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

Dynamic Stability Control III System• Antilock Braking System ABS • Dynamic Stability Control System DSC • Automatic Stability Control System ASC+T Electric Power Steering EPS • Componen

Trang 1

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

Trang 2

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

Trang 3

ACTIVE TRANSMISSION GEARBOX

5 Planetary gear set 1

14 Transmission output shaft

GENERAL VIEW

Trang 4

MULTIDISC CLUTCH

Trang 5

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

Position of electric machines on active gearbox

5

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 rpmMaximum speed 10,500 rpm 13,500 rpm

Nominal current

Trang 6

PLANETARY GEAR SET

Index Explanation

1 Planetary gear set 1

Trang 7

TRANSMISSION OIL SUPPLY SYSTEM

B Detailed view of the electrical connection

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

Trang 8

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.

Trang 9

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

Trang 11

01 ECVT 1

11Power line of ECVT 1 mode in running pure electric

Planetary gear set 3

Trang 12

01 ECVT 1

Trang 13

02 ECVT 2

Planetary gear set 3 Planetary gear set 1

Multidisc clutch 2

Trang 14

Planetary gear set 3 Planetary gear set 1 Planetary gear set 2

Trang 15

Planetary gear set 3 Planetary gear set 1

Planetary gear set 2 Multidisc clutch 2

Trang 16

05 FORWARD GEAR 3

Planetary gear set 1 Multidisc clutch 2

Trang 17

Trang 18

Operating by opening 4 multidisc clutches simultaneously.

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

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

Trang 19

Planetary gear set 1 Planetary gear set 2 Planetary gear set 3

Trang 20

POWERTRAIN SYSTEM (xDrive)

GENERAL VIEW

Main purpose of the system is to improve both traction and control capability on slippery road conditions It’s an innovative system that

controls and regulates driving torque

to front and rear axles.

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

Trang 21

21

A Servomotor with coding resistor

B Servomotor with motor position sensor

Trang 22

Inputs Processor Outputs

COMPONENTS

Trang 23

Components of the ATC 500 Transfer case

1 Transmission input shaft

2 Output to the rear axle propeller shaft

3 Output to the front axle propeller shaft

Trang 24

PRINCIPLES OF OPERATION

1 Input from transmission

2 Output to rear propeller shaft

3 Output to front propeller shaft

Power flow of the transfer case

Trang 25

01 PRE-CONTROL

The pre-control logic reflects the

driver’s command and is calculated

In normal driving, driving torque

distribution is 60% on the rear axle

and 40% on the front axle.

25

Trang 26

Trang 27

DYNAMIC STABILITY CONTROL III SYSTEM

OVERVIEW OF FUNCTIONS

27

Diagram of functions in the DSC III system

Trang 28

GENERAL VIEW

The main purpose of the DSC III system is to

improve overall stability control of the

vehicle.

New/changed functions of DSC III include:

New Hill Decent Control (HDC) function.

New Differential Brake Control (ABD) function.

Changed traction control function.

Including all functions and features of the DSC III system on previous models such as:

Maintaining traction under all driving conditions.

Maitaining the directional control.

Correction for oversteer/understeer.

Providing Corner Brake Control (CBC).

Providing dynamic control features of Dynamic Braking Control (DBC) and Maximum Braking Control (MBC).

Trang 29

Diagram of functions and sub-functions of DSC III system

29

Trang 30

ANTILOCK BRAKING SYSTEM

DSC III Control unit

DSC III Control unit Roadwheel speed

Inlet and outlet solenoid valves

Trang 31

ABS regulation has 3 phases:

• Pressure Build

• Pressure Hold

• Pressure Release

ABS regulation at front wheels 31

Trang 32

2 SUB-FUNCTIONS OF ABS

The activation conditions of CBC include:

• The vehicle is cornering.

• ABS regulation is not working.

• Transverse acceleration exceeds 0,6g.

CORNER BRAKE

CONTROL (CBC)

Trang 33

DSC III control unit DSC III control unit Hydraulic valves

OUTPUT

Roadwheel speed sensors Yaw rate sensor

ELECTRONIC BRAKE

PROPORTIONING (EBV)

33

Trang 34

2 SUB-FUNCTIONS OF ABS

Trang 35

The DSC regulation sequence initiates when the control unit detects

differences between the driver’s desired turning angle and the actual

rotation angle of the vehicle.

The control unit determines vehicle stability based on:

• Steering wheel angle.

• Rotation angle and speed

DYNAMIC STABILITY CONTROL

35

Trang 36

Trang 37

2 DYNAMIC BRAKE CONTROL (DBC)

DBC is designed to provide an increase in braking pressure up to ABS threshold during emergency braking situations

The triggering conditions are:

• Brake light switch on.

• Brake pressure in the master cylinder above threshold.

• Brake pressure build-up speed above threshold.

• Vehicle road speed above 5 km/h.

• Pressure sensor self test completed and sensor not faulted.

• Vehicle traveling forward.

• Not all the wheels in ABS regulation range.

37

Trang 38

DBC will stop working under these conditions:

• The driver release the break pedal.

• Brake pressure falls below threshold.

• Vehicle road speed below 5 km/h.

Trang 39

ASC prevents unintentional wheel slip of the drive wheels

in every situation.

ASC controls longitudinal wheel slip by two means:

• Automatic Stability Control (ASC Engine Intervention) by

reducing engine torque.

• Automatic Differential Brake (ABD Brake Intervention) by

locking differential to improve traction.

AUTOMATIC STABILITY CONTROL

39

Trang 40

2 SUB-FUNCTIONS OF ASC+T

If the vehicle is driven in low gear when coasting downhill,

or there is a sudden shift to lower gear, the engine braking

effect can slow down the drive wheels rapidly and result in

an unstable situation

The DSC III control unit signals the DME via the CAN bus

to raise the engine torque, allow the drive wheels to

accelerate to match the speed of the non-driven wheels.

The MSR regulation is cancelled if the brake pedal or hand

brake is applied.

AUTOMATIC STABILITY CONTROL

Trang 41

1 HILL DECENT CONTROL (HDC)

HDC is design for off-road use to automatically slow the vehicle and maintain a steady speed on steep gradients.

The triggering conditions include:

• HDC button is pressed.

• Vehicle speed < 40 km/h.

• Accelerator pedal pressed < 15%.

• Downhill driving recognized.

The HDC function will be switch off when vehicle speed > 60 km/h.

NEW FUNCTIONS OF DSC III SYSTEM

41

Trang 42

2 TRACTION CONTROL

NEW FUNCTIONS OF DSC III SYSTEM

3 OFF-ROAD ABS CONTROL MODULE PROGRAMMING

This function allow a higher threshold for ABS regulation

when driving off-road in loose gravel or dirt.

The traction control function provides anti-spin control at

all times when driving the vehicle off road.

This function will be cancelled temporarily when

temperature of brakes goes above 600oC.

Trang 43

GENERAL CHARACTERISTICS

Damping disturbances which originate from the road surface Active steering wheel return.

No hydraulic circuit.

Requirements-based activation of electric motor.

Steering servo independent of the speed of the ICE.

43

ELECTRIC POWER STEERING (EPS)

Trang 44

MECHANICAL DESIGN

The steering torque sensor provides the EPS control unit with information about steering torque applied by the driver.

Steering torque sensor EPS control unit and electric motor with position sensor

Trang 45

1 Ball bearing outfeed mechanism

2 Ball bearing return channel

3 Ball bearing infeed mechanism

4 Nut of the ball screw drive

5 Ball screw thread on steering rack

7 Reduction-gear housing

The reduction gearing transmits the torque generated by the

electric motor to the steering rack.

The overall transmission ratio is approximately 1:20

Trang 46

S1 Input signals for EPS control and modulation function

S2 Input signals for EPS status control

F1 “Speed-dependent power steering assistance” function

F2 “Active steering-wheel return” function

F3 “Active damping” function

F4 “Active roadwheel feedback” function

F5 “Status control” function

F6 “Co-ordination of specified settings” function

S3 Output signals of EPS control and modulation function

Trang 47

1 Steering torque applied by driver

2 Power assistance torque provide by EPS

3 Vehicle road speed equal to 0

4 Vehicle road speed increases

5 Vehicle road speed at maximum

EPS speed-dependent power steering assisstance

47

Trang 48

The following signals required to activate this function are:

• Road speed

• Steering angle

• Steering angle rate of change

This function will be activated when the drive let the

steering wheel slip while exiting tight corner with:

• Steering angle is not at zero degree

• Steering torque applied by driver

approximately equal to zero

Trang 49

3 ACTIVE DAMPING

2 Steering wheel angle

3 Steering angle progression

4 Yaw rate

5 Theorical vehicle response without active damping

6 Desired vehicle response with active damping

Damping roadwheel feedback Damping steering input from the driver

49

Trang 50

4 ACTIVE ROADWHEEL FEEDBACK

The EPS control unit analyses information that describes the vehicle’s dynamic handling situation.

From that information, the EPS computes additional

“EPS road surface data”

The driver obtains better roadwheel feedback characteristics.

Trang 51

5 EPS STATUS

CONTROL

The conditions for allowing operation of EPS status control are following:

• Ignition must be switched on.

• Engine must be running.

• There must be no EPS input signal faults or EPS internal faults present.

When detecting faults, EPS functions will be shut down to prevent incorrect control of the electric motor.

51

Trang 52

END STOP AS SOFTWARE FUNCTION

Trang 53

THANK YOU FOR YOUR LISTENING!!

Do you have any questions?

Định dạng
Số trang	53
Dung lượng	22,34 MB