What is ESP and how to use it?

Electronic Stability Program (ESP) is a patent of Bosch Company.

ESP system is actually a traction control system. Compared with other traction control systems, ESP can control not only the driving wheel but also the driven wheel. For example, rear-wheel drive cars often turn too much. At this time, the rear wheel is out of control and the ESP will slow down the outer front wheel to stabilize the car. When the steering is too little, ESP will slow down the inner rear wheel to correct the tracking direction, thus correcting the driving direction.

ESP system includes ABS (Anti-lock Brake System) and ASR (Driving acceleration slip regulation), which are the functional extensions of these two systems. Therefore, ESP can be regarded as the most advanced form of automobile anti-skid device at present. ESP system consists of control unit, steering sensor (monitoring the steering angle of the steering wheel), wheel sensor (monitoring the rotating speed of each wheel), sideslip sensor (monitoring the rotation state of the car body around the vertical axis), lateral acceleration sensor (monitoring the centrifugal force when the car turns) and so on. The control unit judges the driving state of the vehicle through the signals of these sensors, and then sends out control instructions. The difference between a car with ESP and a car with ABS and ASR is that ABS and ASR can only react passively, while ESP can detect and analyze the condition of the car and correct the driving mistakes before they occur. ESP is particularly sensitive to oversteer or understeer. For example, when a car turns left and oversteers (turns too fast), it will flick its tail to the right. When the sensor senses the slip, it will quickly brake the right front wheel to restore its adhesion, and generate the opposite torque to keep the car in the original lane. Of course, there is a limit to everything. If the driver drives too fast blindly, it will be difficult to keep any existing safety devices.