Bicycle Hardware‐in‐the‐Loop Simulatorfor Braking Dynamics Assistance System

IPG Apply & Innovate 2016 ConferenceSession: Off‐Highway

Cornelius Bott, Martin Pfeiffer, Oliver Maier, Jürgen Wrede21.09.2016

Outline

Introduction to BikeSafeMotivationVision

MethodologyHIL Testbench

Structure and ComponentsUsage in Development

ResultsConclusion

2

Motivation for Active Safety Systems on Bicycles

3

• Low wheel moment of inertia

• Risk of overbraking

• Mainly on roads with low

friction coefficient & in curves

Front wheel lockup

• High centre of gravity

• Emergency or shock braking

• Mainly on roads with high

friction coefficient & downhill

Nose over(falling over the handlebars)

• Properly adjusted:

always very powerful

• Modern hydraulic technology: 

stronger and more robust

• High risk of falling due to 

users’ mistakes

Bicycle braking systems

• Availability of electric energy

• Favourable mass & cost ratio

Electrifiedbicycles

Sources:Gustav Magenwirth GmbH, Robert Bosch GmbH

Vision Functional Prototype

• Purpose: algorithm development

• Rapid‐control‐prototyping system

• Purpose: brake pressure modulation

• Hydraulic unit of motorcycle ABS 

• Measurands: 1) longitudinal and vertical accelerations

2) pitch rate

• Micromechanical sensor unit

4

Control unit

Actuator

• Measurand: front wheel speed

• Active sensor based on Hall Effect

Sensors

Mechatronic Structure of the Braking Dynamics Assistance System (BDA)

5

Environment

PlantActuatorsController

Driver

Sensorsu y x rzuD

6

Methodology of Development

Proof of Concept

Functional model evaluation

System integrationand testing

④

Requirements Profile

Accident research and respective applications

①

Requirements identification and quantification

②

⑤

System design and implementation

③

Validation

Validation

Structure of HiL‐Testbench

User‐PC

dSPACE MAB

Sensor Signals

BrakeActuation

Parameters, Stimuli

Measurement Values Simulation

BDA‐Function

Measure‐mentValuesBrakeSystem

ControlSignals HU

MeasurementValues Experiment

Hardware‐Installation

BoschHU

HydraulicBrake

PneumaticSystem

Xeno Realtime‐Computer

CarMaker

I/O Modules

BicycleModel

7

Simulation Model 

8

Software: SimHydraulics/ SimMechanics

Extensions:

Dynamic effects of brake hydraulic

Repeated rear‐wheel lift‐off

Movement of driver during brake process

Code generation and cross compilation supported

except for tyre model

Software: Simulink

Features:

Static effects of hydraulic brake system

Plain movement (longitudinal and vertical)

Driver is modeled as a point mass

Code generation and cross compilation fully

supported

13 DoFPhysical Multi‐Body Model

4 DoFEquation‐basedModel with three

Bodies

9

Real‐Time Computer & M‐Modules

M400WheelSpeed

M62NAnalog Outputs

M36N00Analog Inputs

M514x CAN

Front‐ and

Rear‐Wheel

60 Teeths

Measurement 

Trigger

Lift‐Off Sensor

Brake force

Measurement

Brake lever Sensor

Pressure sensors

Acceleration sensors

HiL‐Testbench

Real time computer RCP System

Brake force sensorCharge amplifier

Brake lever

Battery

10

Video of automated braking system

Pressure: 100barGradient: 1000bar/s

Controllable movementConditions can be reproduced

11

Usage in Development

MiL HiL Real Experiment

• Wheel Speed Signal Analysis 

under real conditions

• Investigation of hydraulic brake 

system (especially HU)

• Cover a wider parameter space

• Reproducibility

12

13

Results – BDA‐Function not engaged

14

Results – BDA‐Function engaged

Conclusion – Usage of HIL for development of a BDA function

15

Requirements for BikeSafe function development were met

Very useful for investigation of Brake System and HU

Good validation of BDA function before real experiments

Limitations of BDA function could be accessed

Transfer of known method to a new domain

16

Thank you for your attention!