We have developed a new method for building a vibration model of an actual gear-drive system. Each gear has six degrees of freedom: three translational and three rotational motions. Stiffness matrixes representing each gear shaft and tooth meshing were made and overlapped into one stiffness matrix for the whole system. This enabled easy modelling of complex gear-drive systems such as multi-stage gears and branched gears. The results are in good agreement with experimental results with respect to the major resonance frequencies and vibration modes.

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This paper investigates the robust adaptive fuzzy control of low frequency modes of a rectangular thin plate with pointwise actuators and sensors. The control system applies a finite number of actuators and sensors to damp actively the undesirable transient vibrations of the plate. In the proposed control scheme, a robust observer-based controller is first adopted to maintain loop stability while in the presence of the high-frequency unmodeled residuals. The second part of the controller is an adaptive fuzzy inference system, which is introduced to improve regulation performance. To maintain overall stability robustness, confinement imposed on the adaptive fuzzy command is performed to ensure that it will not overshoot the permissible upper bound. Simulation results for an all-clamped plate show that the proposed design provides efficient vibration suppression while maintaining robust stability.

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This paper proposes an operating mode of a BR bank, which was originally installed in generation system to promote the stability as well as improve the transient response, to suppress turbine blade vibrations arising from power system faults. Because most of cumulative blade damages are produced in the beginning cycles, this approach is mainly to restrict the initial amplitude of vibrations to reduce the vibration damage to turbine-generator blades. Also, only turning on the BR bank about a cycle time is adequate to effectively restrict the peak system-frequency E/M disturbing torques. Since the system-frequency responses always play an essential role on blade vibration behaviors arising from power system disturbances, vibrations can be significantly suppressed accordingly. The BR bank is activated at the instant of power system disturbances, it will dissipate only small amount of energy.

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In environmental vibration test, the fixture is inserted between the shaker and the test specimen. It is desirable that the test specimen is excited with uniform force through the mounting points connected to the fixture. The flexural vibration of the fixture sometimes makes it impossible to excite the specimen uniformly. The deviations of the transmitted force cause the under-test, especially at anti-resonance frequencies, in vibration test control. In this paper, the method of experimental structural dynamic modification using transfer function synthesis method is applied to the design of vibration test fixture. The responses at any points on the fixture can be predicted utilizing the experimental data. Structural dynamic modification of fixture is performed so that the spectra at the mounting points may meet the specified reference spectrum. The values of the added masses, which will be attached on the fixture, are used as design variables for removing the under-tests in environmental vibration test. From the experimental results of vibration test control applied to the modified fixture and unmodified fixture, this method is shown to be an effective one.

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An actuating subsystem considered as a black-box transfer function in combination with real state space description of an acoustic duct is developed to establish a model for active noise control study. A periodic internal model that can generate 2 periodic signals is further connected to this model to design feedback active noise controllers to attenuate periodic disturbance as well as to improve noise reduction bandwidth. Both results of computer simulation and experiments demonstrate global noise attenuation at a large frequency bandwidth (∼71-Hz bandwidth of sound pressure attenuation ratio ≤0.5) along the duct after the control input location. In addition, the developed controllers can be applied for periodic disturbance of a varying frequency and attain effective noise reduction. Taken together, the proposed design method provides a feasible and applicable way for effective noise attenuation in ducts.

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A theoretical analysis model for the lateral vibration of beams with a bonded single-lap-joint and partial layered dampers has been proposed in this paper. Both shear and normal forces acting along the interface between the elastic and viscoelastic layers were considered in the vibration analysis. The analytical results were comparable to those obtained by the modal strain energy method and the harmonic response analysis, which were based on a finite element model. The effects of the location and thickness of the partial dampers on the system loss factor η_s were studied. The characteristic variations of η_s, with changes of the modulus and loss factor of the viscoelastic layer in the lap joint part and partial dampers were also studied. Consequently, the geometrical and material conditions at maximizing η_s were suggested.

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Robust error compensation algorithm for tooth form grinding works of an involute spur gear is proposed. The proposed algorithm is insensitive for the measurement error of the tooth form profile data. Relationship between indirect measurement quantity; the grinding error and direct measurement quantity; the tooth profile data are expressed by an implicit function. Error propagation analysis for the implicit model is derived using implicit derivative of the model function. Error ellipsoid of the indirect measurement quantity, which expresses the projection of the error hyper sphere of the direct measurement quantity, is defined. By taking the structural restrictions of the grinding error model into the least square calculation of the error estimation, the primary axis length of the error ellipsoid became smaller, which means the algorithm became more insensitive for the measuring error. Proposed algorithm was implemented on an in-process measuring system with personal computer. Accurate grinding error compensation was confirmed by experimental results.

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The fundamental properties of active magnetic bearing controllers are investigated from the standpoint of output regulation in the presence of deterministic disturbances. A transfer function approach is used in the analysis. The variable to be regulated is selected from rotor displacement, coil current and bearing force. The treated disturbance is stepwise or harmonic; the latter is caused by rotor unbalance. The essential properties of the controller achieving output regulation for step disturbances are derived. Those for unbalance disturbance are also shown by using complex-variable representation, which makes the procedure of analysis similar to that for constant disturbances. The derived controllers for unbalance compensation are converted into two types of real-variable representation: state equation and convolution integral. It clarifies the equivalence between the independently developed unbalance compensation controllers. It is also shown that the obtained results can be utilized in designing controllers.

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Problem to date: Similar in nature to the knapsack problem and the indivisible investment problem, there exists a static optimal problem the variables of which have both discrete and continuous values as the optimum variables: that is, a mixed-integer programming problem as one optimal problem of the mixed programming problems. A relaxed method or a group method etc. has been used for these problems hitherto. Just like the dynamical indivisible investment problem and the resource allotment problem/the disposition of personnel problem through several periods, there are few optimal control methods for the mixed-quantized dynamical optimal control problem which has both discrete and continuous values. The proposed method in this paper: For the mixed-quantized optimal control problem in which the state equation is linear, the control problem is given by the formulation of Halkin’s discrete time optimal control problem. The mixed-quantized discrete maximum principle is given as the algorithm for this control problem. Where, for the maximization of Hamiltonian in each discrete time, the relaxed method—which improved branch and bound method—is used. Effects obtained in this paper: As the applications in this control problem, the above dynamical investment and the allotment problem through the several periods etc. are considered. In this paper, the solution to the discrete time mixed-quantized optimal control problem is given, and the efficiency of this method (mixed-quantized discrete maximum principle)—which is applied infrequently to this field—is shown, along with a numerical example.

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In the present study, a previously developed finite-element model of the neck was modified by adding the Hill-type muscle elements. The modified model was utilized to investigate the muscle effects on the kinematic responses of the head-neck complex in a frontal impact at a speed of around 60 km/h. The behavior of this model was consistent with the literature data describing kinematic responses of volunteers and cadavers subjected to such an impact. The present results suggest the following: 1) It is likely that, when the neck muscles are activated at around 25-50 ms after the start of the impact acceleration, they can significantly reduce the peak values of the head-gravity center displacements and angular acceleration in a high-speed frontal impact; and 2) When the activation of neck muscles starts at around 100 ms or later, their effects can be disregarded.

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In this study a MIMD parallel numerical algorithm for computationally intensive bio-flow simulations has been proposed in the finite element framework. The segregated variable approach in conjunction with the domain decomposition strategy employed in the current parallel scheme is easy to implement, makes it amenable to handle complex bio-flow domains, and is less demanding on computational resources. The parallel method has been successfully tested in simulating hemodynamics in arteries with multiple aneurysms. Encouraging speedup and efficiency factors have been obtained in the parallel fem simulations.

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In this paper we present a model for an automotive active suspension system which includes the dynamics of an asymmetric hydraulic actuator. In this model the force exerted by a single-rod cylinder is regarded as an internal state, and the sum of the oil flow rates through the orifice of a servo valve as the control input. We obtain a linear time-invariant (LTI) state state equation and propose a force-tracking-free one-step control method which can accept various linear control techniques. An optimal state-feedback control is applied as an example. Quarter car test rig experiment results show the effectiveness of the proposed approach in modeling and control.

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This paper proposes a new H_∞ yaw-moment control scheme using brake torque for improving vehicle performance and stability especially in high speed driving. Its characteristics is that brake torque is applied at only one wheel at a time depending on the driving situation. Steering angles are modeled as a disturbance input to the system and the controller minimizes the difference between the performance of the actual vehicle behavior and that of its “model behavior” under the disturbance input. Various simulations with a nonlinear 8-DOF vehicle model show that the controller enhances the vehicle performance and stability, and their robustness to the changes in vehicle parameters.

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In this paper, an integral variable structure control scheme is proposed for a class of MIMO linear systems with matched uncertainty and constant disturbance. In our method, the integral term of tracking error is not only in the switching surface but also in the control algorithm. Hence, the problem of tracking error when the system is in the sliding layer can be effectively handled. Based on the pole assignment applied to the overall system, a novel and simple switching surface design is presented. Finally, a numerical example is given to demonstrate the applicability of the proposed control scheme.

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Out-of-sphericity error is degree of deformation of an air bearing sphere deviated from a perfect sphere. This paper investigates numerically the effect of out-of-sphericity error on the radial stiffness of an air bearing. Three types of out-of-sphericity modes are considered. In this study, the stiffness is calculated from pressure distribution at the bearing surface, which is obtained by solving the Reynolds equation. In some cases, large out-of-sphericity errors are found to improve the stiffness of an air bearing. This implies that an air bearing of perfect hemispheres is not necessarily of the best performance. Thus, much labor and cost in manufacturing air bearings can be saved. In addition, the radial stiffness depends greatly on the force applying direction for bearings of radially deformed stator hemisphere.

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In this work, a new non-Lyapunov approach is presented to investigate the robustness problem of eigenvalue-clustering in a specified region for linear systems subjected to parameter perturbations. Based on the essential properties of matrix measures, we propose some new sufficient conditions to ensure that the system’s eigenvalues cluster in a specified region irrespective of the system perturbations. By mathematical analysis, the presented non-Lyapunov criteria are proved to be less conservative than the existing non-Lyapunov ones reported recently.

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This paper proposes a new method for detecting a license plate and recognizing its numeric charachers regardless of its image size. With this method, numeric characters on the license plate can be picked out using binarization with a feature that a contrast of the license plate is higher than the other part of the image. The numeric characters are detected and recognized using a neural network that has two functions; one judges whether each pattern is a numeric character or not, and the other recognizes what character it is. The license plate is detected using positions of the detected characters. To show the effectiveness of this method, experiments were performed. In these experiments using 126 pictures that were taken under various conditions, each numeric character recognition percent is 94.0% and the license plate detection percent 97.6%.

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It is shown that structure parameters of a flexible manipulator can be virtually adjusted via tip-displacement feedback. By rearranging the structure parameters, transient performance can be significantly enhanced with the help of a collocated PD law. A procedure is developed to transform a lumped-parameter flexible arm into a set of simple mass-spring pairs connected in parallel to the base. The effect of tip-displacement feedback on each substructure can be visualized through this serial-to-parallel transformation, and the gain margin be readily found. It is seen that proportional feedback of the tip displacement virtually scales up or down each of the lumped masses and the lumped springs. A case study is provided to illustrate the design procedure and to demonstrate the performance of the proposed scheme.

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For highly accurate and highly efficient tooth surface finishing, a vitrified cubic boron nitride (CBN) wheel or an electro-deposited CBN wheel exhibits superior performance. Honing by an involute spline tooth meshing is effective due to the generating motion. However, a lack of wheel rigidity and an inadequate feed motion of the wheel tend to reduce the finishing performance. As a result, it is difficult to keep the tooth surface smooth. In this study, the finishing with a vitrified CBN wheel is carried out using a new honing tool. The finishing performance is compared with that obtained using an electro-deposited wheel, and the finishing is carried out by braking an internal spline axis. The influence of different feed methods is investigated on the roughness of the finished tooth surface. The finishing using a vitrified CBN wheel and braking an internal spline axis shows superior performance.

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Friction and pull-off forces were measured between an atomic force microscope (AFM) probe made of Si₃N₄ and submicron asperity arrays on a single-crystal tungsten plate, a silicon wafer, and a platinum film. A focused ion beam was used to produce the two-dimensional asperity arrays. The tip of the AFM probe had a flat, square surface measuring 0.7×0.7 μm². The pull-off force was proportional to the curvature radius of the asperity peak, but was not affected by micro-roughness at the peak. The friction force was proportional to the pull-off force. These findings suggest that the Laplace pressure of the condensed water was the predominant pull-off force and that the pull-off (adhesion) force worked as an external normal load for the friction. The friction coefficients calculated by regarding the pull-off force as an external normal load were compared for the platinum and silicon patterns, and this proved that the friction coefficient on the silicon was about twice as high as on the platinum.

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In this paper we present results of the dynamic response analysis of a rarefied gas lubricated slider bearing on a magnetic recording disk. Although the head slider is subjected to random air lift by disk movement, and there may be some irregularities on the disk surface, it is desired that the head-disk spacing vary periodically even if the acceleration is random, because if not, the head will crash onto the disk surface and magnetic recording memories will break as a result. The object of the present study is to simulate the behavior of the head slider in this case. Various response analyses were conducted on periodic disk movement, but the results of experiment showed that the disk movement is random rather than periodic. To our knowledge, there is no study on treating the response analysis due to random disk vibration. Therefore, it is necessary to conduct a dynamic response analysis on the head slider subjected to random acceleration.

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Self-acting air bearings are increasingly used in supporting small high-speed rotating bodies. In this study we report on the effects of design parameters on the axial stiffness of spiral-grooved air bearings of various curvatures. The design parameters selected in this study include fundamental clearance, groove depth, and bearing number. Coordinate transformation is performed to deal effectively with bearings of various curvatures. The pressure distribution at the gap between the stator and rotor of the bearing is obtained numerically, and the axial load and the stiffness of the bearing are calculated from the pressure distribution results.

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The basic research into the area of the behavior of piezoelectrics under static loading condition in far behind the effort put forth in the study of the vibrational behavior of piezoelectrics. Also, the application of the vibrational characteristics of piezoelectrics has been widespread, but the application of the static characteristics has been relatively left untapped. The piezoelectric based actuators are gaining more pupularity in many areas ranging from micro-motion control as positioners to macro-motion in space applications. So, it is very vital to understand the behavior of practical piezoelectric micro actuator under arbitrarily applied external voltage. The solution for moderately complex piezoelectric model using analytical methodology is very challenging. So, a numerical solution scheme based on the method of finite elements has been developed to analyze the deformations of and potentials within piezoelectric materials subjected to external static voltage loading. The formulation of the finite element equations developed and used for computer implementation is also dealt with. Computer software has been created to model piezoelectric three-dimensional geometries, based on the equations developed. The case studies chosen for evaluation of this numerical scheme are representative of real-world piezoceramic materials. The results are found to be in excellent agreement with published product data. This work carried out would be a foundation for the development of a powerful analysis tool, capable of testing multiple conceptual designs of piezoelectric actuators.

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A flexible and incremental sheet metal bulging method using a high-speed water jet has been developed for the small-batch manufacture of nonsymmetrical shallow shells, for the erasure of tool marks and for clean forming without the need for lubricating oil. The computer-controlled bulging machine shaped a wide range of complex shapes of sheet metal, for example, pyramidal shells, shells of pyramid frustums, shallow pans and embossed panels. An approximate deformation analysis for the bulging height and the strain distributions of a shell was proposed, using a plane-strain deformation model, the membrane theory and the momentum theory of hydrodynamics. Predictions for the shell of a quadrangular pyramid frustum and the shell of a circular cone frustum were generally in good agreement with experimental values for an annealed aluminum sheet.

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A C-shaped constant-force spring is made of pre-stressed material in various sizes that offer the advantage of a constant tensile load, suitable for a variety of applications (for example, extension spring, motor-brush holder, power feed, retracting and restoring mechanism). Essentially, this spring consists of a coil of flat spring material and when unstressed it takes the form of a tightly wound spiral. This spiral is placed on a drum. When a tensile load is applied, the spiral uncoils. The load is practically independent of the amount of deformation. In this report, the extension mechanism of constant-force spring and the state of deformation are analyzed by using a large deformation theory. Moreover, experiments are carried out to confirm the applicability of the proposed theory. The experimental results agree well with the theoretical estimations.

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Authors reported theory of hourglass worm gearing whose worm is generated by high speed screw generating method, on previous report. CNC high speed hourglass worm generating machine has been developed according to the theory. And worm cutting test and performance test of worm gearing was made. The test results are as follows: (1) Newly developed machine has high speed cutting ability same as mach type screw generating apparatus. (2) Surface roughness of worm tooth surface generated by the CNC high speed hourglass worm generating machine has same order of roughness of screw surface cut by mach type screw generating apparatus. (3) Hourglass worm gearing generated by the newly developed machine showed high efficiency and ran 1000 hours without trouble.

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The internationally reported nuclear criticality accident at JCO in Tokaimura, Japan has further eroded public confidence in nuclear energy, its related facilities and the (Japanese) government’s ability to handle such a crisis. The JCO accident marked the sixth nuclear-related incident since 1995. The existing state of “safety culture” is being questioned and re-evaluated at a national level. In this work the safety culture associated with engineered systems (ES) such as the automobile, commercial airplane and nuclear power plants (NPP) are evaluated based on a scale-analysis (SA), via proposition of two fundamental parameters called eigenmetrics. The identified eigenmetrics are time- (τ) and number-scales (N) describing both ES and human factors, at the individual and/or societal levels. The SA approach is appropriate because human perception of risk (POR), perception of benefit (POB) and level of (technology) acceptance (LOA) are inherently subjective, therefore “fuzzy” and rarely quantifiable in exact magnitude. POR expressed in terms of the psychometric factors “dread risk” and “unknown risk”, contain both time- and number-scale elements. The JCO accident, as well as auto-fatalities, commercial airline accidents and hypothetical NPP accidents are characterized in terms of τ, N and two additional derived parameters of relevance, Nτ and N/τ. We contend that LOA infers a POB at least two orders of magnitude larger than POR. The “amplification” influence of mass-media is also deduced as being 100 to 1000 fold the actual number of fatalities/serious injuries in a nuclear-related accident.

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A simple method for extracting emotion from a human face, as a form of non-verbal communication, was developed to cope with and optimize mobile communication in a globalized and diversified society. A cartoon face based model was developed and used to evaluate emotional content of real faces. After a pilot survey, basic rules were defined and student subjects were asked to express emotion using the cartoon face. Their face samples were then analyzed using principal component analysis and the Mahalanobis distance method. Feature parameters considered as having relations with emotions were extracted and new cartoon faces (based on these parameters) were generated. The subjects evaluated emotion of these cartoon faces again and we confirmed these parameters were suitable. To confirm how these parameters could be applied to real faces, we asked subjects to express the same emotions which were then captured electronically. Simple image processing techniques were also developed to extract these features from real faces and we then compared them with the cartoon face parameters. It is demonstrated via the cartoon face that we are able to express the emotions from very small amounts of information. As a result, real and cartoon faces correspond to each other. It is also shown that emotion could be extracted from still and dynamic real face images using these cartoon-based features.

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A CAD/CAM link is developed for rotational components. The link consists of three modules, namely, structured modeling, feature recognition, and feature sequencing for machining. An algorithmic approach is used to generate a structured component model. A feature recognition knowledge base is developed for identifying turning surfaces on the structured component model without any human intervention. The automatic recognition process is achieved by matching entities of the component model with predefined entities to identify the types of turning features required to produce the component. The recognized features are sequenced in an operational machining sequence that produces best results

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In this study, a systematic approach to achieve a globally optimal Chemical Mechanical Polishing (CMP) process is carried out. In this new approach, the orthogonal array technique adopted from the Taguchi method is used to realize an efficiently experimental design. The RBFNF neural-fuzzy network is then applied to model the complex CMP process. The signal-to-noise ratio (S/N) analysis (ANOVA) technique used in the conventional Taguchi method is also implemented to obtain the local optimum process parameters. The globally optimal parameters are successively acquired in terms of the trained RBFNF network. In order to increase CMP throughput, a two-stage optimal strategy is also proposed. Experimental results demonstrate that the two-stage strategy performs better than the original approach even though the total processing time is reduced by 1/6.

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Resistance spot welding (RSW) is used for the fabrication of sheet metal assemblies. The major advantages of spot welding are high speed and adaptability for automation in high-volume and/or high-rate production. Despite these advantages, resistance spot welding suffers from a major problem of inconsistent quality from weld to weld. This problem results from both the complexity of the basic process as well as from numerous sources of variability, noise, and errors. Any or all of these complicate automation, reduce weld quality, demand over welding and drive up production costs. For this reason, ensuring weld quality has been and remains a major challenge and goal. The objective of this research is to explore the phenomenon of how changes in a controllable parameter of % heat input affect a measurable output signal indicative of strength and weld quality for various sheet steels used in the automotive industry. The approach of this research is to create a relationship between a key process input variable and the key process output of a quality weld. The input parameter chosen is % heat input, as this directly effects the size and strength of the resulting weld. The output chosen is electrode displacement, as this has been shown to accurately reflect the formation and growth of a weld nugget. A series of experiments was conducted to explore how changes of % heat input and process variations affect the electrode displacement curve for various sheet steels used in the automotive industry. Experimental results show that the electrode displacement increased when higher % heat input was applied. Weld nugget starts to grow when electrode velocity cube changes from positive to negative. Characteristic electrode displacement curves were developed for process variations. A poor part fit-up condition shifted the electrode displacement curve to the right as a result of a smaller weld nugget being formed. Worn electrode lowers the electrode displacement curve. For bare steel, electrode displacement is higher than electrogalvanized and hot-dip galvanized steel. The higher strength steels have higher electrode displacements than for plain carbon steel.

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This paper discusses the adaptation of the Preisach model to describe the hysteresis behavior of piezoceramic actuator system and presents a modified geometric interpretation and numerical implementation method for the Preisach model especially for the hysteresis modeling of piezoceramic actuator system. The demagnetized-state, which refers both input and output equal zero state, and the generalized demagnetized-state are used as the basis of Preisach model rather the saturation states. Experiments on the hysteresis behavior of a piezoceramic actuator were carried out and the experimental measurements are compared with the hysteresis predictions. The comparison results verify the application of the modified Preisach model to piezoceramic material system.

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Gas Metal Arc(GMA) welding is extensively employed in the metal industries to weld a variety of ferrous and non-ferrous metals because of its potential for increasing the productivity and quality of welding which is controlled by the process parameters. The objective of this paper is to develop the algorithm that enables the determination of process variables from the optimized bead geometry for robotic GMA welding. It depends on the inversion of empirical equations derived from multiple regression analysis of the relationships between the process variables and the bead dimensions using the least square method. The method directly determines those variables which will give the desired set of bead geometry. This avoids the need to iterate with a succession of guesses employed Finite Element Method(FEM). These results suggest that process variable from experimental equation for robotic GMA welding may be employed to monitor and control the bead geometry in real time.

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In this paper, a method to detect lanes and obstacles from the images captured by a CCD camera fitted in an automobile is proposed, and a new terminology, “Moving Window”, is defined. Processing the input dynamic images in real time can cause quite a few constraints in terms of hardware. In order to overcome these problems and detect lanes and obstacles in real time using the images, the optimal size of moving window is determined, based upon road conditions and automobile states. The real time detection is made possible through the technique. For each image frame, the moving window is moved in a predicted direction, the accuracy of which is improved by the Kalman filter estimation. The feasibility of the proposed algorithm is demonstrated through the simulated experiments of freeway driving.

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