Aiming at status that majority of small trucks on market do not have reversing radar

using infrared measurement technology

adopting STM32 microcontroller unit（ MCU） as core

car reversing collision avoidance system is designed. The system uses SPL—LL90—3 as infrared emission tube and AD500—8 photosensitive device as photodetector. The driving circuit uses monostable flip-flop SN74 LS221 as the core

and the second-order bandpass filter and the LM339 voltage comparator are used to form echo signal processing circuit. Time proportional amplifier circuit is used to calculate signal pulse flight time. The experimental results show that the system can detect the obstacle in the range of 15

450 cm

and can accurately detect and display

the obstacle. It can alarm timely when the detection distance is less than the preset value

and achieve the expected effect

and has certain practical value.