Electronic control hydraulic impactor based on pressure feedback
The impact energy of the traditional hydraulic impactor can be regulated manually between the second and the third grade, and its impact frequency can not be adjusted independently. Also, they have to stop working for adjustment. In order to alter this situation, a new hydraulic impactor DBS500, which controlled by micro-electronic system, has been designed and its functions are showed as following: The impact energy can reach 500 joules and its impact frequency also realizes regulation from 0 to 8Hz steplessly. It can estimate the work object's nature by piston's rebound behavior. It can self-regulate the impact energy and frequency according to the object's nature, so that can improve the working efficiency and adapt the power of the loader.
Application of fuzzy control for a hydraulic forging machine
Abstract Most metal-forming processes are non-linear, non-stationary and time-variant. Nonetheless, linear controllers or LTI-control systems are used for many of these processes. Because of their simplicity of application, fuzzy controllers have recently been implemented for many industrial processes in Europe, in Japan and in the USA. Fuzzy control may be characterized as an approach using controllers which can be designed without a mathematical model of the process and which are inherently non-linear. Fuzzy control is based on a priori expert knowledge which can be described in the form of a language. This paper discusses one application of fuzzy control, an adaptive fuzzy controller for a hydraulic forging machine which minimizes geometrical and material defects of the workpiece by controlling the servo valve and the pump power. The paper describes the use of the fuzzy controller with two processes, upsetting and thixoforging. The design procedure for the controller and experimental results are discussed.
Numerical tools applied to power reactor noise analysis
In order to be able to calculate the space- and frequency-dependent neutron noise in real inhomogeneous systems in two-group theory, a code was developed for the calculation of the Green's function (dynamic transfer function) of such systems. This paper reports on the development as well as the test and application of the numerical tools employed. The code that was developed yields the space-dependence of the fluctuations of the neutron flux induced by fluctuating properties of the medium in the two-group diffusion approximation and in a two-dimensional representation of heterogeneous systems, for both critical systems and non-critical systems with an external source. Some applications of these tools to power reactor noise analysis are then described, including the unfolding of the parameters of the noise source from the induced neutron noise, measured at a few discrete locations throughout the core. Other concrete applications concern the study of the space-dependence of the Decay Ratio in Boiling Water Reactors, the noise-based estimation of the Moderator Temperature Coefficient of reactivity in Pressurized Water Reactors, the modeling of the beam- and shell-mode core-barrel vibrations in Pressurized Water Reactors, and the investigation of the validity of the point-kinetic approximation in subcritical systems driven by an external source. In most of these applications, calculations performed using the code are compared with at-power plant measurements. Power reactor noise analysis applications of the above type, i.e. core monitoring without disturbing plant operation, is of particular interest in the framework of the extensive program of power uprates worldwide.