A high accuracy hydraulic pressing actuation system for superplasticity forming equipment

Author(s):  
Yufeng Qu ◽  
Bing Li ◽  
Shuai Wu ◽  
Zongxia Jiao ◽  
Hong Xiao ◽  
...  
Author(s):  
Stan van der Meulen ◽  
Rokus van Iperen ◽  
Bram de Jager ◽  
Frans Veldpaus ◽  
Francis van der Sluis ◽  
...  

A reduction in the fuel consumption of a passenger car with a pushbelt continuously variable transmission (CVT) can be established via optimization of the hydraulic actuation system. This requires a model of the dynamic characteristics with low complexity and high accuracy, e.g., for closed-loop control design, for closed-loop simulation, and for optimization of design parameters. The hydraulic actuation system includes a large number of hydraulic components and a model of the dynamic characteristics is scarce, which is caused by the complexity, the nonlinearity, and the necessity of a large number of physical parameters that are uncertain or unknown. In this paper, a modular model for the hydraulic actuation system on the basis of first principles is constructed and validated, which is characterized by a relatively low complexity and a reasonably high accuracy. A modular approach is pursued with respect to the first principles models of the hydraulic components, i.e., a hydraulic pump, spool valves, proportional solenoid valves, channels, and hydraulic cylinders, which reduces complexity and improves transparency. The model parameters are either directly provided, directly measured, or identified. The model of the hydraulic actuation system is composed of the models of the hydraulic components and is experimentally validated by means of measurements that are obtained from a production pushbelt CVT. Several experiment types are considered. The correspondence between the measured and simulated responses is fairly good.


2014 ◽  
Vol 658 ◽  
pp. 700-705 ◽  
Author(s):  
Ciprian Radu Rad ◽  
Olimpiu Hancu ◽  
Vistrian Maties ◽  
Ciprian Lapusan

The key element in a servo-pneumatic actuation system is the control valve. This paper presents a method for parameter identification and modeling the flow characteristic of a FESTO MPYE-5-1/8-HF-101B proportional valve. An experimental setup and a procedure for parameter identification is presented in the paper. Simulation and experimental results are in agreement and the model of the valve could be used in high-accuracy positioning control design of pneumatic servo-systems.


1970 ◽  
Vol 4 ◽  
pp. 5-6
Author(s):  
Alejandro Márquez ◽  
Nicolás Medrano ◽  
Belén Calvo ◽  
Pedro A. Martínez

This paper presents a CMOS 1.8V-180nm analog quadrature sine oscillator. Thanks to a custom 12-bit bidirectional DAC-based architecture, the frequency can be digitally programmed over two decades with high accuracy, making it suitable as the actuation system in low-cost high-performance embedded lock-in measurement systems.


Author(s):  
M. Nishigaki ◽  
S. Katagiri ◽  
H. Kimura ◽  
B. Tadano

The high voltage electron microscope has many advantageous features in comparison with the ordinary electron microscope. They are a higher penetrating efficiency of the electron, low chromatic aberration, high accuracy of the selected area diffraction and so on. Thus, the high voltage electron microscope becomes an indispensable instrument for the metallurgical, polymer and biological specimen studies. The application of the instrument involves today not only basic research but routine survey in the various fields. Particularly for the latter purpose, the performance, maintenance and reliability of the microscope should be same as those of commercial ones. The authors completed a 500 kV electron microscope in 1964 and a 1,000 kV one in 1966 taking these points into consideration. The construction of our 1,000 kV electron microscope is described below.


The paper describes the main trends in the development of BIM technologies in the field of restoration and reconstruction of historical and cultural heritage buildings. The practical part of the paper presents the experience in using information modeling technologies when restoring the building, where the VI Congress of the Chinese Communist Party in Moscow took place. The use of laser scanning technologies made it possible to reproduce with high accuracy in the information model the original appearance of the building using Autodesk RevitR software. It is shown, how the use of information modeling technologies affects the duration of restoration process, taking into account the calculation of the structural scheme and bearing structures of the building, ensuring the identity of the decoration and the effective organization of electromechanical installation. Operating in a single BIM information environment makes it possible to continuously obtain reliable information on the project, which provides more effective information interaction and communication of participants compared to using traditional design methods.


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