Bremslenkmomentoptimierte Kurvenbremsung von Motorrädern
Brake Steer Torque Optimized Corner Braking of Motorcycles
Zusammenfassung
This thesis deals with the Brake Steer Torque (BST) induced stand-up tendency of Powered Two Wheelers (PTW) and measures to lower the associated risk for running wide on curve accidents with sudden, unforeseen braking. Focus is set on the BST Avoidance Mechanism (BSTAM), a chassis design that eliminates the BST through lateral inclination of the kinematic steering axis. A simple mathematical model is used to identify its main influences on the driving behavior and derive an optimized system layout. Its theoretical potential is evaluated against the standard chassis using different cornering adaptive brake force distributions and riding styles. For the first time ever, a motorcycle with state-of-the-art brake system (Honda CBR 600 RR, C-ABS) is equipped with a BSTAM and tested in corner braking experiments. Compared to the baseline, it is significantly reducing BST related disturbances and improving directional control. The gained insights can be stepping stones to enhance PTW safety by...
Schlagworte
- Kapitel Ausklappen | EinklappenSeiten
- 1–10 1 Introduction and Aims 1–10
- 1.1 Motivation
- 1.2 Working Hypothesis and the Brake Steer Torque Avoidance Mechanism
- 1.3 Research Objectives
- 1.4 Methodology & Structure of this Thesis
- 11–70 2 The BST Chain of Effects and State of the Art Countermeasures 11–70
- 2.1 Fundamentals of Motorcycle Dynamics
- 2.1.1 Coordinate Systems and Basic Chassis Geometry
- 2.1.2 Roll Equilibrium, Tire Scrub Radius & Riding Styles
- 2.1.3 Influences on Steering Torque Demand
- 2.1.4 Tire Road Interaction
- 2.1.5 Steering Kinematics and Steering Angle
- 2.1.6 Bi-Directional Coupling of Steer & Roll (Stabilization & Maneuvering)
- 2.1.7 Tire Forces and Ideal Brake Force Distribution during Corner Braking
- 2.1.8 Braking Stability
- 2.2 The BST Chain of Effects
- 2.2.1 The Main Chain of Effects
- 2.2.2 Further Primary and Secondary Influences
- 2.2.3 The Influence of Riding Style
- 2.2.4 The Inverse Effect
- 2.2.5 The Role of the Rider as a Controller
- 2.3 State of the Art of BST-Countermeasures
- 2.3.1 Avoiding BST-Critical Situations
- 2.3.2 Training the Rider
- 2.3.3 Influencing the Brake Force
- 2.3.4 Influencing the Lever Arm(s)
- 2.3.5 Influencing Wheel Load and Chassis Geometry Changes
- 2.3.6 Influencing Secondary Effects on Steering Torque
- 2.3.7 Influencing the Steering Torque and Movement
- 2.3.8 Influencing the Rolling Moment and Movement
- 2.3.9 Using Multi-Track Tilting Vehicles with Two Front Wheels
- 2.4 Conclusions
- 71–124 3 Analytic Considerations on the Kinematic Layout and Effectiveness of BSTAM 71–124
- 3.1 Force Transmission Ratios of a Generic BSTAM and Standard Chassis
- 3.2 Steering Torque Demand (STD) of a Standard Chassis
- 3.3 Layout and STD of a BSTAM with Laterally Inclined Steering Axis (KPI)
- 3.3.1 Remarks on the STD of a BSTAM with Parallel Steering Axis Offset
- 3.3.2 Definition & STD of a BSTAM Optimized for Neutral Free Cornering
- 3.3.3 The Influence of Pitch on the STD and BSTAM Layout
- 3.3.4 STD of the BSTAM Realized in the Prototype Motorcycle
- 3.3.5 Discussion of Neglected Influences on STD
- 3.3.6 The Inertia Effect Created Through a BSTAM with KPI
- 3.4 Layout and STD of a BSTAM with Parallel Steering Axis Offset
- 3.4.1 Optimization Potential of a Parallel BSTAM for Neutral Free Cornering
- 3.4.2 Considerations on Effectiveness of Multi-Lever Steering
- 3.5 Conclusions on Optimal BSTAM Design
- 3.6 Effectiveness Comparison of BSTAM and Standard Chassis
- 3.6.1 Model Extensions & Overview of Simulated Experiments
- 3.6.2 Maximal Braking on Constant Radius
- 3.6.3 Partial Braking on Constant Radius with Different BFD
- 3.6.4 Partial Front Braking under Special Conditions
- 3.6.5 Conclusions on the Effectiveness of Different BFD
- 3.6.6 Comparison of Simulated and Real BFD
- 3.7 Hypotheses for Riding Experiments and Concluding Remarks
- 3.7.1 Hypotheses on the Expected Performance of Standard Chassis and BSTAM in Riding Tests
- 3.7.2 Concluding Remarks
- 125–156 4 Implementing BSTAM in a Motorcycle 125–156
- 4.1 General Considerations on Mechanical Setup
- 4.1.1 Basic Kinematic Concepts of a BSTAM
- 4.1.2 Combining BSTAM with Different Chassis Designs
- 4.1.3 Bearing Trajectory and Actuation Concept
- 4.1.4 Alternative BSTAM Actuation Concepts
- 4.2 Mechanical Setup of the BSTAM Prototype
- 4.2.1 Definition of Prototype Motorcycle and Choice of BSTAM Concept
- 4.2.2 Excentricity Layout
- 4.2.3 Simple Geometric Control Algorithm and Computation of Lever Arms
- 4.2.4 Chassis Geometry Changes through BSTAM
- 4.3 Overview of the BSTAM Prototype
- 4.4 Measurement and Control Setup
- 4.4.1 Overview of Main Components
- 4.4.2 Accuracy of Relevant Measurements
- 4.4.3 Data Sampling and Post Processing
- 4.4.4 System Performance
- 4.4.5 Extended Control Algorithms
- 4.4.6 Relevance of Elevated Curve Detection
- 4.5 Concluding Remarks
- 157–205 5 Driving Tests 157–205
- 5.1 Test Design
- 5.1.1 General Requirements
- 5.1.2 Test Track Definition
- 5.1.3 Test Maneuver and Riding Task
- 5.1.4 Test Setups and Maneuver Variations
- 5.1.5 Comments on the Conduct of Tests
- 5.2 Criteria for Evaluation
- 5.2.1 Definition of Characteristic Values
- 5.2.2 Exemplary Comparison of Characteristic Values in Corner Braking Experiments with Standard Chassis vs. BSTAM
- 5.2.3 Arrangement and Display of Results
- 5.3 Global Analysis of All Test Results
- 5.3.1 Correlation Analysis of Characteristic Values
- 5.3.2 Performance of Centered Steering Axis vs. BSTAM
- 5.3.3 Interim Conclusions from Global Analysis
- 5.4 Detailed Analysis of Individual Test Results
- 5.4.1 Test Setup Nomenclature of Abbreviations
- 5.4.2 ABS Braking with Standard Steering under Variation of Brake Application, Riding Style, and Steering Damper
- 5.4.3 Partial Front Braking with Standard Steering vs. BSTAM
- 5.5 Concluding Remarks
- 206–220 6 Discussion and Outlook 206–220
- 6.1 Results
- 6.2 Transferability of Results
- 6.3 Relevance of Results for other Systems and Stakeholders
- 6.4 Outlook
- 221–255 A Appendix 221–255
- A.1 Appendix to Chapter 1
- A.2 Appendix to Chapter 2
- A.3 Appendix to Chapter 3
- A.3.1 Equation Set for the Derivation of the Optimized Instantaneous Center of Steering Axis Inclination of OPT BSTAM
- A.3.2 Equation Set for the Computation of Tire Contact Forces with different Brake Force Distributions (BFD)
- A.3.3 Equation Set for the Computation of Measured Brake Force Distributions for the Entry in the BFD Diagram
- A.4 Appendix to Chapter 4
- A.4.1 Alternative Actuation Concepts
- A.4.2 Technical Data of the Prototype Motorcycle
- A.4.3 Considerations on Steering Torque Measurement
- A.4.4 Considerations on Roll Angle Measurement
- A.4.5 Definition of Filter Parameters
- A.5 Appendix to Chapter 5
- A.5.1 Results of Global Analysis in CDF-Plot Format
- A.5.2 Correlation Tables for ALL Experiments
- A.5.3 Correlation Tables for Exp. with Centered Steering Axis
- A.5.4 Correlation Tables for Exp. with BSTAM Active
- 256–262 Bibliography 256–262
- 263–264 Own Publications 263–264
- 265–268 Student Research Work 265–268
