Satoko Abiko

Analysis of drop test using a one-legged robot toward parachute landing by a humanoid robot

Discussions on how to perform tasks at disaster sites are actively conducted, but there is little debate on important issues such as how to deliver robots to disaster sites. To drop a humanoid robot with a parachute from an airplane is one of the promising ways of delivering robots. In this paper, the behavior of falling during parachute landing is modeled with an inverted pendulum model and the validity of the model is verified by the drop tests with a small single-legged robot. In addition, it was found that when the robot was dropped with a half-sitting posture, the impact acceleration is reduced. Based on this result, a parachute landing fall motion is designed and is succeeded in reducing the impact acceleration to 41%.

Fundamental numerical and experimental evaluation of attitude recovery control for a quad tilt rotor UAV against disturbance

This paper presents attitude recovery control for a quad tilt rotor UAV. The quad tilt rotor UAV has ability of flying with completely independent 3 DOF position and 3 DOF attitude control by changing the thrust directions. This type of UAV is expected to perform better response to the disturbance by virtue of the mechanism of changing the thrust directions compared to the conventional multi-rotor UAV. This paper proposes disturbance detection method using IMU sensor and develops attitude recovery control against impact disturbance. The numerical simulation and fundamental flight experiments were carried out to evaluate the effectiveness of the proposed method compared to the conventional PID control.

Encountered-type visual haptic display using MR fluid

This paper proposes a visual haptic display with an encountered-type haptic interface using MR (Magneto-Rheological) fluid. The proposed system can display arbitrary force by controlling the magnitude of yield stress of MR fluid and provide realistic visualization by displaying computer graphics images on the container of MR fluid directly. An operator can feel resistance force by putting instruments in the MR fluid container and can sense reality by virtue of the visual display on the MR fluid container. This type of system would be useful for surgical simulator since an operator can freely move and easily change the instruments as in real operation. In the demonstration, one of fundamental brain surgery operations, cutting arachnoid trabecular, is considered as an application.

2P1-D06 Contact Dynamics Analysis of a Biped Robot on Loose Soil

This paper addresses contact dynamic model between loose soil and feet of a legged robot. Most of studies for biped robots have assumed the floors as undeformable rigid ones. This paper deals with a locomotion of a biped robot on deformable loose soil like sand. Since the ground reaction force varies according to the contact condition between the feet and ground in case of loose soil, it is necessary to formulate mathematically this relationship. The ground reaction force can be analyzed in the two conditions: static and driving state. In the static state, the ground reaction force is determined by the sinkage of feet, the pressure distribution under feet. In the driving state, besides the factors in static state, the sinkage by slipping also affects the ground reaction force. The approach for calculating the ground reaction force in these situations is proposed.