What signals need to be detected for anti-skid control in the braking system?
2 Answers
The anti-skid control of the braking system requires the detection of sensitivity and anti-skid failure monitoring signals. Braking slip control is generally divided into two control methods: air braking slip and electric braking slip. These two control methods work together to complete the adjustment of braking slip. The anti-skid failure monitoring device is an independent device of the anti-skid control unit. If an abnormal anti-skid phenomenon occurs during the anti-skid control process, this monitoring device can promptly cut off the output to prevent the air braking from losing braking force or excessive loss. When a relatively independent anti-skid failure monitoring system is used, if the anti-skid control system fails due to air braking, only the anti-skid control function is unilaterally affected, while the air braking function remains unaffected, ensuring the effectiveness of the air braking force. During the braking process, the adjustment of electric braking slip is generally performed first, followed by the adjustment of air braking slip. If the anti-skid control malfunctions, the direct result is an excessively long braking distance for the vehicle, and in severe cases, it may lead to wheel skidding. When the brake pedal is continuously pressed, the vehicle does not decelerate. If the brake pedal does not rise when continuously pressed and there is no resistance felt, the following items should be checked. Specifically, observe whether the brake fluid in the brake fluid reservoir is severely lacking and whether there are any traces of brake fluid leakage at the brake cylinders and joints. If there is no oil leakage, check whether the mechanical connecting parts of the brakes are disengaged or broken. If the brake pedal still does not return, disassemble and inspect the technical performance of the brake cylinder, piston, rubber oil seal, caliper, and return spring, and replace any faulty components.
The anti-slip control of the braking system, such as ABS, relies on several signals to prevent wheel lock-up and skidding. First, the speed of each wheel is detected using wheel speed sensors installed on the wheels, which track the rotation speed in real-time. If any wheel decelerates too rapidly, the system intervenes to adjust the braking force. The vehicle speed signal is also crucial, typically calculated from the average wheel speed, helping to determine the overall speed of the car. Brake pressure sensors monitor the force applied to the brake pedal—if the pressure is too high and likely to cause skidding, the system balances the braking force. Body motion sensors, such as yaw rate and accelerometers, detect body sway during turns or on slippery roads to prevent skidding. These signals are processed by the control unit to ensure smooth braking. If any signal is missing, the ABS warning light will illuminate, and the system may deactivate, increasing the risk of skidding during hard braking. Therefore, it's essential to check dashboard warning lights before driving, especially in rainy or icy conditions, to significantly enhance safety. During regular maintenance, have a technician test the sensors to prevent minor issues from becoming major problems.
