EotProtn_MDD

Module Design Document

For

EotProtn

Aug 16, 2017

Prepared By:

Matthew Leser

Software Engineering

Nexteer Automotive,

Saginaw, MI, USA

Change History

Table of Contents

1 EotProtn & High-Level Description 5

2 Design details of software module 6

2.1 Graphical representation of EotProtn 6

2.2 Data Flow Diagram 7

2.2.1 Component level DFD 7

2.2.2 Function level DFD 7

3 Constant Data Dictionary 8

3.1 Program (fixed) Constants 8

3.1.1 Embedded Constants 8

4 Software Component Implementation 9

4.1 Sub-Module Functions 9

4.1.1 Init: EotProtn_Init1 9

4.1.1.1 Design Rationale 9

4.1.1.2 Module Outputs 9

4.1.2 Per: EotProtn_Per1 9

4.1.2.1 Design Rationale 9

4.1.2.2 Store Module Inputs to Local copies 9

4.1.2.3 (Processing of function)……… 9

4.1.2.4 Store Local copy of outputs into Module Outputs 9

4.2 Server Runables 9

4.3 Interrupt Functions 9

4.4 Module Internal (Local) Functions 9

4.4.1 Local Function #1 9

4.4.1.1 Design Rationale 10

4.4.1.2 Processing 10

4.4.2 Local Function #2 10

4.4.2.1 Design Rationale 10

4.4.2.2 Processing 10

4.4.3 Local Function #3 10

4.4.3.1 Design Rationale 10

4.4.3.2 Processing 10

4.4.4 Local Function #4 11

4.4.4.1 Design Rationale 11

4.4.4.2 Processing 11

4.4.5 Local Function #5 11

4.4.5.1 Design Rationale 11

4.4.5.2 Processing 11

4.4.6 Local Function #6 11

4.4.6.1 Design Rationale 11

4.4.6.2 Processing 11

4.4.7 Local Function #7 11

4.4.7.1 Design Rationale 12

4.4.7.2 Processing 12

4.4.8 Local Function #8 12

4.4.8.1 Design Rationale 12

4.4.8.2 Processing 12

4.4.9 Local Function #9 12

4.4.9.1 Design Rationale 13

4.4.9.2 Processing 13

4.5 GLOBAL Function/Macro Definitions 13

5 Known Limitations with Design 14

6 UNIT TEST CONSIDERATION 15

Appendix A Abbreviations and Acronyms 16

Appendix B Glossary 17

Appendix C References 18

EotProtn & High-Level Description

The End of Travel Protection function specifies performance attributes as the steering system approaches the mechanical end of travel of the steering gear.

Design details of software module

Graphical representation of EotProtn

Data Flow Diagram

See FDD

Component level DFD

See FDD

Function level DFD

See FDD

Constant Data Dictionary

Program (fixed) Constants

Embedded Constants

Local Constants

Software Component Implementation

Sub-Module Functions

Init: EotProtn_Init1

Design Rationale

Refer FDD

Module Outputs

Refer FDD

Per: EotProtn_Per1

Design Rationale

EotProtn_Per1 function is divided into various functions to reduce the cyclomatic complexity.

The limiting of ‘EotAssiSca’ output is performed in SoftEndStop subsystem in FDD. But in code it is limiting calculations are done where the output is calculated i.e. FildEotGain function.

The model is incorrectly handling a Case Statement by not having a default case. A solution was discussed with designers and has been implemented where the default case is Case 2 and Case 3.

Store Module Inputs to Local copies

Refer FDD

(Processing of function)………

Refer FDD

Store Local copy of outputs into Module Outputs

Refer FDD

Server Runables

None

Interrupt Functions

None

Module Internal (Local) Functions

Local Function #1

Design Rationale

None

Note: Outputs of “EotVelImpct” function is - EotMotTqLim_MotNwtMtr_T_f32.

Processing

Refer to the “EotVelImpct” subsystem of the Simulink model of the design

Local Function #2

Design Rationale

None

Note: Outputs of “LimPosnDetd” function is - LimPosn_HwDeg_T_f32.

Processing

Refer to the “LimPosnDetd” subsystem of the Simulink model of the design

Local Function #3

Design Rationale

None

Note: Outputs of “CalcEntrGain” function is - EntrGain_Uls_T_f32.

Processing

Refer to the “CalcEntrGain” subsystem of the Simulink model of the design

Local Function #4

Design Rationale

Calculation of Filtered Handwheel torque is done after ‘CalcExitGain’ function is executed.

Note: Outputs of “CalcExitGain” function is - FildHwTq_HwNwtMtr_T_f32

Processing

Refer to the “CalcExitGain” subsystem of the Simulink model of the design

Local Function #5

Design Rationale

None

Note: Outputs of “CalcEotGain” function is - EotGain_Uls_T_f32

Processing

Refer to the “CalcEotGain” subsystem of the Simulink model of the design

Local Function #6

Design Rationale

Limit of EotAssiSca is moved to local function FildEotGain.

Note: Outputs of “FildEotGain” function is - EotAssiSca_Uls_T_f32

Processing

Refer to the “FildEotGain” subsystem of the Simulink model of the design

Local Function #7

Design Rationale

None

Note: Outputs of “CalcEotDampg” function is - EotDampgCmd_MotNwtMtr_T_f32

Processing

Refer to the “CalcEotDampg” calculation of the Simulink model of the design

Local Function #8

Design Rationale

None

Note: Outputs of “EotActvCmdCalc” function is - EotActvCmd_MotNwtMtr_T_f32

Processing

Refer to the “EotActvCmdCalc” calculation of the Simulink model of the design

Local Function #9

Design Rationale

None

Processing

Refer to the “SoftEndStopStCtrl” calculation of the Simulink model of the design

GLOBAL Function/Macro Definitions

None

Known Limitations with Design

None

UNIT TEST CONSIDERATION

Source Model Mismatch will occur in PIL Testing. This is because the model is incorrectly handling a Case Statement by not having a default case. A solution was discussed with designers and has been implemented where the default case is Case 2 and Case 3. The design will be updated later through ICR EA4#14690.

Abbreviations and Acronyms

Glossary

Note: Terms and definitions from the source “Nexteer Automotive” take precedence over all other definitions of the same term. Terms and definitions from the source “Nexteer Automotive” are formulated from multiple sources, including the following:

• ISO 9000

• ISO/IEC 12207

• ISO/IEC 15504

• Automotive SPICE® Process Reference Model (PRM)

• Automotive SPICE® Process Assessment Model (PAM)

• ISO/IEC 15288

• ISO 26262

• IEEE Standards

• SWEBOK

• PMBOK

• Existing Nexteer Automotive documentation

References