1. SENSOTRONIC BRAKE CONTROL

2. Introduction Introduction electronics necessary
Sensotronic Brake Control (SBC) works electronically
faster and more precisely
large number of mechanical components are simply replaced by
electronics
Computer makes an exact calculation of the brake force
necessary
particular driving situation, calculates the optimum brake
pressure for each wheel

3. Sensotronic Brake Control - the Brakes of the Future

5. What is Twin SBC ?
Twin SBC system is based on the electro-hydraulic brake system that was recently introduced on the SL (R230) and E(W211) model
The twin concept results in two SBC systems being utilized to provide vehicle braking

6. Units are located on the right and left side of the vehicle
COMPONENTS OF SBC
SBC Hydraulic Units
Units are located on the right and left side of the vehicle
Each unit has it’s own fluid
reservoir
Only use DOT 4+ brake fluid
Do not overfill fluid reservoirs

7. Brake Operating Unit (BOU)
• Located near the fire wall on the
driver’s side of the vehicle
• Incorporates the following:
- fluid reservoir
- two pedal value sensors
- tandem master cylinder
- brake pressure simulator

8. Front Axle Brake Calipers
• Two calipers on each wheel
• Fore and aft calipers are controlled by
different control units
• Insures brake force application at the
front axle if there is a failure with one
system
• Square blocks on front calipers are used
for vibration dampening

9. Rear Axle Brake Calipers
• One caliper on each wheel
• Calipers are split (top /bottom)
• The top portion of each caliper is
controlled by one SBC system
• The bottom portion of each caliper is
controlled by the other SBC system
• Insures brake force application at the
rear axle if there is a failure with one
system

10. Electrical Components

11. Wheel Speed Sensors

12. Pedal Value Sensors • Located on the brake operating unit
• Signals sent to SBC control modules to
determine the amount of braking
requested
• Each sensor contains two hall effect
sensors
• Redundancy of sensor signals is
monitored- if one sensor malfunctions,
the value for the other will be used

14. Twin SBC Communication

15. One SBC System Failure
Two SBC System Failures

16. Driving stability
SBC once again offers the benefits of greater dynamics and precision: thanks to the even faster and more accurate braking impulses from the SBC high-pressure reservoir, ESP® is able to stabilize early and comfortably a vehicle which is about to break away
This is evident, for example, from the results of the VDA lane-change test which suspension engineers use to simulate a quick obstacle-avoidance manoeuvre and to demonstrate the high capabilities of the Electronic Stability Program

18. Braking in a curve. Left: conventional. Right: with SBC

19. SBC Add-on Functions
The so-called Soft-Stop function of the SBC software ensures particularly gentle and smooth stopping which provides significant comfort benefits particularly around town when you need to slow down frequently for traffic lights
The Sensotronic Brake Control also incorporates a so-called Traffic Jam Assist function, which is activated using the cruise control stalk while the car is stationary
On hills or steep drives the Sensotronic Brake Control Drive-Away Assist prevents the car from rolling backwards or forwards – stepping onto the brake pedal quickly but sharply is all it takes to activate the brake

20. SBC Incorporates these Functions
ABS (Anti lock Brakes 1984)
ASR (Automatic Slip Regulation 1991)
ETS (Electronic Traction System 1995)
ESP (Electronic Stability Program 1996)
BAS (Brake Assist System 1998)

21. Driving with SBC - Wake-Up
SBC is functional as soon as it is “wakened” by:
opening a door (via CAN)
operating the central locking system (via CAN)
depressing the brake pedal
turning key to position 1

22. The Chip Design
SEM picture of the chip structure and X-ray picture of the bonded wafer showing the circular and square sensor design

23. Optimum deceleration during cornering Stabilization of the vehicle
Advantages
More stable braking
Optimum deceleration during cornering
Stabilization of the vehicle
Shorter stopping distances
Better brake response
Even wear on brake pad linings

24. each wheel can be precisely controlled
monitors release of accelerator pedal and application of brake
faster response to brake request inputs

25. Conclusion
Mechatronics – a new term is gaining popularity within the automotive industry
Mechatronics brings together two disciplines which in many cases were thought to be irreconcilable, namely mechanics and electronics
Hence automobile functions which hitherto worked purely mechanically and partly with hydraulic assistance will in future be controlled by high-performance microcomputers and electronically controllable actuators

26. References

27. Thank You