scholarly journals The Effect of Manufacturing Quality on Rocket Precision

Aerospace ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 160
Author(s):  
Zvonko Trzun ◽  
Milan Vrdoljak ◽  
Hrvoje Cajner
Keyword(s):  
Monte Carlo Simulation ◽  
Manufacturing Process ◽  
Degrees Of Freedom ◽  
Cad Model ◽  
Impact Point ◽  
High Quality ◽  
Six Degrees Of Freedom ◽  
Manufacturing Quality ◽  
3D Cad ◽  
Manufacturing Errors

The effect of manufacturing quality on rocket impact point dispersion is analyzed. The approach presented here applies to any type of rocket. Here, manufacturing quality is demonstrated for the unguided rocket, and by simulating four typical manufacturing errors: erroneously manufactured warhead, misalignment between the warhead and engine chamber, asymmetrically installed propellant, and error in nozzle manufacturing. A new methodology is proposed, which combines a 3D CAD model of the asymmetrical projectile (due to manufacturing errors) and the improved Six-degrees-of-freedom (6DOF) model of its flight into a comprehensive Monte-Carlo simulation. In that way, the rocket trajectory dispersion is correlated directly to the imperfection of the manufacturing process. Three quality levels are simulated (low, standard, and high quality), and each of the analyzed manufacturing errors depends on the chosen quality. The results show how important it is to impose the highest quality on nozzle manufacturing, and if this condition is not met, reveal if strict tolerances applied to other steps of the manufacturing process can compensate for the consequential drop of precision.

scholarly journals Simultaneous Measurement Method and Error Analysis of Six Degrees of Freedom Motion Errors of a Rotary Axis Based on Polyhedral Prism

2021 ◽  
Vol 11 (9) ◽  
pp. 3960
Author(s):  
Dong Ma ◽  
Jiakun Li ◽  
Qibo Feng ◽  
Qixin He ◽  
Yaowen Ding ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Motion Error ◽  
Six Degrees Of Freedom ◽  
Rotary Axis ◽  
Position Errors ◽  
Manufacturing Errors ◽  
Polyhedral Prism ◽  
Novel Method ◽  
Six Dof ◽  
Geometric Motion

A novel method is proposed for measuring the six degrees-of-freedom (DOF) geometric motion errors of a rotary axis based on a polyhedral prism. An error-sensitive unit which consists of a polyhedral prism and a planar reflector, is designed to carry out measurement of all six DOF errors, including the angular positioning error, the tilt motion error around the Y axis, the tilt motion error around the X axis, the radial motion error along the X and Y axes, and the axial motion error along the Z axis. The mathematical error model, including the six DOF geometric motion errors of the rotary axis, the installation errors between the polyhedral prism and the rotary axis, the manufacturing errors of the polyhedral prism, and the position errors of the sensors, are established. The effectiveness of the proposed method and the compensation model was simulated and experimentally verified.

Kinematic Modelling and Simulation of 8 Degrees of Freedom SCARA Robot

2019 ◽  
pp. 77-97
Author(s):  
Saravana Mohan M. ◽  
Anbumalar V.
Keyword(s):  
Degrees Of Freedom ◽  
Block Diagram ◽  
Dynamic Study ◽  
Cad Model ◽  
Dynamic Parameters ◽  
Scara Robot ◽  
3D Cad ◽  
Pick And Place ◽  
Kinematic Modelling ◽  
Pick And Place Operation

Robots are electromechanical systems that need mechatronic approach before manufacturing to reduce the development cost. In this chapter, the modelling of the 8 degrees of freedom (DOF) SCARA robot with a multiple gripper using SolidWorks CAD software and the dynamic study with the aid of MATLAB/SimMechanics is presented. The SCARA with multiple gripper is used for pick and place operation in manufacturing industries. The SolidWorks CAD model of SCARA with multiple grippers is converted into SimMechanics block diagram by exporting the 3D CAD model to the MATLAB/SimMechanics second generation technology environment. The motion sensing capability of the SimMechanics is used for determining the dynamic parameters of the manipulators. The SimMechanics block diagrams and the results of the dynamic study presented in this chapter infer that the structure of the robot can be changed to get the required dynamic parameters.

Remanufacturing of Damaged Parts Using Selective Laser Melting Technology

2014 ◽  
Vol 693 ◽  
pp. 285-290 ◽  
Author(s):  
George Răzvan Buican ◽  
Gheorghe Oancea ◽  
Alexandru Manolescu
Keyword(s):  
Selective Laser Melting ◽  
Manufacturing Process ◽  
Additive Technologies ◽  
Cad Model ◽  
Laser Melting ◽  
3D Scanner ◽  
Melting Technology ◽  
3D Cad ◽  
Original Part ◽  
Complex Parts

This paper presents the stages taken to remanufacture a damaged part, for which no documentation is available, using the SLM additive technologies. A damaged part is scanned using the COMET L3D scanner and the points cloud is used to redesign and reconstruct the part as a 3D CAD model. Using the generated 3D CAD model the build job for the SLM is created by designing and adding the construction supports, the material type and the type of hatching strategy for each slice. The slices are used by the SLM250HL equipment and the new metallic part is manufactured. The manufactured part was scanned with the same 3D scanner and the data from the original part was compared with the new reading. The results can be used to reconstruct more complex parts, to redesign the broken parts and to improve the manufacturing process.

APPLYING THE ISF TECHNOLOGY TO PRODUCE THE CAR PART MODELS

2010 ◽  
Vol 13 (4) ◽  
pp. 91-98
Author(s):  
Tuan Dinh Phan ◽  
Binh Thien Nguyen ◽  
Dien Khanh Le ◽  
Phuong Hoang Pham
Keyword(s):  
Rapid Prototyping ◽  
Incremental Sheet Forming ◽  
Cad Model ◽  
Post Processing ◽  
Technological Parameters ◽  
Batch Production ◽  
Complex Products ◽  
3D Cad ◽  
Real Size ◽  
Single Batch

The paper presents an application the research results previously done by group on the influence of technological parameters to the deformation angle and finish surface quality in order to choose technology parameters for the incremental sheet forming (ISF) process to produce products for the purpose of rapid prototyping or single-batch production, including all steps from design and process 3D CAD model, calculate and select the technological parameters, setting up manufacturing and the stage of post-processing. The samples formed successfully showed high applicability of this technology to practical work, the complex products with the real size can be produced in industries: automotive, motorcycle, civil...

Control of processing at multi-tool two-support setup

2020 ◽  
pp. 67-73
Author(s):  
N.D. YUsubov ◽  
G.M. Abbasova
Keyword(s):  
Degrees Of Freedom ◽  
Factor Model ◽  
Angular Displacement ◽  
Factor Models ◽  
Technological System ◽  
Displacement Control ◽  
Model Accuracy ◽  
Six Degrees Of Freedom ◽  
Angular Displacements ◽  
And Control

The accuracy of two-tool machining on automatic lathes is analyzed. Full-factor models of distortions and scattering fields of the performed dimensions, taking into account the flexibility of the technological system on six degrees of freedom, i. e. angular displacements in the technological system, were used in the research. Possibilities of design and control of two-tool adjustment are considered. Keywords turning processing, cutting mode, two-tool setup, full-factor model, accuracy, angular displacement, control, calculation [email protected]

scholarly journals Design and Calibration of a Hall Effect System for Measurement of Six-Degree-of-Freedom Motion within a Stacked Column

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3740
Author(s):  
Olafur Oddbjornsson ◽  
Panos Kloukinas ◽  
Tansu Gokce ◽  
Kate Bourne ◽  
Tony Horseman ◽  
...  
Keyword(s):  
Hall Effect ◽  
Degrees Of Freedom ◽  
Reactor Core ◽  
Degree Of Freedom ◽  
Life Extension ◽  
Scale Model ◽  
Design Development ◽  
Seismic Safety ◽  
Six Degrees Of Freedom ◽  
Six Degree Of Freedom

This paper presents the design, development and evaluation of a unique non-contact instrumentation system that can accurately measure the interface displacement between two rigid components in six degrees of freedom. The system was developed to allow measurement of the relative displacements between interfaces within a stacked column of brick-like components, with an accuracy of 0.05 mm and 0.1 degrees. The columns comprised up to 14 components, with each component being a scale model of a graphite brick within an Advanced Gas-cooled Reactor core. A set of 585 of these columns makes up the Multi Layer Array, which was designed to investigate the response of the reactor core to seismic inputs, with excitation levels up to 1 g from 0 to 100 Hz. The nature of the application required a compact and robust design capable of accurately recording fully coupled motion in all six degrees of freedom during dynamic testing. The novel design implemented 12 Hall effect sensors with a calibration procedure based on system identification techniques. The measurement uncertainty was ±0.050 mm for displacement and ±0.052 degrees for rotation, and the system can tolerate loss of data from two sensors with the uncertainly increasing to only 0.061 mm in translation and 0.088 degrees in rotation. The system has been deployed in a research programme that has enabled EDF to present seismic safety cases to the Office for Nuclear Regulation, resulting in life extension approvals for several reactors. The measurement system developed could be readily applied to other situations where the imposed level of stress at the interface causes negligible material strain, and accurate non-contact six-degree-of-freedom interface measurement is required.

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