RESUMO
In order to effectively detect the contact state between the operator and the collaborative robot, a sensor with excellent external force detection performance is needed. The existing force/torque sensor and joint torque sensor, which are the two main external force sensors methods in cooperative robots, have limitations; only the force exerted at the end effector is detected, and it induces a low stiffness in the overall structure which affects the control performance. In the case of sensorless collision detection methods that utilize the current sensor that is used for motor control, the estimation of the performance of external force is sensitive to the sensor noise and dynamic model accuracy only to the extent that it can be used for collision detection. In this paper, we propose a strain gauge-based three-axis sensor of a cylindrical shape, which is often used as a link in a robot. By integrating sensors with robot links, the external force can be precisely measured without compromising the stiffness and is decoupled with joint disturbances, such as motor friction. Sensor calibration is conducted using static load evaluation equipment, and the reliability of collision detection is confirmed by comparing the theoretical/structural analysis results. Through the weight test and sensor characteristic evaluation, the performance and output stability are validated.
Assuntos
Robótica , Fricção , Fenômenos Mecânicos , Reprodutibilidade dos Testes , TorqueRESUMO
Recent outbreaks and the worldwide spread of COVID-19 have challenged mankind with unprecedented difficulties. The introduction of autonomous disinfection robots appears to be indispensable as consistent sterilization is in desperate demand under limited manpower. In this study, we developed an autonomous navigation robot capable of recognizing objects and locations with a high probability of contamination and capable of providing quantified sterilization effects. In order to quantify the 99.9% sterilization effect of various bacterial strains, as representative contaminants with robots operated under different modules, the operating parameters of the moving speed, distance between the sample and the robot, and the radiation angle were determined. We anticipate that the sterilization effect data we obtained with our disinfection robot, to the best of our knowledge, for the first time, will serve as a type of stepping stone, leading to practical applications at various sites requiring disinfection.
Assuntos
COVID-19 , Robótica , Inteligência Artificial , Desinfecção , Humanos , SARS-CoV-2 , EsterilizaçãoRESUMO
Biological experiments for developing efficient cancer therapeutics require significant resources of time and costs particularly in acquiring biological image data. Thanks to recent advances in AI technologies, there have been active researches in generating realistic images by adapting artificial neural networks. Along the same lines, this paper proposes a learning-based method to generate images inheriting biological characteristics. Through a statistical comparison of tumor penetration metrics between generated images and real images, we have shown that forged micrograph images contain vital characteristics to analyze tumor penetration performance of infecting agents, which opens up the promising possibilities for utilizing proposed methods for generating clinically meaningful image data.
Assuntos
Redes Neurais de ComputaçãoRESUMO
Most elderly people complain about the discomfort of movements such as a sit-to-stand (STS) motion through losing their muscular strength of lower extremity over aging. This paper presents a novel passive sit-to-stand and walking (STSW) assistance device to aid in physical support for indoor daily life of the elderly. The STSW assistance device is actuated by a pneumatic cylinder and a gas spring. The standing motion is driven by extension of actuators and the sitting motion is driven naturally with gravitational force of user's weight that reloads actuators. The effect of physical support by using this device was evaluated by experiment with measuring electromyograph signals of subjects during STS motion. As a result, the reduction rate of average maximal voluntary isometric contraction with assistance by the STSW device is about 51.2%. This means that users with the assistive device can stand up by using only about half of muscular activation in the case of natural standing up.