21-06-2012, 01:43 PM
Collision Avoidance System
[attachment=24978]
Collision Avoidance System
Problem Statement
What is CAS?
How it works
System Configuration
Warning Devices
Collision Avoidance Maneuvers
Conclusions
Target of safety measures Government of Japan
More than 90% all car accidents are being caused by losing of driver concentration.
75% of collisions take place at speed up to 30 km/hr and 50% of drivers haven't braked at all before collision.
for intersections In 2003 in USA, approximately:
9500 FATALITIES
1,300,000 INJURIES
2,600,000 CRASHES
There for Automotive engineers started to develop a Safety systems for cars Like CAS
What is CAS?
CAS : is a system of sensors that is placed within a car to warn its driver of any dangers that may lie ahead on the road and assists brake operation to reduce the impact.
CAS predicts a collision based on driving conditions, distance to the vehicle ahead and relative speeds. It then uses visual and audio warnings to prompt the driver to take preventative action and also initiates braking if the driver fails to respond to the warnings.
How it Works?
First, the sensors measure the distance between the car and other vehicles and any differences in speed, and an onboard computer judges the risk of a collision based on this information and on data about the course of the car.
Then if the system judges that there is a risk of a crash, such as when the car gets too close to the vehicle in front, it alerts the driver by sounding an alarm and lighting up a “BRAKE” warning on the dashboard. This is the first warning stage, aimed at alerting the driver to the danger and encouraging the driver to slow down.
The system works in conjunction with the "E-Pretensioner" seatbelt retraction system. If the car continues to get closer to the other vehicle and the computer decides that it will be hard to avoid a collision, it tightens the seatbelt more firmly and applies the brakes forcibly and hard.
The CMS has three staged modes:
An audible warning,
An audible warning, light braking and light seat-belt retraction.
An audible warning, strong braking and strong seat-belt retraction.
CMS configuration
E-Pretensioner ECU: Sends instructions to the motorized E-Pretensioner to retract the seatbelt, based on braking instruction signals from the CMS ECU and electronically controlled brake assist signals.
E-Pretensioner: Retracts the seatbelt using an internal motor, based on instructions from the E-Pretensioner ECU. Used in combination with conventional pretensioners.
Meter unit: Receives signals from the CMS ECU, and warns the driver of potential danger using a buzzer and a visual warning.
CMS Warning Devices
Visual head-up displays: warnings are displayed on the windshield in the driver's field of view.
Audio/Voice signals: auditory signals appear to be less intrusive on driving tasks.
CMS Collision Avoidance Maneuvers:
Headway distance control: the system warns the driver whenever his/her car is following the leading car too closely
Hazard warning: the system warns the driver of an object within its projected path, so that the driver has sufficient time to avoid a crash.
Automatic vehicle control: the system controls the vehicle's brakes and steering wheel
Precise breaks Actuator Systems depend a lot on sensors:
Sensors fulfill the tasks of headway control and obstacle detection, which are the basis of Collision Avoidance Systems (CAS) Sensing.
Indicators:
Sensing range: the maximum range over which the technique can be used
Resolution: the relative change in distance that can be measured
Directionality: the width of the beam over which the sensor is sensitive
Response time: how quickly the sensor can respond to a change in distance
Conclusion
Automatic braking systems can detect an obstacle and bring the car to a complete halt just before impact. The technology has reached the level where the systems can even detect the speed of a vehicle in front, compare it with the speed of the user's car, and stop the car to avoid an accident.
[attachment=24978]
Collision Avoidance System
Problem Statement
What is CAS?
How it works
System Configuration
Warning Devices
Collision Avoidance Maneuvers
Conclusions
Target of safety measures Government of Japan
More than 90% all car accidents are being caused by losing of driver concentration.
75% of collisions take place at speed up to 30 km/hr and 50% of drivers haven't braked at all before collision.
for intersections In 2003 in USA, approximately:
9500 FATALITIES
1,300,000 INJURIES
2,600,000 CRASHES
There for Automotive engineers started to develop a Safety systems for cars Like CAS
What is CAS?
CAS : is a system of sensors that is placed within a car to warn its driver of any dangers that may lie ahead on the road and assists brake operation to reduce the impact.
CAS predicts a collision based on driving conditions, distance to the vehicle ahead and relative speeds. It then uses visual and audio warnings to prompt the driver to take preventative action and also initiates braking if the driver fails to respond to the warnings.
How it Works?
First, the sensors measure the distance between the car and other vehicles and any differences in speed, and an onboard computer judges the risk of a collision based on this information and on data about the course of the car.
Then if the system judges that there is a risk of a crash, such as when the car gets too close to the vehicle in front, it alerts the driver by sounding an alarm and lighting up a “BRAKE” warning on the dashboard. This is the first warning stage, aimed at alerting the driver to the danger and encouraging the driver to slow down.
The system works in conjunction with the "E-Pretensioner" seatbelt retraction system. If the car continues to get closer to the other vehicle and the computer decides that it will be hard to avoid a collision, it tightens the seatbelt more firmly and applies the brakes forcibly and hard.
The CMS has three staged modes:
An audible warning,
An audible warning, light braking and light seat-belt retraction.
An audible warning, strong braking and strong seat-belt retraction.
CMS configuration
E-Pretensioner ECU: Sends instructions to the motorized E-Pretensioner to retract the seatbelt, based on braking instruction signals from the CMS ECU and electronically controlled brake assist signals.
E-Pretensioner: Retracts the seatbelt using an internal motor, based on instructions from the E-Pretensioner ECU. Used in combination with conventional pretensioners.
Meter unit: Receives signals from the CMS ECU, and warns the driver of potential danger using a buzzer and a visual warning.
CMS Warning Devices
Visual head-up displays: warnings are displayed on the windshield in the driver's field of view.
Audio/Voice signals: auditory signals appear to be less intrusive on driving tasks.
CMS Collision Avoidance Maneuvers:
Headway distance control: the system warns the driver whenever his/her car is following the leading car too closely
Hazard warning: the system warns the driver of an object within its projected path, so that the driver has sufficient time to avoid a crash.
Automatic vehicle control: the system controls the vehicle's brakes and steering wheel
Precise breaks Actuator Systems depend a lot on sensors:
Sensors fulfill the tasks of headway control and obstacle detection, which are the basis of Collision Avoidance Systems (CAS) Sensing.
Indicators:
Sensing range: the maximum range over which the technique can be used
Resolution: the relative change in distance that can be measured
Directionality: the width of the beam over which the sensor is sensitive
Response time: how quickly the sensor can respond to a change in distance
Conclusion
Automatic braking systems can detect an obstacle and bring the car to a complete halt just before impact. The technology has reached the level where the systems can even detect the speed of a vehicle in front, compare it with the speed of the user's car, and stop the car to avoid an accident.