In this paper, we discuss the leader-following formation navigation (LFFN), which is one of the most important issues in formation control. In this formation, one leader is controlled by a human operator, while multiple followers pass along the leader's trajectory in the same motion to the leader. The collision avoidance problem in the LFFN has been discussed in a previous work. However, the problem of initial movements of followers still remains. The followers move along the leader's path behind the leader at some intervals. Thus, around the initial time, the followers cannot determine routes to track because there is no leader's path before the initial time. This paper discusses how the followers should move around the initial time in order to start up naturally and to achieve the LFFN afterwards. The effectiveness of the proposed method is demonstrated by a simulation with three mobile robots.

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The studies of fuel saving aspects and vehicle control for optimum consumption have recently received tremendous attention from researchers in the field of transportation systems. This paper presents an enhancement of the idea that is applied for the centralized control of a platoon of vehicles to optimize overall fuel consumption. Model predictive control of the vehicles, incorporating vehicle-aerodynamics in the state formulation, ensures optimum consumption of the platoon even while driving them from unsteady situations. Performance of the proposed platooning system is evaluated through simulations. Simulation results consisting of fuel saving characteristics of the vehicles on a typical driving scenario are graphically illustrated, analyzed and compared to signify the merits of the proposed system.

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In recent years, predictions of changes in the environment on earth and studies on ecodevelopment have both become important. Such research requires ongoing ocean data in time and space, and this has been obtained using mooring systems. However, a conventional mooring system can observe only discrete data in perpendicular space, and moreover, construction of such a system requires manpower and great expense. To solve this problem, we propose a virtual mooring system using an underwater vehicle. The vehicle that houses various pieces of observation equipment glides back and forth between the sea surface and the seabed collecting ocean data. This paper presents the developed vehicle and its field experiment.

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In this paper, we describe a basic underwater sound source localization system designed for mounting in underwater robots aimed at a robust localization against noises. The developed system uses four hydrophones and a pinger. Time delays of each hydrophone is detected and obtained by micro controller. Sound source positions are calculated by the time delays and baseline length. Then, particle filter is calculated by external PC for developing a robust sound source localization system. Estimation of three dimensional positions are simulated by particle filter. According to the simulation results, estimation errors of a sound source position are within 0.21[m] even sensors have envisaged interference-noises following gaussian noise σ_0^2=0.005625.

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Multi-link mobile robots can move several environments. Especially, amphibious multi-link robot can move on surface of water and ground. In previous work, we developed an amphibious multi-link mobile robot (AMMR). AMMR's motion patterns depend on parameters such as amplitude and frequency of target joint angles and phase difference between each joint angle. However, travel velocity, energy efficiency and behavior of robot are different on environments even if parameters are same. In this research, experimental analysis of dynamics property of an amphibious multi-link mobile robot is carried out. As target joint angles, sinusoidal waves are used and behavior, travel velocity and energy efficiency are compared between on surface of water and ground adjusting amplitude, frequency and phase difference.

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This paper describes a research of fish type underwater robot for oceanic observation. Recently, biotechnology mechanism application research has been paid much attention in the world, for instance the development of fishes' high swim performances for the robotic development in an underwater field. Most organisms obtain propulsion with the vibration of the fin. Moreover, in the underwater robot, low fluid resistance body is one of the important problems to obtain kinematic performances. In the research, the authors developed a propulsion actuator with the vibration of the fin, and establish a theoretical design method with numerical calculation of low fluid resistance body of the underwater robot. As results of underwater experiments, the fish type underwater robot is found to be applicable to oceanic observation.

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In this paper, we propose the design method of a high gain adaptive feedback controller to uncertain non-holonomic systems with unknown constant inertia parameters. The controller has high robustness for unknown dynamics and bounded disturbances, since it is designed based on high gain feedback. The application of it to a non-holonomic wheeled mobile robot is described in the numerical simulation.

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In the case when wheeled mobile robots run fast on rough surface, due to the body acceleration and oscillation, the sensors mounted on the robot body may be destroyed. In this paper, we propose a combined ideal robot model is designed. In the combined ideal robot model, the location where the acceleration performance becomes best can be moved easily by setting only two design parameters. Next, a robust model tracking controller is developed so that the behavior of an actual mobile robot tracks that of the combined ideal robot model. It is ascertained by numerical simulations that the body acceleration at any specified location can be improved easily and good robustness for uncertainties of robot mass, pitch and roll moment of inertia of robot body, and the position of the center of gravity is confirmed.

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This paper considers an adaptive H_∞ control method for decoupling model of parallel linear sliders. The decoupling model that divide the dynamic model of the parallel linear sliders into translatory movement and rotary movement is proposed. Based on this model, an adaptive H_∞ control strategy is also given. The proposed method ensures that the unknown parameters are estimated, besides, an approximated errors of external disturbances are attenuated by means of H_∞ control performance. In spite of considering the nonlinear adaptive H_∞ control problems, the compensator can design without solving the Hamilton-Jacobi-Isaacs equation. Simulation results are given to illustrate the effectiveness of our proposed method.

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This paper proposes a design scheme of self-tuning generalized minimum variance control (GMVC) having a new design parameter. The design parameter is introduced by applying coprime factorization approach and Youla-Kucera parameterization of stabilizing compensators to a generalized minimum variance controller. And it is selected by using a genetic algorithm so that the controller is designed to be stable. Therefore the proposed method gives a strongly stable system, that is, not only the closed-loop system is stable, but also the controller itself is stable.

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In this paper, a Perceptual Motor Control Model(PMCM) based on output feedback adaptive control theory is considered from the viewpoint of voluntary movement such as hand-tracking control. We give an account of the PMCM structure using together with both of the output feedback controller designed by using an almost strict positive real characteristics for the controlled plant and the Smith predictor for plant with pure time delay. hi the proposed method, the attractive structural similarity exists between the cerebrum-cerebellum neuro-motor signal feedback loop and the adaptive controller - compensators local minor feedback loop. The proposed perceptual motor control model is evaluated through the comparison of between the experiment and the simulation for handling 1-link mechanism in order to track an indicator.

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On active noise control in 3-dimensional acoustic field, a control effect becomes worse when an evaluation point moves. Against this problem, we proposed control with filter map. Effectiveness of this algorithm was shown by simulations and experiments. While, this method needs many memories for accumulating FIR filters. In this paper, a method that regards a FIR filter as several modal parameters is proposed for reducing required memories. Results of numerical simulations show effectiveness of control is reduced 3dB but required memories is reduced 80%. An adaptive algorithm is also proposed. The algorithm adapts the residues. Enough effectiveness is shown by numerical simulations.

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This paper presents a new-structure rotating gyros using magnetic suspension. A rotating gyro based on an active magnetic bearing (AMB-based gyro) was proposed. However, the miniaturization of the AMB-based gyro is technically difficult because of the limitations on its design and structures. A new structure has been proposed to solve the problem. A prototype of the new gyro has been designed and fabricated. In this paper, the performance of the magnetic suspension of the prototype is evaluated from a viewpoint of frequency response. In addition, angular velocity measurement using the prototype is curried out. The accuracy of measurement is reported.

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This paper describes a new zero power control strategy for a hanging type maglev system. In this maglev device, a permanent magnet generates the levitation force, and a Voice Coil Motor (VCM) maintains the device stably in an equilibrium- levitated position. In order to realize zero power control, a spring is installed in the maglev device so as to counterbalance the force of the actuator on the mass gravitation, and a current integral feedback loop is used in the controller so as to adjust the actuator current zero in the balance state. A prototype of the maglev system was constructed; a theoretical model was developed; a zero power controller was designed and constructed; and numerical simulations and experiments were performed. The results shown here suggest that this zero power control strategy is feasible and effective for the hanging type maglev system using a permanent magnet and VCM.

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This paper proposes an input modification method in model predictive control by using augmented plant. Generally, optimal control generates a discontinuous input. From a practical point of view, it is difficult for an actuator to generate discontinuous input. Augmented plant is configured using an integrator that integrates a control input, in order to generate a continuous input. This method is applied to control an electromechanical valve. The effectiveness of the proposed method is shown by computer simulation result.

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A control method of adjusting the stiffness of suspension was proposed for magnetic suspension systems whose bias flux is provided by permanent magnets. In such magnetic suspension systems, zero-power control has often been applied. Since the zero-power magnetic suspension system behaves as if it has negative stiffness. So that it is applied to vibration isolation system. However, the amplitude of negative stiffness cannot be adjusted. In this paper, a proportional feedback is incorporated into the minor current feedback loop of the zero-power controller. It is shown that the stiffness can be adjusted by the gain of the added current feedback. This system improves static load performance for magnetic suspension system. The principle and experiment results are presented. When a gap changes in this system, the stiffness also changes. Therefore a nonlinear compensation is included in this system to improve the linearity.

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We designed controller of a two-dimensional large shaking table to reproduce of earthquake records in the seven range of the seismic intensity scale. But when a shaking-table of an earthquake simulator is driven for the seismic experiment of a specimen, its motion is affected by a reaction force caused by the specimen on the table. This paper presents a reaction force compensation methodology for shaking tables in earthquake simulators. This methodology is designed by using the RFC (Reaction Force Compensation) based on the disturbance observer method in real time. RFC observes the reaction force and compensates the observed reaction force by using a phase lead compensator. The effectiveness of the proposed technique is verified by using a two-dimensional large shaking table.

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In general, in analysing the stability of a control system, most of that calculate with a mathematical model of the actual plant. However, to simplify the calculation afterwards, an actual plant with a complex characteristic is omitted by the making process to the mathematical model. Therefore, there is, in no small way, the wrong evaluation that the unstable system as stable with modeling error. On the other hand, Nyquist criterion is useful technique to identify stability of the control system by experimentation, certainly. But in many cases, in the actual operation, there is only chance to experiment several times to identify the plant. To secure safety, the controller that applies to a actual plant sacrifices the control performance, by above reasons. In this study, the technique that calculate open ioop characteristic of any controller using the element of experimental data of the plant to evaluate its stability was proposed. Finally, the usefulness of that technique was shown with application examples.

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Recently, stacker cranes are often used for carrying large industrial parts such as liquid crystal panels. The stacker crane consists of 3 parts, that is, trucking device, lifting device, and forking device. The trucking device carries the object horizontally to the target position, then the lifting device lifts it up vertically to the correct height. Finally, the forking device bring it on the final position by expanding the device. In this process, the forking device frequently generates undesirable vibration. Therefore it is required to control this vibration rapidly. In this system, natural frequencies of the forking device change with the fork length and the object weight (LPV system), and this makes control problem more difficult. In this paper, we propose new strategy to control the vibration by utilizing the lifting device's motion. In order to show the proposed method, we use a linear table and a flexible specimen as a dynamically equivalent model of the crane system. First, dynamics of the experimental equipment is identified, then the controller is designed by Dual Model Matching (DMM). Effectiveness of the DMM control method is verified through simulations and experiments.

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The detached house designed by old design index that was damaged at Hyogo-ken Nanbu earthquake is over 47% in total detached houses in Japan. The upgrading for seismic safety such detached houses is urgent duties because a possibility of occurrence of huge earthquake is expected in a high probability. This study tries to apply urethane material not only to seismic safety element but also to energy absorbing element for detached house as a vibration reduction material at the same time. A linearity of basic mechanical characteristics of urethane rubber is generally much stronger than viscoelastic material such as a natural rubber. Moreover, it is possible to arrange a proper mechanical characteristics that is satisfied the design demand to fit each application cases. The application of urethane material to a detached house contributes to expand the techniques for seismic safety of structures that is a social imperative duties, and also to realize ultra long life of detached house in Japan. As the result, it is confirmed that the test specimen using urethane rubber indicates high linearity in mechanical characteristics and deformation performance by loading tests in condition with the test parameters of shaking frequency and amplitude

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Tri-axial shake table tests on the piping system with wall thinning were conducted to obtain the effect of wall thinning on vibration characteristics and failure modes of piping system. The excitation test reached the fatigue failure of the elbow applied in the piping system but the failure could not cause under the excitation level beyond the limit of the piping design criteria. The test results suggest that the seismic design criterion for piping system has too much margin.

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In order to verify the seismic performance of medical facilities including its function maintenance, E-defense shaking tests with a full-scale four-story reinforced concrete model assuming a hospital were conducted. Two types of building were prepared: a seismic isolation structure and a seismic resistant structure. Both of the structures were input short period earthquake and long period earthquake, and then the seismic performance was compared. In general, the wave form reproducibility on the shaking table is import in the comparative excitation test. In this report, the results of considering of the relation between the excitation control methods and the structural characteristics and the wave form reproducibility are described.

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This paper presents an analytical and experimental study for increasing structural damping by installing high damping alloy in steel structures. In the experiment, free vibration tests using experimental plate models composed of stainless steel plate and Mn-Cu alloy plate are performed to investigate natural frequencies and damping properties of the plate models. In the analysis, vibration analyses using FEM plate models are carried out to investigate the effects of the shape, the setting size and the setting position of Mn-Cu alloy plate in the stainless plate on natural frequencies, damping properties and mode strain distributions of the plate models. Further, the validity of the analytical method for evaluating the structural damping of the steel structure including Mn-Cu alloy is examined by comparison of experimental results with analytical results. From these results, it is clarified that the structural damping can be improved by installing Mn-Cu alloy with an appropriate shape and size in the steel structure.

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Long period seismic waves having predominant period of from a few seconds to a few ten seconds have recently been observed in various earthquakes. Therefore extension of natural period of isolated structure is being required so as to avoid resonance with long period seismic wave. This paper proposes a new type isolation system having no natural period. The isolation system consists of air bearings as isolation devices, and an Early Earthquake Warning (EEW) system as a trigger of isolation. Air bearing is a bearing that can reduce contact friction between floor and the bearing by thin air film produced by compressed air. This paper describes a concept and components of the isolation system, properties of the air bearing, and results of vibration experiment. Finally good performance of isolation is confirmed.

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This paper presents a response evaluator which evaluates the response of the system and decides the control input to the system. The characteristics of the response evaluator is designed with the source region and ground motion of earthquake. It is applied to a base isolated structure with a semi-active oil damper whose damping coefficient has large or small values. The response evaluator is designed by the multi-layered neural network which consists of the building responses and the peak ground velocity as input data and switching signal for damping coefficient as output data. Some earthquake records are divided into 8 regions by the epicenter, and the representative record of each region is normalized to 3 levels of its peak velocity which is 25, 50 and 75 cm/s. The 8 response evaluators are designed for each earthquake region and the computer simulations are carried out. Absolute acceleration and relative displacement of each story are reduced when the response evaluator corresponding to the designed region is used, but the control performance is not so good used by the most of response evaluators designed at the other region. When the response evaluator is selected corresponding to the designed region and the appropriate criterion function is set, good control effect is obtained to the wide range of amplitude of earthquake.

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This study examines to design a lane keeping controller for motorcycles and to evaluate it by using a multibody-dynamics model and a rider control model. By examining simulation with a rider-in-the-loop system consisting of the motorcycle, the lane keeping controller, and the rider control model, the lane keeping controller improves the lane keeping performance without interference between the control input and the rider's input. The steer-by-wire system also improves the lane keeping performance in comparison with the conventional motorcycles and cooperates with the lane keeping controller.

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The development of a clean and the fuel efficient diesel engine control method is required for the purpose of global environmental protection. However, in the EGR control of turbo-charged engines, the system has nonlinear characteristics, and there is mutual interference between the EGR valve and the VNT guide vane. We propose a cooperative control method to support the nonlinearity of the diesel engine. In this paper, a method for model identification and ILQ (Inverse Linear Quadratic) design is introduced. As the result of using this method, which can be systemized from model identification to the mapping of the controller gain, high environmental performance and efficiency are achieved.

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In this paper, the dynamically stabilized human-powered vehicle is examined as a Personal Mobility Vehicle (PMV). The basic mechanism of this vehicle consists of the system of the stabilization control for an inverted pendulum and the pedaling torque by a human. We made the prototype vehicle and the experiments on the human riding were carried out. We confirmed the successful cases of the ride. The results showed that the vehicle moved forward by human pedaling, at the same time, the stabilization control was successfully performed.

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In general, when sudden turbulence like a crosswind acts on the direction of the roll, the behavior of the motorcycle becomes unstable. As a result, the rider's load to stabilize the behavior of the motorcycle is grown. In this research, we aim at the construction of the steer cooperation type front wheel steer control system to reduce the rider's steer load by stabilizing behavior of motorcycle when turbulence in direction of roll acts when low speed driving.

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To solve various traffic issues existing in urban terminal, the high energy-saving new public transportation system called the Eco-Ride has been developed. The Eco-Ride merits are low initial cost and high flexibility to install. The Eco-Ride vehicle that does not have on-board driving devices runs using potential energy. The priority part of the Eco-Ride development is to develop light-weight, safety and durability vehicles. In the design phase, the vehicle structure was examined by using the FEM analysis. The stress measurement tests of the prototype vehicles were executed, and the safety of the vehicle was verified. The test track of about 100 m in total length was constructed. Various experiments that include speed measurement and acceleration measurement were conducted. As a results of experiments, the issues to improve the Eco-Ride were able to be clarified.

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The acceleration measurement of the high energy-saving new public transportation system called the Eco-Ride was conducted on the test track. Then analyses of vibration and ride comfort on the Eco-Ride were performed through results of acceleration measurement. Especially, since a suitable method of evaluation of ride comfort on the Eco-Ride has not clarified yet, ride comfort was evaluated by the major method on a railway system this time. As a result, it seemed that ride comfort was almost good on all directions of longitudinal, lateral and vertical. These results are described in this paper.

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To realize stable operation of micro grid, it is necessary for gas engines to compensate the load changes due to demand variation as well as the power provided by other renewable energy device. It is important to grasp the load following capability of gas engines because gas engines can be controlled in response to the demands. In addition, because of the variability of component of biomass gas which depending on the operating condition of gasification or raw material in case of supplying biomass gas to gas engine, dynamic characteristics against the fuel component variation must be investigated. In this study, newly developed dynamic simulation model of turbocharged gas engine is proposed and used to simulate transient operation. The constructed simulation model consists of Discrete Event Turbocharged Model (DETM) and Mean Value Turbocharged Model (MVTM). DETM calculates completely combustion state in gas engines and MVTM calculates the transient response of gas engines in a short time. The comparison calculated result with experiment result indicates the utility of constructed model. As a result, the combination DETM and MVTM can calculate the transient response of turbocharged gas engine sufficiently in a short time.

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FDI(Fault Detection and Isolation) filters are very important scheme for guaranteeing safety and reliability of realistic active control systems. FDI filters based on the sliding mode observer proposed by Edwards provide desirable performances for detection of faults. This method can effectively estimate the size and the shape of faults. However, this method cannot estimate all faults in spacecraft systems because the systems involve poles at the origin. This paper proposes a method of estimation of faults using virtual sensor outputs to avoid the pole problem. The proposed method provides desirable fault estimation results for a spacecraft system.

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Matlab and Mathematica are famous as useful software tools for the design of control system. But these software tools are very expensive for the under-graduate students learning control engineering. Therefore, some design tool that is able to use without circumstance is needed. Excel VBA is a very convenient software language that is available for all personal computer installed OFFICE. We are now constructing a control system design software tool for all of the students who have OFFICE.

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This paper proposes a human power assist system that attenuates load force for stand-up, sit-down and walk operation. The proposed assist equipment can be manipulated of thighed mechanomyogram: MMG and waist angles. Human motional intention is also presumed by usign neural network inputted MMGs and angles. It is confirmed that power assist equipment can operate according to the result of presumption for a certain human motion.

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We developed biological signal sensing system of a driver based on the vibration input through air pack sensor to detect drowsiness of the vehicle driver. To realize this system, a sensor seat capable of measuring pulse wave and detecting autonomous nerve activity change is developed. To show the effectiveness of the proposed system, we compared chronological average frequency pattern of pulse wave obtained from both finger plethysmogram and the air pack sensor pulse wave and investigated the possibility of sleep prediction detection and sleep point detection.

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Systems capable of monitoring the biological condition of a driver and issuing warnings during instances of drowsiness have recently been studied. Moreover, many researchers have reported that biosignals, such as brain waves, pulsation waves, and heart beat are different between people who have and have not consumed alcohol. Currently, we are developing a noninvasive system to detect individuals driving under the influence of alcohol by measuring biosignals. In this paper, a new algorithm to distinguish between the normal and intoxicated state of a person is proposed as the basic theory of the sensing system.

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Bedding that suits the person to obtain good quality sleep is requested to be used. However, it is extremely difficult to judge whether it is a mattress that suits the person in a short time when choosing in the showroom etc. In this report, with four kinds of mattresses with different spring arrangement density, the adaptability of the mattress was evaluated by analyzing changing the biosignal of 90 seconds. And, the physiological index was developed that easily evaluates the characteristic of the mattress.

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Delicious taste of puffer meat has been determined by texture and its degree of freshness in Japan. If more exact estimation method of delicious taste is desired, the method associated with nondestructive method is most suitable. The texture of puffer meats is defmed as its stiffness associated with mechanical dynamics. This paper experimentally proposes new estimation method on texture of raw puffer meat. Proposed method has been exercised by the measurement about frequency response function based on added vibration to puffer meat. This estimation method is characterized by nondestructive, quantitative, speedy and concise procedure. In this research, determination parameter on texture of puffer meat has been composed by applied non dimensional parameters called area ratio which is obtained from frequency response function of raw puffer meat.

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To judge a difference and sleep depth of the quality in the sleep state and relations of the quality of the sleep, we developed biological signal sensing system of the person who sleeps based on the vibration input through unconstraint air pack sensor to detect sleep state. In this study, we collected a biological signal with an unconstraint sensor and inspected whether judging quality of the sleep by measuring the state of a sleeping person.

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This paper is concerned with a control design methodology for vibration control of flexible structures by the wave control. In the wave control, controllers are usually designed to minimize the reflection coefficient by utilizing the wave analysis. However, because the method is based on the wave analysis, the method has been mainly applied to simple uniform structures. In this paper, to establish a control design method for more complex systems, we propose a control design method base on the impedance matching index, which represents the difference of the transfer functions of the closed system and the controller. The index is selected from an observation of the facts for the wave analysis and control for uniformly varying ladder networks. Optimal tuning of passive dampers and dynamic absorbers by the impedance matching index is especially considered as a first step for control design. Numerical example of vibration control of a damped mass-spring system with auxiliary masses is conducted to show effectiveness of the proposed method.

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At present, many of cranes are used in order to carry a load at harbor facilities and a factory, etc. Anti-sway methods are required for those cranes, because the sway of a load occur when the crane accelerate and decelerate rapidly. So, various control methods such as Fuzzy control and optimum control and H control are reported, but almost applied for the cranes with simple pendulum. Therefore, we will propose to control the position and the sway for one with double pendulum, and mention that we use the wireless inclination sensor as an applicable sensor

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The basic motions of the slewing crane as construction machines are classified into cargo windup, boom derricking and boom slewing. The purposes of controlling the crane are to transfer to the target point the cargo as quickly as possible with suppressing the swaying and to quickly minimize the residual sway at the target point. At present, crane operation depends on the skill and sense of the operator, so its automatic operation is desirable from the standpoint of economy and safety. Methods based on an optimum reference pattern of suppressing the swaying and the feedback control system using a linear approximation around and the method based on which is proposed by authors are known until now. However, these methods are not effective for disturbance such as wind, and the stability is not shown in the proposed method. So, we have developed a method using the backstepping approach and have got remarkable effects.

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For micro drilling, it has been said that application of ultrasonic vibration can help the precision and efficiency of it. Many types of ultrasonically assisted drilling have been researched and developed. In the developments, piezoelectric ultrasonic transducers are installed in spindles. Therefore, they need mechanism like slip rings to provide driving electric energy to the transducers. On the other hand, the spindle is needed to turn at high speed. Contact elements, such as the slip ring, avoids the high speed operation. To solve the problem, we propose non-contact vibration transmission through air gap. The transmitted vibration direction can be converted by a vibration direction converter. This paper describes the development of the converter and vibration transmission through the air gap. Experimental results to evaluate the feasibility of our method is also reported.

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In order to apply active magnetic bearings to new industrial application such as heating roller, we propose a novel active magnetic bearing which can support a heavy load with a compact body. In the previous paper, we reported structure of the new magnetic bearing and availability of it showing results of experiments using a small testing machine. Now, we made a practical sized testing machine based on the results of the previous report. In this paper, we show the structure of the new testing machine and the result of levitating test using it.

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The controllability of parallel multiple magnetic suspension systems is discussed based on their basic analytical models. The multiple magnetic suspension systems are classified according to power amplifier and coil connection. This paper focuses on the voltage-controlled multiple suspension system with parallel connected coils. The conditions are clarified under which the system becomes controllable.

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This paper describes a magnetic suspension system using a rotary motor and a disk magnet. In this suspension system, the suspension force to the suspended object is provided by a disk-type permanent magnet and controlled by a magnetic resistance control device, which controls the angle of disk magnet to change the flux flowing through the suspended object. This suspension system can generate a zero attractive force, change the polarity of the stator poles, and realize zero power control for any suspension poison. In this paper, the suspension principle of this suspension system is introduced, the model and simulation are carned out, and some suspension experiments are executed.

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A fuel injection system for marine engine is studied in this paper. A hydraulic pump is driven by an electric motor and a cylinder motion is controlled by the pump flow rate. The cylinder piston pushes a plunger pump and fuel is pressured. The fuel injection system is controlled by the electric signal. This paper, simulation study is carried out using a model of the DDVC system. Simulated results are compared with experimental results. It has been shown that the simulation model good enough to predict the dynamic characteristics of the DDVC system.

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This paper describes modeling techniques of pipeline dynamics using an optimized finite-element model. The optimized finite-element model is used to predict transient flow in a pipeline considering pressure losses due to friction. By the fmite-element method, basic equations of pipeline dynamics are approximated to be a set of ordinary differential equations which can be represented in state-space equations. In this paper, modeling techniques of a straight pipeline is studied using the optimized fmite-element models in series.

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