An axle weighing system is equipment that measures each axle weight of an in-motion vehicle. Signal processing methods by designing a FIR filter for weight signals from the system have been studied to improve the accuracy of measured axle weights. A plan for determining the order of the filter and a reduced-order filter are newly proposed for preventing miscalculation of axle weights using the methods. The availability of the method adapting the new considerations are discussed and confirmed based on results obtained by processing actual weight signals.

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Examination of the safety about dynamic force has been investigated in many fields. However, the design method of the structure subjected to dynamic force is not yet established. Relationship between the dynamic load and the static load was examined through dynamic load test based on the deflection of beam. The experimental results indicated that the dynamic load generating the identical deflection is several score times of the static load. In addition, it was revealed the deflection of beam was proportional to not the magnitude of dynamic load but its impulse of the dynamic load.

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Recently, robot research that coexists with people and is helpful for them is active. To perform high manipulation as human by robot hand, it is necessary for us to obtain distributional information of tri-axial force acting on finger-tip. In a past study, we suggested original structure of tri-axial force sensor which can be mounted on robot finger-tip plurally. In this article, we suggest an optimization method of the structure of that sensor, and inspect the effectiveness of proposed method by simulation.

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The calibration for the traceability of acceleration has long been based on the measurement using one-axis accelerometer, the one-axis vibration table and the laser interferometer. However there has been no description on multi-axis accelerometers in conventional techniques. On the other hand, the application of multi-axis MEMS accelerometers and gyros has become remarkable these days. This paper discusses the mathematical derivation of the matrix sensitivity very precisely. Three kinds of acceleration vector spaces are introduced. The relationship between the number of axis of the accelerometer and the dimension of the calibration vector space is discussed. New classification of cross sensitivity is introduced. The concept of the matrix sensitivity is expanded and each component of the sensitivity matrix stands for a transfer function when the shock acceleration is applied. The simple numerical example shows how large the influence of cross sensitivity is in the multi-axis accelerometers. New classification of accelerometers is proposed in terms of the sensitivity.

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In general, reliable measurement competences of sound and vibration are needed in development and quality assurance for product. Especially in industrial field, such as automotive and aero-space industry, high performance measuring platform and efficient calibration procedure for keeping good measurement are strongly requested, in which is not allowing to have down time due to failure of measuring instruments. So, this article describe following technologies: transducer electronic data sheet (TEDS), extremely wide dynamic range (Dyn-X), response equalization of transducer (REq-X), charge injected calibration (CIC), and vibration transducer calibration system based on improved FFT method (calibration by substitution).

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The MCF conductive rubber, combining the MCF in a silicon-oil rubber, has been developed with Shimada laboratory a few years ago. Recently, by means of the MCF electric conductive rubber, we are developing a haptic sensor for the applications to a robotic finger, artificial skin, and so on. For the purpose of the applications, it is important to understand dynamic characteristics of the MCF electric conductive rubber. In this paper, at first, we made two type experiments to observe the MCF conductive rubber's static conductivity and dynamic conductivity. The experiment results showed when the MCF conductive rubber is pressured it will change from an insulator to a good conductor and in same time if it is pulled too, the sensitivity of this haptic sensor improves

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In an engine development, several types of pressure sensors are applied for indication of the cylinder pressure and the manifold pressure. The authors have developed a new synthetic measurement system of pressure with piezo-type and diffused type sensors. In the very high temperature field at the exhaust pipe, the precise and high response pressure waves have been indicated with the new synthetic system.

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In resent years, higher combustion efficiency and lower emissions are required in engine development and therefore higher combustion control is necessary. To realize higher combustion control in reciprocating engine, cycle to cycle flow rate measurement is important. Especially it is a key factor to control HCCI combustion. Traditional laminar flow meter has a problem with response. However, fast response differential pressure transducer allows cycle to cycle dynamical flow measurement. The availability of Fast-response Laminar Flow Meter on cycle-to-cycle flow rate measurement is shown in this paper.

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Exhaust Gas Recirculation (EGR) is useful technology for purification of the exhaust gas and for better fuel efficiency in gasoline and diesel engines. Recently, many car makers have improved engine performance through positive EGR control. It is now vital to understand dynamic EGR with internal combustion engines running for better combustion control and for gas exchange analysis. We produced a fast response EGR flow meter experimentally to as approach of EGR system. In this report, dynamic flow rate at each cycle of EGR in single cylinder HCCI engine was measured and evaluated.

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Where a positive displacement meter is used to measure a fluid at very low flow rate, discharge volume per rotor revolution should be reduced. Volume reduction is achieved by downsizing the rotors in a homothetic way or by reducing the thickness of the rotors themselves while keeping the teeth profile as they are. Decided to be employed, in the course of engineering development of peripheral devices for fuel batteries for household use, was flow meters for modified water, whose thickness of rotors are reduced.

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In fuel injection measurement, Ideal-State is a state that quantity of flow in pipe will become ZERO flow just before fuel injection. It is necessary a continuous balance control between reduced and intensified pressure. It is achieved by volume up of intensifier and low speed feed control of piston. Fuel supply equipment is consists of hydraulic servo system controlled adaptive robust controller. It is adapted with oil hammer disturbance and parameter change at piston position. The test results are satisfactory as shown in this paper.

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A magnet supported by a high-Tc superconductor levitates stably without control. However, magnetically-levitated rotor supported by a high-Tc superconducting bulk shows complex dynamical behaviors because of nonlinearity of the magnetic force. One of the phenomena is internal resonance. In this study, we used magnetically-levitated rotator supported by a high-Tc superconducting bulk using D.C. motor as driving source to study behavior of internal resonance by experiments and numerical analysis. We investigated effects of rate of increasing the voltage applied to D.C. Motor on passing through resonance of a rotor with and without internal resonance.

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This research investigates nonlinear dynamics of a beam supported at both its ends by High-T_c superconducting bearings. High-T_c levitation systems have very small damping and keep stable levitation without control. But this system can show complicated phenomena of dynamics caused by nonlinearity in their electromagnetic force. We focus on the combination resonance of plural eigenmodes of vibration under vertical excitation of superconducting bulks. This nonlinear oscillation of the beam have been theoretically explained by applying the method of multiple scales directly to partial differential equations. Furthermore, these analytical predictions have been confirmed by experiments.

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In micro-processing fields such as semiconductor manufacturing and precise measuring, vibration isolation system is an extremely important configuration element. The purpose of this study, by using the layout effect of a magnetic material piece on the passive magnetic levitated bulk HTS sample, is to finding out the performance of variable magnetic stiffness for adaptable to "vibration from ground" and "variation of payload". In this paper, we describe the preliminary experimental result of the magnetic stiffness acting on a bulk HTS sample putting on a ferromagnetic material piece on Halbach permanent magnet array.

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In this research, it proposes the development of High-Tc Superconducting Levitation flywheel. The permanent magnet magnetized in the thickness direction where the sectorial magnetic material plate is adsorbed creates the multipole field outside of the magnet. The levitation body achieved the stable rotation without the control by giving the driving force from the axial direction to the multipole field of the levitation body, and thus it succeeded in riding past the resonance. And, the voltage correction that considered the counter-electromotive force and impedance was executed so that this system might obtain the stable torque. As a result of measurement of electric power generation at the high-speed rotation region, it was confirmed that this system had about 84% conversion efficiencies. The result of the experiment and the theoretical value of the magnetic flux density, the torque, the frequency response, and the conversion efficiency of this system were compared. As a result, because measurements and the analytic value were corresponding well, it was confirmed that this analysis was useful.

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A linear power amplifiers are usually used to drive small or middle class magnetic bearings. Recently power IC has been developed especially for audio applications. Pulse Width Modulated (class D) power amplifier ICs are also developed. Cost effective power amplifiers are also requested for magnetic bearings. In this paper low cost PWM amplifier is tried to develop and to apply to the HB type magnetic bearings.

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This paper introduces a small displacement sensor for active magnetic bearings. A magnetic bearing has merits of low loss supporting capability, maintenance-free drive and so on. However, active magnetic bearings require feedback control for stabilization of the magnetic force, and needs many expensive sensors, amplifiers and control devices. In recent years, the demand of a small high speed-rotating machine is growing, and development of a small and low-cost magnetic bearing is required. In this paper, a small and low-cost displacement sensor suitable for a small magnetic bearing is proposed. The proposed sensor consists of the sensor target made from ferromagnetic material, and four double coils placed around the sensor target. The displacement is measured by the principle of a differential transformer. In this paper, a simple analysis shows that the sensor output is proportional to the displacement. Then it is confirmed by results obtained by simple experiment.

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This paper presents a control system for active magnetic bearings (AMBs) considering motions of the AMB stator. Many control systems for AMBs have been proposed. However, most of the control systems neglect the stator motions because the stator is usually fixed on the base. Recently, AMB-based gyroscopic sensors have been developed. The stator moves with the measured object in such application. In this paper, the effect of the stator motions to the dynamics of the rotor is investigated theoretically and experimentally. In addition, the effect of the stator motions is compensated by estimated signals from a disturbance observer.

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The nonlinear modelling of the magnetic levitation system is performed considering the dynamics of both the electric and magnetic circuits. The linear coefficients of the system are identified explicitly because they are important for the detail design of the control system. Other characteristic including nonlinearity is modelled by using Neural network. In order to perform this method in the actual system, the teaching signal is made by adding the disturbance signal to the control voltage signal. Numerical simulation results show that the linear coefficients of the system are accurately identified.

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This paper presents a method of increasing the load capacity of magnetic suspension system with a PID or zero-power controller. In the magnetic suspension systems, load capacity is determined by coil current and suspension gap. In the PID controlled system, the displacement is kept zero and the coil current increases when load is added to the floater. In the zero-power controlled system, the current is kept zero and the gap decrees. The load capacity is therefore determined by the current limit in the former and the gap limit in the latter. This paper shows that the load capacity can be increased by combining both the controls.

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This paper presents a new modeling method and control system design procedure for a flexible rotor using active magnetic bearings as actuators for vibration control also. The goal is to let the flexible rotor revolve above the second whirling speed. To express the motion and the vibration by using a unified model, the new modeling method named specified for Extended Reduced Order Physical Model is applied. A LQ controller to suppress the vibration of the rotor and a PID controller to levitate the rotor are designed by using the unified model. Control simulation and experimental results are shown.

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This paper describes a zero power control method of a hanging type magnetic suspension system, using a linear actuator to control the permanent magnet attractive force to maintain the levitation device suspending. A spring was installed in the magnetic suspension device to counterbalance the force of the actuator on the mass gravitation, and an integral feedback loop was used in the controller to adjust the actuator current zero in the balance state. According to a theoretical model, numerical simulations and experiments were completed, and some results are shown here.

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Homopolar flywheel is considered to be very efficient and a good candidate for next-generation energy storage device, compared to the conventional (heteropolar) flywheels. By the help of active magnetic bearings, in this paper we are proposing a method to control the attitude of this low-loss flywheel. Many researchs had been established in the past using gain-scheduling control and other methods but these need additional information (that is, the rotation speed of the flywheel) as an input. Without this information, it was difficult to control the flywheel. Here we introduce a new and more robust method using Multi-Input Multi-Output Simple Adaptive Control (MIMO-SAC) with an improved adaptive identification.

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