Algorithm Design of 3D Measurement System Based on FPGA

Aiming at improving the 3D shape measurement speed and accuracy, the design of floating point algorithm for 3-D shape measurement using FPGA, is proposed. By using four-step phase shifting method for measuring 3D measurement system, using CORDIC algorithm to achieve phase calculation of the phase shift method, the algorithm is realized by Verilog language in FPGA, and to make simulation and verification in Modelsim. The study of 3D shape measurement system have a breakthrough from the design performance and hardware.Finally, the MATLAB simulation proved its effectiveness and viability.The experimental results show that the advantages of high data processing speed, high efficiency and high precision,etc.

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A Robot-Driven 3D Shape Measurement System for Automatic Quality Inspection of Thermal Objects on a Forging Production Line

Sensors ◽

10.3390/s18124368 ◽

2018 ◽

Vol 18 (12) ◽

pp. 4368 ◽

Cited By ~ 7

Author(s):

Liya Han ◽

Xu Cheng ◽

Zhongwei Li ◽

Kai Zhong ◽

Yusheng Shi ◽

...

Keyword(s):

Measurement System ◽

Production Line ◽

Heat Radiation ◽

Shape Measurement ◽

Quality Inspection ◽

3D Measurement ◽

Online Environment ◽

3D Shape ◽

3D Shape Measurement ◽

3D Data

The three-dimensional (3D) geometric evaluation of large thermal forging parts online is critical to quality control and energy conservation. However, this online 3D measurement task is extremely challenging for commercially available 3D sensors because of the enormous amount of heat radiation and complexity of the online environment. To this end, an automatic and accurate 3D shape measurement system integrated with a fringe projection-based 3D scanner and an industrial robot is presented. To resist thermal radiation, a double filter set and an intelligent temperature control loop are employed in the system. In addition, a time-division-multiplexing trigger is implemented in the system to accelerate pattern projection and capture, and an improved multi-frequency phase-shifting method is proposed to reduce the number of patterns required for 3D reconstruction. Thus, the 3D measurement efficiency is drastically improved and the exposure to the thermal environment is reduced. To perform data alignment in a complex online environment, a view integration method is used in the system to align non-overlapping 3D data from different views based on the repeatability of the robot motion. Meanwhile, a robust 3D registration algorithm is used to align 3D data accurately in the presence of irrelevant background data. These components and algorithms were evaluated by experiments. The system was deployed in a forging factory on a production line and performed a stable online 3D quality inspection for thermal axles.

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A Real-Time 3D Measurement System for the Blast Furnace Burden Surface Using High-Temperature Industrial Endoscope

Sensors ◽

10.3390/s20030869 ◽

2020 ◽

Vol 20 (3) ◽

pp. 869 ◽

Cited By ~ 2

Author(s):

Tianxiang Xu ◽

Zhipeng Chen ◽

Zhaohui Jiang ◽

Jiancai Huang ◽

Weihua Gui

Keyword(s):

Blast Furnace ◽

High Temperature ◽

Real Time ◽

Measurement System ◽

Reconstruction Method ◽

3D Measurement ◽

3D Shape ◽

Camera Array ◽

3D Measurement System ◽

High Dust

Capturing the three-dimensional (3D) shape of the burden surface of a blast furnace (BF) in real-time with high accuracy is crucial for improving gas flow distribution, optimizing coke operation, and stabilizing BF operation. However, it is difficult to perform 3D shape measurement of the burden surface in real-time during the ironmaking process because of the high-temperature, high-dust, and lightless enclosed environment inside the BF. To solve this problem, a real-time 3D measurement system is developed in this study by combining an industrial endoscope with a virtual multi-head camera array 3D reconstruction method. First, images of the original burden surface are captured using a purpose-built industrial endoscope. Second, a novel micro-pixel luminance polarization method is proposed and applied to compensate for the heavy noise in the backlit images due to high dust levels and poor light in the enclosed environment. Third, to extract depth information, a multifeature-based depth key frame classifier is designed to filter out images with high levels of clarity and displacement. Finally, a 3D shape burden surface reconstruction method based on a virtual multi-head camera array is proposed for capturing the real-time 3D shape of the burden surface in an operational BF. The results of an industrial experiment illustrate that the proposed method can measure the 3D shape of the entire burden surface and provide reliable burden surface shape information for BF control.

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