scholarly journals Measurement of Spindle Thermal Growth on a Machine Intended for Micro/Meso Scale Milling

2010 ◽  
Vol 447-448 ◽  
pp. 55-60 ◽  
Author(s):  
J.B. Saedon ◽  
Sein Leung Soo ◽  
David K. Aspinwall
Keyword(s):  
Control System ◽  
Literature Review ◽  
Injection Moulding ◽  
Micro Milling ◽  
Measuring Systems ◽  
Warm Up ◽  
Micro Scale ◽  
Thermal Growth ◽  
Acceleration And Deceleration ◽  
Meso Scale

Micro milling is gaining ground as the preferred process for the manufacture of micro/meso-scale components in conventional workpiece materials, in particular for miniature moulds and tooling inserts (~ 60HRC), for the plastics injection moulding industry. Following a brief literature review on microscale milling and associated machine tool/tooling developments, experimental results are presented in relation to spindle thermal growth for a compensated/cooled spindle operating at up to 60,000 rpm, designed to accommodate the machining of meso-scale/micro-scale components. The work involved investigation of spindle warm up and cool down rates for speeds ranging from 30,000 - 60,000 rpm and subsequently the evaluation of spindle growth using both non-contact and contact measuring systems. Growth levels of up to 16µm were detected despite active spindle cooling and the incorporation of a standard compensation algorithm within the control system. Modification to spindle acceleration and deceleration rates reduced error levels by up to 50%.

MICRO AND MESO SCALES OF DESCRIPTION CORRESPONDING TO A MODEL OF TISSUE INVASION BY SOLID TUMOURS

2005 ◽  
Vol 15 (11) ◽  
pp. 1667-1683 ◽  
Author(s):  
MIROSŁAW LACHOWICZ
Keyword(s):  
Mathematical Models ◽  
Type Equation ◽  
Reaction Diffusion ◽  
Solid Tumours ◽  
Macroscopic Model ◽  
Scale Level ◽  
Micro Scale ◽  
Tissue Invasion ◽  
Mathematical Relationships ◽  
Meso Scale

In this paper two new mathematical models are proposed that correspond to a macroscopic model of tissue invasion of solid tumours, in terms of a system of reaction-diffusion-chemotaxis equations. The first model is defined at the micro-scale level of a large number of interacting individual entities, and is in terms of a linear (Markov) equation. The second model refers to the meso-scale level of description of test-entities and is given in terms of a bilinear Boltzmann-type equation. Mathematical relationships among these three possible descriptions are formulated. Explicit error estimates are given.

Research on Digital Control of Meter-In and Meter-Out Independent Regulating for High Inertia Load

1999 ◽  
Author(s):  
Qingfeng Wang ◽  
Linyi Gu ◽  
Yongxiang Lu
Keyword(s):  
Control System ◽  
Feedback Control ◽  
Dynamic Process ◽  
Control Algorithm ◽  
Damping Ratio ◽  
State Feedback Control ◽  
Hydraulic Systems ◽  
Outlet Pressure ◽  
Acceleration And Deceleration ◽  
Valve Control

Abstract The smoothness of acceleration and deceleration process is a serious problem in valve control system with high inertia load, especially in the hydraulic systems in construction machines. In this paper, a meter-in and meter-out independent regulating method, in which the two sides of actuator are controlled by a meter-in valve and a meter-out valve respectively, is put forward, in one hand, the meter-out valve could control the actuator’s outlet pressure to avoid the ultra-high outlet pressure when actuator decelerates or brakes suddenly. On the other hand, the dynamic damping ratio of valve control system could be raised through calculated flow feedback control algorithm. Secondly, a grading control algorithm in dynamic process of high inertia load is adopted. When the actuator’s velocity is far from its command value, the actuator’s inlet and outlet pressure are controlled. After the velocity error decrease to a threshold, a state feedback control algorithm based on parameters on line estimating is employed to realize both its velocity accuracy and the smoothness of dynamic process. Experiments show that the actuator’s velocity could increase or decrease to its command value accurately, smoothly and rapidly after the above method and algorithm are applied.

Effect of micro-scale morphological parameters on meso-scale response of Asphalt Concrete

2014 ◽  
pp. 1775-1784 ◽  
Author(s):  
Ibrahim Onifade ◽  
Denis Jelagin ◽  
Alvaro Guarin ◽  
Björn Birgisson ◽  
Nicole Kringos
Keyword(s):  
Asphalt Concrete ◽  
Morphological Parameters ◽  
Micro Scale ◽  
Scale Response ◽  
Meso Scale

Study on Micro Mill-Grinding Technology

2013 ◽  
Vol 390 ◽  
pp. 586-590 ◽  
Author(s):  
Chao Wang ◽  
Ya Dong Gong ◽  
Guo Qiang Yin ◽  
Xue Long Wen ◽  
Jun Cheng
Keyword(s):  
Surface Roughness ◽  
Abrasive Particle ◽  
Three Dimensional ◽  
Micro Milling ◽  
Mechanical Processing ◽  
Micro Machining ◽  
Micro Scale ◽  
Abrasive Grains ◽  
Machining System ◽  
Spraying Method

Micro mechanical processing is the effective method for machining micro scale parts. Micro mill-grinding technology is presented based on micro milling and micro grinding processes. The machining principle of micro mill-grinding is studied, and compound tools for micro mill-grinding are fabricated based on spraying technology. Experiments are performed on Al 6061-T6 with the three-dimensional micro machining system. The results show that submicron surface roughness can be obtained by micro mill-grinding. Abrasive grains of mill-grinding tools fabricated by spraying method shed easily. Smaller abrasive particle size improves the surface quality and increases the tool life.

scholarly journals Fabrication of beam structures with micro-scale cross-sections and meso-scale spans

2007 ◽  
Vol 17 (12) ◽  
pp. 2516-2521 ◽  
Author(s):  
Michael James Martin ◽  
Robert D White ◽  
Katsuo Kurabayashi ◽  
Iain D Boyd
Keyword(s):  
Cross Sections ◽  
Beam Structures ◽  
Micro Scale ◽  
Meso Scale

Desired Signal Planning of Flexible Arm for Reduction Control of Residual Vibration

2001 ◽  
Vol 13 (1) ◽  
pp. 12-16
Author(s):  
Hiroyuki Kojima ◽  
Keyword(s):  
Control System ◽  
Joint Angle ◽  
Equations Of Motion ◽  
Equation Of Motion ◽  
Pd Controller ◽  
Flexible Link ◽  
Residual Vibration ◽  
Flexible Arm ◽  
Acceleration And Deceleration ◽  
Nonlinear Equations Of Motion

In this paper, first, the nonlinear equations of motion of a horizontal one-link flexible arm are obtained by use of mode functions of a cantilever beam with a mass. Then, the algorithm of the desired signal planning of the joint angle for the purpose of reducing control of residual vibration of the flexible arm is derived by using the initial and final conditions of the flexural displacement of the flexible link and the constraint conditions of the desired signal of the joint angle during the acceleration and deceleration terms as well as the linearized equation of motion of the flexible arm. The rotation control system of the flexible arm is constructed with the desired signal planning for the joint angle and the PD controller. Furthermore, numerical simulations of the rotation control of the flexible arm have been carried out, and it is confirmed that residual vibration of the flexible arm can be effectively reduced by the present desired signal planning for the joint angle.

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