Performance Analysis And Experimental Study Of Differential Light Screen

The sky screen is a non-contact photoelectric trigger device which detects the time when the flying target reaches the predetermined position in space.when it works,it takes the bright sky as the background,and an optical lens and slit aperture form its probe light screen.When a target flies over the probe light screen,the change in light flux will cause a change in the photocurrent of the photoelectric sensor inside the instrument,thereby generating a pulse signal that identifies the time at which the target passes through the light screen.Due to the influence of various factors,how to analyze the specific moment from the bullet pulse is a key engineering problem.The structure characteristics and principle of traditional sky screen are summarized along with its output signal features.The principle and performance characteristics of common signal analysis methods are deeply analyzed.the shortcomings of traditional sky screen in anti-common mode interference performance and improving the sensitivity of time feature extraction are summarized in depth.a principle and implementation method of differential light screen technology is proposed.The structure characteristics and working principle of differential light screen are described in detail.,the mathematical model is used to analyze its performance and output signal characteristics.The relationship between the moment when the goal passes the screen and the time-domain characteristics of the bullet pulse are discussed in detail,and the test method was designed and verified.In addition,the sensitivity and anti-common-mode optical interference performance of the differential screen are discussed,and the verification test has been completed.The research results show that when the illumination is uniform,the output signal of differential light screen has obvious time-domain characteristics and good environmental adaptability.Strong resistance to common mode light interference,common mode rejection ratio up to 14.53 dB,the circuit system is more stable.it is about 0.5 times higher than the sensitivity of the traditional sky screen.