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Nanjing, China

Yoshimitsu S.,Hayatocho Shinkou | Satonaka S.,Kurokami | Kawano Y.,Hayatocho Shinkou | Iwamoto C.,Kurokami | And 2 more authors.
Key Engineering Materials | Year: 2012

This report describes a two-dimensional monitoring system for milling machines using small-diameter tools. Small-diameter tools are used for high-speed milling, and they are indispensable for high-quality and high-productivity manufacturing. However, tool breakage occasionally occurs, and this becomes a serious problem in automated production. This study aims to develop a system for monitoring the cutting state that can prevent tool breakage. The proposed system consists of two charge-coupled device (CCD) cameras, an image processing device, a man-machine controller (MMC), and a machining center with an open computer numeric (CNC). This monitoring system is connected to the machining center by Ethernet. It enables the precise measurement of tool deflection during high-speed milling. In an experiment, we applied this system to the end milling of a steel plate under different cutting conditions, and we examined the relationship between tool deflection and the cutting conditions. In addition, we applied this monitoring system to measure tool wear, and we examined the relationship between tool deflection and tool wear. It was found that the proposed system enabled in-process monitoring of the cutting state and tool wear. © (2012) Trans Tech Publications, Switzerland.

Xu L.,Nanjing University of Aeronautics and Astronautics | Jiang Y.L.,29 Yudao St
Advanced Materials Research | Year: 2014

As a result of the strict restrictions on the use of power supply under the mine disaster, the Open loop cycle CO2 refrigeration system is used in the Mine Rescue Cabin. Traditional system has got a couple of equipment malfunctions frequently, such as the Ice-block in Cold-start, Cold-frost and Overheating. In this paper, a new type of refrigeration system is designed after the Thermodynamic analysis of extreme limit condition. The new system avoids the Ice-block and the cold-frost by limit the refrigerant flow, it also can improve the capability of the evaporator. It has a important reference value to the research and application of the open loop cycle CO2 refrigeration system in the extreme condition. © (2014) Trans Tech Publications, Switzerland.

Wang Y.,29 Yudao St | Yu K.,29 Yudao St | Tan J.,29 Yudao St
Key Engineering Materials | Year: 2014

A hydrodynamic experiment apparatus is constructed to accomplish the measurement of hydrodynamic force on three-dimensional. This paper firstly introduces the mechanical structure of the novel hydrodynamic experiment apparatus. Then, it introduces the mathematical modeling of the hydrodynamic experiment apparatus which is based on the relationship between measurement data and the force on experiment subject. Finally, the error source of the mechanical structure and load cells were analyzed and the error compensation model is established to improve the measurement accuracy. © (2014) Trans Tech Publications, Switzerland.

Wang Y.,29 Yudao St | Gu B.,29 Yudao St | Tan J.,29 Yudao St | Sang P.,29 Yudao St
Key Engineering Materials | Year: 2014

Stingrays have expanded and highly flexible pectoral fins that extend over the entire length of their body. Locomotion is controlled by modulations of the undulating fin surface which produce steady swimming, acceleration, or complex maneuvers. In this paper, a robotic fish inspired by stingray was presented. Structure of the biomimetic prototype and layout of the control system were illustrated. In order to mimic the undulations, parameters of the biomimetic pectoral fin need to be accurately controlled including frequency, amplitude, wavelength, and undulatory mode. Several control strategies were proposed to realize different kinds of locomotion. Lastly, swimming experiments were carried out in the water tank according to the control methods. Experiment results demonstrate the viability of our methods. © (2014) Trans Tech Publications, Switzerland.

Wang Y.,29 Yudao St | Tan J.,29 Yudao St | Gu B.,29 Yudao St | Zhao D.,29 Yudao St
Key Engineering Materials | Year: 2014

Fishes have evolved remarkable swimming abilities after years of evolution which inspire scientists and engineers to develop new underwater robots that mimic different kinds of fishes. Stingray is a unique species among median and/or paired fin (MPF) mode fishes which undulates the enlarged pectoral fins while swimming. In this paper, a biomimetic prototype design and a developed undulating fin propulsor that mimics stingrays are presented. Kinematic model of the undulating fin is built. The flexibility of the curved surface is checked by the fitting results. Detailed mechanism structure and control system design of the bionic prototype are illustrated. The simulation experiments of the propulsor were conducted on the ground and the results show that an approximated harmonic wave can be generated on each side fin. The feasibility of the motion control method is verified.

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