In the previous studies, the authors have studied a software platform for robotic system integration, and proposed a component based software platform called the RT-Middleware (RTM) and the RT-Component (RTC). In the networked robotic systems, such as an intelligent space or ambient intelligence, a lot of embedded devices are distributed and networked. In such systems, very light-weight middleware for microprocessors is needed. In this paper, a model based robotic system integration approach to realize interoperability between microprocessor based devices and conventional RT-Component based systems is proposed. Based on the scheme of the model driven way, a lightweight RT-Component named RTC-Lite is derived from the original RT-Component's abstract model, and it is implemented as a new platform specific definition for microprocessors. Finally, it is shown that the microprocessor based RTC and the conventional PC based RTC can be developed by the almost same manner, and interoperability can be realized.
This paper offers a significant evaluation of reader's placement for wheeled robots to estimate their posture from a lattice of RFID (Radio Frequency Identification) tags. RFID systems where IC tags are installed under/on floors have been widely utilized in recent years as the next positioning infrastructure. There is a model room in the Wabot-house Laboratory of Waseda University, where the floor has a lattice of RFID tags, and some actual experiments previously revealed that robots could accurately estimate their posture. The readers' antennas should be properly configured on a robot so that such an environment can give full play to its potential capabilities of positioning the robot. This problem calls for something like guidelines in designing the placement of readers. Experiments using actual robots cannot offer sufficient data because of time and physical limitations, which prevent helpful and reproducible evaluations of configurations. We construct a simulation environment using a localization model and evaluated the effects of configurations on positioning accuracy by using detailed computations. Then we obtain the simulation results, which enable us to identify some useful clues in designing where readers should be placed. In addition, a validation experiment using an actual robot verifies a part of the simulation results.
This paper presents an automated calibration method for laser range finders distributed in the environment. The laser range finder has recently been considered to be one of the most useful sensors for applications for Intelligent Space (iSpace) which is a space with many distributed sensors and actuators since it can realize both object tracking and map building. In this research, the object tracking function is used for pose estimation of the sensors. In the proposed method, each sensor first obtains positions of moving objects in the environment in its local coordinate system. If these sensors have overlapping observation regions, position of the same object is acquired as a corresponding point. The relative position and orientation of two laser range finders are then estimated from the set of corresponding points. Finally, poses of the laser range finders with regard to an arbitrary coordinate system are calculated based on the relative pose estimations. The proposed method does not require global positions of objects and information on the objects. In addition, multiple objects can be utilized in order to calibrate laser range finders distributed in a wide area efficiently.
Human-symbiotic humanoid robots that can perform tasks dexterously with their hands are needed in our homes, welfare facilities, and other places. To improve their performance of tasks, we propose a scheme of controlling motion aimed at appropriately coordinated hand and arm motions. By observing human manual tasks, we identify an active body-environment contact as a kind of human manual skills and devise a motion control scheme based on it. We also analyze the effectiveness of the combination of the active body-environment contact and our proposed scheme in example tasks of the adding/removing constraint task. We validate our motion control scheme through actual tests on a prototype human-symbiotic humanoid robot.
In this paper, a finger pose estimation method is presented. A direct use of fingers is useful in some applications which require handling of 3D position information. Our finger pose estimation method exploits anatomical constraints on finger motion and ring-shaped markers to achieve simple and practical measurements applicable to daily life situations. The use of anatomical constraints ensures that no exact placement of the markers is required.
This paper discusses discrimination and implementation of emotions on a zoomorphic robot aiming at designing emotional robot movements and improving robot friendliness. We consider four emotions; joy, anger, sadness, and fear. Two opposite viewpoints, performer and observer, are considered to acquire emotional movement data for analysis. The performer subjects produce emotional movements and movements that are easy to be recognized as expressions of the intended emotion are selected among the measured movements by the observer subjects. Discriminating the emotion embedded in a movement is tried using feature values based on the Laban movement analysis (LMA) and the principal component analysis (PCA). By the discrimination using PCA, the resultant rates of the correct discrimination are about 70% for all four emotions. The features of emotional movements are presumed from the coefficients of the discrimination function obtained in the emotion discrimination using PCA. Emotions are implemented by converting a setup for basic movements by employing the design principle based on the movement features. The result of the verification experiment suggests that four emotional movements are divided into two groups; the joy and anger group and the sadness and fear group. The emotional movements of joy or anger are dynamic, large-scale and frequent being relatively easy to interpret the intended emotion, while the emotional movements of sadness or fear are static, small-scale and little making difficult to understand the feature of movements.
The electrochemical and electromechanical characteristics of ion polymer metal composite (IPMC) are investigated using impedance analysis. The capacitance and resistance of IPMC are measured with various IPMC thicknesses, plating repetitions, and preheating times, which are the contributing factors of force generation. The generated force of IPMC increases with increasing IPMC thickness, number of plating repetitions, and extended preheating time. IPMC capacitance correlates with the generated force in all three cases, whereas IPMC resistance shows an independent change. These results show a strong correlation of the generated force of IPMC to its capacitance and structure and to the conditions for the IPMC fabrication process that increase its capacitance.
Modeling, control, and stabilization of dynamics of two-dimensional object grasping by using a pair of multi-joint robot fingers are investigated under rolling contact constraints and an arbitrary geometry of the object and fingertips. First, a fundamental testbed problem of modeling and control of rolling motion between 2-D rigid bodies with an arbitrary shape is treated under the assumption that the two contour curves coincide at the contact point and share the same tangent. The rolling constraint induces the Euler equation of motion that is parameterized by a common arclength parameter and constrained onto the kernel space orthogonally complemented to the image space spanned from the constraint gradient. By extending the analysis to the problem of stable grasp of a 2-D object with an arbitrary shape by a pair of robot fingers, the Euler-Lagrange equation of motion of the overall fingers/object system parametrized by arclength parameters is derived, together with a couple of first-order differential equations that express evolutions of contact points in terms of the second fundamental form. It is shown that 2-D rolling constraints are integrable in the sense of Frobonius even if their Pfaffian forms are characterized by arclength parameters. A control signal called “blind grasping” is introduced and shown to be effective in stabilization of grasping without using the details of the object shape and parameters or external sensing. An extension of the Dirichlet-Lagrange stability theorem to a class of systems with DOF-redundancy under constraints is suggested by using a Morse-Bott-Lyapunov function.
A simple adaptive servosystem with a tuning parameter is considered for a linear continuous-time plant. A reference model is introduced for specifying a desirable transient response, while an integral compensator is used in order to cope with a constant disturbance input. Then, an adaptive control law is proposed, which achieves a suitable model following control independently of the selection of the integral gain. In other words, the disturbance rejection property can be tuned by the gain without changing the adaptive control law. This is a feature of the proposed simple adaptive servosystem.
Computed tomography (CT)-based quantifications of emphysema encompass, and are not limited to, the ratio of the low-attenuation area, the bullae size, and the distribution of bullae in the lung. The standard CT-based emphysema describing indices include the mean lung density, the percentage of area of low attenuation [the pixel index (PI)] and the bullae index (BI). These standard emphysema describing indices are not expressive for describing the distribution of bullae in the lung. Consequently, the goal of this paper is to present a new emphysema describing index, the bullae congregation index (BCI), that describes whether bullae gather in a specific area of the lung and form a nearly single mass, and if so, how dense the mass of bullae is in the lung. BCI ranges from zero to ten corresponding to sparsely distributed bullae to densely distributed bullae. BCI is calculated based on the relative distance between every pair of bullae in the lung. The bullae pair distances are sorted into 200 distance classes. A smaller distance class corresponds to a closer proximity between the bullae. BCI is derived by calculating the percentage of the area of bullae in the lung that are separated by a certain distance class. Four bullae congregation classes are defined based on BCI. We evaluate BCI using 114 CT images that are hand-annotated by a radiologist into four bullae congregation classes. The average four-class classification accuracy of BCI is 88.21%. BCI correlates better than PI, BI and other standard statistical dispersion based methods with the radiological consensus-classified bullae congregation class.While BCI is not a specific index for indicating emphysema severity, it complements the existing set of emphysema describing indices to facilitate a more thorough knowledge about the emphysematous conditions in the lung. BCI is especially useful when it comes to comparing the distribution of bullae for cases with approximately the same PI, BI or PI and BI. BCI is easy to interpret and potentitally helpful for the purpose of comparative study and progressive monitoring of emphysema.
This paper is concerned with a forward method in inversion systems for identifying crack profiles arising in eddy current testing, using the reduced order Proper Orthogonal Decomposition (POD) techniques. First, an optimal ‘ordered’ basis of parameter-to-output mapping simulation data is created in the sense that the information captured in the first few basis elements is maximized. Then, in the forward algorithm, a fixed number of the first few basis elements, called the reduced POD basis, are used for computing relevant information with the variation of crack parameters. Since only a small number of basis elements are used, it is able to create an optimized forward algorithm in terms of calculation speed and usage of system resource. Numerical experimental results confirm the effectiveness and reliability of this method.
In this paper, left and right Floquet factorizations for the state transition matrices in finite-dimensional linear continuous-time periodic (FDLCP) systems are defined and their general existence is discussed. Then, mutual relationships and major characteristics of the left and right Floquet factorizations and their miscellaneous variants are examined. In particular, reducibility/irreducibility, commutativity, and trace relationships among others are scrutinized. The results are significant for analysis and synthesis of FDLCP systems.