A suspended-from-ceiling type tea serving robot for household use is proposed in this paper. The duty of the tea serving robot is to serve a drink to a bedridden person. A bedridden person can order the robot to bring a cup of tea without hesitation, and therefore can avoid his dehydration. A hand of the robot is suspended from a ceiling, of a house, and driven three dimensionally in the orthogonal coordinates. No installing area is required to utilize the robot because of the suspended structure from a ceiling. The hand swings as a pendulum. A vibration reducing control is proposed to decrease the hand vibration. The swing of the hand is detected by a swing angular detection system. The tea serving experiments are carried out. The robot will be sure to carry the filled teacup without spilling out its contents.

Tea serving robot suspended from ceiling

Taiwan and other developed countries have being experienced an emergence of a growing aging population. Home-caring robot is an excellent candidate capable of supporting such an aging society. In the paper, a robot is designed to move up-and-down stairs to provide service for the elders. The robot consists of a main body for moving, a front arm and a rear arm for moving up and down stairs. The main body is equipped with two brushless dc motors (BLDCMs) and their drives for locomotion, worm gears for torque amplification, two dc motors to control two arms, and DSP-based board as control center. The robot is equipped with roller chains attached with rubber blocks used to generate friction with ground and stairs for moving. The distance between any two rubber blocks is properly arranged to fix the stair brink. The moving direction of the robot is steered based on the speed difference of two BLDCMs and the information from ultrasonic sensors. A walking experiment of moving up and down stairs with the rise of 120 mm and depth of 400 mm is shown in the video.

Design and implementation of a stair-climbing robot

A human posture assist robot for elderly and disabled persons, with badly balanced physique is proposed. The robot has a structure with two joints of an ankle, a waist, and a foot force pad. The robot can raise the patient when he/she happens to fall down by sensing the body balance. The human balance is detected by a foot force pad where strain gages are embedded. We have fabricated the scale-down experimental setup to confirm the principle of the human posture assist robot. The program developed can simulate the responses of the classical control and H/sub 2/ control.

Human balance measurement and human posture assist robot design

In the near future, robots are expected to be more acceptable and commonly used by human beings. Therefore, human robot interface (HRI) is essential to enable efficient and effortless communication between humans and robots. The main objective of this work is to develop, evaluate and then to improve current HRIs, such as teleoperation, manual, speech and vision interaction, by eliminating the weakness in these techniques. An enhanced teleoperation technique using portable devices was introduced as a better HRI technique for human to wirelessly control and communicate with mobile robot. Through this method, user can use their portable device to communicate with the robot as long as they are using the same wireless communication protocol and wireless devices. The portable devices tested in the project were the Personal Digital Assistant (PDA), a laptop and a remote PC. Comparison between different HRIs through experiments shows that portable device interaction is more reliable, efficient and easy to use compared to manual, speech and vision interaction.

Development and evaluation of various modes of human robot interface for mobile robot

In the paper, a robot is designed to move up-and-down stairs for providing service. This robot consists of a main body, actuating system, roller chains, a front arm and a rear arm for assisting in moving up and down stairs. The actuating system includes two brushless DC motors for locomotion, two worm gears for torque magnification, and two DC motors to control arms. A DSP-based board acts as control center. Some rubber blocks attached to the roller chains are used to generate friction with ground and stairs for moving. A fuzzy logic controller integrates the outputs of DC bus current sensor and an inclinometer to steer the robot. Two walking experiments of moving up and down stairs with the rise/depth of 120/400 mm and 175/280 mm are shown in the taped pictures from videos to verify the proposed design.

Fuzzy Logic Control Design for a Stair-Climbing Robot

Welfare robot technology to assist aged persons is presented. The tea serving robot can carry a cup of tea according to human instructions. The suspended-from-ceiling type tea serving robot requires no installation area since the robot hand is suspended from the ceiling of a house. The standing-on-floor type tea serving robot can be easily moved due to its rod structure which is equipped with a three directional drive mechanism and a robot hand. The idea for the standing-on-floor type robot came from a drip transfusion stand in hospitals. Two types of robots which assist in walking and moving up-and-down stairs were also developed. Both types use a handrail of a house to assist aged persons. The stick type robot can assist in walking and moving up-and-down stairs using tires and rubber belts. The biped type robot can assist using a structure with two legs.

E. Hirata

Papers

Robotic assistance for aged people