ANTI-LOCK BRAKE SYSTEM, ABS, ANTI-SKID BRAKE SYSTEM, BANK ANGLE SENSOR

ABS Its Operation and defects 

Anti-Lock brake 

Anti-Locking of brakes is a safety measure that save the bike and riders from skidding while braking. Braking is very prune to skid at corner or slippery roads and its become fatal at high speed. Generally moving wheels skid when it is locked by braking forces. ABS prevents the wheel to lock thereby maintaining tractive contact with the road surface.
यदि आप इसे हिन्दी में पढ़ना चाहते हैं तो यहाँ क्लिक करे 

The techniques which is  practiced by skillful drivers. They save them selves and others life with their skills without ABS vehicles widespread. However ABS operates at much faster rate and more effectively than most drivers can manage. Although ABS offers improved vehicle control and decreases stopping distances on dry and some slippery surfaces. ABS is used on aircraft and on land  vehicles, such as cars, motorcycles, trucks, and buses.

ABS is  used in all hydraulically, air and mechanical operated brakes. However as bike is concerned ABS is applied in disc brakes which are hydraulic brakes.

Here We discuss the types ANTI- LOCK BRAKES SYSTEM

• Electric or digital ABS • Traction control module • Combined braking system • Single channel ABS • Dual channel ABS • Dual channel with switches ABS 

Electric or Digital ABS

Typically ABS consists  of flowing parts 

• central electronic control unit (ECU)

• wheel speed sensors(Hal sensor)

• hydraulic valves within the brake hydraulics

• Pumps

OPERATION OF ABS

Speed sensors:-

ABS system starts with the function of speed sensors (Encoders). These sensors use a magnet and a Hall effect.  It is also called Hall sensor. And an other types of sensor a toothed wheel and an electromagnetic coil to generate a signal.  The rotation of the wheel or differential induces a magnetic field around the sensor.  Speed sensor which sends the signals to ECU is used to determine the speed of the wheel. 

Electric control Unit/ module:-

The ECU constantly monitors the rotational speed of each wheel by analysing the signals sent by speed sensors. When it detects the wheel rotating significantly slower than the speed of the bike that is indicative of impending wheel lock. The ECU actuates the valves to reduce hydraulic pressure to the brake at the affected wheel. thus reducing the braking force on that wheel. Then the wheel turns faster.

Valves:-

The valves are fitted in hydraulic brake channel for reducing and increasing the braking pressure. It is actuated electrically by ECU. There are three different positions of valves operation.

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 rising further by pushing the brake pedal harder.

In position three, the valve releases some of the pressure from the brake.

Pumps :- 

When the ECU detects a wheel rotating significantly faster than the others. Now pump comes in to action and starts pumping the brake fluid in brake system. 

The hydraulic pressure to the brake is increased so the braking force is reapplied and slowing down the wheel. This process is repeated continuously. 

Traction control system (TCS) 

In this system the ABS equipment may also be used to control the braking pressure along with to control the acceleration of the vehicle. When a driver accelerates the vehicle, the tire loses traction, the ABS controller can detect the situation and take suitable action so that traction is regained. In more sophisticated versions of bikes TCS is induced. Traction control module controls throttle levels and brakes simultaneously. This is monitored by programed ECU (Engine Control Unit) some times it is also called ECM (Engine Control Module).

Combined Braking System (CBS)

Generally two channels braking system is applied in all vehicles. It guidelines or Motor Transport Act.

Motorcycle has also rear and front two channels of braking in which both wheels are controlled separately. If the rider apply brakes on one wheel before than other, this braked wheel tends to lock up faster than other.  Or both brakes had been applied. A Combined Braking System therefore distributes the brake force also to the non-braked wheel to lower the possibility of a lock up.

A delay valve is used to cuts the hydraulic pressure that assure only when strong braking is applied, and pressure is also created at the front wheel.

Honda is the first to combined braking system in street motorcycle. It is called Unified Braking.

Single channel ANTI-SKIS BRAKE SYSTEM with one sensor:- 

A bike with Single channel ABS consists one speed sensor and one control valve in drive wheel only. As you know the Hydraulic channels for both wheels are separate and ABS is applied in rear wheel only that is drive wheel in case of single channel ABS. If the speed sensor detects lock up at individual wheel, the control module pulses the valve for the wheel and controls the braking pressure resulting wheel to roll. Such it is preventing the skid of wheel.

Double channel ABS with two sensor:-

If ABS is applied In both wheels of bikes it is called double channel ABS. It uses a speed sensor at each wheel, with one control valve each for the front and rear wheels as a pair. If the speed sensor detects lock up at any individual wheel, the control module pulses the valve for both wheels. Such Dual ABS manage the Hydraulic pressure in brake system to prevent the wheels to lock on braking. 

General Defects in ABS 

The majority of problems with the valve system.

 This occurs due to clogged valves.

 When a valve is clogged it is unable to open, close, or change position. 

A defective valve will prevent the system from modulating the valves and controlling pressure supplied to the brakes.

Only replacement is solutions. 

For maintenance you can keep it clean.

Bank angle sensor or steering angle sensor 

Bank angle sensor 

When you are turning or changing the direction your motorcycle leans/tilts inside of turning. Bank angle is the tilting angle of your motorcycle to the horizontal ground.

 Bank angle sensor is a magnetic encoders which measures inclined angle of your motorcycle and sends signals to ECU. ECU analyses the signals and cut the incommig supply of ignition coils and engine switches off when bike inclines more than limit.

It is also called steering angle, inclined angle or tilting angle sensor. It saves the rider by reducing speed, eliminating fire hazards and minimizing bike damage.