A safety system that allows the driver to control and maintain the steering of a vehicle during hard braking times is known as Anti-Lock Braking System. A computerized anti-lock braking system is designed to control the wheels from locking while the brakes are applied. It also helps the vehicle from skidding. It is normally developed to reduce stopping distances in dry surfaces and to increase braking distances in loose surfaces.
Components of Anti-Lock Braking System:
An anti-lock braking system includes four key components. They are:
- Speed Sensors,
- Controller, and
Valves: In ABS, each brake has a valve in brake line. In few systems, the valve features 3 positions. First position: When the value is opened, the pressure exits from master cylinder and it is passed to the brakes. Second position: When the value restricts the line, the brake is isolated from master cylinder. It provides the prevention of pressure to rise further. Third position: In this position, some pressures are released by valve from brake. Speed Sensors: It is placed in all wheels for providing information about lock up. Controller: It is used to receive information from every wheel through speed sensor. It helps to send signals to controller about loss of traction. In this situation, the controller limits the EBD and activates anti-lock brake system modulator. Pump: It is used to get back the pressure that is lost
during the operation of a valve.
Types of Anti-Lock Braking System:
An ABS uses various schemes according to the brake types. It can be distinguished using number of channels i.e. number of speed sensors and number of separately controlled valves.
- 1 channel – One sensor ABS: It helps to control rear wheels combined.
- 3 channels – Three sensors ABS: It helps to control real wheels combined and front wheel independently.
- 4 channels – Four sensors ABS: It is the system that achieves high level of braking force due to separate speed sensors in each wheel.
Recently developed anti-lock braking system is not only used to provide locking of wheel during braking but also used to control front to rear brake bias electronically. A function that implement on this specific abilities are called as EBD (Electronic Brakeforce Distribution), Emergency Brake Assist, Traction Control System, or ESC (Electronic Stability Control). Therefore, ABS is one of the important safety systems that is required in every cars for fast and safety driving.