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Design of the Electronic Target for Shooting Sports and Sensor Suitability Analysis
Grega, Matej
Electronic scoring targets (ESTs) are designed to overcome the drawbacks of classic paper targets, particularly the inability to score individual hits in groups if they overlap and the time-consuming manual scoring process. This paper presents the design of a prototype of an acoustically based EST for 10m air pistol discipline and examines the suitability of microelectromechanical system (MEMS) microphones and sealed flexural ultrasonic transducers (FUTs) as hit point localization sensors. The proposed prototype of the EST is mobile and battery-powered, with built-in illumination and radiofrequency communication. The position of the hit point is calculated using a closed-form, combined weighted method based on time difference of arrival (TDOA) measurements. FUTs were used as sensors due to their filtering properties of shot and ambient noise and overall higher signal-to-noise ratio than MEMS microphones, without saturation of the output signal. The sensor positions for TDOA localization were accurately obtained using an iterative calibration method. The proposed EST prototype achieved a mean position error of 0.29 mm and a standard deviation of 0.19 mm for hit point localization.
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Acoustic target for shooting sports
Grega, Matej ; Junasová, Veronika (oponent) ; Tomíček, Pavel (vedoucí práce)
Electronic scoring targets (ESTs) are designed to overcome the drawbacks of classic paper targets, particularly the inability to score individual hits in groups if they overlap and the time-consuming manual scoring process. This thesis presents the design, realization and testing of an acoustically based EST for 10 m air pistol discipline and examines the suitability of microelectromechanical system (MEMS) microphones and sealed flexural ultrasonic transducers (FUTs) as hit point localization sensors. The proposed EST is mobile and battery-powered, with built-in illumination and radiofrequency communication. The position of the hit point is calculated using a closed-form, combined weighted method based on time difference of arrival (TDOA) measurements. FUTs were used as sensors due to their filtering properties of shot and ambient noise and overall higher signal-to-noise ratio than MEMS microphones, without saturation of the output signal. The sensor positions for TDOA localization were accurately obtained using an iterative calibration method. The proposed EST prototype achieved a maximum position error of 0.39 mm, mean position error of 0.25 mm and a standard deviation of 0.10 mm for hit point localization.
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External ballistics of airgun projectiles
Melichar, Tomáš ; Strouhalová, Jitka (oponent) ; Průša, Stanislav (vedoucí práce)
Throughout the paper, the reader is introduced to basic concepts and issues of exterior ballistics. Considering the problem stiffness, a suitable model of atmosphere is determined and combined with the optimal method of ballistic trajectories numerical modeling. Using PRODAS V3 software a basic aerodynamical characteristics of the small caliber reference projectile (diabolo type) model are estimated. Detailed attention is given to the description of the measurement platform, its errors, and optimization. Based on the experimental measurements of the given standard projectile, a new drag law JSBE is determined. The results between numerical solutions and real measurements are compared against measured drag law JSBE, G1/GA drag law, and software PRODAS V3 drag law estimation.
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