An optimal control concept is proposed regarding gear shift operations of automatic transmission systems being part of a complete power train. The optimization is carried through by a dynamic programming approach with a performance measure including passenger comfort and control expenditure. The gear synchronization appears as a constraint at the end of the process. A control law is derived analytically by minimizing the performance measure over each process stage. Simulation results show a significant improvement in terms of gear shift comfort for different driving load cases. Furthermore the shift time and the frictional losses in the shift elements can be reduced by applying the proposed control.

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Slippage of an automobile often occurs during acceleration and braking. As a result, travel performance is adversely affected, since the gripping force of the tires on the road surface is lost. In this paper, we propose a traction control system design method by using the model-following sliding mode control, in which we consider the friction coefficient between the road surface and the tires as an uncertainty in the controlled object. Generally, car-body speed must be known for traction control of an automobile, but it is impossible to detect car-body speed in an automobile system. In this paper, we performed simulations using the speed estimated by a disturbance observer, in which the road surface friction coefficient μ was considered as a torque disturbance. We confirmed that the control system has good performance in simulations.

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We developed an easy-to-operate, heavy duty cart comprising a power assist technology available for both longitudinal and rotational motions of the cart. The omni-directional, motor-assisted traveling mechanism uses universal wheels that provide a smooth operation of the cart. This paper describes the system configuration and power assist technology that we have applied, and some of the challenges that we addressed during the development of this new power-assisted cart.

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This paper proposes a new railway vehicle which realizes both good curving performance and high speed running stability using the active steering control. Unlike another vehicle implementing actuators on conventional one with simple control law, this vehicle system consists of two parts, intelligent controller having adaptive property and controlled object, which is possible to design. In our research, authors name the vehicle with optimized structure for active steering control as the "Mechatronic Vehicle". As a first step to develop such design procedure, authors consider an active steering control law, which makes possible ideal curving behavior of wheels on the basis of inverse dynamics while minimizing actuator input. A learning control algorithm, which enable the vehicle to be adapting to the track by making use of the repetitive running, is proposed. The effectiveness of proposed control method is also confirmed in the numerical simulation.

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The superconducting Maglev, for which running tests are performed in Japan, is a high-speed transportation system of the next generation. In order to realize the superconducting Maglev as a high-speed transportation system, it is important to improve its ride comfort at high-speed. In this paper, we study the vibration control system suitable for superconducting Maglev vehicles.

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This paper presents results of recently carried out studies toward an environment-friendly, safe and intelligent marine transportation system. Firstly, a broad view of current status of Marine Transportation Systems and contents of Virtual Vessel Traffic service (V-VTS), Intelligent Marine Traffic Systems and Marine Intelligent Transport Systems (Marine ITS) is given. Then, a concept of fully automated and intelligent ships is presented in order to realize the environment-friendly, safe and intelligent marine transportation system. Finally, main conclusions from this study are drawn and further study directions are pointed out.

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This paper deals with controlling of large ships in harbour manoeuvres by applying the Decoupling Control Method (DCM). Ship motions are expressed by a multi-term non-linear model. The DCM applied to the ship non-linear model is described and issues concerning designing the controller are discussed. The method and its excellent effectiveness are illustrated by simulation of a Very Large Crude Carriage (VLCC) in a typical pattern of approaching and berthing manoeuvres. Robustness of the controller is also studied by examining its ability in dealing with influences of parameters' uncertainty and environmental disturbances' effects (such as strong wind and current).

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This paper proposes a new modeling technique for motion and vibration in flexible structures. We call this modeling technique the 'extended reduced order physical model'. Because vibration is generally influenced by motion, it is necessary to analyze vibration and motion together. A new modeling technique can be used to represent both motion and vibration. The effectiveness of this modeling technique is confirmed by simulated as an elastic vehicle using a flexible rectangular plate. Two elastic vibration modes as well as the bouncing, rolling and pitching of the vehicle were controlled using the LQ control method.

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In this contribution problems relating to the non-linear interaction between an elastic tire and soft soil are discussed. A basic approach for solving this problem is described, where the friction force is modeled as a function dependent on the lateral displacement of the tire. The sinking of the tire is not accurately modeled-it is approximated by increasing the friction coefficient both linearly and non-linearly. The behavior exhibited using the approaches described is compared with measured behavior from real tests and the potential of the approach is appraised.

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This paper describes a method for modeling of crawler-type running equipment with a bogie mechanism as a multibody system. By using the model, in traveling on a firm ground with a rectangular bump, some simulations to analyze the dynamic behavior are conducted and the acceleration at the operating seat position and the suspension loads are calculated. The simulation results are compared with experimental ones and the validity of the modeling and simulation method is verified.

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In this paper, we demonstrate a method of motion control for a three-link space robot which has two torque inputs only around the second and third joints. This space robot has redundancy, and the body and the first link of the manipulator are connected freely to minimize the interaction between them. One of the final postures corresponding to the desired position of the end effector is obtained using the concept of the enhanced disturbance map. We set the rotational velocity of the body to zero as the constraint condition, and reconstruct the state equation of the three-link space robot. Based on this state equation, we obtain the feedforward torque input using the final-state control. It is verified from simulation that the proposed method of motion control is useful.

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This paper describes the stabilizing control system design for small-scale helicopter based unmanned aerial vehicle Sky Surveyor. For full-autonomous control, the original hardware and software which can be equipped with small-scale helicopter, including small-sized lightweight control unit, have been newly developed. System identification method has been used for analysis of system dynamics in the frequency domain and the time domain. On-axis input/output data collected through the identification flight experiment achieved a coherence close to unity, and reliable transfer functions could been calculated. The modern control theory was applied to design lumped control system which can stabilize velocities of a fuselage. Good control performance has been shown in simulation.

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This paper studies a control of the extending space structures in orbit under gravity-gradient environment. To this end, it first introduces an equation of motion of the satellite that extends on the orbit and shows that it is a linear time-varying system. Then it is represented as a linear parameter varying system and the way applying Gain-scheduling control method is described. Finally, by using a simple column model, it gives an example that the gravity-gradient stability condition which stands up for the non-extending satellite becomes ineffective for the extending one and that the obtained controller can stabilize it within the sufficient accuracy.

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Studies on attitude controllers for spacecraft by two reaction wheels were started recently. In the research, the optimal trajectories of large angle maneuvers are figured. The required maneuver is a rest-to-rest reorientation around uncontrolled z-axis which is no reaction wheel in this paper. The criterion of the minimum energy problem is given as an integration of the sum of squared torque. The z-axis slants largely during such maneuver. A large z-axis slant causes some attitudinal problems, which are cutting sunlight or breaking the communication links during maneuver and so on. Therefore, this paper treats with the minimum energy problem with slant constraint of z-axis for satellite maneuvers. Numerical solutions are shown and the features of the optimal trajectories are discussed from the equations of motion analytically. The results of this paper could be an effective for minimum energy controllers with attitude constraint

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This paper proposes a new method for controlling vibrations using the interactive force of a pair of identical flexible structures arranged in parallel such as solar panels of a space station. The key feature of this new method is to connect to arms with the actuators to different positions on a two flexible structures. The modes of bending from first to third and first torsional mode are well controlled using our proposed modeling method and a filtered LQ control theory. Computer simulations and control experiments are carried out and the effectiveness of the mechanism presented is confirmed.

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Uncertainties in the dynamics model of a smart structure are often of significance due to model errors caused by parameter identification errors and reduced-order modeling of the system. Design of a model-based FDI (Failure Detection and Isolation) system for smart structures, therefore, needs a careful consideration about robustness with respect to such model uncertainties. This paper proposes a new method of robust fault detection that is insensitive to the disturbances caused by unknown modeling errors while it is highly sensitive to the component failures. Capability of the robust detection algorithm is examined for the sensor failure of a flexible smart beam control system. It is shown by numerical simulations that the proposed method suppresses the disturbances due to model errors and remarkably improves the detection performance.

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The effect of the spring and damping characteristics of a floating bush bearing on the stability is investigated numerically. The characteristics of the bearing's inner and outer oil film are calculated separately. In this calculation, the configuration of the bearing's surfaces, namely, the oil paths, and the increase of the temperature due to the bearing loss are taken into account. The rotor dynamics are then calculated and the characteristics of the unstable vibration of the rotor investigated. This kind of shaft-bearing system has four rigid vibration modes : two in which the bushes move in phase with the shaft and two in which the bushes move out of phase with the shaft. The spring constant of the outer oil film mostly affects the former two modes, whereas the damping characteristics of the outer oil film affects all modes. By taking the advantage of these effects, we can control the unstable vibration and eliminate the mode we need to avoid.

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In this paper, the mechanism and dynamic stability of gas-lubricated bearing are considered. The pressure distribution which is generated in compressible fluid at the gap of bearing is calculated. The equation of motion is derived using the fluid force acting on journal which is calculated from the pressure distribution. Based on the derived equation, the numerical simulation of the dynamic behavior of the journal is performed and the stability of the behavior of the journal is investigated. Finally parameter studies are discussed.

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In this paper, we discuss countermeasures for the polygonal deformation phenomena of a hot leveler. We propose a method to delay the growth of polygonal deformation by changing the operation speed, and investigate its effectiveness by numerical simulation. Also, we propose the method to apply modal analysis to a time retardation system accompanied by wear. We propose some parameters which is useful for designing a hot leveler, and investigate the influence of the parameters on pattern formation.

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In the field of mechanical engineering, a large number of contact rotating systems are used. While the systems are operating, periodic polygonal deformation patterns are often formed on the peripheral surfaces of rolls due to viscoelastic deformation, plastic deformation, cutting, grinding, wear and so on. Such phenomena are caused by the unstable vibrations generated in time delay systems. In this report, the authors suggest a simplified method for stability analysis by using energy factor, and develop a prevention measure of the unstable vibration. The validity of the present methods is confirmed from the numerical computational results.

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The dynamic equation of the cracked rotor in dimensionless form is modelled, which is based on the simple hinge crack model and the local flexibility theorem. The numerical simulation solutions of the uncracked rotor and the cracked rotor are obtained from the model. By the continuous Wavelet Transform, the wavelet magnitude map features of the uncracked rotor and the cracked rotor are investigated; the difference between them is presented, and a new detection algorithm using wavelet magnitude map to identify the crack is proposed. The influence of the scale factor on the accuracy and validity of the wavelet magnitude map is analyzed; the preferred scale factor is suggested. Experiments on the cracked rotor and the uncracked rotor verify the availability and validity of the wavelet magnitude map in identification of cracked rotor for engineering practices.

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This paper considers the derivation and application of closed loop vibration controllers that are designed for attenuation of multiple discrete frequency rotor vibration components. The component complex amplitudes are evaluated in real-time and used for dynamic feedback control with frequency matched control signals. Gain matrices are derived from on-line identification routines, performed under a finite set of different operating conditions. Controller gain matrices are synthesised using linear matrix inequality existence conditions for closed loop system stability and performance. Thus, the controllers can be designed with a degree of robustness to changing/non-linear dynamics. Implementation and testing is undertaken on a flexible rotor/magnetic bearing test rig. The controllers are shown to simultaneously attenuate vibration due to direct rotor disturbance forces and other indirectly forced non-synchronous frequency components.

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The abilities of neural networks combined with fuzzy logic offer interesting prospects for the active control of structures. In this study the neuro-fuzzy controller design method is described. It is then applied to control the functioning position of a rigid rotor suspended on active magnetic bearings. Although the controller characteristics and the desired response reference are chosen as simple as possible, the results of simulation permits the efficiency of this type of controller to be shown and the simplicity of their implementation to be underscored.

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This study deals with "Vibration behavior of rotating shaft due to contact with casing". Such problem has not solved yet enough, due to complexity of phenomenon and collision mechanism. We tried to solve this problem by experimental and analytical approach. Then we get some typical "contact-vibration" behavior, and effect of change in parameters of rotor and casing for vibration behavior.

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The subject of our study is to develop a new method that aims at cancelling the effect of the unbalance for rotational speeds below the rigid modes frequencies. We propose hear two different approaches : an open-loop method and a closed-loop algorithm called AVR. A full physical model is also developed. A modal state-space model is extracted from a FEM (Finite Element Method) software. The resulting complete model is coupled to a model of the rest of the system, including actuators, detectors, anti-aliasing filters, amplifiers and numerical controller. Then, the first method for unbalance cancellation is used on the complete model. It's a four-step method that consists in identifying the unbalance with two measurements, thanks to two different synchronous signals added. For this open-loop method, a statistical study, considering the variance of the estimator and various extra signals give good insight on the result. Concerning the closed-loop method for unbalance suppression (AVR), the global model is used in order to study precisely the limits of stability and validate the theoretical approach based on the model. We finally apply this method to an air turbine machine.

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Two kinds of disk brakes are used in cars. One is called a "floating type disk brake", and the other is called a "rigid type disk brake". In this paper, the squealing mechanism and the effect of squeal reduction by cutting a part of the pad surfaces in the circumferential direction are investigated in both types of disk brakes. These results are compared with each other. Moreover, the frictional vibration of a block subjected to distributed friction at the contact surface was treated analytically and experimentally, and a common mechanism of vibration of the block and disk brake was found.

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This research is to investigate the dynamic function of the grinding process. A new approach to determine grinding force components in dynamic grinding is proposed. Attention is paid to the mechanisms of dynamic grinding from the kinematics viewpoint. A non-linear dynamic model is developed to investigate the dynamic characteristics of the grinding process. The relationship between grinding force variations and vibration frequency is revealed. The dynamic model of the cutting process is integrated with the model of structural dynamics of the spindle-bearing unit. The integrated model demonstrates the expanded opportunities for the development of control system for grinding machines.

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A remote inductive powering system for driving electrostatic actuators is proposed. The actuators can be controlled selectively by matching transmitter's frequency to the resonance frequency of the receiver LC-circuits. An 8(mm)^2 square and 20 turns planar coil are used as a receiver coil. The operational frequency of the transmitter is set from 4 to 7MHz. The output voltage of the receiver was obtained maximally about 45V with a load resistance of more than 100kΩ. A conventional electrostatic comb drive microactuator was used for a prototype of a receiver. The coil and the actuator were fabricated on the same surface of a commercially available silicon on insulator (SOI) wafer. The displacement of the actuator was selectively controlled by changing the transmitter's frequency.

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Nanostructures are constructed with destructively fabricated nano building blocks based on multi-walled carbon nanotubes (MWNTs) through nanorobotic manipulations. The building blocks are positioned together with nanorobotic manipulators under real-time observation with a field-emission scanning electron microscope (FESEM), and are connected through electron-beam-induced deposition (EBID) or chemical bonding with mechanochemical nanorobotic assembly.

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A MEMS device for the measurement of profile on high aspect-ratio microstructures has been developed. The goal was to develop a method to be used when the known methods were inappropriate. The main part of the tool is a silicon micro-probe with a sharp tip at its end and an integrated piezoresistive strain gauge sensor. The probes are from 500μm to 1mm long with a cross section area of 20×20(μm)^2; they were mainly designed for the characterization of narrow and deep "EDM" micromachined micro-holes having a radius as small as 50μm and a depth up to 800μm. The profile measurement method has been extended to the characterization of several other microstructures. The measurement accuracy is around ±30nm.

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This paper reports on an actuated micro probe with a force sensor for inserting it into a cell. The resistance of the insertion was measured by a strain gauge located on the beams of an SOI wafer. The micro probe supported by 4 beams (1000×10×5[μm]) was vibrated by electrostatic actuators. This micro probe was inserted into a fish egg. The spring constant of a fish egg membrane, the fracture load of a fish egg, and the friction between the probe and an egg were measured. Two types of insertion, with/without vibration, were carried out in the experiment. The forces during the insertion with/without vibration are about 10[μN] and 6[μN], respectively. Therefore the vibration of the probe is useful for precise positioning.

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A novel micromachined actuator which is developed to produce precise and unlimited displacement. The actuator is driven by impact force between a silicon micro-mass and a stopper. A suspended silicon mass is encapsulated between glass plates and driven by electrostatic force. By hitting a stopper, it generates impact force to drive the whole actuator in a small step (∿10nm). It is a micromachined and electrostatic version of the impact-drive actuator. The overall dimension of the device is 3mm×3mm. The driving voltage is 100V and average speed is 2.7μm/s. The total thickness is 600μm.

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The authors are developing electrostatic levitation systems as a non-contact bearing to solve the problems that are caused by large friction force and rapid wear in high vacuum. This paper reports three experimental results that support good feasibility for practical application of electrostatic levitation in vacuum chambers. First, and aluminum disk that weighs 442g is experimentally levitated to confirm that electrostatic levitation force in vacuum is strong enough to levitate objects such as positioning tables and conveyer carriages. Secondly, to reduce the cost for amplifiers, which are essentially employed in the systems, a voltage application method that utilizes amplifiers, constant DC voltage suppliers and smooth input profile is introduced. This method successfully reduces output voltage range of amplifiers by a factor of about eighth. Thirdly, to apply electrostatic levitation technology to more practical systems such as conveyers, an electrostatic levitation system that constrains the whole motions of its levitated body except one axis of translational motion on horizontal plane.

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Electrostatic glass actuators are a promising new concept for data storage devices. Their stunning simplicity, together with their ability to outperform their electromagnetic counterparts at small size, make them the solution of choice for a potential flat one inch hard disc drive. This paper presents an analytical model of the electrostatic glass actuator, validated by experimentation and determines the best glass blend for this application. Futhermore, a functional prototype of a one-inch drive will be presented.

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This paper describes a sensor-less magnetic force control method using a magnetic force control device composed of a giant magnetostrictive rod, a permanent magnet and a piezoelectric actuator, with which the magnetic force can be controlled by adjusting the input voltage to piezoelectric actuator. If the secondary voltage induced by the displacement of the moving yoke can be separated from the control input voltage, the composite device can also be used as a sensor in magnetic force control. In this study, a RC bridge circuit for the separation of the secondary sensor voltage from the control input voltage was proposed and examined in the experiment. The results show that composite device can be used as a self-sensing actuator in magnetic force control if the RC circuit is properly adjusted.

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In an attempt to validate the effectiveness of magnetorheological (MR) damper in controlling wind-induced response of a building model in wind tunnel, a small-scale rotary shear-mode type of MR damper is designed. A prototype damper with forces of few newtons is manufactured and tested in laboratory. A phenomenological model based on the original Bouc-Wen model is then developed. Additionally, a simplified yet relatively accurate inverse dynamic model that directly relates the damper force to the input voltage is proposed for the shear-mode MR damper. Numerical examples and experiments demonstrate that MR damper used with the inverse model can closely reproduce prescribed forces. This inverse model provides an alternative means to command MR damper for control applications.

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This paper proposes a new type of electromagnetic valve actuator for engine valve drive. The cylindrical actuator has bias permanent magnet on the side wall which produces holding force. When the driving current flows and cancels the holding force, the armature starts moving to the opposite position. First, the concept of electromagnetic valve actuator is explained. Then the value actuator is designed using FEM. The experimental setup is made to confirm the capability of the proposed actuator. The experimental results showed admissible characteristics. In order to reduce the landing speed and the power consumption, the energy regenerative driving circuit is proposed. The results showed relatively good performance and high possibility for practical application.

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Although active magnetic guides (AMG) can obtain an infinite static stiffness and high damping using sophisticated multi-degree-of-freedom control, still a non-negligible dynamic compliance is inherent. This is especially true when high controller gains cannot be achieved due to spill over effects. Several approaches are known to overcome this problem, repetitive control and frequency estimation being two of them. Both have drawbacks concerning flexibility, robustness and compensation quality. This paper proposes a smart frequency identification and compensation scheduling algorithm along with tracking compensation oscillators to cancel arbitrary periodic disturbances. The proposed algorithm has been implemented and tested on an AMG. The introduced smartness provides a very robust behavior and leads to an infinite steady state stiffness.

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Much effort on modeling, identification and tuning of control parameters is required in order to stabilize magnetic levitation systems because of their negative stiffness and nonlinearity. The purpose of this study is to propose a practical control method which achieves the stability and compensates the nonlinearity without trial and error. The stable levitation and fast positioning of the object are realized in an experimental one-degree-of-freedom system.

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We are developing a clean robot which operates in an ultra high vacuum and clean environment without a mechanical contact and moves 3-dimensional motion, namely vertical direction, rotational motion round the vertical axis and radial direction perpendicular to the vertical direction. A linear actuator for the radial motion is levitated by linear magnetic bearings and propelled by a linear stepping motor and have an end effecter (hand) to hold a silicon wafer. A rotary actuator takes in charge of vertical and rotational motions and is levitated by outer type active radial magnetic bearings and a passive thrust magnetic bearing. In this paper, we propose a new controller for the rotary actuator using the H-infinity method. Previously PID and LQG controller was designed for rotary actuator [1] [2]. And rotor's contact-free levitation was achieved using these controllers. But there were some problems. The problem of prime importance was that the sensitivity from disturbance input to error output indicated high gain. So we aim to achieve lower sensitivity using newly designed H_∞ controller. Firstly, a dynamic model of the rotary actuator is presented considering 4 degrees of freedom in the rotor, 4 degrees of freedom in the stator and the flexibility of the stator. Secondly, a H_∞ controller is designed for the radial magnetic bearing. Thirdly, a series of experiments are carried out for estimating a performance of the H_∞ controlled system. We have confirmed from the experiment result that the changes of relative displacement between the rotor and the stator of the radial bearing are less than the radial clearance and the control currents in the magnetizing coils are also under the current capacity of the power amplifiers. And we have confirmed that H_∞ controller's performance achieves lower sensitivity than that of PID and LQG controller.

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This paper proposes a new Electro-Magnetic-Suspension (EMS) system which has the ability of self-banking in curve section. This new EMS system is able to tilt automatically corresponding to the magnitude of the centrifugal force. Four hybrid-magnets (HMs : combination of permanent and electro-magnet) are used to guide and suspend a vehicle at the same time, that is different to a conventional EMS system getting necessary force from a guidance system when running in sharp curve. The Nearly-Zero-Power control method is applied to minimize energy consumption of the HMs. Five degrees of freedom are considered in the simulation and experiment. The results of simulation and experiment show this new EMS system has the ability to tilt automatically corresponding to the magnitude of the centrifugal force, and cancel the constant disturbance forces added in five directions only with the attraction forces of the permanent magnets (PMs) in the HMs and the gravity of earth.

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This paper addresses real-time magnetic levitation control using the TMS320C31 Digital Signal Processing Starter Kit (DSK). A phase-lead controller is designed. The controller coefficients are then included in an assembly language program that implements the phase-lead controller. A MATLAB program is used to activate the phase-lead controller, calculate and plot the root locus of the control system. When the MATLAB program is run, it plots the root locus of the system on the PC screen, assembles the phase-lead controller assembly language program, and loads/runs the resulting executable file on the C31 DSK to achieve real-time control. Results show the system outputs are as expected with a phase-lead controller, with actual system outputs matching theoretical calculations.

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Various structural measures against vibration and noise were taken in a training ship, 'Oshima maru'. However, unpleasant sound persisted in the mess hall where crews take their breaks. In order to reduce the noise, an optimal active controller was investigated to satisfy the causality constraint in their update. Some of them are preconditioned using the inverse of the plant because the convergence rate of its algorithm is limited by the dynamics and coupling within the plant response. They are compared under the same conditions to investigate differences in their properties and corrected for satisfying the causality on their update processes. After the results of investigating the convergence speed in various gradient descent adaptationion algorithms are integrated. the active control of ship interior noise can be applied.

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A new method for predicting the vibration and sound-radiation of a total gear system, including multi-stage gear pairs, shafts, pedestals, and a gearbox, was developed. The method consists of three separate analyses : gear vibration analysis, FEA, and BEA. To verify the effectiveness of the method, sound-pressure levels at two points in the horizontal and the vertical directions from a gearbox of an experimental apparatus were measured. These measurements agree well with the corresponding levels calculated by developed method. It is thus concluded that the method can accurately predict vibration and noise and can effectively design a low-noise gearbox.

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This paper concerns the minimization of total acoustic power radiated from a vibrating planar structure using both active noise and vibration control with acoustic secondary sources and vibration control forces. First, the total acoustic power radiated from the model used in this paper is calculated using the reciprocity principle. And the optimal feed-forward control law for minimizing the total acoustic power is derived. Next, we show the phenomena under the optimal control condition, which are the control acoustic power becoming zero and the control vibration power also becoming zero. Finally, we show the control effects and the phenomena by using a specific example.

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This paper presents a new control method of structure-borne sound radiated from a planar structure using acoustic cluster filtering and cluster control. Acoustic cluster is filtered out by using microphones. To verify the validity of the proposed method (combing both the acoustic cluster filtering and cluster actuation), this paper conducts the experiment in an effort to suppress structure-borne sound radiated from a distributed-parameter planar structure.

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Four time domain inverse methods for load identification of mechanical systems are surveyed. The study focuses on situations where the load locations are known a priori and the corresponding magnitude is unknown. The main emphasis is laid on the accuracy with which the excitation is reconstructed versus the computational complexity. A numerical example is given to elucidate advantages and deficiencies of the four methods. Three of the methods produce excellent force estimations for the model problem, even for measurement data contaminated by noise. Suggestions for applying the studied methods are also given.

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In this paper, a design method of decoupling control system for multiple-degrees-of-freedom (DOF) systems is proposed. In general, decoupling control systems have been designed by dividing the motion modes into vibration modes via a modal matrix used in the field of modal analysis. However, estimation methods of the modal matrix have not been proposed except for experimental modal analysis in case of physical parameters are unknown. Then, this paper proposes a new estimation procedure of the modal matrix based on the state space model identified by subspace method, and also illustrates a design method of an independent modal control system using the estimated modal matrix. The effectiveness of the proposed method is examined through numerical simulations.

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This paper proposes a method to do condition diagnosis about non stationary signal generated by operating rotary machineries which are bearing, gear, rotor and so on. Especially, a signal processing technique in order to eliminate slight non stationary noises including operating sound is described by adopting locally stationary AR model [1] a kind of system identification. The effectiveness of this modeling has been identified by numerical simulation based on a rotary simulator device on a failure rolling bearing.

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