Nonconventional instrument transformers based on intensity modulation of optical signals have been reported in the literature for more than 20 years. Recently described devices using passive bulk optical sensor elements include the electro-optical voltage transducer (EOVT) and magneto- optic current transducer (MOCT). These technologies offer substantial advantages over conventional instrument transformers in accuracy, optical isolation, bandwidth, environmental compatibility, weight and size. This paper describes design and manufacturing issues associated with the EOVT and the optical metering unit (OMU) recently introduced by ABB with field installation results presented for prototype units in the 345 kV and 420 kV voltage classes. The OMU incorporates an EOVT and MOCT to monitor the voltage and current on power transmission lines using a single free-standing device.

Self-calibrated interferometric/intensity-based (SCIIB) fiber sensors are describe in this paper. The sensor operates on the absolute detection of signals form a Fabry- Perot interferometric cavity. The incorporation of coherence-sliced self-calibration allows compensation for all unwanted factors, such as source power variations and fiber loss changes. Pressure sensors with various dynamic ranges were designed and fabricated based on the SCIIB scheme. Experimental results indicate that the novel sensor scheme offers excellent resolution and accuracy with absolute measurement and self-calibration function.

A practical fiber optic transmitting system of analog sensing signal has been introduced. This system has the advantages of high transmitting precision, immunity from disturbance, long transmitting distance and low cost.

This paper describes sapphire fiber-based EFPI sensors incorporated with wavelength scanning absolute signal demodulation. Silica-based optical fiber extrinsic Fabry- Perot interferometric (EFPI) sensors have been very successfully used in measuring a wide range of physical and chemical parameters. However, these fibers can only sustain temperatures of 800 degrees C because of germanium thermal diffusion affecting both the attenuation and waveguide multi-mode properties of the fiber. Since sapphire has a melting point above 2000 degrees C, sapphire optical fiber can be potentially used up to 2000 degrees C in an EFPI scheme. We obtain a resolution of 0.02 micrometers with a dynamic range of 27 micrometers for micro-displacement measurement.

The advanced method for straightforward spectral signal processing in interferometric fiber-optic sensors is presented. It is based on the analysis of the output spectrum of sensing interferometer in the domain of Fourier images. The main idea of the proposed method is to use the sensing interferometer with finesse > 2 and process the higher harmonics in addition to the first one. The technique does not suffer from power and spectral fluctuations of LED and sufficiently noise resistant.It is insensitive to the influence of parasitic interferometers appearing in the optical connectors, multimode fibers and other parts of the instrument. Devices based on such principles does not recalibration after switching on and further operation. The optimization of sensor's parameters based on numerical simulations is presented switching on and further operation. The optimization of sensor's parameters based on numerical simulations is presented.

We have developed a highly responsible probing system for inspection of electrical properties of assembled PCBs. However, as the duration of the impact occurring between a probe and a solder joint on PCB is very short, it is very difficult to control the harmful peak impact force and the slip motion of the probe to sufficient level only by its force feedback control with high gains. To overcome these disadvantages of the prototype, it needs to obtain some information of the solder joint in advance before the contact. In addition, to guarantee the reliability of the probing task, the probing system is required to measure several points around the probable target point at high sped. Therefore, to meet such requirements, we propose a new non-contact sensor capable of detecting simultaneously position and normal vectors of the multiple points around the probable target point in real time. By using this information, we can prepare a control strategy for stable contact motion on impact. In this paper, we described measuring principle, design, and development of the sensor. The effectiveness of the proposed sensor is verified through a series of experiments.

A new method of detecting displacement by using a time interval is presented. A novel optical-electric sensor based on this method for displacement detecting was designed. In the mechanical structure of the sensor, the non-clearance mechanical joint and mechanical amplifying device are used to amplify the displacement accuracy. An optical-electric transition system is designed. There are two photoswitches in the system one is fixed, the other is movable. The change of the latter position acts on the change of displacement. By detecting a high frequency and constant pulse signal, the photoswitches transfers the position signal into time signal. With suitable transferring circuit, the system makes the certain displacement corresponding to the certain digital display. As a result, it realizes the displacement detecting. The sensor has high resolution and high stability. It is with a simple structure and a low cost and very suitable for long-period displacement condition monitoring.

The segmentation of medial images is the first step along the series of events that need to take place during the automated design and rapid prototyping of orthopedic devices. The segmentation algorithm presented in this work, the discrete surface model, is an automated 3D segmentation method that attempts to optimize an energy function based on three distinct potentials: a deformation potential that expands the model, an image potential that causes it to stop at image boundaries, and a topology potential that maintains a smooth curvature. Since the deformation of the discrete surface model is local in nature, a global optimization routine encapsulates the deformation of the model using simulated annealing to avoid local energy minima such as are caused by false edges. In addition, the model has no inherent way of checking for self intersections. Global topology is also maintained using a ray-shooting technique that prevents self intersections for occurring in concave models. This segmentation algorithm is ideal for the creation of physical 3D models using rapid prototyping.

We report progress towards a miniaturized laser illumination module (LIM) for illuminating objects with structured light for 3D imaging purposes. The module, when combined with an off-axis camera and a PC, will image volumes in near-real- time at a range-dependent resolution using 256 X 256 resolution elements. The miniaturized LIM comprises a red laser diode source, a hologram, a spatial light modulator and a projection lens.We present optical and electronic design features of the device in terms of constraints on size and manufacturability. The miniature LIM can be applied to diverse 3D imaging problems to include industrial reverse engineering and inspection and medical diagnostics and prosthetics design.

A new method is described for obtaining accurate range images at high sped in a low-cost instrument. A prototype has been built and tested, and a patent application submitted. The method resembles grid-coding in that a camera and a stripe projector are directed at a scene, but the projector is different. It consists of a thin light source on the axis of a turntable, and a binary mask conforming to a cylinder coaxial with this. The mask has alternate black and clear stripes parallel to the axis. It forms a DeBruijn sequence, i.e., a sequence in which all possible sub- sequences of given length occur. No lens is used, deliberately smoothing the resulting illumination. In operation, the turntable rotates, and six consecutive images are taken at uniform intervals. A given pixel records six consecutive samples of a scene point. This six-vector, when normalized to unity to accommodate reflectance variations, is unique to the place in the sequence form which it came. Thus we can compute the position in 3-space of the surface point at which the pixel is looking. Observed accuracy is .1 millimeter at 30 centimeters range.

A highly flexible, modular design and production framework for microelectromechanical systems, suitable for mid-scale production at reasonable costs, is presented. The modulator framework, similar to unit construction system well-known in the macro world, consists of a manufacturer set and an application kit. It allows for considerable reduction of design and production expenditure while retaining maximum technical flexibility. The feasibility of the modular approach is demonstrated by the presentation and discussion of a novel modular vertical integration technique.

The role of reuse and recycling has become more and more important due to environmental reasons during the last years. To realize this goal, flexible automatic disassembly is needed. We have investigated a robotized work station supported by sensors as one possible solution. As an example an electrical motor has in detail been disassembled with the aim to separate the different materials. In an industrial motor the copper is situated in the stator windings and in the junction box. There are three pats in the proposed disassembly work, an inspection phase where the functionality of the motor is determined, a manual disassembly task where the junction box, the shields and the rotor are removed and finally the last part is an automatic removal of the stator windings. The focus in this paper is on the first part, the functionality test. In this test different faults of the motor is identified and a decision in made whether the motor should be repaired or disassembled. The test is performed during start-up of the motor without any load. Current, voltage, vibration and rotation sped is measured. The tested conditions results in a performance classification of the motor by Principal Component Analysis, PCA.

A novel materials handling system is being developed at Carnegie Mellon University's Mechanical Engineering Department. This system contains an array of cells, each of which has two actuators. The two actuators are orthogonally oriented motorized roller wheels which, in combination, can generate a vector of motion in any planar direction. This work develops control laws for transporting and manipulating objects which rest on the array. Towards this goal, we consider the dynamics of parcel transport and manipulation. The parcel dynamics are based on an exact discrete representation of the system, unlike other methods where a continuity assumption is made. Two types of contact models are considered. This work extends the previous 1D discrete model into 2D.

Robust vibration suppression (RVS) is a methodology developed for selecting and synthesizing preshapes that will reduce residual vibration in a wide variety of open and closed-loop multi-degree of freedom systems. Furthermore RVS requires only basic information about the system fundamental frequency and no information about higher modes in the system. There are many aspects to the RVS method; one particular RVS synthesis method called the binomial synthesis technique is discussed in this paper, and experimental data is presented for one RVS type preshape.

Techniques for increasing the reliability of ultrasonic range measurements are described in this paper. Measurement errors are reduced considering two dominant error sources; environmental instability and random noise. To compensate for alterations in measurements due to surrounding conditions, a small reflector is placed at a known distance in front of the sensor and the measurements of the known distance are used as the reference for correcting the measurements of unknown distances. The conditions to prefer this way of compensation is determined by analyzing probable errors of the measurements. The reliability is increased further by tackling random noise with receivers employed redundantly. Assuming a jointly Gaussian distribution, signals of the receivers are combined to get statistically more accurate estimates. An experimental system is built with 40kHz transducers and the results show considerable reduction of measurement errors.

We have proposed a novel wavelength scanning fiber-optic interferometer for absolute distance measurement. Based on the digital signal processing techniques, an algorithm to effectively discriminate phase information, eliminate perturbations and overcome the random sway of the scanning, is established. So that the practical demands of precision 0.05 micrometers and resolution 0.01 micrometers can be satisfied.

We have developed a reflecting fiber-optic temperature sensor with a small quartz crystal, based on the birefringence effect. The methods of designing and selecting the optical system parameters, such as optical source, crystal, and transmission fibers, are illustrated comprehensively in this paper. These theoretical and experimental methods proposed in this paper have important roles in other polarization-modulated fiber-optic sensors.

A novel reflective bridge-shaped compensation configuration has been developed for the polarization-modulated fiber- optic temperature sensors. We comprehensively study the compensation effects with this configuration in terms of theory. Then we design the corresponding experiments to verify the theoretical analysis. It proved that this system can improve the measuremental accuracy and long-term stability.

Recently, many researches on sensors have focused on sensor functions, but a few of them on sensor reliability. Screen technique for a sensor is important for ensuring the quality of a sensor. In the previous screen methods, the screen time is determined empirically and no suitable theory could apply for it, especially, in developing a new product. The method presented here can determine screen time quickly. In this paper, the relation between reliability life distribution of a sensor with initial failure and screen time was discussed. The failure data from life distribution's corner was dealt with computer and the life distribution curve was inferred. Finally, the screen time was determined by the study of the life distribution. To further interpret the new method, a practical example was given and a satisfy result was obtained.

As well known, polarization-maintaining optical fiber and its components can be used in many areas related to fiber optics, such as coherent optical communication and optical fiber sensors based on interferometric techniques. In this paper, we proposed a Mach-Zehnder interferometer with two 2 by 2 fused taper polarization-maintaining optical fiber couples, in which a 1.3 micrometers LD is used as light source and the polarization-maintaining optical fiber is Bow-Tie fiber. Using this fiber interferometer, the measurement of displacement and vibration can be realized.

Optical gating techniques provide an important method for the non-destructive evaluation of a number of different transparent, translucent, and even highly scattering materials. We have used optical coherence tomography with 1.3 micrometers wavelength light to probe the subsurface region of ceramic, diamond film, single crystal silicon carbide, and other samples. We have demonstrated sample penetration depths of 100 to 1300 micrometers . We have achieved lateral spatial resolutions of 5 micrometers and depth resolutions of 10 micrometers . We have developed scanning techniques that allow planes in the sample to be imaged in less than 1 second and we have extended the scanning capabilities to allow for scanning over spherical convex or concave surfaces.

A twisted fiber otic sensor based on intensity modulation is described. The principle, structure of the sensor and the choice of steep strand modules are introduced. The sensor is used to determine the tensile strain and distribution. The experimental results show that the change of the transferring light power has an approximate linear relation with the outer force. The intelligent steel strands with this kind of sensor will have a good application to monitor the concrete crack and deformation distribution in huge structure such as dams and bridges.

According to the properties of Electro-Rheological/Magneto- Rheological Fluid (ER/MR fluid), a device whose stiffness can be adjusted by electric field and/or magnetic field was designed. The basic mechanical properties were analyzed theoretically. The relation of resistance of piston movement to sped of piston movement is discussed, especially asymptotically relation of slow moving and to fast moving was given. And the basic mechanical properties was tested actually. The stiffness of element combined a device with a spring was characterized with accumulation of energy of the unit in vibration. And then the character of stiffness change of the device element with change of yield stress of ER/MR fluid was discussed. The method of optimizing parameters to improve control capability for some condition was discussed. The results indicate that the device is an effective controllable stiffness element. For a controllable stiffness element, its best working state is that its critical resistance is nearly equal to vibration force. For the device used for high frequency, the duct with a larger width and gap is recommended. But for the device demanding large critical force, as used in civil engineering, the duct with larger length and smaller gap is recommended.