29-12-2010, 05:03 PM
PRESENTED BY
MANIK CHANDRA MAHAPATRA
MANIK CHANDRA MAHAPATRA
ABSEMINAR.pptx (Size: 736.92 KB / Downloads: 144)
FUNCTION
To maintain the stability & steer-ability of the vehicle while the wheels are impending lock or skid in varying road conditions during braking.
To maneuver in your intended direction during “panic-stop” situation.
To stop the vehicle with minimum stopping distance.
DESIGN & WORKING-EARLY ABS
Consisted of Mechanical components only-Drum, Flywheel.
Relative angular speed difference between Drum & Flywheel causes some drop in main hydraulic line & thereby reducing brake pressure in the adequate amount.
DESIGN & WORKING-TODAY’S ABS
COMPONENTS
Speed Sensors-The anti-lock braking system needs some way of knowing when a wheel is about to lock up. The speed sensors, which are located at each wheel, or in some cases in the differential, provide this information.
Pump-Since the valve is able to release pressure from the brakes, there has to be some way to put that pressure back. That is what the pump does; when a valve reduces the pressure in a line, the pump is there to get the pressure back up.
Valves-There is a valve in the brake line of each brake controlled by the ABS. On some systems, the valve has three positions:
In position one, the valve is open; pressure from the master cylinder is passed right through to the brake.
In position two, the valve blocks the line, isolating that brake from the master cylinder. This prevents the pressure from rising further should the driver push the brake pedal harder.
In position three, the valve releases some of the pressure from the brake.
Controller-The controller is a computer in the car. It watches the speed sensors and controls the valves.
PRODUCT ARCHITECTURE
FLOW CHART
AGENDA
ABS – Function, Design & Working.
ABS types.
Recent Advancements.
Effectiveness & Limitations.
Testing & Validation.
Job of the Driver.
Closing Remarks.
Anti-Lock Brake Types
Four-channel, four-sensor ABS-This is the best scheme. There is a speed sensor on all four wheels and a separate valve for all four wheels. With this setup, the controller monitors each wheel individually to make sure it is achieving maximum braking force.
Three-channel, three-sensor ABS-This scheme, commonly found on pickup trucks with four-wheel ABS, has a speed sensor and a valve for each of the front wheels, with one valve and one sensor for both rear wheels. The speed sensor for the rear wheels is located in the rear axle.
One-channel, one-sensor ABS-This system is commonly found on pickup trucks with rear-wheel ABS. It has one valve, which controls both rear wheels, and one speed sensor, located in the rear axle.