Takeshi Morishita

Integer inverse kinematics method using Fuzzy logic

In this paper, we propose an integer inverse kinematics method for multijoint robot control. The method reduces computational overheads and leads to the development of a simple control system as the use of fuzzy logic enables linguistic modeling of the joint angle. A small humanoid robot is used to confirm via experiment that the method produces the same cycling movements in the robot as those in a human. In addition, we achieve fast information sharing by implementing the all-integer control algorithm in a low-cost, low-power microprocessor. Moreover, we evaluate the ability of this method for trajectory generation and confirm that target trajectories are reproduced well. The computational results of the general inverse kinematics model are compared to those of the integer inverse kinematics model and similar outputs are demonstrated. We show that the integer inverse kinematics model simplifies the control process.

Advanced community model using daily life information transmitter for supporting welfare workers and senior citizens living alone in a welfare society

Over the last few decades, the number of senior citizens living alone in Japan has increased rapidly, to the point of dampening economic activity, increasing the load on the social security system, and decreasing the vitality of the local society. In particular, the lack of communication between a large number of elderly people and the local community has become a social problem, and such individuals are a burden on welfare workers and volunteers. With support from Kanagawa Prefectural Government, our joint research team has constructed a support system that would assist welfare workers and volunteers in serving elderly people living alone and building an active local community network. In this paper, we discuss an advanced community model based on the aforementioned information transmission welfare support system for the aging society. We also propose a system that estimates an individuals living conditions by measuring the vibrations caused by sounds such as opening/closing of doors, flushing of the toilet, etc. Experiments revealed that this system efficiently identifies unusual/abnormal activities in households where senior citizens live alone and sends alert signals. This network model provides the necessary support to rescue workers and helps in establishing interactions between elderly citizens and their neighbors; further, it can be used to organize patrol activities.

Experimental evaluation of high-intensity ultrasound source system using acoustic waveguide for calibration of hydrophone

In recent years, the use of high-intensity ultrasound equipment has increased in both medical and industrial fields. Consequently, we proposed a high-intensity ultrasound source system using a cylindrical acoustic waveguide for the development of an ultrasound source for the absolute calibration of the receiving sensitivity of hydrophones. We fabricated the experimental ultrasound source system using the cylindrical acoustic waveguide with particular considerations of the material selection and cutting methods to be used. The measured spatial distribution of acoustic pressure generated by our fabricated ultrasound source almost coincides with the results obtained by numerical simulation. In particular, the measured and simulated −6 dB main beam widths agreed within 15%. The linearity was measured using ultrasound waveforms with applied peak-to-peak voltages within the linear range of the power amplifier. Nonlinear phenomena were observed for the measured acoustic pressures of about 130 kPa or more.

Simple observation sensor system and local community network model: Real society experiment on solitary death prevention for low-income single elderly residents in collective housing

This paper proposes a sensor system for monitoring elderly residents living alone in low-income housing, and a local community network model to support these residents. This observation sensor system estimates living conditions by detecting entry point door movement, and safety information on the target residents is delivered to family and support staff via e-mail. In addition, the sensor unit is equipped with a networked flash-lighting and e-mail warning function to notify those in the community about accidents. Design and development costs were minimized by dispersing the flash light-emitting unit of the sensor unit on multiple units, making this a feasible option for low-income elderly residents. In addition, we implemented this sensor system and operated the local community network model at a collective housing to test its efficacy as a new system in real-world conditions. We present that this community network prevents the isolation of the elderly residents using the sensor system installed in their community, and improves communication between residents, their families, and their neighbors, thereby improving their safety. We also show that the community network prevents the isolation of elderly people by quietly keeping constant involvement with people in broader society, and is a social network system aimed at preventing solitary death.

Integer inverse kinematics for arm control of a compact autonomous robot

This paper proposes a new and simplified method of motion interpolation based on integer inverse kinematics to control the arm of a compact autonomous robot. The proposed method is based on fuzzy logic control, and hence, facilitates the construction of a joint control model and enables target point tracking control while interpolating fingertip coordinates on a two-dimensional plane. The validity of the proposed control model is verified by the target point tracking control of the fingertip with respect to the input coordinates through experiments. The proposed integer inverse kinematics method used in the experiments was confirmed to be applicable to a compact autonomous robot system. The experimental results indicated that the control error level between the input coordinates on the two-dimensional plane and the fingertip coordinates of the robotic arm was desirable. Moreover, the motions of the robotic arm were similar to those of humans.

Acoustic field measurement of high-intensity ultrasound source system using acoustic waveguide for calibration of hydrophone

In recent years, high-intensity ultrasound equipments have been used. It is expected that nonlinear calibration and evaluation will be needed more often. It is necessary to develop a high-intensity ultrasound source that transmit a plane wave in far-field for calibration of hydrophone in order to evaluate high intensity acoustic field. We proposed an ultrasound source system using a cylindrical type acoustic waveguide and a concave type piezoelectric transducer. The focused ultrasound wave is emitted from the concave type transducer, propagated through the acoustic waveguide, and the output from that forms high-intensity acoustic beam. We simulated the output acoustic pressure of the proposed source system using axisymmetric 3D acoustic field simulation based finite element method, compared with that of a flat disk type transducer with the same aperture size as the acoustic waveguide, and the simulated data showed the acoustic pressure of our proposed system was higher than that of the flat disk type tran...

Proposal and evaluation of integer inverse kinematics for multijoint small robot

In this paper, we propose an integer inverse kinematics method for multijoint robot control. The method reduces computational overheads and leads to the development of a simple control system as the use of fuzzy logic enables linguistic modeling of the joint angle. A small humanoid robot is used to confirm via experiment that the method produces the same cycling movements in the robot as those in a human. In addition, we achieve fast information sharing by implementing the all-integer control algorithm in a low-cost, low-power microprocessor. Moreover, we evaluate the ability of this method for trajectory generation and confirm that target trajectories are reproduced well. The computational results of the general inverse kinematics model are compared to those of the integer inverse kinematics model and similar outputs are demonstrated. We show that the integer inverse kinematics model simplifies the control process.

Development of educational material for manufacturing engineering using stereo vision and 3D CAD/CAM

This paper proposes a technical education program for engineering students; this program is based on a 3D CAD/CAM technology and a stereo vision technology, and it encourages the students to use a CAD/CAM circuit board and an image information processing system. Further, in this study, control experiments involving the use of a simple and compact robot equipped with a stereo vision system were performed. In addition, this education program that introduces students to the attractive 3D CAD/CAM technology and the stereo vision technology can expect to provide students an interesting experience on both constructing a robot and programming.