication of language	In the communication with the overseas affiliated company, it allows to narrow the language gaps.

Figure 1 Overview of the model.

Furukawa Review, No. 44201347

Upgrading plan for utilizing of MBD

3.

APPROACH FOR THE MBD

The company has been introducing the MBD in the development of an algorithm in the research area and to use
the Hardware-in-the-Loop Simulator (HILS) in the development department. However, the conventional softwaredevelopment has the following concerns stated below.
Research Department·	The man-hour of defining the algorithm specificationby the algorithm developer is large.
·	The change of the software specification is repetitive
through trial and error for the algorithm in the upperstream.
Development department
The following improvement is expected through thedecreasing of the skill dependency· Productivity improvement· Review efficiency improvement
On the other hand, the investment in the MBD has beenproceeding to get the improvement of the design process
and the software inspection through the simulation, as
shown in Table 1.
Table 1

Investment for MBD.

Switch (Operation System)
Development of GUI(Switch)
Graphical display
by guide

Controller (Control system)

Lump (Display system)

Development of controller
model

Development of plant
model

Experiment of Interfacepart for model/C-language

Graphical display
by S-function

MBD

The simple verification of the controller model operating on the PC
The Auto code
The optimization determination(the Auto code generation of the C-Program)for the auto code

Actualoperationenvironmental
The verification of the auto code operating on the microcomputer

Figure 3 Composition of the trial manufacture.

3.2 EffectivenessThe result of the trial manufacture is shown in Figure 4.
The man-hour of the base design, the detail design andthe programming process sharply dropped. The resultshows that it is more effective at the development of algorithm (Algorithm design, Software design and validity).

（Day）
45

Conventional type
MBD

40

YearContents35

2006

Introduction of Hardware-In-the-Loop Simulation (HILS)

30

2010

Development of the tool chain, Partial trial Manufacture

25

2011

Partial trial Manufacture

20

2012

Trial manufacture, Development of Guideline

1510503.1 Trial Manufacture
The trial manufacture was carried out and the capture ofthe issues/its solution and the validation was completed.
The framework of the trial manufacture is shown in Figure
3 and the controller model, the plant model and theGraphical User Interface (GUI) were made. After checking
the whole operation on the PC, the auto code generationof C-language program was made from the controllermodel and was integrated with the driver module composed of C-language, which in turn was installed in themicrocomputer and checked the operation, and the generation of the expected program was confirmed.

Algorithm
designBasedesignDetaildesignProgramming

Figure 4 Comparison of the man-hour.

It also demonstrates that MBD is effective on solving
the issues of the conventional software development.
·	As the interactive development with the hardware isachieved, the risk of the schedule for software development decreases.
·	Since the quality is checked in the prior process withthe front loading, hours of production rework decrease
as shown in Figure 5.
·	High verification (Repetition of irregular operation, repetition of test, automatic execution) can be achieved.

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2013

48

Upgrading plan for utilizing of MBD

Table 2
Conventional type
MBD

Subject in near future.

Process

Upgrading of the standard of the operating procedure

Quality

Version up of the guideline and improving of the review

Productivity The automation operating

Base Design

Detail Design

Programming

Verificationof Algorithm

For more information, please contact:
Automotive System & Device Laboratories
Furukawa Electric Co., Ltd.
Phone: +81-463-24-8003 Fax: +81-463-8006

Figure 5 Comparison of bag appearance.

4.

ACTION PLAN IN FUTURE

As increasing of the size and the complexity of the software in vehicle, the improving of the development efficiency and the quality assurance are very important.
Furukawa Electric keeps dealing with the above issue andimproves the efficiency of the research and development.

Furukawa Review, No. 44

201349