Performance evaluation of time-critical data transmission in automotive communication systems [Elektronische Ressource] = Leistungsbewertung zeitkritischer Datenübertragung in automobilen Kommunikationssystemen / vorgelegt von Thomas Herpel

Thomas Herpel

Sujets

• Informatik

Informations

• Publié par: friedrich-alexander-universitat_erlangen-nurnberg
• Publié le: 01 janvier 2009
• Nombre de lectures: 27
• Poids de l'ouvrage: 7 Mo

Extrait

Performance Evaluation of
Time-Critical Data Transmission in
Automotive Communication
Systems
Leistungsbewertungzeitkritischer
Datenübertragunginautomobilen
Kommunikationssystemen
Der TechnischenFakultätder
Universität Erlangen-Nürnberg
zur ErlangungdesGrades
DOKTOR-INGENIEUR
vorgelegtvon
ThomasHerpel
Erlangen-2009AlsDissertationgenehmigtvon
derTechnischenFakultätder
UniversitätErlangen-Nürnberg
TagderEinreichung: 24.08.2009
TagderPromotion: 26.11.2009
Dekan: Prof.Dr.-Ing.ReinhardGerman
Berichterstatter: Prof.Dr.-Ing.German
Prof.Dr.-Ing.JürgenTeichContents
Acknowledgements xi
Abstract xiii
Zusammenfassung xv
1 Introduction 1
1.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Airbag Control Systems . . . . . . . . . . . . . . . . . . . . . . 2
1.2.1 Airbag Control Unit . . . . . . . . . . . . . . . . . . . 2
1.2.2 Crash Sensors . . . . . . . . . . . . . . . . . . . . . . . 4
1.2.3 Airbags and Belt Tensioners . . . . . . . . . . . . . . . 6
1.2.4 Functional Safety of the Airbag Control System . . . . . 6
1.3 Future Vehicle Safety Approaches . . . . . . . . . . . . . . . . 7
1.3.1 The Intelligent Car . . . . . . . . . . . . . . . . . . . . 8
1.3.2 Precrash Systems . . . . . . . . . . . . . . . . . . . . . 9
1.3.3 Time-Critical Precrash Data Transfer . . . . . . . . . . 13
2 Related Work 15
2.1 Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.2 Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.3 Analytical Modeling . . . . . . . . . . . . . . . . . . . . . . . 16
3 In-Car Communication System 19
3.1 CAN - Controller Area Network . . . . . . . . . . . . . . . . . 19
3.2 FlexRay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
3.3 Automotive Gateway Architectures . . . . . . . . . . . . . . . . 23
3.4 Other Communication Technologies . . . . . . . . . . . . . . . 25
iContents
4 Prototype Measurements of In-Car Data Transmission 27
4.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
4.2 Measurement Hardware Setup . . . . . . . . . . . . . . . . . . 28
4.3 Software Tooling for Data Evaluation . . . . . . . . . . . . . . 29
4.3.1 Communication Access Programing Language and VEC-
TOR CANoe . . . . . . . . . . . . . . . . . . . . . . . 29
4.3.2 ExpertFit® . . . . . . . . . . . . . . . . . . . . . . . . 31
4.4 Measurement Studies of In-Car Communication . . . . . . . . . 31
4.4.1 Frequency Drift of Controller Quartzes . . . . . . . . . 31
4.4.2 Durations and Distributions of CAN ECU Startup Times 39
4.4.3 Cycle Time Jitter of CAN Messages . . . . . . . . . . . 43
4.4.4 Routing Delay in Central Gateway . . . . . . . . . . . . 46
4.5 Discussion of Prototype Measurements and Data Evaluation Results 54
5 Discrete Event Simulation of In-Car Data Transmission 57
5.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
5.2 Discrete Event Simulation . . . . . . . . . . . . . . . . . . . . 58
5.3 AnyLogic™ . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
5.4 Modeling Elements for Simulation of In-Car Data Transmission 60
5.4.1 Message Objects . . . . . . . . . . . . . . . . . . . . . 60
5.4.2 CAN . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
5.4.3 FlexRay . . . . . . . . . . . . . . . . . . . . . . . . . . 69
5.4.4 Gateway . . . . . . . . . . . . . . . . . . . . . . . . . 75
5.4.5 Overall In-Car Communication Network . . . . . . . . 78
5.5 Discussion of Discrete Event Simulation Approach . . . . . . . 79
6 Worst-Case Analysis of In-Car Data Transmission 81
6.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
6.2 Network Calculus . . . . . . . . . . . . . . . . . . . . . . . . . 82
6.2.1 Theoretical Foundations . . . . . . . . . . . . . . . . . 84
6.3 Application of Network Calculus to CAN Communication . . . 90
6.3.1 Input Data . . . . . . . . . . . . . . . . . . . . . . . . . 90
6.3.2 Generation of Arrival Curves . . . . . . . . . . . . . . . 91
6.3.3 Determination of the Service Curve . . . . . . . . . . . 93
6.3.4 Calculation of Delay Bounds . . . . . . . . . . . . . . . 94
6.3.5 Exemplary Message Schedule . . . . . . . . . . . . . . 99
iiContents
6.4 Application of Network Calculus to Overall In-Car Communica-
tion Topology . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
6.4.1 Methodical Approach . . . . . . . . . . . . . . . . . . . 101
6.5 Discussion of Worst-Case Analysis Approach . . . . . . . . . . 112
7 Application Examples 113
7.1 Local CAN Bus Communication . . . . . . . . . . . . . . . . . 113
7.1.1 Simulation Experiments . . . . . . . . . . . . . . . . . 113
7.1.2 Network Calculus . . . . . . . . . . . . . . . . . . . . . 115
7.1.3 Performance Evaluation Results . . . . . . . . . . . . . 115
7.1.4 Comparison and Discussion . . . . . . . . . . . . . . . 117
7.2 Network-Wide Data Transmission . . . . . . . . . . . . . . . . 119
7.2.1 Simulation . . . . . . . . . . . . . . . . . . . . . . . . 120
7.2.2 Network Calculus . . . . . . . . . . . . . . . . . . . . . 121
7.2.3 Performance Evaluation Results . . . . . . . . . . . . . 122
7.2.4 Comparison and Discussion . . . . . . . . . . . . . . . 131
8 Conclusions and Future Work 135
8.1 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
8.2 Future Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
iiiList of Figures
1.1 Time Plot of Airbag Activation in a Crash [3] . . . . . . . . . . 2
1.2 ACU (left) and Crash Sensors (right: g-Sat, p-Sat) [3] . . . . . . 3
1.3 Placement and Interconnection of Passive Safety Electronics . . 5
1.4 Side-Airbags, Front-Airbags and Belt Tensioner [50] . . . . . . 6
1.5 Functional Safety Concepts for Airbag Deployment . . . . . . . 8
1.6 Future Vehicle Safety and Road Traffic Scenario [55] . . . . . . 9
1.7 Examples of Future Vehicle Precrash Functions and Employed
Safety Devices [50] . . . . . . . . . . . . . . . . . . . . . . . . 12
3.1 Network Topologies: Central Gateway (left) and Cascaded (right) 20
3.2 CAN Serial Line Architecture . . . . . . . . . . . . . . . . . . 21
3.3 CAN Frame Structure . . . . . . . . . . . . . . . . . . . . . . . 22
3.4 FlexRay Communication Cycle . . . . . . . . . . . . . . . . . . 22
3.5 FlexRay Frame Structure . . . . . . . . . . . . . . . . . . . . . 23
3.6 Typical Automotive Gateway Layout . . . . . . . . . . . . . . . 24
3.7 Cyclic Polling Routing Functionality . . . . . . . . . . . . . . . 25
3.8 Interrupt-based . . . . . . . . . . . . . . 25
4.1 CONDALO CCO DLIII Data Logging Device [8] . . . . . . . . 29
4.2 Prototype Measurement Infrastructure . . . . . . . . . . . . . . 29
4.3 Processing of Measured Communication Data Samples in CAPL 30
4.4 Effect of Frequency Drift of CAN ECUs [30] . . . . . . . . . . 32
4.5 Effect ofy Drift of FlexRay ECU [30] . . . . . . . . . 33
4.6 Measurement Setup for Evaluation of Data Logger Drift [30] . . 34
4.7 Timing Error of Data Logger . . . . . . . . . . . . . . . . . . . 35
4.8 Statechart for Determination of ECU Frequency Drift . . . . . . 36
4.9 CAPL Output File for ECU Frequency Drift Evaluation . . . . . 37
4.10 Change to Sleep Mode of Clamp-30 ECU . . . . . . . . . . . . 40
4.11 Statechart for Determination of ECU Startup Durations . . . . . 41
vListofFigures
4.12 Measurement Data Analysis (Airbag) . . . . . . . . . . . . . . 44
4.13 Data (LCA) . . . . . . . . . . . . . . . 44
4.14 Data Analysis (RBT) . . . . . . . . . . . . . . . . 45
4.15 Distribution of Cycle Times for High Priority CAN Message . . 47
4.16ution of Cycle Times for Low CAN . . 47
4.17 Safety-Relevant Data Exchange between ECUs in the Network . 48
4.18 Statechart for Routing Delay Evaluation . . . . . . . . . . . . . 51
5.1 Event-based Progress in Simulation . . . . . . . . . . . . . . . 59
5.2 Screenshot of AnyLogic™ Modeling Environment . . . . . . . 60
5.3 Conceptual Top-Level View on CAN Communication . . . . . . 63
5.4 Structure of the CAN ECU Object . . . . . . . . . . . . . . . . 63
5.5 CAN ECU Operating System Statechart . . . . . . . . . . . . . 64
5.6 Cyclic Communication of CAN ECUs after Startup . . . . . . . 64
5.7 CAN Controller Statechart . . . . . . . . . . . . . . . . . . . . 65
5.8 CAN Bus Statechart . . . . . . . . . . . . . . . . . . . . . . . . 67
5.9 CSMA/BA Mechanism in the Simulation Model . . . . . . . . . 68
5.10 Conceptual Top-Level View on FlexRay Communication . . . . 69
5.11 Organization of FlexRay Communication with Linked Lists . . . 70
5.12 Structure of the FlexRay ECU Object . . . . . . . . . . . . . . 70
5.13 FlexRay Controller Statechart . . . . . . . . . . . . . . . . . . 72
5.14 FlexRay Bus Statechart . . . . . . . . . . . . . . . . . . . . . . 75
5.15 Conceptual Top-Level View on Central Gateway . . . . . . . . 75
5.16 Switching Unit Statechart for Cyclic Polling . . . . . . . . . . . 76
5.17 Unit for Priority-based Routing . . . . . . 78
5.18 Conceptual Top-Level View on In-Car Communication System . 79
6.1 System-theoretical View on Network Calculus . . . . . . . . . . 83
6.2 Token Bucket Arrival Curve . . . . . . . . . . . . . . . . . . . 85
6.3 Rate-Latency Service Curve . . . . . . . . . . . . . . . . . . . 87
6.4 Delay Bound and Bac