Virtual Driveability & NVH Development of HEV Impulse Start · ability & NVH development of hybrid impulse start. Model Based Development of critical HW/SW interactions & virtual

Dr. Stephen Jones

[email protected]

+43 664 850 9172

AVL List GmbH (Headquarters)

Public

Virtual Driveability &

NVH Development of

HEV Impulse StartFrom Concept to SOP

mailto:[email protected]

Jones, Stephen John, Böhm, Hannes | DS | 28 June 2018 | 3Public

OVERVIEW

▪ Introduction / Background

▪ 3D Co-Simulation Toolchain

▪ Driveability Evaluation of Impulse Start

▪ Validation of Methodology

▪ Simulation Examples

▪ Summary


OVERVIEW






▪ Summary


INTRODUCTION & BACKGROUND

What is HEV Impulse or Bump Start:

Refers to ICE Start with HV E-Motor in P2 Hybrid e.g. from Electric Driving.

Impulse Start via E-Motor (EM) supported by kinetic energy of EM rotor etc.

Very critical with w.r.t. comfort & performance.

Critical interaction of ICE, Separation Clutch CL0, EM, Transmission Clutch CLX.

Highly coordinated control & calibration essential to balance comfort & performance.


TSS

AVL-DRIVE™AVL VSM™

AVL TSS Mdl

Performance & Comfort Challenges:

Drop in propulsion power

resulting from cranking ICE

via EM power.

High propulsion power

demand in electric driving

reduces available EM power

for impulse start Critical

w.r.t. comfort &

performance.

Trade-off between

performance, comfort &

operation strategy.

INTRODUCTION & BACKGROUND

AVL Solution:

Frontloaded virtual drive-

ability & NVH

development of hybrid

impulse start.

Model Based Development

of critical HW/SW

interactions & virtual

driveability evaluation.

Addressing all aspects:

Control function & SW,

powertrain complexity, 3D

vehicle, driveability.


OVERVIEW






▪ Summary


TSS


AVL TSS*

Co-Simulation via AVL Model.CONNECT™ with Driveability Assessment:

3D CO-SIMULATION TOOLCHAIN

AVL TSS* – PT/Driveline, Function & SW

Mechatronic Powertrain/Driveline Model withcrank angle resolved accuracy.

Concept to SOP level Impulse Start ControlFunction, SW & Calibration.

AVL VSMTM – 3D Vehicle

Simulates Chassis & Powertrain Block Motions.

Export of Driveability relevant signals for VirtualAssessment of (P)HEV Impulse Start.

AVL-DRIVETM – Driveability Evaluation

Simulates Chassis & Powertrain Block Motions.

Export of Driveability relevant signals for VirtualAssessment of (P)HEV Impulse Start.

TSS

* TSS = Torsional System Simulation


AVL TSS* for Non-Linear Physical Simulation of Mechatronic Powertrain & its Torsional Response:

Gasoline or Diesel ICE: fast with crank angle

resolved torque.

ECU Functions (e.g. State Control, Idle, OBD-Misfire).

Torsional Vibration Damper e.g. DMF (MBS).

Separation Clutch CL0 incl. Controller.

E-Motor Model incl. Controller.

Detailed TM: PGS, Clutches & Brakes

including TCU Model.

Elastic Driveline, Differential, Suspension,

Elastic Tire incl. Interface to AVL VSM™.

Powertrain Block Support Torque.

3D CO-SIMULATION TOOLCHAIN - AVL TSS

TSS Model

Engine

DMF

Sep. CL

E-Motor

TM & DL

Vehicle

Impulse Start Controller

Results Output

* TSS = Torsional System Simulation

TSS


AVL VSM - Precise Non-Linear Physical Simulation of 3D Vehicle Dynamics:

Tire Slip Model e.g. Pacejka (1).

Wheel Suspension.

Powertrain Block Suspension with 6 DoF (2).

3D Vehicle Chassis Motion.

Realistic simulation of signals required for

Driveability Evaluation with AVL-DRIVE™.

AVL Model.Connect - Co-Sim. Platform:

Signal interfacing between TSS & VSM (3).

Align very different sample rates of TSS & VSM.

3D CO-SIMULATION TOOLCHAIN - AVL TSS & MODEL.CONNECT

(3)

(1)

(2)


AVL-DRIVETM for Evaluation of Driveability:

3D CO-SIMULATION WITH AVL-DRIVE BASED VIRTUAL DRIVEABILITY EVALUATION


OVERVIEW






▪ Summary


Main Impulse Start Driveability Evaluation Criteria:

Evaluation of Dynamics

1) Acceleration Build-Up Delay

2) Acceleration Increase Delay

3) Impulse Torque Build-Up

Evaluation of Comfort

4) Acceleration Build-Up Delay

5) Acceleration Increase Delay

6) Impulse Torque Build-Up

DRIVEABILITY EVALUATION IMPULSE START:CRITERIA & ASSESSMENT SCALE

Driveability Assessment Scale:

Critical Simulated Signals evaluated with AVL-DRIVETM

w.r.t. listed evaluation criteria & rated vs.Driveability Assessment Scale:‘DR’ = Driveability Rating from 1 to 10

Note calibration of rating function for Impulse Starts not fully validated yet.


Dynamics Criteria:

(1) Acceleration (Ax) Build-Up Delay

Duration until 50% of Final LongitudinalVehicle Acceleration reached.

(2) Acceleration (Ax) Increase Delay

Duration until 90% of Final LongitudinalVehicle Acceleration reached.

(3) Impulse Torque Build-Up

Ratio between Surface Areas under Normalized Pedal Value & Longitudinal Acceleration Curves (i.e. green positive area minus red negative area, divided by area below black curve).

IMPULSE START DRIVEABILITY EVALUATION: CRITERIA 1/2

Pedal [%

]

Trigger

100% Final Accel

0% Accel

Accel. [

%]

Normalized Pedal Value

zero level

Time [s]

Pedal [%

]

Normalized long.

Acceleration


Zero Level @Trigger of Imp.Start

Normalized long.

Acceleration


Zero Level @Trigger of Imp.Start A

ccel[

%]

Pedal [%

]

Accel[

%]

Time [s]

(1)

(2)

(3)Poor

(3)Good


Comfort Criteria:

(4) Traction Reduction

Magnitude of drop in longitudinal acceleration signal; integration of acceleration over time where acceleration drops.

(5) Jerks (Standard Criterion)

Modulation of longitudinal acceleration up to 10Hz (not shown).

(6) Surge, & Surge Lateral:

Acceleration Vibration Dose Value (VDV) functions (10 to 50Hz, not shown).

IMPULSE START DRIVEABILITY EVALUATION: CRITERIA 2/2

Trigger

Accel. [

%]

Pedal [%

]

Time [s]

(4)


OVERVIEW






▪ Summary


Simulation Methodology validated on:

HEV SUV with 2.0L Gasoline, AT, 4WD

Measured Signals on Validation Vehicle:

CAN Bus Signals.

High-Resolution Speed Signals on Crank-shaft, E-Motor, Transmission Output Shaft, Rear Differential, Wheel Hubs.

Torque Sensor in Rear Propshaft.

Transmission Clutch & Brake actuation pressure level to assess current torque capacities.

Powertrain Block motion.

Vehicle Chassis Accel. (& other signals required for Driveability Evaluation with AVL-DRIVETM).

VALIDATION OF METHODOLOGY

CL0… Sep. Clutch: Controlled Transfer of EM Torque to ICE during Impulse Start.

Brake B inside AT: Slipping Elements maintain Isolation of Speed Fluctuations from TM Output Shaft.

PG

S1 PG

S2

PG

S3

PG

S4

InputshaftOutputshaft

Autm. Transmission

Wheels

Front Prop-Shaft

Rear Prop-Shaft

Sideshaft

SideshaftWheels

CL0

Brake B


Impulse Start – Measurement (4th Gear):

METHODOLOGY VALIDATIONCORRELATION 1/3

(1) Transmission Pre-Control

(3) E-

Motor Speed Phase

Trig

ger I

mp

uls

e S

tart

(4) ICE

Acceleration via CL0

(2)CL0 Filling Phase

(1) Transmission Pre-Control: Slip Brake B

(2) Separation Clutch CL0: Filling Phase

(3) E-Motor Speed Phase (Kinetic Energy rise)

(4) Ramp up CL0:

Acceleration ICE Crankshaft

(5) ICE Firing & CL0 Opening

(6) Torque Handover: EM ICE

(7) Brake B Closing(5) ICE Firing

& CL0 Opening

(7) Brk B

closing

(6) Trq

HandoverEMICE


Impulse Start – Measurement vs. Simulation (4th Gear):


(1) Transmission Pre-Control

(3) E-

Motor Speed Phase

(4) ICE

Acceleration via CL0

(5) ICE Firing

& CL0 Opening

(7) Brk B

closing

(6) Trq

HandoverEMICE

Trig

ger I

mp

uls

e S

tart

(2)CL0 Filling Phase


Impulse Start Driveability Evaluation – Measurement vs. Simulation (4th Gear):


SimMeas

DDR = 0.1

DDR = -0.3

DDR = 0.1

DDR = 0.9

DDR = 0.3

(3)

MeasSim

DDR = 0.0

DDR = -0.6

DDR = -0.1

DDR = 0.0

DDR = 0.0

(2)


OVERVIEW






Example #1 – Control Functions & Driveability

Example #2 – Robustness & Driveability

Example #3 – E-Motor Sizing & Driveability

▪ Summary


Proven methodology now applied to:

PHEV SUV with 1.8L TGDI & much more powerful E-Motor 90kW, AT8, 4WD, north/south configuration.

PHEV impulse starts at significantly higher initial propulsion power demand & driving speeds vs. earlier HEV validation vehicle.

SIMULATION EXAMPLES: APPLICATION OF METHODOLOGY

PG

S1 P

GS

2

PG

S3

PG

S4

InputshaftOutputshaft

Autm. Transmission

Wheels

Front Prop-Shaft

Rear Prop-Shaft

Sideshaft

Sideshaft Wheels

CL0

CLC


Impulse Start - Initial Configuration

PHEV, 55 mph, 6th Gear, ~50kW Propulsion Power with Hot ICE Condition

EXAMPLE #1a CONTROL FUNCTIONS & DRIVEABILITY

Trigger

Impuls

e S

tart

Partly lower Driveability Ratings

(1) Flat CLC Torque(2) Accel. Overshoot(3) Slow Accel of EM(4) Accel. Dip

(1-4) Decel/accel. of inertia in AT affects acceleration signal

+ -

(1)

(3)

(4) (2)

Ax_

Bu

ild

-U

p D

ela

y

Ax_

In

creas

e D

ela

yIm

pu

lse

Trq

Bu

ild

-U

pT

racti

on

R

ed

ucti

on

Jerks

Su

rg

e

DR 9.8 7.0 7.7 6.0 8.6 9.2


Shaped Torque in Transmission Clutch CLC


EXAMPLE #1b CONTROL FUNCTIONS & DRIVEABILITY

Trigger

Impuls

e S

tart (1+4) Shaped CLC Torque

(2+6) Flat Accel.(3+5) Steeper EM Accel./Decel. (7) Late CL0 Opening(8) Accel. Oscillation

+(1)

(3)

(2)

-(4)

(6)

(5)

(7)

(8) Jerks/Surge

Driveability Ratings improved

Ax_

Bu

ild

-Up

D

ela

y

Ax_

In

creas

e D

ela

y

Im

pu

lse T

rq

B

uil

d-U

p

Tracti

on

R

ed

ucti

on

Jerks

Su

rg

e

DR 8.8 8.6 8.7 9.3 8.8 8.4

DDR vs. Exmpl.#1a

-1.0 +1.6 +1.0 +3.3 +0.2 -0.8


Shaped Torque in CLC & Timely Opening of CL0


EXAMPLE #1cCONTROL FUNCTIONS & DRIVEABILITY

+-

Trigger

Impuls

e S

tart (1) Timely CL0 opening

(2) Acceleration now smooth

(1)

(2)

Driveability Ratings high& balanced

Ax_

Bu

ild

-U

p D

ela

y

Ax_

In

creas

e D

ela

y

Im

pu

lse T

rq

B

uil

d-U

p

Tracti

on

R

ed

ucti

on

Jerks

Su

rg

e

DR 8.5 8.6 8.6 9.2 9.0 9.4

DDR vs. Exmpl.#1b

-0.3 0.0 -0.1 -0.1 +0.2 +1.0


Torque Overshoot in Separation Clutch CL0 e.g. poor µ adaption


EXAMPLE #2 ROBUSTNESS & DRIVEABILITY

Trigger

Impuls

e S

tart (1) CL0 Trq over-shoot

(2) Lock-Up CLC No vibration isolation

(3) Acceleration oscillation

(1)

(2)

(3)

Ax_

Bu

ild

-U

p D

ela

y

Ax_

In

creas

e D

ela

yIm

pu

lse

Trq

Bu

ild

-U

pTracti

on

R

ed

ucti

on

Jerks

Su

rg

e

DR 8.5 8.6 8.6 8.7 8.9 8.9

DDR vs. Exmpl.

#1c

0.0 0.0 0.0 -0.5 -0.1 -0.5

Various Driveability Ratings lower


Impulse Start with very low EM Power Reserve

PHEV, 65 mph, 6th Gear, ~65kW Propulsion Power, Cold ICE as 1st start from eDrive

EXAMPLE #3aE-MOTOR SIZE & DRIVEABILITY

Trigger

Impuls

e S

tart (1) Reduced torque compensation

(2) Long EM accel-eration phase(3) Low available CL0 torque for ICE accel.(4) Very small slip speed (5) Early firing required(6) Strong acceleration fluctuations

(1)

(2)

(4)(5)

(3)

(6)


As before but +5% EM Power & Recalibration

PHEV, 65 mph, 6th Gear, ~65kW Propulsion Power, Cold ICE as 1st start from eDrive

EXAMPLE #3bE-MOTOR SIZE & DRIVEABILITY

(1)

(3)

(4)

(5)

(2)(1) Stronger torque compensation(2) Short EM acceleration phase(3) Safer slip speed (4) Early firing still required Jerks

(5) Smoother (6) Faster

(6)


OVERVIEW






▪ Summary


Novel & validated Co-Simulation Toolchain for:

Model to Driveability Based Development or M2DBDof Hybrid Topology, Requirements, Features & Control SW.

Early Concept Finding with simplified models (controllers, powertrain, vehicle), later upgraded with complex ones.

MiL, SiL development of Functions, SW & Calibration.

Robustness investigation including driveability.

Continuous monitoring of vehicle behavior through dvpt. process & informed refinement of detailed HW/SW design.

Driveability focused optimization.

SUMMARY

TSS


AVL TSS Mdl


ABBREVATIONS

AT Automatic TransmissionHW/SW

Hardware/Software

BMEP

Brake Mean Effective Pressure ICE Internal Combustion Engine

CA Crank Angle IL In Line

CL Clutch MiL Model-in-the-Loop

CPA Centrifugal Pendulum Absorber SiL Software-in-the-Loop

DCT Dual Clutch Transmission OBD On-Board Diagnostics

DMF Dual Mass Flywheel PT Powertrain

DR Drivability Rating p2p Peak to Peak

ECU Electronic Control Unit TSS Torsional System Simulation

EM Electric Motor w.r.t. with respect to

HV High Voltage w / wo with / without

www.avl.com

Thank You

Virtual Driveability & NVH Development of HEV Impulse Start · ability & NVH development of hybrid impulse start. Model Based Development of critical HW/SW interactions & virtual

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