The smelling screen is a new olfactory display that can generate a localized odor distribution on a two-dimensional display screen. The generated odor distribution is as if an odor source had been placed on the screen, and leads the user to perceive the odor as emanating from a specific region of the screen. The position of this virtual odor source can be shifted to an arbitrary position on the screen. The user can freely move his/her head to sniff at various locations on the screen, and can experience realistic changes in the odor intensity with respect to the sniffing location.

We propose a new olfactory display system that can generate an odor distribution on a two-dimensional display screen. The proposed system has four fans on the four corners of the screen. The airflows that are generated by these fans collide multiple times to create an airflow that is directed towards the user from a certain position on the screen. By introducing odor vapor into the airflows, the odor distribution is as if an odor source had been placed onto the screen. The generated odor distribution leads the user to perceive the odor as emanating from a specific region of the screen. The position of this virtual odor source can be shifted to an arbitrary position on the screen by adjusting the balance of the airflows from the four fans. Most users do not immediately notice the odor presentation mechanism of the proposed olfactory display system because the airflow and perceived odor come from the display screen rather than the fans. The airflow velocity can even be set below the threshold for airflow sensation, such that the odor alone is perceived by the user. We present experimental results that show the airflow field and odor distribution that are generated by the proposed system. We also report sensory test results to show how the generated odor distribution is perceived by the user and the issues that must be considered in odor presentation.

A new olfactory display that can present a virtual odor source at an arbitrary position on a two-dimensional screen is proposed in this paper. The proposed device can give a sensation that an odor is emanating from a certain position on the screen. Fans are placed at the four corners of the screen. The airflows generated by the fans are deflected multiple times by making them collide with each other, and are finally directed toward the user from the position of a virtual odor source on the screen. By introducing odor vapor into the airflows, the odor is spread from the virtual odor source toward the user. The position of the virtual odor source can be shifted to an arbitrary position on the screen by adjusting the balance of the airflows from the four fans. The user can freely move his/her head and sniff at various locations. Potential applications of the proposed device include digital signage, video games, and exhibitions in museums. The result of odor-distribution measurement is presented here to show the validity of the device design.

A new device has been developed for generating airflow field and odor-concentration distribution in a real environment for presenting to the user. This device is called a multi-sensorial field (MSF) display. When two fans are placed facing each other, the airflows generated by them collide with each other and are radially deflected on a plane perpendicular to the original airflow direction. By utilizing the deflected airflow, the MSF display can present the airflow blowing from the front to the user without placing fans in front of the user. The directivity of the airflow deflection can be controlled by placing nozzles on the fans to adjust the cross-sectional shape of the airflow jets coming from the fans. The MSF display can also generate odor-concentration distribution in a real environment by introducing odor vapors into the airflow generated by the fans. The user can freely move his/her head and sniff at various locations in the generated odor distribution. The results of preliminary sensory tests are presented to show the potential of the MSF display.

This article describes the investigations on the effect of airflow on the perception of odors presented by an olfactory display device. A clear sensation of the direction to an odor source can be given to the user of the olfactory display when the air currents are provided to the user's face by using fans. When the air currents are not provided, the user feels as if the source is placed nearby. We hypothesize that this sensation is caused by the upward air currents generated by our body temperature. When there is no wind, only the odors from nearby sources are brought to our noses by the upward air currents. The result of a sensory test shows that the perceived location of an odor source changes with the airflow presented to the panelist. Providing airflow together with odors is thus promising to reproduce complicated situations that cannot be reproduced by olfactory stimulation alone.

This article describes the experiments on an interactive application of an olfactory display system into which computational fluid dynamics (CFD) simulation is incorporated. In the proposed system, the olfactory display is used to add special effects to movies and virtual reality systems by releasing odors relevant to the scenes shown on the computer screen. To provide high-presence olfactory stimuli to the users, a model of the environment shown in the scene is provided to a CFD solver. The airflow field in the environment and the dispersal of odor molecules from their source are then calculated. An odor blender is used to generate the odor with the concentration determined based on the calculated odor distribution. In the experiments, a virtual room was presented on a PC monitor, and the panel were asked to stroll in the room to find an odor source. The results showed the effectiveness of the CFD simulation in reproducing the spatial distribution of the odor in the virtual space.

The results of our current multidisciplinary research efforts on the development of an olfactory display system are demonstrated. To present odors with a vivid sense of reality, we propose to use computational fluid dynamics (CFD) simulation in conjunction with the olfactory display system. In this demonstration, an odor is released with a movie clip using the olfactory display. A CFD solver is employed to calculate the turbulent airflow field in the given environment and diffusion/advection of odor molecules from their source. The olfactory display system generates an odor with the concentration determined by the calculated odor distribution. The user is assumed to be a small animal slowly walking through a virtual room, and experiences the spread of the odor in the room.

An active stereo nose (ASNose) is proposed for localization of gas sources. Dogs actively deform their nostrils when they sniff. The air in front of a dog is drawn to the nose by inhalation, and then, ejected backward. This backward jet further induces air currents flowing from the front of the dog to the nose, which assist in collecting odors. To mimic this mechanism, ASNose is equipped with two diaphragm pumps and two gas sensors. Air is sucked through two pipes, and delivered to the two gas sensors. The exhaust of the pumps is expired backward. Moreover, backflows inevitably generated by the diaphragm pumps make air currents flowing in the direction away from ASNose and work like an air curtain. Experimental results show that the actively generated air currents facilitate the directional determination of a gas source by enhancing the difference between the right and left gas sensor responses.

This paper reports on an underwater wheeled robot developed for locating chemical sources under stagnant flow conditions. To draw the chemical staying in the vicinity of the source, the robot generates water currents by waving the arms that mimic maxillipeds of a crayfish. Depending on the patterns for waving of the arms, various flow fields are generated. Determination of the direction of the chemical source is enabled by collecting water samples from different directions. Active flow generation thus serves for extracting desired information from the surrounding chemical concentration field. The development of SPR (surface plasmon resonance) chemical sensors for the crayfish robot is also described. SPR sensors compact enough to mount on the robot are realized by employing gold nanostructures for SPR excitation. Comparison between the SPR sensors and the electrochemical sensors used in the previous paper is made to show the importance of sample collection on the sensor surfaces.

In this paper we present initial experiments towards environmental monitoring with a mobile platform. A prototype of a pollution monitoring robot was set up which measures the gas distribution using an ldquoelectronic noserdquo and provides three dimensional wind measurements using an ultrasonic anemometer. We describe the design of the robot and the experimental setup used to run trials under varying environmental conditions. We then present the results of the gas distribution mapping. The trials which were carried out in three uncontrolled environments with very different properties: an enclosed indoor area, a part of a long corridor with open ends and a high ceiling, and an outdoor scenario are presented and discussed.

In the weather routing, it is very important to take account of encountered weather and sea states, which are major factors of the function in a weather routing simulation model. To clarify the criteria for the safety navigation of practical navigators quantitatively, the weather routing simulation and the interview were carried out to the navigators. According to the interview, the upper limit of wind force for the navigators is the Gale rank in the Beaufort scale. For the upper limit of the wave height, the navigators had two criteria, 5 to 8 m and 10 to 12 m. From the results of the weather routing simulation, the criteria for wind speed are 40 knots in the following wind case, 30 knots in the side wind case, and 30 to 40 knots in the head wind case. The criteria for the wave height are 5 m in the case of wave from right ahead, 5 to 6 m in the beam wave case, and 7 m in the case of wave from the right astern. Moreover the criteria for the wave height in the head wave case is 7 m, in the side wave case is 8 m, and in the following wave case is 11 m.

In the fields of urban search and rescue (USAR), it is important that crawler-type mobile robots explore occluded areas (collapsed buildings, underground shopping centers, etc.) in preference to rescue workers from the point of view of safety. To map such an occluded environment, it is important for robots to localize their position and pose. In this paper, we propose two three-dimensional localization algorithms for crawler-type mobile robots. The algorithm is based on "three-dimensional scan-matching" using the three-dimensional laser range finder information. Several experiments using our crawler-type mobile robot verifies the validity and limitation of this method in a simulated disaster environment.

This paper presents a new approach to search for a gas/odor source using an autonomous mobile robot. The robot is equipped with a CMOS camera, gas sensors, and airflow sensors. When no gas is present, the robot looks for a salient object in the camera image. The robot approaches any object found in the field of view, and checks it with the gas sensors to see if the object is releasing gas. On the other hand, if the robot detects the presence of gas while wandering around the area, it turns toward the direction of the wind that carries the gas. The robot then looks for any visible object in that direction. These navigation strategies are implemented into the robot under the framework of the behavior-based subsumption architecture. Experimental results on the search for a leaking bottle in an indoor environment are presented to demonstrate the validity of the navigation strategies.

To relieve damages of earthquake disaster, "The Special Project for Earthquake Disaster Mitigation in Urban Areas" have been kicked off in Japan. Our research group is a part of the sub-project "modeling of disaster environment for search and rescue" since 2002. In this project, our group aims to develop a three-dimensional mapping's algorithm that is installed in a mobile robot to search victims in a collapsed building. To realize this mission, it is important to map environment information, and also the mapping requires localization simultaneously. (This is called "SLAM problem".) In this research, we use three-dimensional map by laser range finder, and we also estimate its location in a global map using correlation technique. In this paper, we introduce our localization and mapping method, and we report a result of preparatory experiment for localization.

A three-dimensional odor compass is proposed to develop a navigation tool used in searching for an odor source. The compass, which continuously points to the source, is equipped with four semiconductor gas sensors and a small fan to draw air to the sensors. The direction of the source is obtained by rotating the compass head to obtain the direction where the responses of the sensors along the horizontal and vertical directions are balanced. The following algorithmic improvements have been made to reduce the measurement time after the previous report on the two-dimensional compass. First, the transient sensor response model is introduced to compensate the response delay of the gas sensors. Secondly, the head of the compass is made to rotate continuously and three-dimensionally during the directional estimation to gather plenty of data over a short time period. As a result, the measurement time at a practical level (20 s) has been achieved. The experimental results demonstrate the effectiveness of the compass in practical environments where the wind blows three-dimensionally and/or where the odor distribution is modified by an obstacle.