Jing Bai, Yuchang Zhang, Xiansheng Qin, Zhanxi Wang and Chen Zheng
The purpose of this paper is to present a visual detection approach to predict the poses of target objects placed in arbitrary positions before completing the corresponding tasks…
Abstract
Purpose
The purpose of this paper is to present a visual detection approach to predict the poses of target objects placed in arbitrary positions before completing the corresponding tasks in mobile robotic manufacturing systems.
Design/methodology/approach
A hybrid visual detection approach that combines monocular vision and laser ranging is proposed based on an eye-in-hand vision system. The laser displacement sensor is adopted to achieve normal alignment for an arbitrary plane and obtain depth information. The monocular camera measures the two-dimensional image information. In addition, a robot hand-eye relationship calibration method is presented in this paper.
Findings
First, a hybrid visual detection approach for mobile robotic manufacturing systems is proposed. This detection approach is based on an eye-in-hand vision system consisting of one monocular camera and three laser displacement sensors and it can achieve normal alignment for an arbitrary plane and spatial positioning of the workpiece. Second, based on this vision system, a robot hand-eye relationship calibration method is presented and it was successfully applied to a mobile robotic manufacturing system designed by the authors’ team. As a result, the relationship between the workpiece coordinate system and the end-effector coordinate system could be established accurately.
Practical implications
This approach can quickly and accurately establish the relationship between the coordinate system of the workpiece and that of the end-effector. The normal alignment accuracy of the hand-eye vision system was less than 0.5° and the spatial positioning accuracy could reach 0.5 mm.
Originality/value
This approach can achieve normal alignment for arbitrary planes and spatial positioning of the workpiece and it can quickly establish the pose relationship between the workpiece and end-effector coordinate systems. Moreover, the proposed approach can significantly improve the work efficiency, flexibility and intelligence of mobile robotic manufacturing systems.
Details
Keywords
Zhengfeng Jia, Yuchang Su, Yanqiu Xia, Xin Shao, Yanxin Song and Junjie Ni
– The purpose of this paper is to investigate the tribological properties of a Cu–Cr–Zr alloy lubricated with acid rain.
Abstract
Purpose
The purpose of this paper is to investigate the tribological properties of a Cu–Cr–Zr alloy lubricated with acid rain.
Design/methodology/approach
The Cu 2.5 weight per cent–Cr-0.08 weight per cent–Zr alloy was produced in a vacuum induction furnace. The H2SO4 + H2O, HNO3 + H2O and H2SO4 + HNO3 + H2O mixtures with pH of 5 were used as acid rain. Pure water was used as rain. The friction and wear properties of Cu–Cr–Zr alloy/American Iron and Steel Institute (AISI) 52100 steel couples lubricated with acid rain were investigated using a reciprocating ball-on-disc friction and wear tester (Optimol SRV, Germany). For investigating the properties of the alloy and wear scars, scanning electron microscopy, X-ray diffraction microscopy, energy dispersive X-ray spectrum, transmission electron microscopy and X-ray photoelectron spectroscope were used.
Findings
The wear rate of the Cu–Cr–Zr alloy lubricated with H2O containing HNO3 (pH = 5) was larger than pure water under the same conditions. The tribofilms containing Cu, Cr, Zr, S and N formed during sliding with acid rain, but corrosion also took place at that time.
Originality/value
The wear rate of the Cu–Cr–Zr alloy lubricated with H2O containing HNO3 (pH = 5) was larger than pure water, the wear and corrosion took place during sliding. As the trolley wires, the life of the Cu–Cr–Zr alloy was influenced by the environment.
Details
Keywords
Linhao Ouyang, Zijian Zhang, Xiaoling Huang and Shi Xie
The purpose of this study is to restore the spatial distribution of overseas remittance businesses in Shantou during the 1940s. It explores various socioeconomic factors that…
Abstract
Purpose
The purpose of this study is to restore the spatial distribution of overseas remittance businesses in Shantou during the 1940s. It explores various socioeconomic factors that influenced the concentration of local remittance business investment in real estate. By reconstructing the spatial distribution of remittance business activities in Shantou, this study hopes to lay a foundation for further analysis of the business strategies of Chaoshan merchants.
Design/methodology/approach
This research draws on information from the published Swatow Guide, archival sources and cadastral maps to identify the location of remittance enterprises and the native place and overseas networks of property owners.
Finding
This study reveals that the spatial distribution of the remittance enterprises was determined by the native place origins of local property owners, and that the inflow of overseas Chinese capital contributed to real estate development in Shantou.
Research limitations/implications
Despite the limited access to Chinese official archives, this paper manages to identify several building blocks and neighbors in Shantou for spatial analysis.
Practical implications
This study is the first attempt to use the geographical information system (GIS) method in Chinese urban history research and hopes to establish a larger historical database of Shantou as a sample for comparison.
Originality/value
This investigation advances the spatial study of urban history and overseas Chinese remittances in the maritime society of South China.
Details
Keywords
Yushen Wang, Wei Xiong, Danna Tang, Liang Hao, Zheng Li, Yan Li and Kaka Cheng
Traditional simulation research of geological and similar engineering models, such as landslides or other natural disaster scenarios, usually focuses on the change of stress and…
Abstract
Purpose
Traditional simulation research of geological and similar engineering models, such as landslides or other natural disaster scenarios, usually focuses on the change of stress and the state of the model before and after destruction. However, the transition of the inner change is usually invisible. To optimize and make models more intelligent, this paper aims to propose a perceptible design to detect the internal temperature change transformed by other energy versions like stress or torsion.
Design/methodology/approach
In this paper, micron diamond particles were embedded in 3D printed geopolymers as a potential thermal sensor material to detect the inner heat change. The authors use synthetic micron diamond powder to reinforced the anti-corrosion properties and thermal conductivity of geopolymer and apply this novel geopolymer slurry in the direct ink writing (DIW) technique.
Findings
As a result, the addition of micron diamond powder can greatly influence the rheology of geopolymer slurry and make the geopolymer slurry extrudable and suitable for DIW by reducing the slope of the viscosity of this inorganic colloid. The heat transfer coefficient of the micron diamond (15 Wt.%)/geopolymer was 50% higher than the pure geopolymer, which could be detected by the infrared thermal imager. Besides, the addition of diamond particles also increased the porous rates of geopolymer.
Originality/value
In conclusion, DIW slurry deposition of micron diamond-embedded geopolymer (MDG) composites could be used to manufacture the multi-functional geological model for thermal imaging and defect detection, which need the characteristic of lightweight, isolation, heat transfer and wave absorption.