Motofumi Hattori

Linear approximate dynamic model of ICPF (ionic conducting polymer gel film) actuator

The ionic conducting polymer gel film (ICPF) actuator is a perfluorosulfonic acid membrane plated with platinum on its both surfaces. It bends in water and in wet condition by applying a low voltage of 1.5 V to its surfaces. This phenomenon was discovered in 1992. The principle of the motion is still unknown. This paper discusses 2-dimensional linear approximate modelling of the ICPF actuator. The authors are proposing a dynamic model of the actuator consisting of an electrical stage, a stress generation stage and mechanical stage. In the stress generation stage, time derivative of current generates the internal stress with a second degree delay. Expansion and contraction of each surface induce bending motion in the mechanical stage. Simulation results were in agreement with actual responses.

A new home robot positioning system (HRPS) using IR switched multi ultrasonic sensors

We propose a very fast measuring system for the location of a mobile robot in an indoor environment. The proposed localization method utilizes ultrasonic and infrared signals simultaneously. The transmitter, which is mounted on the mobile robot, transmits both ultrasonic and infrared signals at the same time. The receivers, which are located at fixed points in the ceiling of the room use the received infrared signal as a trigger to measure the time of flight of the ultrasonic signal. The location of the robot is computed by measuring its distance from three receivers. The heading of the robot is computed by measuring its position in two successive points while the robot moves from one point to the other. The performance and validity of this system are evaluated using one transmitter and six receivers located in a 6 m/spl times/4 m room. The positioning error is less than 5 cm.

Human detection and localization at indoor environment by home robot

The system introduced in the paper estimates the 3D position of a humans head and face by using the depth from focus method. First the system locates the humans head and face by using motion detection, Hough transform and a statistical color model. Then by changing pan, tilt and zoom of camera we put the face in the center of the cameras field of view. Then we use information from focusing the ring of an autofocus camera to measure the distance between the human face and the camera. By having information about the absolute position of the camera and its pan and tilt angles we can compute the absolute position of the person in the room. In the case of a person with small motions, this system measures distance with less than a 10 cm error. The measurable distance range is from 90 cm up to 340 cm.

Multi-modal human robot interaction for map generation

Describes an interface for multi modal human robot interaction, which enables people to introduce a newcomer robot to different attributes of objects and places in the room through speech commands and hand gestures. The robot makes an environment map of the room based on knowledge learned through communication with human and uses this map for navigation. The developed system consists of several sections including: natural language processing, posture recognition, object localization and map generation. This system uses a combination of multiple sources of information and model matching to detect and track a human hand so that the user can point toward an object of interest and guide the robot to go near to it or locate that objects position in the room. The position of objects in the room is located by a monocular camera vision and depth from focus method.

Multi-Modal Interaction of Human and Home Robot in the Context of Room Map Generation

In robotics, the idea of human and robot interaction is receiving a lot of attention lately. In this paper, we describe a multi-modal system for generating a map of the environment through interaction of a human and home robot. This system enables people to teach a newcomer robot different attributes of objects and places in the room through speech commands and hand gestures. The robot learns about size, position, and topological relations between objects, and produces a map of the room based on knowledge learned through communication with the human. The developed system consists of several sections including: natural language processing, posture recognition, object localization and map generation. This system combines multiple sources of information and model matching to detect and track a human hand so that the user can point toward an object of interest and guide the robot to either go near it or to locate that objects position in the room. The positions of objects in the room are located by monocular camera vision and depth from focus method.

An elliptic friction drive element using an ICPF (ionic conducting polymer gel film) actuator

The ICPF (ionic conducting polymer gel film) actuator, which has advantages such as low driving voltage, high speed, and capability for underwater motion, was discovered in 1992. This paper presents a new actuator element using an ICPF which generates an elliptic motion, as used in ultrasonic motors, to drive objects by friction. A method of forming a pattern of ICPF on a membrane was developed for production of the element. The experimental elements effectively functioned as driving devices and successfully drove a rotary motor as an application. Experiments and modeling revealed the relation of the resultant elliptic motion to control signals and design parameters.

Dynamic model of ICPF (ionic conducting polymer film) actuator

An ionic conducting polymer film (ICPF) actuator is a filmy composite made of perfluorosulfonic acid (PFS) membrane and surface platinum layers. It has many merits of low driving voltage, quick responsiveness, high durability, possibility of miniaturizability, and distributableness. In this paper, modeling of ICPF actuator is discussed. There are three stages in the model: an electric stage, a stress generation stage, and a mechanical stage. A linear electric characteristic model was built as the first element of the model of which input is voltage. Electric current is the input for the stress generation stage. Characteristics of time derivative and second-degree delay exist in generation of internal stress. The actuator material includes mechanical internal friction in addition to hysteresis. From many experiments and analyses, a linear approximation model with identified parameters was proposed.

Modeling of ICPF (ionic conducting polymer film) actuator-modeling of electrical characteristics

The ionic conducting polymer film (ICPF) actuator is a filmy composite made of a perfluorosulfonic acid (PFS) membrane sandwiched between porous platinum layers. It can be driven by direct voltage input to its surfaces in wet condition. In this study, the electrical characteristics of the actuator were investigated. The electrical characteristics of the actuator were represented by the surface resistances of the porous platinum layers, resistance of the gel membrane permeated with water, and a series connection of resistance and capacitance. The model was composed of a distributed-constant system of the above elements. Moreover, the distributed current through the series connection of resistance and capacitance was possibly concerned with the generation of internal stresses causing the actuator to bend.

Localization and approaching to the human by mobile home robot

This paper introduces a robotic system that uses a PTZ camera to find the human in the room and locate its position. Then the robot is guided to go near to the human. This includes human detection and localization, robot localization and robot navigation. Humans head and face is detected by using a combination of motion detection, shape analysis and color information. The 3D position of humans head and face is estimated by using the depth from focus method. For robot localization we use a very fast measuring system that utilizes ultrasonic and infrared signals simultaneously. For robot navigation we use a map of environment consisting of doors, walls and static objects. After locating human and robot a visibility graph is searched for the shortest path and obstacle avoidance is done in a reflexive method using ultrasonic sensors.

The description of human movement in computer based on the movement score

Describes a system whereby one can input key frames of movement by Labanotation (the choreographers notation for body movement), modify the movement by field direction symbol and continuous quantities, transform it into body movement data, and show the movement by computer graphic animation.