San-Shan Hung

Optimal Design of a High Speed SPM Motor for Machine Tool Applications

This paper deals with the optimal design of surface-mounted permanent magnet motors for use in a high speed spindle machine tool in glass grinding applications. We apply the Taguchi method to refine the stator structure and use segmented rotor magnets for the motor to yield the desired performance. A thermal analysis is conducted to obtain the temperature distribution within the motor. We examine the results using finite element analysis and validate them by experimental measurements.

Memoryless H∞ controller for singular systems with delayed state and control ☆

In this paper, the memoryless H∞ controllers for singular systems with delayed state and control are presented. Based on the modified Riccati-equation approach, a memoryless linear time-invariant state feedback control law is developed. The controller, which is a delay-independent stabilizer for the singular delayed system will simultaneously reduce the H∞ norm of the closed-loop transfer function from the disturbance to the controlled output to a prescribed level. An illustrative example is included to demonstrate our proposed approach.

Design of High Performance Flux Switching PM Machines with Concentrated Windings

This paper presents a procedure for determining the winding layout for the design of high performance flux switching permanent magnet (FSPM) machines with concentrated windings. Three winding configurations, namely, single-layer, double-layer and multilayer windings are illustrated. A comparison of the electromagnetic performance of the three winding configurations is made using finite element analysis. It may provide a useful reference to be considered in the FSPM machine design.

Design Optimization of a Double-Sided Hybrid Excited Linear Flux Switching PM Motor With Low Force Ripple

This paper describes design techniques for a doublesided hybrid excited linear flux switching permanent magnet motor to achieve low force ripple while satisfying the required average thrust force. In this paper, we employ auxiliary poles fixed to both sides of the mover and determine the switching signal turn-on angle to reduce the force ripple in the initial design. Then, the sensitivity analysis of two split ratios is conducted to provide a feasible search direction for the optimization process. Finally, a finite-element-based optimization is utilized to minimize the force ripple and to satisfy the required average thrust force. Simulation results are validated by experimental measurement.

Analysis of Building Envelope Insulation Performance Utilizing Integrated Temperature and Humidity Sensors

A major cause of high energy consumption for air conditioning in indoor spaces is the thermal storage characteristics of a buildings envelope concrete material; therefore, the physiological signals (temperature and humidity) within concrete structures are an important reference for building energy management. The current approach to measuring temperature and humidity within concrete structures (i.e., thermocouples and fiber optics) is limited by problems of wiring requirements, discontinuous monitoring, and high costs. This study uses radio frequency integrated circuits (RFIC) combined with temperature and humidity sensors (T/H sensors) for the design of a smart temperature and humidity information material (STHIM) that automatically, regularly, and continuously converts temperature and humidity signals within concrete and transmits them by radio frequency (RF) to the Building Physiology Information System (BPIS). This provides a new approach to measurement that incorporates direct measurement, wireless communication, and real-time continuous monitoring to assist building designers and users in making energy management decisions and judgments.

A Portable Array-Type Optical Fiber Sensing Instrument for Real-Time Gas Detection

A novel optical fiber array-type of sensing instrument with temperature compensation for real-time detection was developed to measure oxygen, carbon dioxide, and ammonia simultaneously. The proposed instrument is multi-sensing array integrated with real-time measurement module for portable applications. The sensing optical fibers were etched and polished before coating to increase sensitivities. The ammonia and temperature sensors were each composed of a dye-coated single-mode fiber with constructing a fiber Bragg grating and a long-period filter grating for detecting light intensity. Both carbon dioxide and oxygen sensing structures use multimode fibers where 1-hydroxy-3,6,8-pyrene trisulfonic acid trisodium salt is coated for carbon dioxide sensing and Tris(2,2′-bipyridyl) dichlororuthenium(II) hexahydrate and Tris(bipyridine)ruthenium(II) chloride are coated for oxygen sensing. Gas-induced fluorescent light intensity variation was applied to detect gas concentration. The portable gas sensing array was set up by integrating with photo-electronic measurement modules and a human-machine interface to detect gases in real time. The measured data have been processed using piecewise-linear method. The sensitivity of the oxygen sensor were 1.54%/V and 9.62%/V for concentrations less than 1.5% and for concentrations between 1.5% and 6%, respectively. The sensitivity of the carbon dioxide sensor were 8.33%/V and 9.62%/V for concentrations less than 2% and for concentrations between 2% and 5%, respectively. For the ammonia sensor, the sensitivity was 27.78%/V, while ammonia concentration was less than 2%.

Modified nanoporous membranes on centrifugal microfluidic platforms for detecting heavy metal ions

Abstract The modified nanoporous membranes on centrifugal microfluidic platforms are developed for detecting heavy metal ions with high selectivity. The nanomaterials of polyrhodanine, activated alumina and activated carbon are deposited on nanoporous anodic aluminium oxide (AAO) membranes for enhancing filtration to remove ions of lead (Pb(II)), arsenic (As(III)) and cadmium (Cd(II)) from aqueous solution. By detecting chemiluminescence (CL) reaction, the concentrations of heavy metal ions can be obtained. A pneumatic-and-centrifugal microfluidic detection system was used to perform microfluid separation and CL detection for measuring selected ions concentration. The removal efficiency of 92, 82 and 78% were observed for Pb(II), As(III) and Cd(II) ions, respectively. The removal rate is performed up to 70% for mixed ions filtration by a sequence of multi-modified AAO membranes. The modified nanofiltration films on microfluid platform have potential applications in removing heavy metal ions from water, soil, food and drug.

An Optical Centrifugal-and-Pneumatic Controlled Microfluidic System for Sensing Real-Time Biochemical Reactions

An optical real-time pneumatic-and-centrifugal controlled microfluidic detection system for dynamic information acquisition is developed based on the quasi-stationary imaging technique. The programmable airflow applied on the centrifugal microstructures for improving efficiency in samples separation. The dynamic characteristic of a loaded disc is stable with vibrating under 0.3 mm at a speed of 1000 rpm by applying 3 bar-induced pneumatic forces on a 12 cm-diameter disc. A conversion model for converting RGB images into CIE L*a*b* color space have been used to enhance the inspection images. A linear relationship between threshold frequency and sample density is 167 rpm/g/cm3. The pressures between 0.1 and 0.5 bars are applied to bias microflow from 15° to 80°. The conduction angles between 30° and 90° have better pneumatic control. The control efficiency observed up to 89% and the largest microflow biased angle reached 80°. The pneumatic force dominates microfluidic behaviors when the force is greater than 10 times the centrifugal force. A sequential of triple-reservoir tests has been verified by analyzing enhanced optical images in separation using arranged acid-base indicators for pH reactions.

Building physiology information system for health monitoring in reinforced concrete structures

The health of human bodies can be determined by physiological signs; similarly, the physiological signs displayed by a buildings reinforced concrete (RC) structure (temperature and humidity) are of the same importance to building health management. This study evaluates building health by integrating a low-cost radio frequency integrated circuit (RFIC) with temperature/humidity sensor chips. Concrete inner temperature and humidity data are sent back to the building physiology information system (BPIS) via radio frequency (RF) wireless transmission automatically, regularly and continuously to provide a reference to on-site building managers during health diagnosis and analysis of building structures.

Nano-AAO-Based Microsensor for Monitoring Process Carbon Monoxide

This study developed a porous nano anodic aluminum oxide (AAO) based gas microsensor for detecting process carbon monoxide (CO) at room temperature. The small sensing microdevice has stable response with high sensitivity which includes porous AAO structures, gas sensing membrane, interdigitated sensing electrode, heater and temperature sensor. The tungsten oxide (WO3) sensing membrane covers AAO to enlarge total gas sensing surface area to enhance gas sensing response. The Pt interdigitated sensing electrode can also improve the sensitivity. The experimental results showed that the CO gas concentration sensitivity is proportional to temperature. As compared with the sensor without AAO, the concentration range of CO sensed by this microsensor is 100~1000 ppm, the gas sensing resistance change rate can be increased by 87.4 %.