In indoor environment

using concrete test module

design a device based on CMOS sensor to automatically identify cracks in tunnel test. Crack image gray value distribution is regarded as an important indicator for automatic recognition. Analyze effective pixels

testing effect of distance

light intensity and other factors on automatic detection performance. Simulation results show that the effective pixel and detection distance have little effect on features of image distribution. Effective pixels is increased

detecting distance is reduced

corresponding detecting performance is increased; light intensity not only has great impact on fracture image gray distribution feature

but also has a significant impact on automatic detection performance

too high or too low light intensity will affect detecting performance.