High-precision velocity measuring system for projectiles based on retroreflective laser screen

Zhao, Donge; Zhou, Hanchang; Ji, Liu; Zhang, Bin; Luo, Qing

doi:10.1016/j.ijleo.2012.01.006

Cited by 13 publications

(5 citation statements)

References 1 publication

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“…Non-contact photoelectric detection technology with the use of a laser screen is applied to the measurement of the velocity of the high speed objects, due to its unique advantages such as high test accuracy, fast response velocity, and wide application range [3]. Since the high launch velocity of the armature of the electromagnetic gun may produce fragments during the launch process, meanwhile accompanied by interferences such as the strong flare, vibration, smoke, and magnetic field changes, the test environment is very complicated.…”

Section: Introductionmentioning

confidence: 99%

Data Processing Approaches to Measure Velocity of Electromagnetic Gun on Laser Screen in Complex Environment

Hao

Liu

et al. 2022

Sensors

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The exit velocity of the armature is an important indicator in measuring the launching performance of the electromagnetic gun. The non-contact photoelectric detection technology with the use of a laser screen was applied to the measurement of the armature velocity of the electromagnetic gun. By means of taking the signals that pass through the laser screen obtained by the velocity measurement system as the research object, we solved problems such as the harsh test environment of the launch armature velocity of the electromagnetic gun, the interferences on the armature signal passing through the laser screen unavoidably caused by various factors such as vibration, electromagnetic interference, shock wave, flare, smoke and fragments, and even the non-recognition of the signal passing through the laser screen in severe cases. A data-processing algorithm that combines the Ensemble Empirical Mode Decomposition (EEMD) with Correlation Algorithm (CA) was proposed, with the aim of processing the signals passing through the laser screen, while using the maximum slope point as the time passing through the laser screen so as to calculate the velocity of the armature passing the laser screen. This method can effectively reduce the influence of interference on the test results, and the test results from two sets of velocity measuring systems show that the velocity obtained by the proposed approach is highly consistent.

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Section: Introductionmentioning

confidence: 99%

Data Processing Approaches to Measure Velocity of Electromagnetic Gun on Laser Screen in Complex Environment

Hao

Liu

et al. 2022

Sensors

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“…When the laser beam irradiates the target continuously, the thermal accumulation effect will cause ablation damage to the substrate materials. Moreover, a solid-state laser device has a good beam quality, making the beam energy relatively concentrated in the transmission process [3][4][5]. The irradiation area power density is about as high as 103-105 W/cm 2 .…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulation and Experimental Investigation of Laser Ablation of Al2O3 Ceramic Coating

et al. 2020

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This paper presents an evaluation of the molten pool laser damage done to an Al2O3 ceramic coating. Mechanism analysis of the laser damage allowed for a 2D finite element model of laser ablation of the Al2O3 ceramic coating to be built. It consisted of heat transfer, laminar flow, and a solid mechanics module with the level set method. Results showed that the laser damage mechanisms through laser ablation were melting, gasification, spattering, and micro-cracking. The ablation depth and diameter increased with the increasing laser ablation time under continuous irradiation. The simulation profile was consistent with the experimental one. Additionally, the stress produced by the laser ablation was 3500–9000 MPa, which exceeded the tensile stress (350–500 MPa), and fracturing and micro-cracks occurred. Laser damage analysis was performed via COMSOL Multiphysics to predict laser damage morphology, and validate the 3D surface profiler and scanning electron microscope results.

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“…The laser screen velocity measuring (LSVM) system is a typical interval velocity measuring device. It is the mainstream method of measuring a projectile's velocity because of its real-time, non-contact, high precision [12][13][14]. The method needs to measure the time interval of the timing pulse generated by the projectile passing through the two light screens, and then calculate the projectile's velocity, according to the distance between the two light screens (i.e., the target distance).…”

Section: Introductionmentioning

confidence: 99%

Research on Target Deviation Measurement of Projectile Based on Shadow Imaging Method in Laser Screen Velocity Measuring System

Chu

Zhao

Liu

et al. 2020

Sensors

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In the laser screen velocity measuring (LSVM) system, there is a deviation in the consistency of the optoelectronic response between the start light screen and the stop light screen. When the projectile passes through the light screen, the projectile’s over-target position, at which the timing pulse of the LSVM system is triggered, deviates from the actual position of the light screen (i.e., the target deviation). Therefore, it brings errors to the measurement of the projectile’s velocity, which has become a bottleneck, affecting the construction of a higher precision optoelectronic velocity measuring system. To solve this problem, this paper proposes a method based on high-speed shadow imaging to measure the projectile’s target deviation, ΔS, when the LSVM system triggers the timing pulse. The infrared pulse laser is collimated by the combination of the aspherical lens to form a parallel laser source that is used as the light source of the system. When the projectile passes through the light screen, the projectile’s over-target signal is processed by the specially designed trigger circuit. It uses the rising and falling edges of this signal to trigger the camera and pulsed laser source, respectively, to ensure that the projectile’s over-target image is adequately exposed. By capturing the images of the light screen of the LSVM system and the over-target projectile separately, this method of image edge detection was used to calculate the target deviation, and this value was used to correct the target distance of the LSVM to improve the accuracy of the measurement of the projectile’s velocity.

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High-precision velocity measuring system for projectiles based on retroreflective laser screen

Cited by 13 publications

References 1 publication

Data Processing Approaches to Measure Velocity of Electromagnetic Gun on Laser Screen in Complex Environment

Data Processing Approaches to Measure Velocity of Electromagnetic Gun on Laser Screen in Complex Environment

Numerical Simulation and Experimental Investigation of Laser Ablation of Al2O3 Ceramic Coating

Research on Target Deviation Measurement of Projectile Based on Shadow Imaging Method in Laser Screen Velocity Measuring System

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