An Optoelectronic Targeting System for Measuring the Distribution of Projectile Motion Based on the Subdivision of a Light Screen

This paper proposes a cost-effective, compact, noncontacting optoelectronic targeting system for measuring the distribution of projectile motion. The major elements of this system include a light emitting diode (LED) array, photodiode detecting array, double-layered aperture arrays, adaptive threshold circuit, and date acquisition. Through cooperating with double-layered aperture arrays, the system effectively reduces the radiation width of the light source to the photodiode detecting surface, and filters out the influence of incident light from the adjacent apertures on both sides above each photodiode to the corresponding photodiode detecting surface. It realizes that the response of the photodiode array corresponds to the coordinates of the light screen one by one. Through the sensitivity analysis of the light screen of the system, the system detecting threshold when the projectile passes through the light screen is calculated, and the corresponding adaptive threshold circuit is designed to prevent misjudgment when the system works. The measuring error of the system can reach ±2 mm by experimental verification. Compared with other projectile’s distribution measuring systems, the proposed system has the advantages of having high precision, convenient debugging, is nondestructive, and is a noncontact system.

Row-Based Dual Vdd Assignment, for a Level Converter Free CSA Design and Its Near-Threshold Operation

Subthreshold circuit designs are very much popular for some of the ultra-low power applications, where the minimum energy consumption is the primary concern. But, due to the weak driving current, these circuits generally suffer from huge performance degradation. Therefore, in this paper, we primarily targeted analyzing the performance of a near-threshold circuit (NTC), which retains the excellent energy efficiency of the subthreshold design, while improving the performance to a certain extent. A modified row-based dual Vdd 4-operand carry save adder (CSA) design has been reported in the present work using 45 nm technology. Moreover, to find out the effectiveness of the near-threshold operation of the 4-operand CSA design, it has been compared with the other design styles. From the simulation results, obtained for the frequency of 20 MHz, we found that the proposed scheme of CSA design consumes 3.009 ×10-7 Watt of average power (Pavg), which is almost 90.9% lesser than that of the conventional CSA design, whereas, looking at the perspective of maximum delay at output, the proposed scheme of CSA design provides a fair 44.37% improvement, compared to that of the subthreshold CSA design.