Application of ultrasonic sensor in reversing radar

Reversing radars only work and provide information for drivers when a car is reversing. When a car is reversing, it travels at a speed which can be ignored compared to Sound velocity so the Doppler effect can also be ignored in the system.

Compared to many other ranging methods. Pulse ranging only needs to figure out the round trip time between the measuring point and the object , which is simple.

As picture 1 shows, Driver turns the handle to reverse gear, reversing radar automatic starts. The ultrasonic reversing radar probe emits signal of 40Khz. The signal will be reflected by obstacles. The probe collects ,amplifies and compares the reflected signal.This signal will be sent to the display module of MCU and at the same time the voice circuit will be triggered. Different alarm will be launched to remind the driver if distance from obstacle is less than 1m , 05m , 0.25m ,