scholarly journals Comparison of Current Five-Point Cylindricity Error Separation Techniques

2018 ◽  
Vol 8 (10) ◽  
pp. 1946 ◽  
Author(s):  
Wenwen Liu ◽  
Penghao Hu ◽  
Kuangchao Fan

Cylindricity is a kind of three-dimensional form distortion of a cylinder. An accurate in situ measurement of cylindricity is relatively complex because measuring and reconstructing cylindrical profile and evaluating out-of-cylindricity should be involved. Any method of in situ measuring cylindricity must solve a common issue, i.e., to eliminate spindle error motions and carriage error motions during measurement and reconstruction. Thus, error separation techniques have played an important role in in situ cylindricity measurement through multipoint detections. Although several valuable five-point methods for in situ measurement of cylindrical profile have been proposed up to present, namely the parallel scan, spiral scan, and V-block scan, there are obvious differences in many aspects, such as the arrangement of probes, error separation model, reconstruction method, adaptability to service environment, accuracy and reliability in practical application, etc. This paper presents the evaluation of their advantages and disadvantages in theory and the actual measurement based on the standard ISO 12180. Suggestions for best meeting the requirements of modern manufacturing and the most prospective one for industrial applications are also given.

2013 ◽  
Vol 457-458 ◽  
pp. 998-1003
Author(s):  
Zhe Zheng ◽  
Ren Jie Zhang

Instantaneous speed measurement system can accurately measure the rotating target and realize the rotation direction judgment. It plays a very important role in industrial applications, as monitoring or controlling the rotation speed of transmitter, motor, turbine. With the development of technology, a modern speed measurement system is demanded to be intelligent, high integration, high precision, high reliability, and low cost etc. Based on the large number of literatures, this paper is a comprehensive review of the principle and application of domestic and foreign mature technology of rotation speed measurement method at present. Through the systematic classification, relationship between the different speed measurements is revealed, and the advantages and disadvantages of different measuring sensor are presented, so that readers can choose reasonable speed measurement method depending on the application, the actual measurement requirements and the test purposes.


2003 ◽  
Vol 2 (4) ◽  
pp. 589
Author(s):  
Douglas R. Cobos ◽  
John M. Baker

2015 ◽  
Vol 84 (8) ◽  
pp. 567-572
Author(s):  
Tadafumi HASHIMOTO ◽  
Masahito MOCHIZUKI

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 536
Author(s):  
Mosab Kaseem ◽  
Karna Ramachandraiah ◽  
Shakhawat Hossain ◽  
Burak Dikici

This review presents an overview of the recent developments in the synthesis of layered double hydroxide (LDH) on the anodized films of Mg alloys prepared by either conventional anodizing or plasma electrolytic oxidation (PEO) and the applications of the formed composite ceramics as smart chloride traps in corrosive environments. In this work, the main fabrication approaches including co-precipitation, in situ hydrothermal, and an anion exchange reaction are outlined. The unique structure of LDH nanocontainers enables them to intercalate several corrosion inhibitors and release them when required under the action of corrosion-relevant triggers. The influences of different variables, such as type of cations, the concentration of salts, pH, and temperature, immersion time during the formation of LDH/anodic film composites, on the electrochemical response are also highlighted. The correlation between the dissolution rate of PEO coating and the growth rate of the LDH film was discussed. The challenges and future development strategies of LDH/anodic films are also highlighted in terms of industrial applications of these materials.


Author(s):  
Philipp Peter Breese ◽  
Tobias Hauser ◽  
Daniel Regulin ◽  
Stefan Seebauer ◽  
Christian Rupprecht

AbstractThe powder mass flow rate is one of the main parameters regarding the geometrical precision of built components in the additive manufacturing process of laser metal deposition. However, its accuracy, constancy, and repeatability over the course of the running process is not given. Reasons among others are the performance of the powder conveyors, the complex nature of the powder behavior, and the resulting issues with existing closed-loop control approaches. Additionally, a direct in situ measurement of the powder mass flow rate is only possible with intrusive methods. This publication introduces a novel approach to measure the current powder mass flow rate at a frequency of 125 Hz. The volumetric powder flow evaluation given by a simple optical sensor concept was transferred to a mass flow rate through mathematical dependencies. They were found experimentally for a nickel-based powder (Inconel 625) and are valid for a wide range of mass flow rates. With this, the dynamic behavior of a vibration powder feeder was investigated and a memory effect dependent on previous powder feeder speeds was discovered. Next, a closed-loop control with the received sensor signal was implemented. The concept as a whole gives a repeatable and accurate powder mass flow rate while being universally retrofittable and applicable. In a final step, the improved dynamic and steady performance of the powder mass flow rate with closed-loop control was validated. It showed a reduction of mean relative errors for step responses of up to 81% compared to the uncontrolled cases.


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