An atomic force microscope can be used to measure the surface topography of samples at the nano-scale. Because the cantilever maintains physical contact with the sample, it is also possible to measure the elasticity of samples in principle. However, compared with the advances of scanning performance, the technologies for measuring viscosity and elasticity are still underdeveloped. The proposed method measures the surface topography during the forward scan (FWS) and the elasticity during the backward scan (BWS). We also introduce a surface topography observer (STO) and perfect tracking control (PTC) in order to improve the measurement accuracy.
This paper presents a method of tuning the proportional band for an arbitrary settling time without overshoot. The materials and human resources management in a factory can be optimized according to the settling time. A temperature controller is widely used in the manufacture of industrial machinery. In general, a temperature-controlled system has a large time constant and dead time. Getting the output close to a set point at an arbitrary settling time is difficult. The proposed method optimizes the proportional band and PID parameter based on the step response of first order plus dead time by using the settling time. The proposed method can be extended to uniform heating and peak power suppression control. Simulation and experimental results showed that the proposed method is effective for a temperature-controlled system.
This paper describes the influence of the PWM inverter harmonic loss and vibration on the concentrated winding interior permanent magnet synchronous motor (IPMSM) characteristics by using a finite element method (FEM) analysis and several measurements. The PWM inverter harmonic mainly caused an increase of eddy current losses in the magnetic steel sheet and the permanent magnet. In addition, the IPMSM with the two-phase modulation inverter has a higher radial electromagnetic force than the IPMSM with the third-harmonic-injection modulation inverter.
This paper proposes vector control specialized for a switched reluctance motor (SRM) drive. Because it is a unipolar drive, a sinusoidal current with a DC offset is applied to each circuit instead of the conventional trapezoidal current. The current consists of DC and AC components which can be identified by their generation of a (virtual) rotor flux and rotating stator magnetic field, respectively. Thus, the vector control system can be developed in the same way as conventional AC machines. The proposed technique provides new mathematical models of SRMs on a rotating reference frame and achieves precise and fast torque response and advanced operations such as linear torque-current control and maximum torque per ampere control. The vector control theory was verified through simulations and experiments.
In this study, we examined an air-conditioning control system using an infrared communication function that aims to balance energy conservation and the indoor environment. The proposed system consists of several distributed controllers and a single global controller and controls the air-conditioning system to save electric power considering the room comfort. The predicted mean vote (PMV) is a well recognized thermal comfort index in the room, which is calculated by the motion of a body, clothing, temperature, humidity, wind speed, and average radiation temperature. In the proposed system, the set temperature of the air conditioner is determined using the PMV. From the experimental results, it was confirmed that it is possible to suppress the power consumption while maintaining comfort with the proposed system.
Energy-efficient driving from selecting of braking notches based on the characteristics of a regenerative brake is efficient at decreasing the energy consumption over the same running time. For example, a weak brake increases not only the powering energy but also the regenerative energy because it reduces mechanical brake loss. We calculated energy-efficient driving by a running simulation. We verified the proposed energy-efficient driving by performing a verification test. In this paper we report on the analysis results for the verification test on energy-efficient driving based on selecting braking notches with a focus on energy loss. We obtained the running test results under two conditions: the regenerative brake is not limited by non-negligible regenerative loads with other trains and regenerative energy absorbing equipment and the regenerative brake is limited by light regenerative loads with regenerative energy absorbing equipment. We determined the breakdown of energy consumption for each result with a focus on energy loss. Based on the analysis results, we determined the mechanical brake loss that corresponds to the regenerative brake characteristic of energy-efficient driving.
In this paper, we propose a novel motor that has a high winding factor and a high slot fill factor. A motor with concentrated windings has a high slot fill factor, but a low winding factor. On the other hand, a motor with distributed windings has a high winding factor, but a low slot fill factor. To incorporate the advantages offered by both the aforementioned types of motors, our proposed motor includes a new distributed winding stator, which can be flat band-shaped without dividing the windings, and can be easily wound.
This paper describes a synchronous motor in which space harmonic power is utilized for field magnetization instead of permanent magnets. The stator has a concentrated winding structure, and the rotor has two different types of windings, i.e., an induction pole (I-pole) winding that primarily retrieves the second space harmonic, and an excitation pole (E-pole) winding for field magnetization. The two coils are connected via a center-tapped full-bridge diode rectifying circuit. The optimum placement of the I-pole on the rotor is mathematically discussed and is analytically determined through FEM-based computer simulations. In addition, it is clarified that the E-pole torque increases owing to the effect of auxiliary poles. Further, the advantages of auxiliary poles are studied, using the torque ripple characteristics.
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