“Virtual” means, “existing in essence or effect though not in actual fact or form.” In order to give the essential effect of the real environment to humans, a realistic display of tactile sensation is inevitable, especially in case of the interactive environment. Recent advances in tactile displays of both proprioception and cutaneous senastion are reviewed and future trends are prospected.

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In this paper, a characteristic of human tactile sense and somatosensory were explained. As a tactile sensor, texture sensing methods which will be important in VR technology near future were described. And present state of the haptics display was explained.

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Topics on tactile sensation of humans are described from the mechanical, analogical and illusional points of view. First, tactile sensation of human finger is described from a physiological and mechanical point of view. It is shown that there are four types of mechanoreceptors and they share frequency band of stimulus. It is also shown that three mechanical non-linearity of skin are important for transforming stimulus at the surface of the skin to the mechanoreceptors. They are non-linearity due to material property, large deformation and contact. Next, analogy and sensor fusion among tactile, visual and auditory sensation are focused on in relation to an illusion. It is shown that tactile sense is detected by transforming space information to vibration information whereas visual sense detects space information directly. Analogy of different sensation is also discussed including stroboscopic motion, phantom sensation and masking. At last, sensor fusion among different sensation is described.

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We have developed a new type of tactile display using electrostatic linear actuator. This device is a kind of force feedback system. The electrostatic linear actuator consists of a thin film slider and a stator, and works as direct drive. Therefore, this device can display fine textures, and a user can operate this device naturally. Since the position sensor is built in the actuator, the construction of this device is very compact and simple. In this paper, first, the construction of the electrostatic actuator and the system of the device using this actuator are described. Secondly, force control algorithm for the actuator to simulate surface bumps is provided. Different kinds of bumps, whose intervals range from 63μm to 1000μm, were successfully displayed using the algorithm. Finally, in comparative experiments, 5 rough surfaces, whose bump intervals range from 70μm to 1055μm, were simulated. Two kinds of discrimination test were done. In the case in which the displayed surface were real surfaces without seeing, the experimental subjects correctly discriminated 78% on the average. In the case in which the displayed surface were simulated surfaces, they correctly perceived 66% on the average.

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The method for monitoring indoor environments using gas sensors has been investigated. Humans and their behaviors generate various gases. Though it is widely known that there is a relation between human behavior and sets of outputs from gas sensors, it is difficult to recognize exact human behavior using only the sets of outputs. Therefore, it would be an efficient means to monitor the indoor environment exactly and search causes of gas generation or the location of gas generation. This paper has presented a method for estimating the location of gas generation using the time delay which arise from each sensor’s response. Besides, this paper has investigated the relation between the number of sensors and the accuracy of the estimation. The applicability of the proposed method has been examined by observing the condition of the dispersion for an unalloyed gas in a controlled environment.

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A new speedometer of vehicle using induction magnetometer has been designed and evaluated, while the wheels of vehicle were magnetized through natural geomagnetic field and by some artificial magnetic field as well. As a magnetized wheel rotated during a movement of a vehicle, periodic magnetic patterns are propagated and then detected by an induction magnetometer or a sensor which is placed nearby the wheel. The high-frequency components, which may cause aliasing, are eliminated using an anti-aliasing filter (Low Pass Filter; cutoff=40Hz). The desired Low-frequency components of the induced electric signals are proceeded and converted into digital data by ADC (Analog to Digital Converter; 10bit) that includes RISC (Reduced Instruction Set Computer). Primary parameters, such as a diameter(r) of a vehicle’s tire and estimated time period T of a rotated tire, should be set to determine the speed of the vehicle from the following equation V=2πr/T. The characteristics of the new speedometer have been evaluated with a conventional speedometer. We expect that our proposed sensor is very proper for speed control or measurement of automatic vehicles for ITS(Intelligent Transport System).

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Demand for various glass-parts is now increasing rapidly as information technology is developed. There are several methods for processing glass-parts, and Precision Glass Molding Method is one of the best processing methods for making precise parts and lowering the price of glass-parts for mass-producing. Recently, quartz glass is studied for new glass-parts materials. But molding of quartz glass is difficult because softening temperature of quartz glass is very high and there is little information about molding of quartz glass. We researched about quartz glass molding and developed Glass Molding Machine for molding quartz glass. This paper describes that how to mold quartz glass, what is important for quartz glass molding, and analyzing of mobility of glass and heat expansion of mold in molding temperature.

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This paper investigates a new process for assembling micro parts by bonding element using magnetic polarity, attraction and taper shape. In the proposed processes, first the parts are positioned and connected tentatively by the magnetic torque and force of bonding elements. The taper shape of the bonding elements is also used for accurate positioning. After being positioned accurately by bonding elements, a hot melt layer of the bonding element is melted by local heating to establish a strong bonding. The positioning error in the tentative connection and the bonding strength of hot melt layer were evaluated. A block assembly equipment was also fabricated. Automatic assembly tests reveal the validity of this new assembly method.

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