Chenjie Wang, Lu Yin, Qing Zhao, Wei Wang, Chengyuan Li and Bin Luo
To ensure the safety of electric power supply, it is necessary to inspect substation equipment. With the dramatic increase in the number of substations, especially indoor…
Abstract
Purpose
To ensure the safety of electric power supply, it is necessary to inspect substation equipment. With the dramatic increase in the number of substations, especially indoor substations, intelligent robot inspection has become an important development direction. This paper aims to describe the design of a trackless robot with a robotic arm, which is capable of navigating autonomously and inspecting the equipment in a narrow and complex indoor substation.
Design/methodology/approach
A robust four-wheel platform powered by electric motors is used to carry the robot. By fusing multiple-sensor data and visual markers, the robot achieves autonomous movement based on simultaneous localization and mapping. In addition, to accurately obtain the reading of meters located at height or in a narrow space, the robot is equipped with a newly designed visual servo robotic arm.
Findings
In practical application, the robot satisfies the requirements of substation inspection, improves work efficiency, saves costs and achieves good results. The robot is also approved by the relevant departments of the State Grid Corporation of China.
Practical implications
After stable operation in a substation for a period of one year, the robot shows high efficiency and stability, meeting the requirements of indoor substation inspection. Meanwhile, the robot greatly promoted the realization of indoor and outdoor integrated substation automatic inspection, and is expected to be further applied in other industrial inspection sites, including mine, tunnel and nuclear power plant.
Originality/value
Due to the complex indoor environment, most of the existing inspection robots are only used outdoors, and there are no good trackless inspection robots for use indoors. The proposed robot is a trackless intelligent inspection robot for use in indoor substations. The robot features a number of important modules, including an autonomous localization and navigation module and a visual servo manipulator module, which can be used in narrow spaces or at height.
Details
Keywords
Dan Zhang, Yanhong Wei, Xiaohong Zhan, Jie Chen, Hao Li and Yuhua Wang
This paper aims to describe a three-dimensional mathematical and numerical model based on finite volume method to simulate the fluid dynamics in weld pool, droplet transfer and…
Abstract
Purpose
This paper aims to describe a three-dimensional mathematical and numerical model based on finite volume method to simulate the fluid dynamics in weld pool, droplet transfer and keyhole behaviors in the laser-MIG hybrid welding process of Fe36Ni Invar alloy.
Design/methodology/approach
Double-ellipsoidal heat source model and adaptive Gauss rotary body heat source model were used to describe electric arc and laser beam heat source, respectively. Besides, recoil pressure, electromagnetic force, Marangoni force, buoyancy as well as liquid material flow through a porous medium and the heat, mass, momentum transfer because of droplets were taken into consideration in the computational model.
Findings
The results of computer simulation, including temperature field in welded plate and velocity field in the fusion zone were presented in this article on the basis of the solution of mass, momentum and energy conservation equations. The correctness of elaborated models was validated by experimental results and this proposed model exhibited close correspondence with the experimental results with respect to weld geometry.
Originality/value
It lays foundation for understanding the physical phenomena accompanying hybrid welding and optimizing the process parameters for laser-MIG hybrid welding of Invar alloy.
Details
Keywords
Hao Wu, Sang Xiong, Wei Lin and Fanxin Kong
The purpose of this paper is to improve lubrication and anti-corrosion properties of the water-in-oil (W/O) microemulsion for rolling of copper strip and sheet to replace the…
Abstract
Purpose
The purpose of this paper is to improve lubrication and anti-corrosion properties of the water-in-oil (W/O) microemulsion for rolling of copper strip and sheet to replace the traditional rolling oil.
Design/methodology/approach
The W/O microemulsion is prepared by using hydrogenated base oil, a deionized aqueous solution of 0.03 mol/L of Na2SO4 and composite emulsifier such as Sp20, Tx-7 or sodium petroleum sulfonate. Tribological behavior of the microemulsions and traditional cold rolling oil was conducted by MR-10A four-ball tester. The lubrication performance of microemulsion for cold rolling of copper strip was performed by cold-rolling experiment. The morphology of worn surface and the rolled copper was characterized. Anti-corrosion properties of microemulsion for rolled copper was investigated, and the corroded surface was analyzed by X-ray photoelectron spectrometer (XPS).
Findings
The results show that the extreme pressure and antiwear properties of the microemulsions have been improved; the average friction coefficient of the improved microemulsion is 0.065, which is 30% lower than the commercial cold rolling oil. For cold rolling of copper strip, the microemulsion has a higher thinning effect than the commercial cold rolling oil, and a smooth surface is obtained and the surface roughness (Sa) is decreased by 6.8%. The XPS analysis indicated microemulsion adsorbed on the copper surface mitigate the corrosion of oils.
Originality/value
This paper used the prepared W/O microemulsion as a new lubricant in the process of rolling for copper strip and sheet in industry, demonstrating the microemulsion has broad application prospects in the future.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-06-2020-0227/