Major Components and Working of ABS System in Cars In a car, apart from the driving force generated by the engine, the other most important factor is the braking force which is much needed for the effective stopping of the vehicle. The brakes are normally used always to bring the car to rest position. But, in case of sudden braking, their working efficiency is always a matter of concern in determining the safety of both the car and its occupants. Thus, in order to avoid such accidents and severe damage to the human and the machine, a new technology called as Anti-lock Braking System (ABS) was introduced in the automobile industry. The anti-lock braking system is an electronic brake control system that provides active safety to the vehicle. This system gets activated whenever the driver suddenly applies the brakes during an emergency. Whenever a driver suddenly applies brakes to a high-speed car, there is always a danger of wheel lock, which means that the respective wheels stop suddenly instead of slowing down in some time. Because of the wheel lock, the driver loses control over the car and can lead to fatal accidents. The ABS prevents the wheels from locking up and avoiding uncontrolled skidding of the vehicle and decreases the distance traveled without slipping.
Components of ABS Generally, the ABS offers improved vehicle control and decreases stopping distances on dry and slippery surfaces. ABS modifies the brake fluid pressure that is independent of the amount of pressure being applied on the brakes to bring the speed of the wheel back to the minimum slip level that is mandatory for optimal braking performance. This is only possible because of some of the major components associated with the ABS system, that are- speed sensor, valves, an electronic control unit and a hydraulic control unit.
Speed sensor These sensors are attached to each wheel and determine whether to accelerate and decelerate the speed of the wheels. It consists of an exciter (a ring with V-shaped teeth) and a wire coil or magnet assembly, which generates the pulses of electricity as the teeth of the exciter pass in front of it.
Valves There is a valve in the brake line of each wheel that regulates the air pressure to the brakes during the ABS action. The resistance that you feel, while braking suddenly at high speeds is actually the brake valves controlling the pressure that is being transferred to the brakes.
Electronic control unit The ECU is an electronic unit that receives, amplifies and filters the sensor signals for calculating the wheel rotation speed and acceleration. It collects the signal from the sensors in the circuit, analyzes them and controls the brake pressure.
Hydraulic control unit The hydraulic control unit receives a signal from the ECU to apply or release the brakes under the anti-lock conditions. It controls the brakes by increasing the hydraulic pressure or bypassing the pedal force to reduce the braking power.
Working of the ABS system Wheel speed sensors consistently screen the speed of each wheel. For whatever length of time that all the wheels have similar speed, the framework does not meddle with their task. In the event that speed sensors find
that the speed of any of the wheels is decreasing definitely, at that point it implies that the wheel will lock. The locked wheel hampers vehicle dependability and along these lines, vehicle quits reacting to controlling info given by the driver. As of now, the vehicle additionally begins to slide along these lines causing a deadly mishap. The ABS comes into play its part in order to maintain a strategic distance from such a disaster. In the wake of getting the flag of low speed from wheel speed sensor, ABS module arranges the brake control unit to diminish the braking power of that wheel. Diminishing braking power implies decreasing the waterpowered weight in the brake line following up on that wheel. Brake control unit does this with the assistance of valves in the framework. At the point when the braking power lessens, the wheel begins pivoting at a higher speed subsequently dodging wheel bolt. As wheel doesn't get locked, steering capability of the car stays unblemished which implies that car moves as per driver's contribution without sliding or skidding. Once the typical condition is reestablished, brake control unit re-establishes the hydraulic pressure in the brake line with the assistance of a pump. The modern ABS systems use a four-channel controller module that features individual sensors and relief valves on all four wheels. But in the older systems come with one, two or three channels having sensors across a front or rear axle depending on the design of the car.
In the end It is no doubt that a car featuring ABS has better traction control on the highways but when you are driving on loose surfaces like dirt, snow or any low-grip surface, the anti-locking function may not work properly and can result in extending the stopping distance. A locked wheel is more effective at stopping on these surfaces and that is the reason many off-road cars have an off-road mode which reduces the effectiveness of the ABS or turns it off completely in order to increase low-speed grip.