The process of measuring geometric parameters of details on cylindrical grinding machines using active control device

Author(s):  
A. V. Tignibidin
Author(s):  
Akira Fukukita ◽  
Tomoo Saito ◽  
Keiji Shiba

We study the control effect for a 20-story benchmark building and apply passive or semi-active control devices to the building. First, the viscous damping wall is selected as a passive control device which consists of two outer plates and one inner plate, facing each other with a small gap filled with viscous fluid. The damping force depends on the interstory velocity, temperature and the shearing area. Next, the variable oil damper is selected as a semi-active control device which can produce the control forces by little electrical power. We propose a damper model in which the damping coefficient changes according to both the response of the damper and control forces based on an LQG feedback and feedforward control theory. It is demonstrated from the results of a series of simulations that the both passive device and semi-active device can effectively reduce the response of the structure in various earthquake motions.


Author(s):  
Kazuhiko Hiramoto ◽  
Taichi Matsuoka ◽  
Akira Fukukita ◽  
Katsuaki Sunakoda

We address a simultaneous optimal design problem of a semi-active control law and design parameters in a vibration control device for civil structures. The Vibration Control Device (VCD) that is being developed by authors is used as the semi-active control device in the present paper. The VCD is composed of a mechanism of a ball screw with a flywheel for the inertial resistance force and an electric motor with an electric circuit for the damping resistance force. A new bang-bang type semi-active control law referred to as Inverse Lyapunov Approach is proposed as the semi-active control law. In the Inverse Lyapunov Approach the Lyapunov function is searched so that performance measures in structural vibration control are optimized in the premise of the bang-bang type semi-active control based on the Lyapunov function. The design parameters to determine the Lyapunov function and the design parameters of the VCD are optimized for the good performance of the semi-active control system. The Genetic Algorithm is employed for the optimal design.


2014 ◽  
Vol 716-717 ◽  
pp. 707-710
Author(s):  
Jin Wei Fan ◽  
Xiao Long Yi ◽  
Chao Liu ◽  
Yong Jun Liu

CNC cylindrical grinding machine reliability is an important performance indicators, the level of reliability will directly affect the use of CNC cylindrical grinding machine. Reliability of the traditional classification method is not clear, standards are not uniform, the paper application taxonomy for 12 CNC grinding machines from September 2012 to July 2014 for two years more than 600 pieces complete failure and repair data for statistical analysis to identify a greater impact on the overall reliability of the fault location and cause of the malfunction. According to the probability of occurrence of each failure mode, the severity of harm's comprehensive evaluation of the degree of fault of each site, identify the weak links of the whole system. As a result, the reliability of CNC cylindrical grinding machine will be greatly improved.


Author(s):  
Ming-Hsiang Shih ◽  
Wen-Pei Sung

In this research, autonomous controller is developed to provide the function of “Sensing-Computing-Transferring” for improving of energy dissipation capability of semi-active control device. This proposed controller has qualifications of detecting structural response under the excitation of earthquake; it depends on the control law to produce control order to adjust and control the action of semi-active control damper. The principle of this controller is: 1.) autonomous controller and damper-added stiffness element are parallel connection; 2.) the direction of pressure force and velocity moving direction of structure are changed simultaneously by this controller; 3.) the action of switching direction of damper has been finished when the tiny displacement of structure is happened by reverse process of moving direction of structure. Practically, this controller was simulated by connecting soft springs, damper and actuator in serial. The experimental results indicate that the function and energy-dissipating behavior of this proposed controller is similar to traditional semi-active controller except that this controller can switch the damper status at the right moment. This proposed controller can replace the detector, central control computer and damping controller included in original semi-active control system. The advantages of this developed autonomous controller are: 1.) low manufacturing cost; 2.) low requirement of system maintenance; 3) high reliability of control system.


2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Kazuhiko Hiramoto

A new control design framework for vibration control, the cooperative control of active and semiactive control, is proposed in the paper. In the cooperative control, a structural system having both of an actuator and a semiactive control device, for example, MR damper and so forth, is defined as the control object. In the proposed control approach, the higher control performance is aimed by the cooperative control between the active control with the actuator and the semiactive control with the semiactive control device. A design method to determine the active control input and the command signal to drive the semiactive control device based on the one-step prediction of the control output is proposed. A simulation example of a control system design for a benchmark building is presented to show the effectiveness of the proposed control framework.


2011 ◽  
Vol 264-265 ◽  
pp. 1124-1129 ◽  
Author(s):  
Ramesh Rudrapati ◽  
Pradip Kumar Pal ◽  
Asish Bandyopadhyay

Good surface finish is one of the important demands from the outputs of a cylindrical grinding machine. Also it is expected that dimensional accuracy, including accuracy in roundness, is fine in traverse cut cylindrical grinding. Now, like any other machine tool, cylindrical grinding machines also do vibrate, and vibration will affect accuracy and surface finish of the parts produced in grinding. The analysis of vibration in cylindrical grinding is then very much important. In the present study some aspects of vibration – behavior of cylindrical grinding machine have been experimented and analyzed. The process parameters have been varied and vibration signals have been measured in different directions by positioning an accelerometer at tail stock of the machine. The data have been analyzed through various statistical techniques to identify and predict vibration at given combinations of process parameters. The results and analysis of data give useful idea about dynamic performance of cylindrical grinding machine in traverse cut cylindrical grinding operation.


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