Shoichiro Fujisawa

Improved moving properties of an omnidirectional vehicle using stepping motor

Many kinds of omnidirectional vehicles driven by DC motors have been proposed and developed for application in robotics systems, but they have various problems like stability or operability in practical use, and have to be controlled by feedback system. This paper describes the improved moving properties of an omnidirectional vehicle driven by a stepping motor. An omnidirectional vehicle, which can move in all directions without changing the body direction of the vehicle, has been developed. This omnidirectional vehicle is used as the base of a calligraphy robot which is able to write Chinese characters using a brush. The movement and the control of this vehicle are evaluated, and the fields where this vehicle can be used are examined. Experimental results show that the proposed device is useful in achieving the desired performance.

A design of CMAC based intelligent PID controllers

PID control schemes have been widely used for most industrial processes which are represented by nonlinear systems. However, it is difficult to find an optimal set of PID gains. On the other hand, Cerebellar Model Articulation Controller (CMAC) has been proposed as one of artificial neural networks. This paper presents a new design scheme of intelligent PID controllers whose PID gains are generated by using CMACs. The newly proposed control scheme is numerically evaluated on a simulation example.

A Skill-Based PID Controller Using Artificial Neural Networks

The works for representing human skills are attracted, which human experts have cultivated in long experiences. Recently, there are many literatures with respect to skill-based controllers which human skills are represented by artificial neural networks. The technique for representing the human skills plays an important role in various industries, for example, manufacturing systems and process systems. In this paper, a skill-based PID control scheme is proposed, which extracts skills of human experts as PID gains. This controller is designed by using three-layered artificial neural networks. The effectiveness of the proposed skill-based PID control scheme is investigated through an application for a pressure control system. Furthermore, the characteristic of the PID controller constructed based on the human skills is interpreted in the frequency domain

Creating swing-up patterns of an acrobot using evolutionary computation

In recent years, the various controller design schemes have been examined for nonlinear mechanical systems with uncertainties. As one of such mechanical systems, acrobots attract attention in last decade, which belong to nonholonomic systems. Several controller design schemes have been proposed for the acrobots. In this paper, a new approach to control the acrobot is considered, in which a suitable swing-up pattern is created using the real-coded genetic algorithm(GA). Then, the energy and the extra motion which are totally consumed in the swing-up motion, are evaluated on the fitness function. The effectiveness of the newly proposed scheme is numerically verified on some simulation results.

Development of training equipment with an adaptive and learning mechanism using balloon actuator-sensor system

This paper proposes training equipment using a balloon actuator-sensor system (BASS) for persons unable to move their hands because of injury or disease. BASS is able to control the stiffness adaptively using an adaptive learning impedance controller. The pneumatic actuator has excellent compliance and flexibility, which is good for a human-mechanical system. However, it is also nonlinear, hence high precision control is difficult. Therefore, a CMAC-PID control scheme is installed. Finally, the BASS control performance is evaluated in a control experiment.

Development of path tracking control for omni-directional mobile robot using visual servo system

Teleoperation research on the remote control of mobile robots using visual screens has grown increasingly popular. In this study, we designed a vision-based mobile robot navigation system. Furthermore, using this vision-based navigation system, we conducted path-tracking experiments of moving objects. For the moving object, we used an omni-directional mobile robot with excellent mobility. This paper presents various running experiment results relating to position and posture control by this navigation system.

GHTA welding phenomena of an aluminium alloy in a vacuum

Abstract The midair disintegration of the space shuttle ‘Colombia’, in which the total crew of 7 members was lost, occurred on 1st February 2003. The circumstances of the crash shown on TV screens reaffirmed the publics view of the risks of space development and the importance of security. NASA has stopped any further space shuttle launches until the causes are fully investigated – a postponement of the completion of the International Space Station is inevitable. The operational life of the ISS is considered to be 10 years but it could be quite possible to prolong this if required for various reasons. Accordingly, it is highly likely that there will be requests for remodelling in order to achieve high levels of functional performance and to repair damage caused by debris impact and for other reasons. In order to meet these requirements it is essential to establish space welding technology.1

Association between ego scores and individual characteristics in EEG analysis: Basic study on individual brain activity

This paper introduces a method for discussing an association between ego scores and individual characteristics in EEG analysis. The ego scores express one of the personality and/or nature on a human. The EEG analysis calculates the power spectra of the frequency weighted of the EEG signal, and evaluates through detecting the EEG patterns while listening to the music. A k-nearest neighbor classifier is used to detect the EEG patterns. The specified weight value to weight frequency of EEG and the results of EEG pattern detection express the individual characteristics in EEG analysis. Finally, we do experiment using a real EEG data for discussing the association the ego scores and the individual characteristics in EEG analysis. An interesting tendency was that the subjects who were the combined ego-type tended to have a powerful response to negative stimuli more than positive stimuli. They had the stable filter weighted frequency.

Study on relationship between personality and individual characteristic of EEG for personalized BCI

It is an important issue that the relationship between personality and individual characteristic of an electroencephalogram (EEG) for using a personalized brain computer interface on daily basis. In this paper, we introduce a method for discussing the relationship between personality based on egogram scores and the results of the EEG pattern detection. The egogram based on psychological testing is used for analyzing human personality. The frequencies of the EEG analyzed are the components that contain significant and immaterial information and have different importance. We express the different importance through the weight value on frequencies using real-coded genetic algorithm. Then, the EEG patterns, which are determined based on the evaluation of the impression on the music, are classified/detected using the knearest neighbor method. Finally, we discuss the relationship between human personality and the individual characteristic in the EEG analysis. An interesting tendency was that the false-detection ratio of the EEG pattern, meaning the response on negative stimuli, did not become low when the score and level on ego states of Adult was extreme.

Vibration Influence of Tactile Walking Surface Indicators on the Running of Manual Wheelchairs and Walking Frames

The riding comfort of manual wheelchairs is greatly influenced by tactile walking surface indicators (TWSIs) that are usually set on sidewalks for visually impaired person. The goal of our research is to understand how block patterns and their vertical vibrations influence the ride of manual wheelchairs. This paper also presents a system that easily measures the vibration characteristic of the walking frame. Using various tactile walking surface indicators as a rugged path, this system measured the vibration when using various walking frames. This paper, therefore, considers the vibration influence of TWSIs on wheelchairs with and without suspension equipped wheels and various walking frames