Three-dimensional Optical Measurement System Research Articles

Physico-mechanical properties of Sapindus mukorossi seed

This work characterized physical and mechanical properties of Sapindus mukorossi seed to explore the mechanical behaviors of the seed during compression in a roll crusher. A new method that combines simulations and calculations with experimental data obtained using a three-dimensional optical measurement system for the measurement of the Poisson ratio and elasticity modulus of the hollow-sphere seed hull was proposed. The modulus of elasticity was derived from a mechanics formulation and verified in a computer simulation based on experimental data. Scanning electron microscopy and energy-dispersive spectrometry were conducted to reveal the mesostructure and components of the seed hull. The results revealed that the average densities of the S. mukorossi seed shell and kernel were respectively 1.49 and 1.07 × 103 kg/m3, the average Poisson’s ratio was 0.185, and Young’s modulus ranged from 1.3 to 0.3 GPa. These values had little dispersion, demonstrating both the consistency of the processing techniques and the stability of the material properties. The given properties of the S. mukorossi can be used as a theoretical basis for the optimized processing of this biomass material. The proposed method provides a new direction in the study of the mechanical properties of biomaterials.

Investigation of the Springback Behaviour of High-strength Aluminium Alloys Based on Cross Profile Deep Drawing Tests

The prediction of springback of sheet metal parts is still a challenge in metal forming processes. To meet the requirements for dimensional accuracy of a sheet metal part, the springback must be compensated and the production process has to be designed accordingly. During forming, elastic energy is stored in the semi-finished product. When removing a part from the deep-drawing tool, the resulting residual stresses with an elastic component cause unwanted changes of the part‘s geometry in forming. Especially sheet materials with low elastic modulus and high yield strength tend to an increased springback. Among others, these materials include aluminium alloys of the 7000 series. For this reason, a fundamental understanding of the material behaviour of these materials is relevant for designing a sheet metal forming process. This contribution uses a novel approach to investigate the springback behaviour of AA7020-T6 and AA7075-T6. For this purpose, cross profiles are deep-drawn with various parameter settings and subsequently digitised with a three-dimensional optical measurement system. By analysing the digitised profiles, the springback behaviour is quantified depending on the experimental parameters. Due to the right-angled structure of the cross profile, the influence of anisotropy in 0 and 90 degree to rolling direction is investigated within one forming operation.

3D optical displacement measurements on dynamically loaded adhesively bonded T-peel specimens

Adhesively bonded T-Peel specimens are loaded in a rotary impact device to investigate the behaviour of adhesive joints under high-strain rates. To gain a better understanding of that kind of tests and their results, the deformation of the samples as well as the movement of specimen support during the test is analyzed. A three-dimensional optical measurement system is used in combination with two synchronized high-speed cameras to obtain the deformations. The paper explains the experimental challenges and discusses the results of the analyses with respect to a planned usage of the experimental results in a finite element crash simulation. As main results of the investigations it can be summarized that the compliant clamping leads to an inadvertent out-of-plane-movement of the load introduction point. Based on finite element calculations it can be concluded that the measured out-of-plane-movement possesses a negligible influence on the obtained force signal, which is of primary interest in a T-Peel test.

Method of Detection for Complex Surfaces Based on Industrial Close-Range Photogrammetry

The rapid detection of the large complex surface was researched with the development of China's manufacturing industry. A industrial close-range photogrammetry new detection Method was put forward based on the analysis of three-dimensional optical measurement principle. The experiment results verify that the accuracy of the three-dimensional optical measurement system independently developed by Xi'an Jiao Tong University meets the Engineering requirements. The main characteristics of large workpiece can be clearly measured and the detection method can be easily used at the production site.

New Large-Size Three-Dimensional Optical Measuring System Investigation

In this paper a new three-dimensional large-size optical measurement system by laser radar has been proposed in combination of double-optic circuit measuring technology, ultra-high frequency modulation technology and laser intellectual tracing and location technology. The system can measure 3d shape unconnectedly for lager-size object, which has the advantages of high accuracy, automatic measurement and freedom from being influenced by material and light ray.

Integrated precision evaluation method for three-dimensional optical measurement system

An integrated precision evaluation method (IPEM) for evaluating the capabilities of sophisticated optical measurement systems is proposed. The method, which has the advantages of the VDI/VDE2634 guidelines and the Standardization Project for Optical Techniques of Strain measurement procedure, is developed on the basis of three-dimensional (3D) optical measurement technology and statistical principles. The application of the IPEM to a combination of an in-house developed 3D optical measurement system and an in-house developed photogrammetry measurement system is investigated for the case of measuring features on a large-scale waterwheel blade. It is shown that the proposed method is appropriate and feasible for application in manufacturing industries.

High-speed, high-resolution, and large-scanning-range three-dimensional optical measurement system using a wavelength-tunable orthogonally polarized ultrashort twin pulse source

A high-speed, high-resolution, and large-scanning-range three-dimensional measurement system was demonstrated using an electronically controlled wavelength-tunable orthogonally polarized high-power ultrashort twin pulse source and an all-fiber interferometer. Thanks to the high peak power, the ultrashort optical pulses propagated along a fiber while maintaining the pulse shape by means of the soliton effect, allowing us to demonstrate high-speed, high-resolution, and large-scanning-range measurement. First, the interference was analyzed by numerical calculations and then the measurement system was demonstrated experimentally. A longitudinal scanning range of about 25 mm, a longitudinal resolution of 33 μm, and a scanning speed of 1000 points/s were achieved without moving parts. For a measurement distance of 0.5 m, a sensitivity of 60 dB was obtained. Clear three-dimensional images of a 100 yen Japanese coin and metal samples were obtained using this system.

広帯域光源と全ファイバ型干渉計を用いた 非接触・高感度・高精度三次元光計測

We investigated a highly functional and practical three-dimensional optical measurement system based

「高強度レーザーの時間・空間制御技術の新展開」特集号によせて－黎明期の高出力レーザー－

We investigated a highly functional and practical three-dimensional optical measurement system based