Public displays, such as liquid crystal displays (LCDs), are often used in urban green spaces. However, these display devices often tarnish the green landscape of urban green spaces due to their ...artificial materials. We previously proposed a green landscape-friendly grass animation display that dynamically controls the grass color pixel by pixel. The grass color is changed by moving a green grass length in yellow grass, and the grass animation display runs simple animations using grayscale images. In our previous study, the color scale is subjectively mapped to the green grass length. However, this method fails to display the grass colors corresponding to the color scale based on objective evaluations. Herein, we introduce a dynamic grass color scale display technique based on the grass length. We develop a grass color scale setting procedure to map the grass length to the five-level color scale through image processing. In the outdoor experiment of the grass color scale setting procedure, the color scale corresponds to the green grass length based on a viewpoint. Finally, we demonstrate a grass animation display to show the animations with the color scale using experimental results.
We are developing a robotic system for an asteroid surface exploration. The system consists of
multiple
small size rovers, that communicate with each other over a wireless network. Since the rovers ...configure over a wireless mesh sensor network on an asteroid, it is possible to explore a large area on the asteroid effectively. The rovers will be equipped with a hopping mechanism for transportation, which is suitable for exploration in a micro-gravity environment like a small asteroid’s surface. However, it is difficult to control the rover’s attitude during the landing. Therefore, a cube-shaped rover was designed. As every face has two antennas respectively, the rover has a total of twelve antennas. Furthermore, as the body shape and the antenna arrangements are symmetric, irrespective of the face on top, a reliable communication state among the rovers can be established by selecting the proper antennas on the top face. Therefore, it is important to estimate which face of the rover is on top. This paper presents an attitude estimation method based on the received signal strength indicators (RSSIs) obtained when the twelve antennas communicate among each other. Since the RSSI values change depending on an attitude of the rover and the surrounding environment, a significantly large number of RSSIs were collected as a training data set in different kinds of environments similar to an asteroid; consequently, a classifier for estimating the rover attitude was trained from the data set. A few of the experimental results establish the validity and effectiveness of the proposed exploration system and attitude estimation method.
We are developing a social mobile robot that has a name calling function using a face memorization system. It is said that it is an important function for a social robot to call to a person by ...her/his name, and the name calling can make a friendly impression of the robot on her/him. Our face memorization system has the following features: (1) When the robot detects a stranger, it stores her/his face images and name after getting her/his permission. (2) The robot can call to a person whose face it has memorized by her/his name. (3) The robot system has a sleep–wake function, and a face classifier is re-trained in a REM sleep state, or execution frequencies of information processes are reduced when it has nothing to do, for example, when there is no person around the robot. In this paper, we confirmed the performance of these functions and conducted an experiment to evaluate the impression of the name calling function with research participants. The experimental results revealed the validity and effectiveness of the proposed face memorization system.
There are various proposals for employing grass materials as a green landscape-friendly display. However, it is difficult for current techniques to display smooth animations using 8-bit images and to ...adjust display resolution, similar to conventional displays. We present ProgrammableGrass , an artificial grass display with scalable resolution, capable of swiftly controlling grass color at 8-bit levels. This grass display can control grass colors linearly at the 8-bit level, similar to an LCD display, and can also display not only 8-bit-based images but also videos. This display enables pixel-by-pixel color transitions from yellow to green using fixed-length yellow and adjustable-length green grass. We designed a grass module that can be connected to other modules. Utilizing a proportional derivative control, the grass colors are manipulated to display animations at approximately 10 fps. Since the relationship between grass lengths and colors is nonlinear, we developed a calibration system for ProgrammableGrass . We revealed that this calibration system allows ProgrammableGrass to linearly control grass colors at 8-bit levels through experiments under multiple conditions. Lastly, we demonstrate ProgrammableGrass to show smooth animations with 8-bit grayscale images. Moreover, we show several application examples to illustrate the potential of ProgrammableGrass . With the advancement of this technology, users will be able to treat grass as a green-based interactive display device.
This paper presents a new robot system consisting of plural small size rovers for an asteroid exploration. Each rover can communicate with others using radio, and a wireless mesh network is ...configured on an asteroid's surface. Our proposed system has the following three advantages against a conventional exploration system using one or two rovers: (1) It is possible to explore a wider area of an asteroid. (2) Since the mesh network has redundant communication paths, it has more robustness against some troubles. (3) It is possible to estimate the relative distances among plural rovers by using the mesh network. This relative distance estimation is useful for asteroid analyses using sensors that rovers have. Simulation results reveal the validity and effectiveness of our proposed rover system with the wireless mesh network and the relative distance estimation method.
When a robot works among people in a public space, its behavior can make some people feel uncomfortable. One of the reasons for this is that it is difficult for people to understand the robot’s ...intended behavior based on its appearance. This paper presents a new intention expression method using a three dimensional computer graphics (3D CG) face model. The 3D CG face model is displayed on a flat panel screen and has two eyes and a head that can be rotated freely. When the mobile robot is about to change its traveling direction, the robot rotates its head and eyes in the direction it intends to go, so that an oncoming person can know the robot’s intention from this previous announcement. Three main types of experiment were conducted, to confirm the validity and effectiveness of our proposed previous announcement method using the face interface. First, an appropriate timing for the previous announcement was determined from impression evaluations as a preliminary experiment. Secondly, differences between two experiments, in which a pedestrian and the robot passed each other in a corridor both with and without the previous announcement, were evaluated as main experiments of this study. Finally, differences between our proposed face interface and the conventional robot head were analyzed as a reference experiments. The experimental results confirmed the validity and effectiveness of the proposed method.
When pedestrians and a mobile robot pass each other in a corridor, it is important for a robot to make an appropriate path in order not to confuse pedestrians. This paper presents a new path planning ...method where the mobile robot follows the rule of "eeping to the right." Three kinds of maps based on laser range finder data are used in the path planning. One is a global cost map made by a simultaneous localization and mapping (SLAM) technique, that expresses a whole environment and is used to make a path from a start position to a goal. Another is a local cost map, that is used for avoiding obstacles near the mobile robot. The other is an attractive force cost map proposed in this paper, that makes the robot keep to the right along a corridor. When there is no pedestrian, the mobile robot goes to a goal position indicated by an operator based on the global cost map while avoiding moving obstacles based on the local cost map in real time. When the robot detects pedestrians, it begins to keep to the right. This method where the robot follows a social norm depending on each country can make a pedestrian pass by the mobile robot more smoothly. Some experimental results reveal the validity of our proposed path planning method.
The sphere packing problem, which involves filling an arbitrarily shaped geometry with the maximum number of non-overlapping spheres, is a critical research challenge. ProtoSphere is a ...prototype-oriented algorithm designed for solving sphere packing problems. Due to its easily parallelizable design, it exhibits high versatility and has wide-ranging applications. However, the controllable regulation of particle size distribution (PSD) produced by ProtoSphere is often neglected, which limits its application on algorithm. This paper proposes a novel PSD-driven technique that extends the ProtoSphere algorithm to achieve multi-sized sphere packing with distribution-specific characteristics, as dictated by a pre-defined cumulative distribution function. The proposed approach improves the controllability and flexibility of the packing process, and enables users to generate packing configurations that meet their specific requirements. In addition, by combining the relaxation method with the ProtoSphere algorithm, we can further improve the packing density and ensure the average overlap below 1%. Our method generates multi-sized particles that can be used to simulate the behavior of various granular materials, including sand-like and clay-like soils.
This paper reports a new myoelectric interface for robotic hand control consisting of two main parts. The first part concerns the motion classification using electromyogram (EMG) signals of a support ...vector machine (SVM). Because there has been little research on the application of the SVM to motion classification using EMG signals, its effectiveness has not yet been established. The SVM has some advantages with respect to generalization and computational complexity, and therefore, we used the SVM to examine its classification ability. The second part concerns the estimation of an operator's joint angle corresponding to the motion determined by the first part. Estimation of the operator's joint angles is based on EMG-Joint angle models, which express the linear relationships between the EMG signals and joint angles. To verify the effectiveness of our interface, we performed off-line hand motion classification and real-time robotic hand control experiments with eight subjects. The experimental results showed that seven hand motions achieved a classification rate of more than 90% for all subjects. In addition, a three-dimensional computer graphics robotic hand was controlled in real-time (62.5 Hz) without delay.
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