ABS anti-lock braking system, what are the sensors where?

The ABS sensor relies on the Hall signal that senses the target wheel to realize the sensing wheel speed, when the speed is lower than the set value when the ABS stops working. Ice road brakes do not need to force, make ABS work is the brake switch, and the ABS sensor is used to detect whether the wheels are locked with the speed of rotation. ABS, as the name suggests is the system that prevents the car from locking up when braking. When the brake pedal is pressed sharply, you will feel the pedal bouncing upward rhythmically, and this is the ABS working. However, sometimes we find that when driving at low speeds, even if we press the brake pedal harder and faster, there is still no feeling of being pushed up by the pedal. The reason is that the ABS system is involved in the work of the response to two conditions, one is the instantaneous speed of the vehicle before stepping on the brake pedal, and the second is the slip rate, the so-called slip rate is (vehicle speed - wheel speed) / vehicle speed ratio. The slip rate is the ratio of (vehicle speed - wheel speed) / vehicle speed. The slip rate can be understood as follows: when the wheel speed = 0, the slip rate = 1, and the wheel is being held at that time (because the wheel speed is already 0). Slippage rate to some extent reflects the degree of urgency of brake application. These two parameters are recorded in the car computer module (ECU), parameter one will set a speed limit before braking, if less than this speed is not involved in the braking response of the ABS, this time the hold is not likely to produce a dangerous, parameter two is the slip rate, according to the basic data given by each speed sensor for the calculation of the slip rate of the size of the slip rate directly determines what way the ABS involved in the response, the response of the ABS. There are three types of response: boost, hold, and buck. Boost, hold, and buck are controlled by the eight solenoid valves in the ABS pump. The electronic control unit is the control center of the ABS system, it is actually a microcomputer, so it is also often referred to as the ABS (ECU) computer.The ABS ECU consists of input circuits, digital controllers, output circuits and warning circuits. The main task is to continuously monitor the acceptance of four wheel speed sensors to send pulse signals, and measurement and comparison, analysis and amplification and discrimination processing, calculated wheel speed, wheel deceleration and braking slip rate, and then logical comparison analysis of the braking situation of the four wheels, once the wheels will be judged to be embracing the dead, it is immediately entered into the antilock control state, through the electronic control unit to the hydraulic unit to issue instructions to Control of the brake wheel cylinder oil solenoid valve on and off and the work of the hydraulic pump to regulate the braking pressure, to prevent the wheels from locking.