Shape Compensation Research Articles

Data Compression by Shape Compensation for Mobile Video Sensors

Most security systems, with their transmission bandwidth and computing power both being sufficient, emphasize their automatic recognition techniques. However, in some situations such as baby monitors and intruder avoidance by mobile sensors, the decision function sometimes can be shifted to the concerned human to reduce the transmission and computation cost. We therefore propose a binary video compression method in low resolution to achieve a low cost mobile video communication for inexpensive camera sensors. Shape compensation as proposed in this communication successfully replaces the standard Discrete Cosine Transformation (DCT) after motion compensation.

2P1-A07 柔軟構造を有するマスタスレーブシステムにおける振動モデルを用いた操作支援法(フレキシブル・メカニズム)

This paper presents an assisting method for positioning task using flexible master-slave system. The proposed assisting method is unilateral control consisting of input shaping compensator in the master side and direct acceleration feedback of the end-effecter of slave manipulator in the slave side. As the input shaping compensator is notch-filter is used, which removes vibration frequency from operating force signal. The effectiveness of the proposed method is verified from standpoints of maneuverability and operator's feeling. The former is based on the evaluation of the time responses and the success time, and the latter the subjective evaluation of an operator (Semantic Differential Method and Principal Component Analysis)

Rollover prevention for heavy trucks using frequency shaped sliding mode control

Control and handling of heavy commercial vehicles carrying liquid cargo are influenced by liquid movement within the partially filled tank. During steering and braking maneuvering tasks, the truck may exhibit unstable behavior at lateral acceleration levels of 0.3 g to 0.4 g [m/s2]. The fluid slosh forces and dynamic load transfers in the lateral and longitudinal directions and parametric uncertainties caused by moving liquid cargo affect the overall dynamics of the vehicle. To solve a physical problem about the minimal excitation of the slosh dynamics associated with the longitudinal and lateral excitation of the vehicle, dynamic sliding surface design combined with recursive backstepping algorithm is introduced. Compensator dynamics are introduced in the sliding mode through a class of switching surfaces which has the interpretation of linear operators such that the resulting closed-loop system retains the insensitivity to uncertainties in the sliding mode while minimizing the excitation of flexible modes and unmodeled dynamics. The frequency shaped backstepping sliding mode algorithm, proposed by Acarman and Özgüner [Frequency shaping compensation for backstepping sliding mode control. Paper presented at the 15th IFAC World Congress, Barcelona, Spain, 2002], is designed to stabilize and to attenuate the sloshing effects of moving cargo by properly choosing the crossover frequencies of the dynamic compensators in accordance with the fundamental frequencies of the slosh dynamics.

Automatic procedure for aberration compensation in digital holographic microscopy and applications to specimen shape compensation

We present a procedure that compensates for phase aberrations in digital holographic microscopy by computing a polynomial phase mask directly from the hologram. The phase-mask parameters are computed automatically without knowledge of physical values such as wave vectors, focal lengths, or distances. This method enables one to reconstruct correct and accurate phase distributions, even in the presence of strong and high-order aberrations. Examples of applications are shown for microlens imaging and for compensating for the deformations associated with a tilted thick plate. Finally we show that this method allows compensation for the curvature of the specimen, revealing its surface defects and roughness. Examples of applications are shown for microlenses and metallic sphere imaging.

移動マニピュレータの未知凹凸路面走行時における軌道追従制御性能の改善―学習的手法を用いた路面形状同定とトルク補償―

移動マニピュレータの未知凹凸路面走行時における軌道追従制御性能の改善―学習的手法を用いた路面形状同定とトルク補償―

Die shape compensation in hot forging of titanium aerofoil sections

Dimensional accuracy is among the most important criteria in hot forging of titanium alloy into aerofoils for aeroengine applications. This paper presents a study of dimensional errors of hot forged aerofoil sections in an entire forging cycle using finite element (FE) simulation. It was found that the die-elasticity and thermal distortion had an important effect on thickness error and profile deviation of the aerofoil sections. By modifying die profiles using two weighting factors representing aerofoil errors due to the die elastic deflections in forging and aerofoil thermal distortion during cooling, a significant reduction of both the aerofoil thickness and profile errors was obtained.

Using magnetic quadrupoles in cathode‐ray tubes

CRTs can be improved by means of magnetic quadrupoles. Areas of improvement are convergence, spot shape, image‐flatness and space charge compensation.

40-channel multi/demultiplexer with dynamic passband shape compensation

This letter presents an integrated multi/demultiplexer that can dynamically and independently control the curvature, tilt, and attenuation of its passband shapes, in order to reduce the signal distortion caused by other filters in the network. 40 Gb/s performance is demonstrated.

051 Discontinuous frequency shaping compensation for uncertain dynamic systems

051 Discontinuous frequency shaping compensation for uncertain dynamic systems

Impulse responses of strong reflection holograms

Strong scattering in broad spatial bandwidth reflection holograms is analyzed by using numerical techniques. Transfer functions and impulse responses for various index modulations are found, and techniques for constructing holograms for optical pulse shaping, coding, and dispersion compensation are discussed.

Discontinuous Frequency Shaping Compensation for Uncertain Dynamic Systems

New approaches for discontinuous control design which preserve the insensitivity properties of standard discontinuous feedback systems are presented. Discontinuous estimators are imbedded in the feedback loop, while the plant control input is guaranteed to be continuous and arbitrarily smooth.

Frequency shaping compensator design for sliding mode

In this paper, compensator dynamics are introduced in sliding mode through a new class of switching surfaces which has the interpretation of linear operators. Two design methods are presented, the first is based on pole placement, whereas the second is based on frequency-shaped quadratic optimal control formulation. The compensators are designed to attenuate the frequency contents of the sliding mode dynamics such that unmodelled dynamics are minimally excited. The design method using frequency shaping is applied to the control of a flexible link robot arm. Simulation results show that the excitation of the link deformations are minimized while preserving the insensitivity of the sliding mode.

Pulse Shaping and Droop Compensation with Nonuniform Transmission Lines

This paper deals with shaping the output pulse of a line-type pulser by means of tapering the distributed elements (L and C) of the line and, secondly, with calculating pulse shape for a given taper. It proves possible to generate perfectly flat pulses on a conventional load (resistance and inductance in parallel) by appropriate line tapering. Also related problems can be solved with exactness. Calculation of pulse shape resulting from a given taper is more difficult. Here only approximations have been obtained. The mathematical method used consists essentially in expressing line voltage and current as Maclaurin series in which the relations existing at load and at front are introduced. This leads to exact or approximate solutions of the problem.