Nghiên cứu hệ thống truyền lực, hệ thống trợ lực lái điện tử và hệ thống an toàn ổn định trên xe BMW active hybrid x6

HCMC UNIVERSITY OF TECHNOLOGY AND EDUCATION
FACULTY OF VEHICLE AND ENERGY ENGINEERING

GRADUATION PROJECT

RESEARCH ON POWERTRAIN SYSTEM
POWER STEERING SYSTEM
AND STABILITY SAFETY SYSTEMS ON BMW ACTIVEHYBRID X6

Instructor: MSc. Duong Tuan Tung
Students:
Huynh Tan Sy

16145508

Ho Dang Hoang 16145391

1


CONTENTS
Active Transmission Gearbox

•
•

Components
Modes of operation

Powertrain System (xDrive)

•
•

Components
Principles of operation

Dynamic Stability Control III System

•
•
•

Antilock Braking System (ABS)
Dynamic Stability Control System (DSC)
Automatic Stability Control System (ASC+T)

Electric Power Steering (EPS)

•
•
•

Components
Principles of operation
DME Functions Used by EPS

2


ACTIVE TRANSMISSION GEARBOX

GENERAL VIEW

Active gearbox of BMW ActiveHybrid X6

Index

Explanation

1

Transmission input shaft

2

Dual-mass flywheel

3

Electric motor for driving the transmission oil pump

4

Transmission oil pump

5

Planetary gear set 1

6

Electric machine A

7

Planetary gear set 2

8

Multidisc clutch 3

9

Multidisc clutch 4

10

Electric machine B

11

Planetary gear set 3

12

Multidisc clutch 1

13

Multidisc clutch 2

14

Transmission output shaft

3


ACTIVE TRANSMISSION GEARBOX

MULTIDISC CLUTCH

Mechanical design and principle operation of multidisc clutch
4


ACTIVE TRANSMISSION GEARBOX
ELECTRIC MACHINE

Position of electric machines on active gearbox

Index

Explanation

1

Electric machine A

2

Electric machine B

3

Rotor of electric machine B

4

Main shaft of the active gearbox

5

Connection for the position sensor of electric machine B

6

Coils on stator of electric machine B

7

High-voltage connection for three phases of electric machine A

8

Coils on stator of electric machine A

Variable

E-machine A

E-machine B

Maximum power

67 kW at 3000 rpm

63 kW at 2500 rpm

Maximum torque

260 Nm at 0 to 2500 rpm

280 Nm at 0 to 2000 rpm

Maximum speed

10,500 rpm

13,500 rpm

Nominal voltage

300 V

300 V

Nominal current level

300 A

300 A

5


ACTIVE TRANSMISSION GEARBOX

PLANETARY GEAR SET

Index

Explanation

1

Planetary gear set 1

2

Planetary gear set 2

3

Planetary gear set 3

Planetary gear sets in active gearbox

6

ACTIVE TRANSMISSION GEARBOX

TRANSMISSION OIL SUPPLY SYSTEM
Index

Explanation

A

EMPI

B

Detailed view of the electrical connection

1

Electric connector

2

Coils of the stator

3

Rotor equipped with permanent magnets

4

Contacts of the high voltage interlock loop

5

Housing of the connector for connection to the power electronic box

6

Contacts for three phases

Electric motor in the oil supply system

Oil pump is driven mechanically by the internal combustion engine via the transmission input
shaft.

Oil pump is driven electronically by an electric motor.

7


ACTIVE TRANSMISSION GEARBOX
HYBRID CONTROL PROCESSOR

Evaluating the drive’s choice and determining the gear (P, R, N, D, S, M).

Select the shift program.

Determine the correct gear.

Adaptive transmission control.

Calculating the necessary torque at the internal multidisc clutches.

Calculating the setpoint torque at the gearbox output.

8


ACTIVE TRANSMISSION GEARBOX
TRANSMISSION CONTROL MODULE

Controlling the transmission oil circuit.

Operating and monitoring the multidisc clutches.

Ensuring cooling of the electric machines.

Reading sensor signals.

Monitoring the gearbox status and activating emergency programs if necessary.

Electronic immobilizer.

9


ACTIVE TRANSMISSION GEARBOX

MODES OF OPERATION

7 FORWARD GEARS + NEUTRAL GEAR

4 FORWARD GEARS

•
•
•
•

Forward Gear 1
Forward Gear 2
Forword Gear 3

3 VIRTUAL GEARS

•
•
•

Electrical Continuosly Variable Transmission 1 (ECVT 1)
Electrical Continuosly Variable Transmission (ECVT 2)
Reverse Gear

Forward Gear 4

10


ACTIVE TRANSMISSION GEARBOX

01

ECVT 1
Planetary gear set 3

Power line of ECVT 1 mode in running pure electric

11


ACTIVE TRANSMISSION GEARBOX

01

Planetary gear set 3

ECVT 1

Planetary gear set 1
Planetary gear set 2

12


ACTIVE TRANSMISSION GEARBOX

02

ECVT 2

Multidisc clutch 2

Planetary gear set 2

Planetary gear set 1

Planetary gear set 3

13


ACTIVE TRANSMISSION GEARBOX
03

FORWARD GEAR 1
Multidisc clutch 4

Planetary gear set 1

Planetary gear set 2

Planetary gear set 3

14


ACTIVE TRANSMISSION GEARBOX
04

FORWARD GEAR 2
Planetary gear set 2

Planetary gear set 1

Multidisc clutch 2

Planetary gear set 3

15


ACTIVE TRANSMISSION GEARBOX
05

Planetary gear set 2

FORWARD GEAR 3

Multidisc clutch 2

Multidisc clutch 4
Planetary gear set 1

Planetary gear set 1

16


ACTIVE TRANSMISSION GEARBOX
06

FORWARD GEAR 4

Planetary gear set 1
Multidisc clutch 2

Planetary gear set 1

17


ACTIVE TRANSMISSION GEARBOX
07

NEUTRAL GEAR

Operating by opening 4 multidisc clutches simultaneously.

2 electric machines rotate freely (neither working as a generator or a motor).

08

RESERVE GEAR

Operating similar to ECVT 1 mode, but electric machine B rotates in the opposite direction.

When in need of more power, ICE can be activated to support.

18


ACTIVE TRANSMISSION GEARBOX

09

AUTOMATIC START/STOP INTERNAL COMBUSTION ENGINE

Planetary gear set 1

Planetary gear set 2

Planetary gear set 3

19


POWERTRAIN SYSTEM (xDrive)
GENERAL VIEW

The first model was introduced on BMW E46 in 2003, and later
became widely used.

It’s an innovative system that controls and regulates driving
torque to front and rear axles.

Main purpose of the system is to improve both traction and control
capability on slippery road conditions.

Transfer case of the xDrive system

20

POWERTRAIN SYSTEM (xDrive)
COMPONENTS
C

B

A

Index

Explanation

A

Servomotor with coding resistor

B

Servomotor with motor position sensor

C

Adjusting levers

1

Disc cam

2

Electric motor

3

Coding resistor

21


POWERTRAIN SYSTEM (xDrive)
COMPONENTS

Processor

Outputs

Inputs

Transfer case control unit (VGSG) in communication with DSC III system

22


POWERTRAIN SYSTEM (xDrive)
COMPONENTS
Index

Explanation

1

Transmission input shaft

2

Output to the rear axle propeller shaft

3

Output to the front axle propeller shaft

4

Servomotor

5

Clutch discs

6

Adjusting levers with ball ramp

7

Chain

8

Disc cam

Components of the ATC 500 Transfer case

23


POWERTRAIN SYSTEM (xDrive)

PRINCIPLES OF OPERATION
01

POWER FLOW IN THE TRANSFER CASE

Power flow of the transfer case
Index

Explanation

1

Input from transmission

2

Output to rear propeller shaft

3

Output to front propeller shaft

24


POWERTRAIN SYSTEM (xDrive)

PRINCIPLES OF OPERATION

01

PRE-CONTROL

The pre-control logic reflects the driver’s command and is
calculated based on:

•
•
•
•
•
•

Accelerator pedal value.
Engine torque.
Engine rpm.
Vehicle speed.
Gear.
Steering angle

In normal driving, driving torque distribution is 60% on the
rear axle and 40% on the front axle.

25