Showing papers on "Filter (video) published in 2009"

Limitations of Voltage-Oriented PI Current Control of Grid-Connected PWM Rectifiers With $LCL$ Filters

Abstract: Voltage-oriented PI control of three-phase grid-connected pulsewidth-modulation rectifiers with LCL filters is addressed. LCL filters require resonance damping. Active resonance damping is state of the art to face the problem, but it is still under investigation because of the manifold solutions. It is often realized using many sensors and/or complex control algorithms. In contrast, pure PI control requires only one set of current sensors, and its implementation and design are rather simple and well known from the L filter control. PI control has already been shown to be a suitable solution also for LCL filters, but there are limitations. These are investigated in this paper. System stability is analyzed with respect to different ratios of LCL filter resonance and control frequencies. The latter are important parameters for system design and control. Both line and converter current control are analyzed. For a certain range of frequency ratios, the voltage-oriented PI control gives stable performance without additional feedback, but for ratios outside this range, stable operation is impossible. Experimental tests validate the theoretical results. In addition, an experimentally determined LCL filter transfer function is shown in this paper, which shows a lower resonance peak as expected from commonly used filter models.

A Statistical Approach to Material Classification Using Image Patch Exemplars

Abstract: In this paper, we investigate material classification from single images obtained under unknown viewpoint and illumination. It is demonstrated that materials can be classified using the joint distribution of intensity values over extremely compact neighborhoods (starting from as small as 3times3 pixels square) and that this can outperform classification using filter banks with large support. It is also shown that the performance of filter banks is inferior to that of image patches with equivalent neighborhoods. We develop novel texton-based representations which are suited to modeling this joint neighborhood distribution for Markov random fields. The representations are learned from training images and then used to classify novel images (with unknown viewpoint and lighting) into texture classes. Three such representations are proposed and their performance is assessed and compared to that of filter banks. The power of the method is demonstrated by classifying 2,806 images of all 61 materials present in the Columbia-Utrecht database. The classification performance surpasses that of recent state-of-the-art filter bank-based classifiers such as Leung and Malik (IJCV 01), Cula and Dana (IJCV 04), and Varma and Zisserman (IJCV 05). We also benchmark performance by classifying all of the textures present in the UIUC, Microsoft Textile, and San Francisco outdoor data sets. We conclude with discussions on why features based on compact neighborhoods can correctly discriminate between textures with large global structure and why the performance of filter banks is not superior to that of the source image patches from which they were derived.

Applying services within MPLS networks

Abstract: In general, techniques are described that facilitate application of service within MPLS networks. More specifically, a router comprises a forwarding plane, a service plane and a routing engine. The routing engine maintains data defining an association between a handle identifying a property common to a plurality of packets of a particular context and one or more MPLS labels associated with these packets. The routing engine automatically generates and installs a filter to identify these packets within both the forwarding and service planes. The forwarding plane applies the filter to incoming packets to determine whether each of the incoming packets includes a label matching any of the labels of the filter and forwards the incoming packets to the service plane upon a match. The service card selects one or more services identified by the filter and applies the selected one or more services to the incoming packet.

Data Association and Track Management for the Gaussian Mixture Probability Hypothesis Density Filter

Abstract: The Gaussian mixture probability hypothesis density (GM-PHD) recursion is a closed-form solution to the probability hypothesis density (PHD) recursion, which was proposed for jointly estimating the time-varying number of targets and their states from a sequence of noisy measurement sets in the presence of data association uncertainty, clutter, and miss-detection. However the GM-PHD filter does not provide identities of individual target state estimates, that are needed to construct tracks of individual targets. In this paper, we propose a new multi-target tracker based on the GM-PHD filter, which gives the association amongst state estimates of targets over time and provides track labels. Various issues regarding initiating, propagating and terminating tracks are discussed. Furthermore, we also propose a technique for resolving identities of targets in close proximity, which the PHD filter is unable to do on its own.

Combined System for Harmonic Suppression and Reactive Power Compensation

Abstract: In this paper, a combined system of static Var compensator (SVC) and active power filter (APF) was proposed. The system has the function of power factor correction, voltage stability, and harmonic suppression. The SVC, which consists of delta-connected thyristor-controlled reactor (TCR) and Y-connected passive power filter (PPF), is mainly for voltage stability and power factor correction. The small rating APF is used to filter harmonics generated by the nonlinear load and the TCR in the SVC and to suppress possible resonance between the grid and the PPFs. The configuration and principle of the combined system were discussed first, and then, the control method of the combined system was presented. An optimal nonlinear proportional-integral control was proposed to improve the dynamic response and decrease the steady-state error of the SVC. Harmonic detection with precompensation method and improved generalized integrator control were proposed to improve the performance of APF. The new combined system is compared to classical SVC. It is implemented in a 200-kVA prototype in the laboratory. Simulation and experimental results show that the proposed combined configuration can effectively stabilize system voltage, correct power factor, and suppress harmonic currents.

Charging apparatus, portable electronic device using the apparatus, and charging method thereof

Abstract: A charging apparatus includes an antenna, a receiver, and a battery. The battery is charged by a harvester, which converts wireless energy sent by antenna to direct current and charges the battery. The harvester includes a sensor coil, a rectifier and voltage regulating filter. The wireless energy is converted by the sensor coil to alternating current (AC). The rectifier is electrically connected to the sensor coil for converting AC to direct current (DC). The voltage regulating filter is electrically connected to the rectifier to regulate DC. The battery can be charged by the wireless charge apparatus.

Phased-array antenna filter and diplexer for a super economical broadcast system

Abstract: A phased-array antenna filter and diplexer for a super economical broadcast system are provided. The filter and diplexer includes a signal divider tee diplexer, a receive filter and a transmit filter. The diplexer includes a tee branch point, an antenna port, a transmit port and a receive port. The receive filter includes a flat, multi-pole bandpass filter, an input port and an output port, where the input port is coupled to the diplexer receive port to define a receive signal path, from the tee branch point to the receive input port, that has a length of approximately one quarter receive wavelength. The transmit filter includes a folded, multi-pole bandpass filter, an input port and an output port, where the output port is coupled to the diplexer transmit port to define a transmit signal path, from the tee branch point to the transmit output port, that has a length of approximately one quarter transmit wavelength.

A narrow-band subwavelength plasmonic waveguide filter with asymmetrical multiple-teeth-shaped structure.

Abstract: Characteristics of a multiple-teeth-shaped plasmonic filter are analyzed. As an extension of this structure, an asymmetrical multiple-teeth-shaped structure is proposed and numerically simulated by using the finite difference time domain method with perfectly matched layer absorbing boundary condition. It is found that the asymmetrical structure can realize the function of a narrow-passband filter. The central wavelength of the passband linearly increases with the simultaneous increasing of d(1) and d(2).

Quadruple-Mode UWB Bandpass Filter With Improved Out-of-Band Rejection

Abstract: A quadruple-mode ultra-wideband (UWB) bandpass filter with sharp out-of-band rejection is presented in this work. As a starting part of designing a quadruple-mode filter, a mode graph of the initial triple-mode resonator is studied to choose its proper dimensions. Based on these pre-determined dimensions of this triple-mode resonator, two short-circuited stubs are introduced in this resonator to generate two transmission zeros near the lower and upper cut-off frequencies, leading to a higher rejection skirt outside the desired passband. Moreover, as these two stubs are installed, the fourth resonant mode falls down and works together with the first three resonant modes to form a novel quadruple-mode UWB filter. Finally, a filter prototype is designed and fabricated to experimentally validate the attractive in-band and out-of-band performances as predicted in theory.

Temperature-independent silicon waveguide optical filter.

Abstract: We have proposed a new design for temperature-independent silicon optical filters utilizing a combination of wide and narrow waveguides. The waveguide structure was optimized to minimize the spectral shift of the filter owing to the environmental temperature change. Based on this new waveguide design, we fabricated Mach-Zehnder interferometer optical filters on silicon-on-insulator substrates. The measured spectrum showed substantially small temperature dependence being in good agreement with the theoretical estimation.

Reconfigurable planar filters

Abstract: Electronically reconfigurable or tunable microwave filters are attracting more attention for research and development because of their increasing importance in improving the capability of current and future wireless systems. For instance, emerging ultrawideband (UWB) technology requires the use of a wide radio spectrum. However, the frequency spectrum as a resource is valuable and limited, so the spectrum is always being used for several purposes, which means it is full of unwanted signals when an operation such as a UWB wireless system is concerned. In this case, existing undesired narrowband radio signals, which vary from place to place and from time to time, may interfere with the UWB system's range. A solution for this is to introduce an electronically switchable or tunable narrow rejection band (notch) within the passband of a UWB bandpass filter. Such an electronically reconfigurable filter is also desired for wideband radar or electronic warfare systems. This paper discusses the development of electronically reconfigurable filter types.

Neural Network and Bandless Hysteresis Approach to Control Switched Capacitor Active Power Filter for Reduction of Harmonics

Abstract: This paper proposes a combination of neural network and a bandless hysteresis controller, for a switched capacitor active power filter (SCAPF), to improve line power factor and to reduce line current harmonics. The proposed active power filter controller forces the supply current to be sinusoidal, in phase with line voltage, and has low current harmonics. Two main controls are proposed for it: neural network detection of harmonics and bandless digital hysteresis switching algorithm. A mathematical algorithm and a suitable learning rate determine the filter's optimal operation. A digital signal controller (TMS320F2812) verifies the proposed SCAPF, implementing the neural network and bandless hysteresis algorithms. A laboratory SCAPF system is built to test its feasibility. Simulation and experimental results are provided to verify performance of the proposed SCAPF system.

Active Damping for Three-Phase PWM Rectifiers With High-Order Line-Side Filters

Abstract: Active rectifiers interfacing the grid have gained much attention in recent years due to their current control capability that enables the application to exchange a certain range of power at the benefit of low harmonic distortion compared to line commutated converters. Moreover, the amount of active and reactive powers can be arbitrarily chosen within certain limits. These limits as well as the degree of harmonic attenuation is determined by the line-side filter. This paper basically focuses on the current control of active rectifiers incorporating a line-side filter of first- up to third-order degree. Thus, it treats both the current-source converter (CSC) as well as the voltage-source converter (VSC). The basic models of the plant are derived for each case, and important dualities are pointed out. As a conclusion, a recipe for the controller design of particularly CSCs with LC filters and VSCs with LCL filters is proposed.

Systematic Design and Modeling of a OTA-C Filter for Portable ECG Detection

Abstract: This study presents a systematic design of the fully differential operational transconductance amplifier-C (OTA-C) filter for a heart activities detection apparatus. Since the linearity and noise of the filter is dependent on the building cell, a precise behavioral model for the real OTA circuit is created. To reduce the influence of coefficient sensitivity and maintain an undistorted biosignal, a fifth-order ladder-type lowpass Butterworth is employed. Based on this topology, a chip fabricated in a 0.18- mum CMOS process is simulated and measured to validate the system estimation. Since the battery life and the integration with the low-voltage digital processor are the most critical requirement for the portable diagnosis device, the OTA-based circuit is operated in the subthreshold region to save power under the supply voltage of 1V. Measurement results show that this low-voltage and low-power filter possesses the HD3 of -48.9 dB, dynamic range (DR) of 50 dB, and power consumption of 453 nW. Therefore, the OTA-C filter can be adopted to eliminate the out-of-band interference of the electrocardiogram (ECG) whose signal bandwidth is located within 250 Hz.

Color filter and liquid crystal display device

Abstract: A color filter includes red, green and blue filter segments and is adapted to be used in a liquid crystal display device using, as a light source, a white LED having specified spectral properties. The red filter segment has a 50% transmittance wavelength within a range of 595 to 610 nm and a transmittance of 85% or more at a wavelength of 630 nm. The blue filter segment has a maximum transmittance wavelength of 455 nm or less and a transmittance of 55% or more at a wavelength of 450 nm. A thickness of each of the red, green and blue filter segments is 3.0 μm or less. A liquid crystal display device including this color filter and the white LED is also disclosed.

An Investigation on the Selection of Filter Topologies for Passive Filter Applications

Abstract: Passive filters have been a very effective solution for power system harmonic mitigation. These filters have several topologies that give different frequency response characteristics. The current industry practice is to combine filters of different topologies to achieve a certain harmonic filtering goal. However, there is a lack of information on how to select different filter topologies. This decision is based on the experience of present filter designers. The goal of this paper is to investigate the filter topology selection issue. It presents our research results on the effectiveness and costs of various filter topologies for harmonic mitigation. The research results show that the association of three single-tuned filters is a very appropriate solution for most typical harmonic problems.

Miniaturized Bandpass Filters With Double-Folded Substrate Integrated Waveguide Resonators in LTCC

Abstract: This paper proposes miniaturized bandpass filters with double-folded substrate integrated waveguide (SIW) resonators using multilayer low-temperature co-fired ceramic (LTCC) technology. Formed by inserting a metal plate with two orthogonal slots into the cavity, the double-folded SIW resonator is used for the circuit size reduction with its footprint about a quarter of the conventional TE101 mode. With LTCC technology, there is more flexibility to organize the cavities of filters because of the 3-D arrangement. The vertically stacked cavities are coupled by ldquoLrdquo- or ldquoUrdquo-shaped slots, and if arranged horizontally, by an inductive window on the common sidewall or a suspended stripline between the cavities. Through experimental measurements and simulations at both the Ka- V -bands, it has been demonstrated that the proposed filter has compact sizes and good frequency responses. The area of the fully stacked Chebyshev filter has 88% size reduction in comparison with a three-pole planar waveguide filter, while the vertically stacked quasi-elliptic filter has 74% size reduction in comparison with a four-pole planar waveguide filter.

Widely Tunable MEMS-Based Fabry–Perot Filter

Abstract: This paper describes the use of strain stiffening in fixed-fixed beam actuators to extend the tuning range of microelectromechanical-systems-based Fabry-Perot filters. The measured wavelength tuning range of 1.615-2.425 mum is the largest reported for such a filter. Curvature in the movable mirror was corrected using a low-power oxygen plasma to controllably alter the stress gradient in the mirror. After curvature correction, the linewidth of a filter was 52 nm, close to the theoretical minimum for our mirror design. As a proof of concept, a filter was bonded to a broadband infrared detector, realizing a wavelength-tunable infrared detector. All measured data have been compared to theoretical models of the optics and mechanics of the filters, with excellent agreement between theory and measurement demonstrated in all cases. Finally, the Young's modulus and stress of the actuator materials were extracted directly from the measured voltage-displacement curves, demonstrating a novel technique for material property measurement.

Flexible multimodal camera using a light field architecture

Abstract: We present a modified conventional camera that is able to collect multimodal images in a single exposure. Utilizing a light field architecture in conjunction with multiple filters placed in the pupil plane of a main lens, we are able to digitally reconstruct synthetic images containing specific spectral, polarimetric, and other optically filtered data. The ease with which these filters can be exchanged and reconfigured provides a high degree of flexibility in the type of information that can be collected with each image. This paper explores the various tradeoffs involved in implementing a pinhole array in parallel with a pupil-plane filter array to measure multi-dimensional optical data from a scene. It also examines the design space of a pupil-plane filter array layout. Images are shown from different multimodal filter layouts, and techniques to maximize resolution and minimize error in the synthetic images are proposed.

The Bin-Occupancy Filter and Its Connection to the

Abstract: An algorithm that is capable not only of tracking multiple targets but also of ldquotrack managementrdquo-meaning that it does not need to know the number of targets as a user input-is of considerable interest. In this paper we devise a recursive track-managed filter via a quantized state-space (ldquobinrdquo) model. In the limit, as the discretization implied by the bins becomes as refined as possible (infinitesimal bins) we find that the filter equations are identical to Mahler's probability hypothesis density (PHD) filter, a novel track-managed filtering scheme that is attracting increasing attention. Thus, one contribution of this paper is an interpretation of, if not the PHD itself, at least what the PHD is doing. This does offer some intuitive appeal, but has some practical use as well: with this model it is possible to identify the PHD's ldquotarget-deathrdquo problem, and also the statistical inference structures of the PHD filters. To obviate the target death problem, PHD originator Mahler developed a new ldquocardinalizedrdquo version of PHD (CPHD). The second contribution of this paper is to extend the ldquobin-occupancyrdquo model such that the resulting recursive filter is identical to the cardinalized PHD filter.

Discriminatively trained particle filters for complex multi-object tracking

Abstract: This work presents a discriminative training method for particle filters in the context of multi-object tracking. We are motivated by the difficulty of hand-tuning the many model parameters for such applications and also by results in many application domains indicating that discriminative training is often superior to generative training methods. Our learning approach is tightly integrated into the actual inference process of the filter and attempts to directly optimize the filter parameters in response to observed errors. We present experimental results in the challenging domain of American football where our filter is trained to track all 22 players throughout football plays. The training method is shown to significantly improve performance of the tracker and to significantly outperform two recent particle-based multi-object tracking methods.

A Practical Iron Loss Calculation for AC Filter Inductors Used in PWM Inverters

Abstract: A novel iron loss calculation method is proposed based on an iron loss map for an AC filter inductor used in a pulsewidth-modulation (PWM) inverter. The iron loss map, previously reported by the authors, is created by measuring the dynamic minor loop on the B-H plane, and this is used for the calculation of inductor iron loss in the dc chopper circuit. However, in the case of an AC filter inductor used in a PWM inverter, the iron loss map cannot be directory applied to the iron loss calculation. In this paper, an iron loss calculation for an ac filter inductor is presented by expanding the loss map method. We describe the principle of expansion and the practical procedure for the calculation, which utilizes the loss map and a conventional circuit simulator. Iron loss for the ac filter inductor under some typical modulation methods of the PWM inverter are calculated and discussed with regard to the relation between the modulation methods and iron loss. The calculated results are verified using experimental results from a 500-W inverter setup. The inductor loss and conversion efficiency of the PWM inverter are measured for each modulation method.

A Novel Crossed Resonator and Its Applications to Bandpass Filters

Abstract: A novel open and short stubs loaded crossed resonator and its applications to cross-coupling filter and tri-band bandpass filters are presented in this paper. Based on the lossless transmission line model analysis, it is found that the first three resonance frequencies of the crossed resonator can be conveniently controlled. Benefiting from this feature, the resonator can be utilized to design not only a cascaded triplet (CT) filter, but also a tri-band bandpass filter. The tri-band filter offers two tunable passbands and one fixed passband. The first and third passband frequencies can be tuned effectively by changing the lengths of the stubs. To demonstrate these applications, a CT filter and two tri-band bandpass filters using a crossed resonator are implemented. The experiments verify the theoretical predictions and simulations.

The multisensor PHD filter: I. General solution via multitarget calculus

Abstract: The theoretical foundation for the probability hypothesis density (PHD) filter is the FISST multitarget differential and integral calculus. The "core" PHD filter presumes a single sensor. Theoretically rigorous formulas for the multisensor PHD filter can be derived using the FISST calculus, but are computationally intractable. A less theoretically desirable solution-the iterated-corrector approximation-must be used instead. Recently, it has been argued that an "elementary" methodology, the "Poisson-intensity approach," renders FISST obsolete. It has further been claimed that the iterated-corrector approximation is suspect, and in its place an allegedly superior "general multisensor intensity filter" has been proposed. In this and a companion paper I demonstrate that it is these claims which are erroneous. This paper introduces formulas for the actual "general multisensor intensity filter." In the companion paper I demonstrate that the "general multisensor intensity filter" will perform badly in even the easiest multitarget tracking problems; and argue that this suggests that the "Poisson-intensity approach" is inherently faulty.

Fuel supply device

Abstract: A fuel supply device is obtained in which joint strength can be maintained in a joint portion of plural filter members configuring a fuel filter. A fuel filter with an overall bag shape is configured by welding together an upper face filter cloth a lower face filter cloth of the fuel filter at a welded portion. A sub tank upper side member and a sub tank lower side member nip the upper face filter cloth and the lower face filter cloth at a nipping position that is at a different position from the welded portion.

Efficient Asynchronous Sample Rate Conversion

Abstract: Asynchronous sample rate conversion for use in a digital audio receiver is disclosed. Different algorithms are applied for the upsampling and downsampling cases. In the upsampling case, the input signal is upsampled and filtered, before the application of a finite impulse response (FIR) filter. In the downsampling case, the input signal is filtered by an FIR filter, and then filtered and downsampled. The FIR coefficients of the fractional delay FIR filter are calculated by evaluation of polynomial expressions over intervals of the filter impulse response, at times corresponding to the input sample points.

Quiet zone control system

Abstract: An active noise control system generates an anti-noise signal to drive a speaker to produce sound waves to destructively interfere with an undesired sound in a quiet zone. The anti-noise signal is generated with an adaptive filter having filter coefficients. The coefficients of the adaptive filter may be adjusted based on a first filter adjustment from a first listening region, and a second filter adjustment from a second listening region. A first weighting factor may be applied to the first filter adjustment, and a second weighting factor may be applied to the second filter adjustment. The first and second weighting factors may dictate the location and size of the quiet zone as being outside or partially within at least one of the first listening region and the second listening region.