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Experiments were carried out using space charge distribution measurements as a major measurement method in order to find effective measures to suppress electrochemical migration (ECM) along the thickness direction of a printed wiring board (PWB). As a result, the following valuable knowledge was obtained. First, in a PWB consisting of paper/ phenol-resin composite and a copper electrode, the electrical...
We have been developing an electromagnetic field intensity measurement system using an absorption screen made of dielectric material. In this developed system, a very small change of temperature on an absorption screen illuminated by the electromagnetic wave is measured using an infrared camera with 2-D lock-in processing technique. An antenna is ordinary used for measurement of electromagnetic field...
We have developed a tactile sensor for tactile tele-presentation systems by focusing on four features of the human finger considered to play an important role in texture perception; the existence of nails and bone, the multilayer structure of soft tissue, the distribution of mechanoreceptors, and the deployment of epidermal ridges. As a result, the developed sensor could detect roughness, softness...
Pulsed electroacoustic (PEA) method was applied as a nondestructive method to detect electrochemical migration in a sheet of epoxy resin and a sheet of laminate consisting of the same resin and a paper/phenol-resin composite. A significant decrease in the amount of negative charge was observed at the interface between the resin and the composite when the sample was the laminate. This is assumed to...
Under DC voltage stress, a negative hetero-charge is generated near the positive electrode in cables insulated with cross-linked polyethylene (XLPE). The generation of negative hetero-charges in XLPE-insulated cable results from cross-linking byproducts, antioxidants, and moisture. Among these inclusions, moisture is known to originate from dehydration of a-methyl styrene, which is a byproduct produced...
In this study, a tactile-roughness transmission system applicable to master-slave systems with a communication time delay is developed. The master-side system constructs a local model of target objects placed in the slave-side environment. Tactile feedbacks presented to an operator at the master side are produced by combining the physical properties of target objects in the local model and the kinetic...
This paper presents a displaying method of button like click feeling using ultrasonic vibration with amplitude of a few micrometers. Artificial click feeling is displayed by recreating rapid change in force arising from buckling of a mechanical push button utilizing squeeze film effect. First, important factors for displaying click feeling were extracted by analyzing the relationship among force-stroke...
Pulsed electroacoustic (PEA) method is applied as a nondestructive technique to detect ion migration that progresses to the thickness direction in insulation composites for printed circuit boards. In both cases of a paper/phenol-resin composite and a glass/epoxy-resin composite, penetration of Cu migration into the bulk after aging was confirmed. Namely, a shift of the peak location of positive charge,...
We have developed a 3-D electromagnetic field measurement system using 2-D lock-in amplifier. In this system, a modulated amplitude of electromagnetic wave is illuminated to an absorption screen to generate a heat distribution. A very small change of temperature on a screen illuminated with the modulated electromagnetic wave is measured using an infrared thermograph camera. To show the usefulness...
Simple grippers with one or two degrees of freedom are commercially available prosthetic hands; these pinch type devices cannot grasp small cylinders and spheres because of their small degree of freedom. This paper presents the design and prototyping of underactuated five-finger prosthetic hand for grasping various objects in daily life. Underactuated mechanism enables the prosthetic hand to move...
This paper presents a hybrid tactile displaying method of realistic texture using ultrasonic vibrator and force display. The aim of this study is to display various realistic tactile senses by controlling multiple factors including roughness, softness and friction sense. First, a tactile displaying system was configured for displaying roughness, softness and friction sense simultaneously by compensating...
A small tactile display that can be attached to a mobile terminal device or a handheld game controller will enhance user experience in virtual worlds. This paper proposes an ultrasonic vibrator which has a compact mechanism to produce vibratory stimulation on human skin using a pin array driven by a single piezoelectric actuator. Amplitude modulations of the ultrasonic vibration can generate tactile...
For electromagnetic (EM) disturbances in vehicle-mounted radios, the main source is known to be conducted noise currents flowing through wiring-harnesses from vehicle-mounted multi-layer printed circuit boards (PCBs). To investigate a design method that can suppress the conducted noise currents, we previously measured noise current outflows from four types of simple three-layer PCBs having two perpendicular...
In this paper, nonlinear dynamic response of a traveling wave type ultrasonic motor is investigated. In particular, understanding the transient dynamics of a bar-type ultrasonic motor, such as starting- up and stopping, is of primary interest. First, the transient response of the bar-type ultrasonic motor at starting-up and stopping was measured using Laser Doppler Velocimeter (LDV), and its driving...
In this paper, nonlinear dynamic response of a traveling wave type ultrasonic motor is investigated. In particular, understanding the transient dynamics of a bar-type ultrasonic motor, such as starting- up and stopping, is of primary interest. First, the transient response of the bar-type ultrasonic motor at starting-up and stopping was measured using Laser Doppler Velocimeter (LDV), and its driving...
Electromagnetic disturbances for vehicle-mounted radios can be caused mainly by conducted noise currents flowing out from vehicle-mounted multi-layer printed circuit boards (PCBs) to wire-harnesses. Using actual electronic equipment for vehicles, we previously showed that combining, not separating, the ground layer patterns of a digital circuit and an analog circuit is more advantageous to reduce...
Tactile telepresence has been expected to be technology which encourages operators of robotic systems to remotely maneuver objects or recognize materials being touched through robotic arms. In remote environments, temporal disparity in tactile sensations is caused by temporal latency between a touch motion of the operator and a tactile stimulus applied on him. A framework of tactile telepresence systems,...
Several types of polymeric materials are used in satellites wings and body. When these dielectrics are submitted to an electronic irradiation, sudden discharge might occur after a period of accumulation. To get a better knowledge on the charging and discharging phenomena in dielectrics, experimental studies are performed on earth. We focused our studies on the effect of the electronic irradiation,...
Charge profiles in LDPE containing both DCP and sulfur-containing antioxidants, which were heat-pressed under different temperatures, were examined to study the heterocharge generation mechanism in polymeric dielectrics. Negative hetero-charges near the positive electrode were detected in samples containing both DCP and the antioxidants when those samples were soaked in acetophenone. The negative...
In our previous paper, we found an interesting packet-like charge behavior in low-density polyethylene (LDPE) under high DC electric field of more than 100 kV/mm. By existence of the injected huge amount of packet-like charge, electric field near cathode electrode was sometimes enhanced up to more than twice of the applied electric field. Therefore, it is thought that the huge packet-like charge must...
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