Dynamic modeling of high precision servo systems with gear backlash

Download
2013
Yumrukçal, Zafer
Although the mechanical solutions, like spring preloaded hinge mechanism, compensate for backlash in servo drive systems with high precision positioning requirement, these solutions may not be preferred because of their drawbacks like high friction forces/torques and diminished life cycles for mating gears. Besides, the use regular gear meshes could be enforced by any reason, like cost efficiency or simplicity of the solution. On such occasions, to maintain performance requirements like high positioning accuracy, alternative control methods can be used with regular gear meshes. For the purpose of developing a controller, it is important to develop a model for the physical system. This thesis work aims to fulfill the requirement for a dynamic model of a servo system with gear backlash which is to be used as a base for the development of a controller. In the scope of this thesis work, firstly, a literature survey has been conducted to examine the approaches for identifying and modeling a dynamic system with gear backlash. Following the literature survey, a real servo system with gear backlash has been identified and a dynamic model of the system has been developed. Simulation results from the system model compared with the test results obtained from physical system and validity of servo system model with varying backlash limits has been presented.

Suggestions

DYNAMIC ANALYSIS OF GEARED ROTORS BY FINITE-ELEMENTS
KAHRAMAN, A; Özgüven, Hasan Nevzat; HOUSER, DR; ZAKRAJSEK, JJ (1992-09-01)
A finite element model of a geared rotor system on flexible bearings has been developed. The model includes the rotary inertia of shaft elements, the axial loading on shafts, flexibility and damping of bearings, material damping of shafts and the stiffness and the damping of gear mesh. The coupling between the torsional and transverse vibrations of gears were considered in the model. A constant mesh stiffness was assumed. The analysis procedure can be used for forced vibration analysis of geared rotors by c...
Nonlinear Dynamic Analysis of a Spiral Bevel Geared System
Yavuz, Siar Deniz; Saribay, Zihni Burcay; Ciğeroğlu, Ender (2017-02-02)
A nonlinear dynamic model of a spiral bevel gear train mounted on flexible shafts and bearings is proposed in this study. The finite element model of shafts is combined with a three-dimensional discrete mesh model of a spiral bevel gear pair. Bearing flexibilities are as well included in the model. Gear backlash is incorporated into the model in the form of clearance-type displacement functions and clearance nonlinearity and stiffness fluctuations of the bearings are neglected. A time-invariant mesh stiffne...
Analytical modeling of the machine tool spindle dynamics under operational conditions
Özşahin, Orkun; Özgüven, Hasan Nevzat (null; 2012-07-27)
Chatter is an important problem in machining operations, and can be avoided by utilizing stability diagrams which are generated using frequency response functions (FRF) at the tool tip. In general, tool point FRF is obtained experimentally or analytically for the idle state of the machine. However, during high speed cutting operations, gyroscopic effects and changes of contact stiffness and damping at the interfaces as well as the changes in the bearing properties may lead to variations in the tool point FR...
Dynamic characterization of bolted joints using FRF decoupling and optimization
Tol, Serife; Özgüven, Hasan Nevzat (2015-03-01)
Mechanical connections play a significant role in predicting dynamic characteristics of assembled structures. Therefore, equivalent dynamic models for joints are needed. Due to the complexity of joints, it is difficult to describe joint dynamics with analytical models. Reliable models are generally obtained using experimental measurements. In this paper an experimental identification method based on FRF decoupling and optimization algorithm is proposed for modeling joints. In the method the FRFs of two subs...
Stability of Milling Operations With Asymmetric Cutter Dynamics in Rotating Coordinates
Comak, Alptunc; Özşahin, Orkun; Altintas, Yusuf (2016-08-01)
High-speed machine tools have parts with both stationary and rotating dynamics. While spindle housing, column, and table have stationary dynamics, rotating parts may have both symmetric (i.e., spindle shaft and tool holder) and asymmetric dynamics (i.e., two-fluted end mill) due to uneven geometry in two principal directions. This paper presents a stability model of dynamic milling operations with combined stationary and rotating dynamics. The stationary modes are superposed to two orthogonal directions in ...
Citation Formats
Z. Yumrukçal, “Dynamic modeling of high precision servo systems with gear backlash,” M.S. - Master of Science, Middle East Technical University, 2013.