Turntable System Research Articles

Dynamical Integral Sliding Mode Control for Permanent Magnet Ring Torque Motor

In view of the characteristics of numerical control turntable servo system directly driven by permanent magnet ring torque motor, which is susceptible to load disturbance and parameter variation, a dynamic-integral sliding mode position controller is designed. Dynamic sliding mode control means making differential operation to switching function of conventional sliding mode control, thus, a new switching function can be obtained. The discontinuous terms are transferred to first or higher derivative of control quantity. Therefore, the dynamic sliding mode control law is continuous timely, and then the chattering can be effectively reduced. Meanwhile, in order to ensure the steady-state accuracy of system, the integral term is introduced in the switching function to realize dynamic integral sliding mode control. The simulation results indicate that dynamic-integral sliding mode control of permanent magnet ring torque motor has favorable dynamic response and strong robustness, and it is effective to weaken the chattering.

Influence of boundary conditions and turntable speeds on the stability of hydrostatic oil cavity

The flow, bearing, and carrying capacity of the cycloidal hydrostatic oil cavity in hydrostatic turntable systems are numerically simulated, considering the rotation speeds of a turntable from 0 to 5 m/s and different boundary conditions. The vortex effect is weakened, and the stability of the oil cavity is enhanced with the increase in lubricant viscosity. However, the increase in inlet speed, depth, and inlet radius of the oil cavity causes the vortex effect to increase and the stability of oil cavity to reduce. With the increase in the oil film thickness, the carrying capacity of the oil cavity diminishes. The oil cavity pressure increases along the direction of the motion of the turntable; it is distributed unevenly because of the rotation of the turntable. With the increase in turntable speed, the location and size of the vortex scope in the oil cavity flow field and the strength of the vortex near the entrance gradually weaken and move away from the entry. The distribution of pressure is determined by the locations of the vortex. When the vortex is close to the wall, the wall pressure increases at its location. Otherwise, the wall pressure decreases first and then increases after the center of the vortex.

Rheological behavior’s effect on the work performance of oil film

A 3D model of hydrostatic turntable’s oil chamber is established to investigate the lubricants performance with different rheological properties by using FLUENT software and the finite volume method. Newtonian oil and non-Newtonian oil’s performance under varied speeds are compared on the large size hydrostatic turntable system considering the temperatureviscosity relationship and pressure-viscosity relationship. The results show that the property of non-Newtonian fluid viscosity influenced by shear rate largely affects the lubricants performance for most oil added polymer additives. Lubricants cannot simply be regarded as Newtonian fluid. The shear thickening non-Newtonian fluid has a better work property. The results are important to design a large size and high-speed hydrostatic support system, choose lubricant oils, and investigate oil film’s work properties.

Single Wavelength Blue-Laser Optical Head-Like Opto-Mechanical System for Turntable Thermal Mode Lithography and Stamper Fabrication

The characterization of novel small size 405 nm blue-laser optical head-like opto-mechanical system for turntable thermal mode lithography system that can provide high quality beam spot profile and real time high precision servo control and feasibility for thermal mode lithography process application are presented. The optical head-like opto-mechanical system consists of a single wavelength laser direct-write blue-laser opto-mechanical module and related servo control main board. An ideally narrow round shape exposure beam spot about 260 nm and high precision power control, focusing servo control are produced for thermal mode inorganic resist exposure. The small size opto-mechanical system combination with thermal mode lithography technology has been successfully applied to fabricate nickel stamper with submicro/nano structure patterns. The minimum pit (or hole) diameter is about 180 nm and ultra-low surface roughness (2 nm) is achieved after electroforming process.

Fault detection of switched linear systems with its application to turntable systems

Fault detection of switched linear systems with its application to turntable systems

线阵CCD遥感器单轴转台的设计

In order to simulate liner CCD remote sensor flying image and check up its image effect in laboratory,one kind of liner CCD remote sensor uniaxial turntable control system was designed.This paper introduces working principle of liner CCD remote sensor uniaxial turntable,analyses imaging error of turntable simulation flying and brings point and parameter design of turntable.The experimental results indicate that the control precision of speed loop is 2%,the stabilization precision is 6',the image is clearly,and the results satisfy the requirement of design.

Suppression of Disturbance from Test Turntable Dynamic Unbalance by using Adaptive Repetitive Control

Through analysis of dynamic unbalance factors of a three-axis test turntable,it is found that the test turntable has periodic disturbance torque. The periodic disturbance torque mainly consists of acceleration torque,coriolis coupling torque and centrifuge coupling torque,which is related to three-axis moment of inertia,position angle and rotating speed of test turntable and will influence the positioning precision and speed precision of test turntable. In order to suppress the periodic disturbance torque with uncertain frequency caused by dynamic unbalance of three-axis test turntable,an adaptive finite-dimensional repetitive control used to eliminate periodic disturbance is proposed. Adaptive algorithm is adopted for on-line identification of disturbance frequency,and finite-dimensional repetitive controller parameters are adjusted to eliminate the disturbance. The convergence of the algorithm and the stability of the system are proved by using averaging method. Simultaneously the algorithm can eliminate multi-period disturbance of different frequency by regulating the structure of adaptive multi-period finite-dimensional repetitive controller. Simulation results show that the proposed method can effectively suppress period disturbance caused by dynamic unbalance of three-axis test turntable and improve the positioning precision and speed precision of test turntable system.

Analyzing a Pattern-Based Model of a Real-Time Turntable System

Designers of industrial real-time systems are commonly faced with the problem of complex system modeling and analysis, even if a component-based design paradigm is employed. In this paper, we present a case-study in formal modeling and analysis of a turntable system, for which the components are described in the SaveCCM language. The search for general principles underlying the internal structure of our real-time system has motivated us to propose three modeling patterns of common behaviors of real-time components, which can be instantiated in appropriate design contexts. The benefits of such reusable patterns are shown in the case-study, by allowing us to produce easy-to-read and manageable models for the real-time components of the turntable system. Moreover, we believe that the patterns may pave the way toward a generic pattern-based modeling framework targeting real-time systems in particular.

The Research on the Orientation Error of Three-Axis Turntable in Theory and Measuring Method Based on Assembling

Based on the analysis of geometric errors of mechanism assembling, this paper applies the multi-body system kinematics theory in building the orientation error model of three-axis turntable induced by assembling errors. The results using the model could be easily applied in controlling turntable by error’s compensation, and shows which assembling error item has the larger effect. Furthermore，referenced by the measuring means of three-axis turntable, this paper conceives the definitions of the volumetric and orientation accuracy aimed at the turntable system, enlightened from the conception of NC machine tool. This research may be helpful to the foundation of the systematic conception of the turntable accuracy no matter in theory or in measuring method.

DISTURBANCE ATTENUATION IN TURNTABLE DYNAMIC UNBALANCE ON THE BASIS OF MULTI-PERIOD FINITE- DIMENSIONAL REPETITIVE CONTROL

The turntable having multi-period disturbance torque is obtained by setting up the dynamic unbalance model of three-axis turntable. The multi-period disturbance torque is related to three-axis rotate speed of turntable and influences localization precision, position precision and speed precision of turntable. In order to attenuate system disturbance torque of three-axis turntable, the method of multi-period finite-dimensional repetitive control is proposed and proves to be a success in attenuating the systematic error of turntable caused by multi-period disturbance. The result of simulation shows that multi-period finite-dimensional repetitive control can attenuate dynamic unbalance disturbance of turntable system effectively.

Analyzing a χ model of a turntable system using Spin, CADP and Uppaal

Nowadays, due to increasing system complexity and growing competition and costs, industry makes high demands on powerful techniques used to design and analyze manufacturing systems. One of the most popular techniques to do performance analysis is simulation. However, simulation-based analysis cannot guarantee the correctness of a system, so it is less suitable for functional analysis. Our research focuses on examining other methods to do performance analysis and functional analysis, and trying to combine the two. One of the approaches is to translate a simulation model that is used for performance analysis to a model written in an input language of an existing verification tool. We translate a χ [D.A. van Beek, K.L. Man, M.A. Reniers, J.E. Rooda, R.R.H. Schiffelers, Syntax and Consistent Equation Semantics of Hybrid Chi, CS-Report 04-37, Eindhoven University of Technology, 2004] simulation model of a turntable system into models written in the input languages of the tools CADP [J.-C. Fernandez, H. Garavel, A. Kerbrat, L. Mounier, R. Mateescu, M. Sighireanu, CADP—a protocol validation and verification toolbox, in: Proceedings of the 8th Conference on Computer Aided Verification (CAV’96), Lecture Notes in Computer Science, vol. 1102, 1996, pp. 437–440], S pin [G.J. Holzmann, The SPIN Model Checker, Addison-Wesley, 2003] and U ppaal [K.G. Larsen, P. Pettersson, W.Yi, Uppaal in a nutshell, Int. J. Software Tools for Technology Transfer 1 (1–2) (1997) 134–152] and do a functional analysis with each of them. This allows us to evaluate the usefulness of these tools for the functional analysis of χ models. We compare the input formalisms, the expressiveness of the temporal logics, and the algorithmic techniques for model checking that are used in those tools.

2806 三箇所の離れた現場の仮想的統合を支援するターンテーブルの開発

This paper proposes a turntable system, which supports communication among three remote locales. This interface system is mainly composed of three co-actuated disk devices and a LCD projector for projecting remote locale situations on a table. Three disks are arranged like a triangle on a tabletop. Existence of remote users is generated around a table by rotating a disk and by projecting remote locales situations. Virtually shared table is expected to support remote collaborative work.

Turntable system with low aggregate resonance

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Letters. Editorial Correction: Authors on turntable diode laser systems (352A)

Letters. Editorial Correction: Authors on turntable diode laser systems (352A)

Turntable system with low aggregate resonance

Systeme de tourne-disque de haute fidelite avec faible resonance d'ensemble. Turntable system high fidelity with low overall resonance. Le systeme de tourne-disque comprend un assemblage de bras de tonalite (6) et un plateau (4) entraine par une courroie fixee de maniere rigide par une sous-structure silencieuse (8) en tube d'aluminium pur et autres formes d'element. The turntable system includes a tone arm assembly (6) and tea (4) results in a fixed belt rigid manner by a silent sub-structure (8) pure aluminum tube and other forms of element. Cette sous-structure de faible masse acoustique (8) est amortie interieurement au-dela de son point de resonance et est suspendue elastiquement a une plaque de base (37) dans un boitier de montage (32) pour isoler le systeme de tourne-disque de toute reaction de resonance. This low acoustic mass substructure (8) is internally damped beyond its point of resonance is suspended elastically and has a base plate (37) in a mounting box (32) to isolate the turntable system any reaction resonance. La masse acoustique du systeme de tourne-disque et, par consequent, la resonance, est encore reduite en decouplant le contre-poids du bras de tonalite (38) de l'assemblage du bras de tonalite (6) a l'aide d'elements elastiques supplementaires (40). The acoustic mass of the turntable system and, therefore, the resonance is further reduced by decoupling the weight against the tone arm (38) of the assembly of the tone arm (6) with the help of elastic additional content (40).

A Hydrostatic Oil Bearing Turntable System for the Laboratory Study of Some Aspects of Weightlessness

A Hydrostatic Oil Bearing Turntable System for the Laboratory Study of Some Aspects of Weightlessness