First generation: when reversing, honk the horn to remind you.
Second generation: Buzzers are used to remind drivers with different sounds.
Third generation: Digital band shows specific distance or distance range.
The fourth generation: LCD dynamic display.
Fifth generation: magic mirror reversing radar.
Sixth generation: specially designed for producing high-end cars. The sixth generation products have added many functions on the basis of the fifth generation: in appearance, they are more exquisite and elegant than the fifth generation products; Functionally, it not only has all the functions of the fifth-generation products, but also integrates the audio-visual system of high-end cars, and can watch DVD images on the display screen.
The above information comes from Hangzhou Library, and I hope it will be helpful to your research.
Wan Qi: Analysis of Domestic Automobile Reversing Radar Technology and Industry Development, China Electronics Technology Group Corporation 52nd Research Institute (Hangzhou)