Transcript Stability control systems and their role for active safety

TECHNICAL UNIVERSITY OF RADOM
University of Applied Sciences
Marko Jets
Lecturer
Faculty of Transport
Ecology and Safety as a Driving Force
in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008
Contents
1. Background and History
2. ESC Operation
3. ESC Construction
4. Effectiveness Studies
5. Future Plans
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008
Safety as Driving Force
Automobile Safety
Active safety
Passive safety
• ABS
• crumple zones
• TCS
• seatbelts
• ESC
• airbags
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008
ESC History
1978 – Antilock Brake System
1987 – Traction Control System, also
known as ASR – AntiSkid Restrain
System
1995 – Electronic Stability Program
EHB – ElectroHydraulic Brake
system called SBC - Sensotronic
Brake Control
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008
ESC, ESP
ESC - Electronic Stability Control
ESP - Electronic Stability Program (trade mark)
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008
Lateral Grip and Skidding
Front Wheel Skid Tendency
• Tires lateral grip
maintains vehicle moving
direction, drivers intention
• When lateral grip is
exceeded the wheel will
slip
• Vehicle with slipped
wheels is hard to handle
Rear Wheel Skid Tendency
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008
Dampening Front Wheel Skid
• Skid Control ECU
– Controls the engine output
– Applies the brake to the rear wheel of the inner circle
of the turn
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008
Dampening a Rear Wheel Skid
• Skid Control ECU
– Applies the brakes of the front and rear wheels of the
outer corcle of the turn
– In some cases, the brakes of the rear wheels are
applied
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008
Component Location
ESC:
• Yaw Rate Sensor
• Steering Angle Sensor
• Wheel Speed Sensors
• Brake Actuator
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008
Main Components
• Steering Angle Sensor
– The steering angle
sensor detects the
steering direction and
angle, and sends this
signal to the skid
control ECU.
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008
Main Components
• Yaw Rate &
Deceleration Sensor
– The yaw rate sensor
detects the vehicle’s
yaw rate.
– The deceleration
sensor detects the
vehicle’s longitudinal
and lateral
acceleration and
deceleration.
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008
Main Components
• Brake Actuator
– The brake actuator
consists of the
actuator portion and
skid control ECU
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008
System Diagram
Parking Brake
Switch
Injector
Engine ECU
Yaw Rate &
Deceleration Sensor
Throttle Control
Motor
Steering Angle
Sensor
Skid Control ECU
Stop Light Switch
Solenoid Valve (8)
Master Cylinder Cut
Solenoid Valve (2)
Wheel Speed
Sensor (4)
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008
Engine Output and Brake Control
• (a) - (d) Engine output control
• (b) - (c) Brake control
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008
Brake Actuator Operation
Fluid pressure in each wheel cylinder is controlled in 3 modes:
1.
pressure increase
2.
pressure holding
3.
pressure reduction
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008
Driver, Vehicle, Road
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008
Longitudinal Forces
• Longitudinal forces
depend on vehicle
acceleration or
deceleration
Fbraking
Ftraction
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008
Lateral Forces
• Centrifugal force is
determined by
– Speed
– Turning radius
Fcentrifugal
Ftraction
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008
Vehicle G-G Diagram
Fresult
Flateral
Flongitudinal
Fmax
traction
• Result force of longitudinal (acceleration or braking) and
lateral (turning) forces must be inside the ring of
maximum available grip force
• Actual passenger car possible grip diagraam has
different shape
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008
Vehicle Stability
• ESC cannot override a car's physical limits or increase
traction.
• If a driver pushes the vehicle's traction beyond its limits,
ESC cannot prevent a crash.
• It is a tool to help the driver maintain control using available
traction.
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008
ESC Promotion
www.chooseesc.eu
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008
Potential Effectivness Study in Europe
100%
80%
Fatal accidents
60%
40%
Injury accidents
20%
0%
ALL ACCIDENTS
LOSS OF
VEHICLE
CONTROL
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008
Crash Reduction by ESC on Cars in USA
100%
80%
Fatal crash
involvements
60%
40%
Police-reported
crash
involvements
20%
0%
RUN-OFFROAD
CRASHES
SINGLE- ROLLOVER
VEHICLE CRASHES
CRASH
REDUCTION
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008
Crash Reduction by ESC on Cars in USA
100%
80%
Fatal crash
involvements
60%
Police-reported
crash
involvements
40%
20%
14%
8%
0%
OVERALL CRASH REDUCTION
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008
Crash Reduction by ESC on Cars in UK
100%
80%
Dry road
60%
Wet road
40%
Snow or icy road
25%
20%
2%
4%
0%
OVERALL CRASH REDUCTION
* - the result on dry road is not statistically significant
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008
Fatal Crash Reduction by ESC
100%
80%
60%
Fatal crash
reduction
40%
20%
0%
SINGLEVEHICLE
CRASHES
among CARS
SINGLEVEHICLE
CRASHES
among SUVs
ROLLOVER
CRASHES
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008
Availability of ESC by Manufacturer
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008
Availability of ESC Cars by Country
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008
Coming Soon
• ESP wide use in small and big family cars, it will be standard
on compact and medium class vehicles not only on executive
and luxury class
• ESP link with Active Steering to improve vehicle stability
• RSC - Roll Stability Control - that works in the vertical plane
much like ESC works in the horizontal plane
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008
TECHNICAL UNIVERSITY OF RADOM
Thanks for Your attention!
Ecology and Safety as a Driving Force
in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008