scholarly journals Correction Strategy of Mortars with Trajectory Correction Fuze Based on Image Sensor

Sensors ◽  
2019 ◽  
Vol 19 (5) ◽  
pp. 1211 ◽  
Author(s):  
Rupeng Li ◽  
Dongguang Li ◽  
Jieru Fan
Keyword(s):  
Coordinate System ◽  
Closed Loop ◽  
Image Sensor ◽  
Inertial Coordinate System ◽  
Trajectory Correction ◽  
Deployment Time ◽  
Accuracy Increase ◽  
Miss Distance ◽  
The Relationship ◽  
Flight Model

For a higher accuracy of projectiles, a novel trajectory correction fuze is proposed. In this design, the sensor and actuator were reduced to achieve a balance between performance and affordability. Following introduction of the fuze concept, the flight model was presented and the crossrange and downrange components of trajectory response under control were investigated. The relationship between the inertial coordinate system and the detector coordinate system was studied so that the imager feedback could be used to derive the actual miss distance. The deployment time of canards and roll angle of the forward fuze were derived and used as the inputs of the control system in this strategy. Example closed-loop simulations were implemented to verify the effectiveness of the strategy. The results illustrate that the accuracy increase is evident and the proposed correction concept is applicable for terminal correction of mortars.

scholarly journals Mechanical and Electronic Video Stabilization Strategy of Mortars with Trajectory Correction Fuze Based on Infrared Image Sensor

Sensors ◽  
2020 ◽  
Vol 20 (9) ◽  
pp. 2461 ◽  
Author(s):  
Cong Zhang ◽  
Dongguang Li
Keyword(s):  
Motion Vector ◽  
Computational Cost ◽  
Infrared Image ◽  
Image Sensor ◽  
Projection Algorithm ◽  
Video Stabilization ◽  
Sensors And Actuators ◽  
Simulation And Experiment ◽  
Transformation Relation ◽  
Trajectory Correction

For a higher attack accuracy of projectiles, a novel mechanical and electronic video stabilization strategy is proposed for trajectory correction fuze. In this design, the complexity of sensors and actuators were reduced. To cope with complex combat environments, an infrared image sensor was used to provide video output. Following the introduction of the fuze’s workflow, the limitation of sensors for mechanical video stabilization on fuze was proposed. Particularly, the parameters of the infrared image sensor that strapdown with fuze were calculated. Then, the transformation relation between the projectile’s motion and the shaky video was investigated so that the electronic video stabilization method could be determined. Correspondingly, a novel method of dividing sub-blocks by adaptive global gray threshold was proposed for the image pre-processing. In addition, the gray projection algorithm was used to estimate the global motion vector by calculating the correlation between the curves of the adjacent frames. An example simulation and experiment were implemented to verify the effectiveness of this strategy. The results illustrated that the proposed algorithm significantly reduced the computational cost without affecting the accuracy of the motion estimation. This research provides theoretical and experimental basis for the intelligent application of sensor systems on fuze.

scholarly journals A new result under weak and non-relativistic approximation from general theory of relativity

2021 ◽  
Author(s):  
Abhijit Samanta
Keyword(s):  
Field Equation ◽  
Energy Density ◽  
General Theory ◽  
Force Field ◽  
Coordinate System ◽  
Theory Of Relativity ◽  
General Theory Of Relativity ◽  
Inertial Coordinate System ◽  
Relativistic Approximation ◽  
Moving Particle

Abstract We have derived a metric field equation in the locally inertial coordinate system from Einstein's field equation considering the energy density of the moving particle with the approximations that the force field under which the particle is moving is weak and the velocity of the particle is non-relativistic. We study the motion of different microscopic systems using this metric equation and compared the results with the experimentally measured values and we find that the results are identical.

scholarly journals Automated Axis Alignment for a Nanomanipulator inside SEM and Its Error Optimization

Scanning ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-8
Author(s):  
Chao Zhou ◽  
Lu Deng ◽  
Long Cheng ◽  
Zhiqiang Cao ◽  
Shuo Wang ◽  
...  
Keyword(s):  
Average Method ◽  
Closed Loop ◽  
Alignment Method ◽  
Visual Servo ◽  
End Effector ◽  
Axis Alignment ◽  
Deposition Effect ◽  
Relationship Of ◽  
The Relationship ◽  
Error Optimization

In the motion of probing nanostructures, repeating position and movement is frequently happing and tolerance for position error is stringent. The consistency between the axis of manipulators and image is very significant since the visual servo is the most important tool in the automated manipulation. This paper proposed an automated axis alignment method for a nanomanipulator inside the SEM by recognizing the position of a closed-loop controlling the end-effector, which can characterize the relationship of these two axes, and then the rotation matrix can be calculated accordingly. The error of this method and its transfer function are also calculated to compare the iteration method and average method. The method in this paper can accelerate the process of axis alignment to avoid the electron beam induced deposition effect on the end tips. Experiment demonstration shows that it can achieve a 0.1-degree precision in 90 seconds.

scholarly journals Approximate Inertial Coordinate System Selections for Rotation Problems - The Gravitational Field of the Celestial Body Higher than the Object Being Rotated

2015 ◽  
Vol 8 (1) ◽  
pp. 102
Author(s):  
Zifeng Li
Keyword(s):  
Gravitational Field ◽  
Coordinate System ◽  
Celestial Body ◽  
Angular Speed ◽  
Calculation Error ◽  
Cartesian Coordinate System ◽  
Inertial Coordinate System ◽  
The Earth ◽  
The Galaxy ◽  
Cartesian Coordinate

<p class="1Body">Selection of the coordinate system is essential for rotation problems. Otherwise, mistakes may occur due to inaccurate measurement of angular speed. Approximate inertial coordinate system selections for rotation problems should be the gravitational field of the celestial body higher than the object being rotated: (1) the Earth fixed Cartesian coordinate system for normal rotation problem; (2) heliocentric - geocentric Cartesian coordinate system for satellites orbiting the Earth; (3) the Galaxy Heart - heliocentric Cartesian coordinates for Earth's rotation around the Sun. In astrophysics, mass calculation error and angular velocity measurement error lead to a black hole conjecture.</p>

scholarly journals The prediction of braking noise in regenerative braking system using closed-loop coupling disk brake model

2019 ◽  
Vol 233 (14) ◽  
pp. 3721-3735
Author(s):  
Pu Gao ◽  
Jiageng Ruan ◽  
Yongchang Du ◽  
Paul D Walker ◽  
Nong Zhang
Keyword(s):  
Closed Loop ◽  
Coupled Model ◽  
Regenerative Braking ◽  
Bench Test ◽  
Disk Brake ◽  
Coupling Stiffness ◽  
Braking Force ◽  
The Impact ◽  
The Relationship ◽  
Brake Noise

Aiming at improving regenerative braking ability in electric vehicles without compromising any safety, two different regenerative braking strategies are proposed in this study. The impact of continuously varying braking force distributions between front/rear wheel and electric/friction corresponding in two different strategies on braking noise are investigated. Based on the closed-loop coupling disk brake model, the relationship between the contact coupling stiffness and the braking force is established by considering the stationary modal test, the nonlinear optimization, and the relationship between brake-line pressure and braking force. The continuously varying braking force is initially transformed to continuously varying contact coupling stiffness, then, the brake noise tendency at each frequency band is calculated in closed-loop coupled model. The predicted result shows good consistency with the result recorded in bench test, verifying the reliability and effectivity of the presented method. The comparison of the two different electric braking strategies shows that the second braking strategy is superior to the first braking strategy in terms of suppressing the brake noise tendency.

scholarly journals Complex Geodynamical Investigations in the Area of the USSR Academy of Sciences Central Astronomical Observatory at Pulkovo

1990 ◽  
Vol 141 ◽  
pp. 72-72
Author(s):  
V. K. Abalakin ◽  
V. I. Bogdanov ◽  
Yu.D. Boulanger ◽  
V. A. Naumov
Keyword(s):  
Coordinate System ◽  
Ussr Academy ◽  
Astronomical Observatory ◽  
Coordinate Systems ◽  
Inertial Coordinate System ◽  
Gravitation Field ◽  
Practical Applications ◽  
Star Catalogue ◽  
Academy Of Sciences

For astronomical, geodetical and geodynamical investigations as well as for practical applications the inertial coordinate system is widely used which is based on the Fundamental Star Catalogue FK5 together with local coordinate systems in observation stations on the Earth's surface which are intrinsically connected with the geometry of the gravitation field.

scholarly journals Automated Kinematic Analysis of Closed-Loop Planar Link Mechanisms

Machines ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 41
Author(s):  
Tatsuya Yamamoto ◽  
Nobuyuki Iwatsuki ◽  
Ikuma Ikeda
Keyword(s):  
Kinematic Analysis ◽  
Closed Loop ◽  
Analysis Procedure ◽  
Linkage Mechanism ◽  
A Algorithm ◽  
Analysis Process ◽  
Type Transformation ◽  
Extraction Algorithm ◽  
Relationship Of ◽  
The Relationship

The systematic kinematic analysis method for planar link mechanisms based on their unique procedures can clearly show the analysis process. The analysis procedure is expressed by a combination of many kinds of conversion functions proposed as the minimum calculation units for analyzing a part of the mechanism. When it is desired to perform this systematic kinematics analysis for a specific linkage mechanism, expert researchers can accomplish the analysis by searching for the procedure by themselves, however, it is difficult for non-expert users to find the procedure. This paper proposes the automatic procedure extraction algorithm for the systematic kinematic analysis of closed-loop planar link mechanisms. By limiting the types of conversion functions to only geometric calculations that are related to the two-link chain, the analysis procedure can be represented by only one type transformation function, and the procedure extraction algorithm can be described as a algorithm searching computable 2-link chain. The configuration of mechanism is described as the “LJ-matrix”, which shows the relationship of connections between links with pairs. The algorithm consists of four sub-processes, namely, “LJ-matrix generator”, “Solver process”, “Add-link process”, and “Over-constraint resolver”. Inputting the sketch of the mechanism into the proposed algorithm, it automatically extracts unique analysis procedure and generate a kinematic analysis program as a MATLAB code based on it. Several mechanisms are analyzed as examples to show the usefulness of the proposed method.

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