Synchronous Control Algorithm Research Articles

3D SHAPE MEASURING INSTRUMENTS USING HIGH STIFFNESS VIBRATION TOUCH SENSOR

In this paper, a novel method to determine the shape of a 3D object is proposed. Instead of a flexible conventional touch probe, a high-stiffness vibration touch sensor was developed. The proposed sensor consisted of a piezo-electric device and thin probe, and generated feedback voltage according to the relative distance from the object. The structure of this sensor is simple, so that it can withstand high rates of acceleration during the measurement process. A nonlinear synchronous multi-axis control algorithm is also proposed. The effectiveness of our proposed sensor and control algorithm is demonstrated through experiments and simulations.

공기압 실린더 구동 장치의 위치 동기 제어

In this study, a position synchronous control algorithm applied to two-axes pneumatic cylinder driving apparatus is proposed. The position synchronous control algorithm is composed of position controller and synchronous controller. The position controller is designed to minimize the effect of several nonlinear characteristics peculiar to the pneumatic cylinder driving apparatus on position control performance. The synchronous controller is designed to reduce the synchronous error. The effectiveness of the proposed control algorithm is proved by experimental results.

High-resolution maskless lithography

An innovative high-resolution maskless lithography system is designed employing a combination of low- and high-numerical-aperture (NA) projection lens systems along with integrated micro-optics, and using Texas Instruments' super video graphic array (SVGA) digital micromirror device (DMD) as the spatial and temporal light modulator. A mercury arc lamp filtered for the G-line (λ = 435.8 nm) is used as the light source. Exposure experiments are performed using data extraction and transfer software, and synchronous stage control algorithms derived from a point array scrolling technique. Each exposure scan produces a field width (W) of approximately 8.47 mm with a field length (longitudinal field) limited only by onboard memory capacity. DMD frame rates of up to 5 kHz (kframes/s), synchronized to the stage motion, are achievable. In this experiment, TSMR-8970XB10 photoresist (PR), diluted to 3.8 cP with PR thinner is prepared. The PR is spin-coated onto a chrome-coated glass substrate to 1.0-μm thickness with 0.1-μm uniformity. A 0.4-μm scan step is used and 27,000 DMD data frames are extracted and transferred to the DMD driver. Results indicate consistent 1.8-μm line space (L/S) resolved across the entire field width of 8.47 mm. Given optimized exposure and development conditions, 1.5-μm L/S is also observed at certain locations. The potential of this maskless lithography system is substantial; its performance is sufficient for applications in microelectromechanical systems (MEMS), photomasking, high-resolution LCD, high-density printed circuit boards (PCBs), etc. Higher productivity is predicted by a custom H-line (λ = 405 nm) lens system designed and used in conjunction with a violet diode laser systems and the development of a real-time driver.

Discrete-Time Queuing Analysis of Dual-Plane ATM Switch with Synchronous Connection Control

In this paper, we propose an ATM switch with the rate more than gigabits per second to cope with future broadband service environments. The basic idea is to separate the connection control flow from the data information flow inside the switch. The proposed switch has a dual-plane switch matrix with the synchronous control algorithm. The queuing behaviors of the proposed switch are shown by the discrete-time queuing analysis. Numerical analyses are taken both in the non-blocking crossbar switch and the banyan switch with internal blocking. Results show that a proposed dual-plane 16×16 switch would have the acceptable performance with maximum throughput of about 95 percent.

Rotor Synchronous Response Control: Approaches for Addressing Speed Dependence

Three new approaches to the design of synchronous response controllers for magnetic-bearing- supported rotors operating over a range of speeds are developed. Previously reported methods have the disadvantage of requiring either on-line estimation or gain scheduling via a look-up table. Both of these approaches increase controller complexity and cost. The controllers presented herein are either robust to operating speed variation or are gain scheduled via a simple function. In either case, the implementation of the synchronous response control algorithm is greatly simplified and, in some cases, may be achieved with simple analog circuits. An example problem is considered, and four synchronous response controllers are synthesized. Extension of the synthesis methods to provide robustness with respect to plant uncertainty is straightforward and is briefly examined.

A digital RF-stabilizer for time-of-flight measurements

We describe a device for the synchronization of the cyclotron radio frequency (RF, 5–50 MHz) with a detector signal (10–10 4 pulses/s), correlated with the beam particles. The digital device achieves a synchronization accuracy of down to ± 20 ps. For the synchronization control algorithm, the RF-Stabilizer measures the time-jitter which can also be used for conveniently tuning the cyclotron.

A multitasking DSP implementation of adaptive magnetic bearing control

Several adaptive on-line synchronous vibration control algorithms are demonstrated on a laboratory rotor supported in magnetic bearings with a high-speed digital controller. Central to the controller hardware developed for this application is a floating-point digital signal processor. The algorithms are executed under a multitasking real-time operating system specifically written for the hardware platform. The multitasking operating system allows the feedback control algorithm and the adaptive vibration control algorithm to be written and executed as separate tasks. This greatly simplifies programming, code verification, and algorithm development. Tests conducted on the laboratory rotor system indicate that greater than 98% attenuation in unbalance response can be achieved with the adaptive control algorithms.

An integrated architecture for modular control systems

This paper describes the design and implementation of the Modular Integrated Control Architecture (MICA) and its use on the HERMIES-III mobile robot system and on the CESARm 7-degee-of-freedom (DOF) robotic manipulator. MICA is designed to allow greater development flexibility in synchronous and asynchronous control systems. An event-driven system is used for asynchronous control among high-level processes that run on a distributed system. For synchronous control, a methodology has been developed for precise control over synchronized multiple processors used in the time-critical applications. Additional constraints are placed on the synchronous portion of MICA in that different control algorithms must be able to be switched in and out at the synchronous loop rate. The first application of MICA is to provide this flexibility in controlling multiple asynchronous processes on HERMIES-III and in adding new synchronous control algorithms to CESARm.