Yun-Feng Teng

Development of a middle-range six-degrees-of-freedom system

Abstract This paper describes the successful development of a middle-range six-degrees-of-freedom stage, using the features of a flexible structure. The system includes two parts: a middle-range positioning X—Y stage and a four-degrees-of-freedom stage. The flexible structure of the four-degrees-of-freedom stage is built from two kinds of flexible bodies: circular hinges and a new two-degrees-of-freedom flexible body. The four-degrees-of-freedom stage was designed to compensate movement errors including linear displacement, pitch, and roll errors. The linear displacement reaches 20 mm along the X-axis, 20 mm along the Y-axis, and 5 μm along the Z-axis. The rotation angle around the X-axis (θ x ), Y-axis (θ y ), and Z-axis (θ z ) were all 10 arcsec. A novel six-degrees-of-freedom measuring system was also designed. Precision feedback control is demonstrated in a series of experiments performed using the proposed measurement system.

Development of a novel multi-axis nano-positioning and the spiral tracking control

This paper presents the design of a sliding-mode controller for a piezoelectric-driven nanometer resolution stage. The nanometer resolution stage is developed using the features of a flexible structure, and is driven by piezoelectric actuators and also uses capacitance sensors for position feedback. The hysteresis characteristic of the piezoelectric actuators is one of the major deficiencies in a wide variety of precise tracking positioning controls. In order to design the control system, the open-loop characteristics of this nanometer resolution stage are investigated. According to the open-loop characteristics, each pair of piezoelectric actuator and capacitance sensor is treated as an independent system and modeled as a first order linear model coupled with hysteresis. When the model is identified, the hysteresis nonlinearity is linearized then the linear system model with uncertainty is used to design the controller. When designing the controller, the sliding-mode disturbance estimation and compensation scheme is used. The structure of the proposed controller is similar to the PID controller. Thus, it can be easily implemented.

Development of the Nano-Measuring Machine stage

In this paper, it was successfully developed a nano- measuring machine stage. It was used the features of a flexible structure to develop the nano-measuring machine stage. This stage includes two parts: one is a long range positioning X-Y stage and the other one is a four degrees-of-freedomicro-range stage. The flexible structure of the four degrees-of-freedom micro-range stage was included two kinds of an arc flexible body and a new two degrees-of- freedom flexible body. The micro-range stage was designed to compensate the moving errors such as vertical straightness error, pitch error and roll errors and its all moving range is 20 mm times 20 mm times 11 mum. Precision feedback is provided by the six degrees-of-freedom measuring system with integrating the three plane mirror interferometers and a two degrees-of-freedom angular sensor.

Development of a flexure hinge-based stack-type five-degrees-of-freedom nanometre-scale stage for a heavy-loading machining process

Abstract The current paper concentrates on the design and manufacturing process of a stack-type nanometre positioning stage with high accuracy and multiple degrees of freedom for a heavy-loading machine. The stack-type stage described in this paper comprises a flexible structure as the primary component and can be easily adjusted from single-axis movement to a five-degrees-of-freedom motion to cope with different needs. Piezoelectric actuators are known for their unique features, such as quick response, high resolution, electrical mechanical coupling efficiency, and low heat generation. Therefore, six piezoelectric actuators are provided to trigger the five-degrees-of-freedom motion for the positioning stage. The stage sensor is provided with five capacitive sensors inside the five-degrees-of-freedom stage to measure the stage displacement. As indicated by the experimental results, the linear displacement reaches 52. 76 μm along the x axis, 51. 79 μm along the y axis, and 12. 08 μm along the z axis. The rotation displacement around the x axis is θ x = 184 μrad and the rotation displacement around the y axis is θ y = 277 μrad. The heavy-loading test indicates that the stage is capable of taking a load of 12 kgs.

To develop an optical system model for image based multi-degree-of-freedom measurement system

This paper subjects an optoelectronic multi-degree-of-freedom (DOF) measurement system to establish the optical system model. Through the optical model, the multi-DOF motion can be carried out by the laser spot variation. The multi-DOF measurement system includes 2 digital image sensors and 4 laser diodes. It improves the disadvantage of conventional multi-DOF measurement system. The conventional multi-DOF measurement system usually needs many position sensing detectors (PSD) and each PSD must have enough space. Therefore, the conventional multi-DOF measurement system needs large space. Because one image sensor can sense multi laser spot simultaneously, the structure of proposed multi-DOF measurement system can be simplified.

To develop a high speed auto-alignment system by dual machine vision based alignment system

In this paper, 2 sub machine vision based alignment systems were used to establish a high speed alignment system for screen printing. It can be used on the solar cell and flat display panel manufacture. The 2 sub alignment system can auto align target simultaneously. When one target was takes out, another target can implement auto alignment simultaneously. It can save the wait time for target take out procedure. The sub alignment system includes 4 CCD cameras, 4 lens, 4 outer coaxial LED light sources, a vacuum table and a 3 axis motorized stage. The alignment accuracy is about 1 μm.

Developing a fast inspection path generation method for an automatic spinneret inspection system

Document Withdrawn from IEEE Xplore: The document that would normally appear here has been withdrawn because it contains proprietary information that was not meant to be made public at this time. Reasonable effort should be made to remove all references to this document. We regret any inconvenience.

Development of the precision long-stroke 3-DOF nano-stage for the photonic crystal process

In this paper, it develops a precision long-stroke 3-DOF nano-stage for the nano photonic crystal process. It integrates a linear motor driven long-stroke stage, a piezoelectric driven three-degrees-of-freedom (3-DOF) nano stage, multi-degrees-of-freedom (MDOF) laser interferometer measurement system and their control systems. The long-stroke nano-stage is a hybrid precision stage that can provide long-stroke and high precision positioning. The common focus horizon regulation system is used to keep the parallelism between writing instrument and the target while the laser direct writing instrument is used to write the nano structure needed. Furthermore, the automatic focusing and horizon control system can compensate the defocusing and angular errors that caused by machining automatically. With this precision 3-DOF nano-stage, the laser direct writing system can improve the process speed, overcome the optical limit of interference to reduce the writing spot, generate arbitrary patterns.

The Application of the Dual-Beam Laser Interferometer for Calibration Precision Machine ToolsAnwendung eines Zweistrahl-Laserinterferometers zur Kalibrierung von Präzisionswerkzeugen

Abstract In this paper, a dual-beam laser interferometer measurement system for precision machine tools was presented. The straightness measurement module and the angular measurement module were combined to form this measurement system such that the operations of precision machine tools, the positioning, vertical straightness, horizontal straightness, pitch and yaw, can be obtained. The resolution of the positioning, straightness and angle has achieved 0.1 nm, 1 nm and 0.1 arcsec, respectively. The performance of this measurement system has been proved by experiments.

A Novel Simple and Low Cost 4-DOF Angular Indexing Calibrating Technique for High Precision Rotary Table

For calibrating an angular rotary table, either a high precision standard table or a laser interferometer and related optics are normally employed at high cost. This paper establishes a novel, simple and low cost technique to calibrate a 4-degrees-of-freedom errors of a rotary table (three angular motion errors and one displacement error) for a 360° full circle by employing one reference rotary table, one 1D grating and two 2D (2 dimensional) position-sensing-detectors. With this technique, no highly accurate reference table with good repeatability is needed. After two full circle tests, the 4 DOF errors of the target rotary table and the reference table can be calculated respectively. The angular uncertainty of the measurement system can be less than 1.5 arc sec, while the displacement uncertainty can be up to 1.5 μm.Copyright