TELEsarPHONE is a conceptual prototype of a mutual telexistence system, designed for face-to-face telecommunication via robots. Because of the development of telexistence technology, we can acquire a feeling that we are present in several actual remote places using remote robots as our surrogates and can work and act freely there. However, people in the place where someone telexists using a robot see only the robot, and they cannot feel the existence of the telexisting person. Mutual telexistence aims to solve this problem so that the existence of a telexisting person (visitor) is apparent to the people in the remote environment by providing mutual sensations of presence. On the basis of the concept of mutual telexistence, we have designed and developed a prototype of a telexistence master-slave system for remote communication by applying retroreflective projection technology. In the TELEsarPHONE system, the face and chest of the slave robot TELESAR II are covered by retroreflective material. To provide the feeling of existence, the real-time image of the visitor is projected onto the robot so that people can see the visitor in real time.
In the industrial field of motion control, many systems are nonholonomic, and thefore are difficult to control by static state feedback. As a controller design method for nonholonomic systems, a time-state control form that is applicable to a broad class of nonholonomic systems has been proposed. This paper describes three applications of controllers designed to utilize the time-state control form for the motion control of the following ground vehicles: a large-scale transfer crane, a rotary snow remover, and the mobile field of the Sapporo Dome stadium. In the first two examples, we develop a control function in a time-state control form into an integral type, and a combination of a filter and the Smith compensator. In the third example, we confirm the validity of the motion control by computer simulations and actual experiments.
The Japanese steel industry started to progress in the 1950s and reached maximum production in the 1970s. In the 1980s it changed its policy of pursuing quantity in production to pursuing quality. A slight decrease in production levels at the beginning of 2000 followed, but the industry has recently recovered production quantity while maintaining quality. In the process it has developed and accumulated a variety of innovative technologies, called “Japan original technologies” which were exported around the world. These are highly advanced control technologies, including sensors, controllers and control logics, and other electrical and automated equipment. This paper introduces some of the technologies developed by the Japanese steel industry that ushered in a new era in steel making worldwide.
In 2007 development and assessment of a precise point positioning (PPP) software for land vehicular navigation have been reported. This paper presents one phase of the continued study at NDA for further extension of the software to helicopter navigation. For 3D users, the height-dependent tropospheric delay is a critical factor, and so the sophisticated correction models and parameter estimation strategies have to be investigated to mitigate the delay effect. Since the precise positioning results become available only after the filter convergence and the filter generally converges rather slowly, speeding up the convergence has to be taken into special attention. In this paper we propose some new ideas to cope with this problem, and report the test using GPS helicopter flight data in post-processing. With proposed techniques including the variable Q and pseudo-observation concept, we show that point positioning accuracy at about decimeter level both horizontally and vertically can be achieved with improved convergence within about half an hour. We also show that the use of the high-rate (30-second) satellite clocks rather than the 5-minute clocks further improves positioning accuracy at sub-decimeter level in each 3D coordinate.
A rigid planar space robot is represented as a Caplygin system and its base attitude can be stabilized by means of geometric phase. However, in cases when flexible arms are used for control of the base attitude, inherent resonance modes are excited and instability is resulted. In this study, we propose to synthesize a stabilizing controller as adaptive tracking control system combined with sliding mode control to track to the arm trajectories derived from the geometric phase of the Caplygin system. Usefulness of the proposed controller is demonstrated by numerical simulations and Laboratory experiments.
The model predictive/optimal control problem for hybrid systems is reduced to a mixed integer quadratic programming (MIQP) problem. However, the MIQP problem has one serious weakness, i.e., the computation time to solve the MIQP problem is too long for practical plants. For overcoming this technical issue, there are several approaches. In this paper, a modeling of mode transition constraints, which are expressed by a directed graph, is focused, and a new method to represent a directed graph is proposed. The effectiveness of the proposed method is shown by numerical examples on linear switched systems and piecewise linear systems.
There exist various applications where tracking of humans or robots in an area is needed. An example of such applications are Intelligent Spaces, where humans and robots share a common space and their positions are tracked by a system of sensors in the space. In this paper a system for tracking both humans and robots that utilizes laser range finders as sensing devices is described. The details of the extraction of objects from the laser scan, data association and estimation are given, and results of tracking humans and robots are described. Calibration of the distributed laser range finders, which is important for the operation of the tracking system is also described, both in a manual and automated variant and experimental results are given. Finally, the inclusion of a laser range finder onboard the mobile robot in the tracking process is described and accompanied with experimental results. The distributed fusion of static and onboard sensors is also discussed.
The authors are studying a u-learning system called KUSEL, which is characterized by being user-adaptive, a property achieved by using scenario-driven operation and a causal network. While highly flexible in providing user adaptability, KUSEL requires completion of a set or complex tasks for the purpose of creating educational materials. This paper reports on the design of an authoring tool that facilitates the creation of educational materials for KUSEL.
In this paper, an asymptotic bias of the recursive least squares (RLS) estimate in the closed loop environment is analyzed and its compensation method is proposed under the assumption that the noise is white. Namely, a bias compensated RLS method in the closed loop environment based on output error (OE) model is proposed. A posteriori error is also analyzed for the estimation of the noise variance.
This paper presents a security design of remote maintenance systems for nuclear power plants. Based on ISO/IEC 15408, we list assets to be protected, threats to the assets, security objectives against the threats, and security functional requirements that achieve the security objectives. Also, we show relations between the threats and the security objectives, and relations between the security objectives and the security functional requirements. As a result, we concretize a necessary and sufficient security design of remote maintenance systems for nuclear power plants that can protect the instrumentation and control system against intrusion, impersonation, tapping, obstruction and destruction.