Study of Power-Assisted Attitude Control with Direct Manipulation for Four DOF

Tomohiro Sawano,Hideto Kojima,Takanori Miyoshi,Kazuhiko Terashima 제어로봇시스템학회 2009 제어로봇시스템학회 국제학술대회 논문집 Vol.2009 No.8

In this paper, a power-assisted attitude control system, of which the purpose is to eliminate a worker’s burden and to support the operation for beginners, is presented. In previous studies, we already suggested a power-assisted system to control the horizontal and vertical axes. However, it did not deal with rotary motion. Therefore, we try to enhance the dimension of motion control in the assembling process because a system with three degrees of freedom (DOF) has limited workability. In this study, we proposed a novel power-assisted system that had a higher degree of freedom to achieve attitude control, and confirmed the effectiveness of this system experimentally.

Application of Grey predictor in controlling 5 DOF power assistant robot

Le Duy KHOA,KIM Cheon,Kyoung Kwan AHN 제어로봇시스템학회 2012 제어로봇시스템학회 국제학술대회 논문집 Vol.2012 No.10

Due to their high power output and reliability, robots can replace humans in most modern industrial tasks associated with heavy loads. However, there are some jobs that require both human flexibility and robot power. Consequently, there is a demand to combine the high power of a robot arm with the dexterity of a human. In this work, a robot system called the power assistant robot (PAR) is proposed to satisfy this demand. The system can be applied not only in heavy industrial tasks, but also in various fields such as rehabilitation, the military, and security. This research focuses on applying a new type of actuator, called an electro-hydraulic system (EHA), in a power assistant robot. The EHA-PAR includes 5 degrees of freedom (1 passive joint and 4 active joints) and interacts with the user through a 4-dimensional intelligent joystick. By analyzing commands from a human, the human-robot interface distributes reference angles for all active joints. However, in some positions, robot operation is suffered from singularity phenomenon; thus it affect to the control quality. This paper proposes a strategy for this problem by combining the Grey predictor and the conventional kinematic solving method. It can be realized that the performance of the system is ameliorated by applying the proposed method.

중견국가와 기여외교:그 유형과 적용

김치욱 국가안보전략연구원 2011 국가안보와 전략 Vol.11 No.2

이 논문은 중견국가의 기여외교 유형을 하드파워와 소프트파워 간의 균형 여부를 기준으로 하여 현실주의형·이상주의형·혼합형으로 분류한다. 나아가 이를 각각 신흥 중견국가, 북유럽 중견국가, 그리고 전통적 중견국가의 대표 사례에 적용, 그 실제 작동 메커니즘을 분석한다. 기여외교는 기본적으로 소프트파워 외교의 일환이라는 점에서 하드파워의 열세를 공통적인 한계로 지니고 있는 중견국가들에게 매우 유용한 외교정책 수단으로 인식된다. 그러나 중견국가의 기여외교는 그 동기, 방식, 추진체계 등 여러 측면에서 차이점을 드러내는데, 이 논문은 하드파워와 소프트파워의 상대적 부존도에서 그 원인을 찾는다. 실제로 브라질과 인도 등 하드파워형 중견국가는 현실주의적 기여외교를 지향한 반면, 북유럽의 소프트파워형 중견국가는 이상주의적 성향을 나타냈다. 호주와 캐나다 등 균형적 중견국가들은 현실주의와 이상주의적인 모습이 공존하는 기여외교를 추구했다. 한국은 신흥 또는 북유럽 중견국가에 준하는 조건을 결여하고 있다. 따라서 창조적인 아이디어의 공급 등 전통적 중견국가에 가까운 혼합형 기여외교를 추진하는 것이 바람직할 것이다. This article explores the types and cases of international contribution diplomacy of middle powers(MPs). Based on the relative endowment between hard and soft power, it classifies the ideal types of contribution diplomacy as realist, idealist and hybrid. Further it applies such typology to the cases of emerging, Nordic, and traditional MPs, respectively, and analyzes their practices in international development and peacekeeping cooperation. The motives and methods of MPs’ contribution diplomacy are theoretically a function of the balance of hard and soft power resources, because international contribution is to increase the latter and to compensate for deficit in the former. Emerging MPs, such as Brazil and India, endowed with relatively abundant hard power, tend to follow a realist model of contribution diplomacy, whereas soft power-rich Nordic MPs follow an idealist model. And the traditional MPs like Canada and Australia are in between the two ideal types, which reflects their balanced hardsoft capabilities. This finding suggests that Korea, a balanced MP, pursue a hybrid model of contribution diplomacy in which realist and idealist elements coexist.

승용차의 개폐력 보조 문

이병수(Byoungsoo Lee),박민규(Min-Kyu Park),성금길(Kum-Gil Sung) 제어로봇시스템학회 2010 제어·로봇·시스템학회 논문지 Vol.16 No.6

SD (Smart Door) is a human friendly power-assisted door system initially targeted for passenger car doors. The Smart Door offers comfort and safety to passengers or/and drivers by supplying additional power. Amount of power supplied by the Smart Door system is depend on the environment where the automotive is situated. It realizes comfort, for example, when the force applied by the passenger to the door is expected to be abnormal, the SD system tries to compensate passenger"s effort by supplying additional force. In this study, to enhance the ease of opening and closing the doors of the passenger vehicle, a Smart Door with a power assist mechanism consisting of a motor was developed and analysed. A power assist mechanism mounted within the vehicle’s door is designed and modeled for simulation purpose. The required force necessary to control the designed mechanism during the vehicle’s roll, pitch and the opening angle of the door has been considered. To this end, we propose a power-assisting control strategy called "gravity cancellation". The system is analysed by numerical simulation with the gravity cancellation control algorithm.

Characteristics of Elbow Movements to Different Amounts of Surface Electromyography-based Assistive Torque

Suncheol Kwon,Youngjin Na,Yunjoo Kim,Jung Kim 제어로봇시스템학회 2013 제어로봇시스템학회 국제학술대회 논문집 Vol.2013 No.10

This study investigated the characteristics of human responses to different amounts of SEMG-based assistive torque. A power assistive device provided proportional torque with respect to the estimated human torque using surface electromyography (SEMG). Seven participants performed self-paced elbow flexion tests under five conditions, each having the different proportion of the assistance. We computed the variability of the angle and angular velocity of the elbow joint to quantify relative stability of the assisted movements. Power spectral density of the angular acceleration of the joint was also computed to characterize the power and bandwidth of the movements in the frequency domain. From the experiments the variability gradually increased with the amount of the assistive torque and it indicated that the movements in response to increased assistive torque became relatively more unstable. In addition, the power and bandwidth of the movements were gradually increased although subject’s physical efforts for the movements were decreased. This study can be used as a cornerstone to determine the amount of SEMG-based assistive torque for maintaining smooth and natural human movements.

인휠형 스마트 휠체어를 위한 힘 보조 제어기 설계

공정식(Jung-Shik Kong),백승엽(Seung-Yub Baek) 한국지능시스템학회 2011 한국지능시스템학회논문지 Vol.21 No.1

본 논문은 인휠형 휠체어에 있어 휠 림에 걸리는 외력을 차량의 전압과 회전 속도를 통해 예측하고 이를 통해 각 바퀴에 사용자의 힘에 따라 차량의 방향 및 속도를 제어할 수 있도록 고안된 제어기 설계에 관한 논문이다. 최근 노인 인구의 증가로 인해 노인 및 장애인을 위한 이동기기에 대한 관심이 증가되고 있다. 특히 많은 수의 고령자들이 휠체어를 이용하고 있다. 하지만 고령자의 경우 수동 휠체어 사용 시 국내 지형상의 문제로 인해 구동에 어려움을 겪는다. 또한 전동 휠체어의 경우 조이스틱으로 구동하므로 하체 근력 약화로 인해 휠체어를 이용하는 고령자의 경우, 상체 근력 또한 약화될 수 있다. 이를 극복하기 위해 림(rim)에 힘이 가해지는 힘의 크기를 파악하여 이에 상응하는 모터를 구동시키는 힘 보조형 인휠 전동기에 대한 연구가 진행되고 있다. 하지만 대부분의 힘 보조형 인휠 전동기의 경우 힘의 크기를 측정하기 위한 센서 모듈이 장착되어야 하며 이를 위해 힘의 크기를 측정하기 위한 별도의 림을 설계해야 하는 등 기구적 장치가 요구된다. 이에 본 논문에서는 이러한 힘의 크기를 측정하기 위한 림 설계 대신에 모터의 수학적 모델을 기초로 모터에 전달되는 전압과 바퀴의 현재 속도를 토대로 인휠형 모터에 걸리는 외력을 추정하고 이를 토대로 사용자의 이동 속도와 방향을 추정하여 모터를 이동시킬 수 있도록 하였다. 본 논문은 제안된 수학적 모델을 기초로 사용자의 구동 의지력을 정확하게 측정할 있었다. 또한 이를 기초로 한 제어기를 적용할 경우 인휠 휠체어를 사용자의 의지에 따라 이동할 수 있음을 시뮬레이션을 통해 검증하였다. This paper presents the design of the power-assisted controller for the in-wheel type smart wheelchair by using torque estimation that is predicted by relationship between input voltage and output wheel angular velocity. Nowadays, interest of the moving assistant aids is increased according to the increase in population of the elderly and the handicapped person. However some of the moving assistant aids have problems. For example, manual wheelchair has difficulty moving at the slope, because users lack the muscular strength of their arm. In electric wheelchair case, users should be weak by being decreased muscles of upper body. To overcome these problems, power-assisted electric wheelchair are proposed. Most of the power-assisted electric wheelchair have the special rims that can measure the user's power. In here, the rims have to be designed to install the sensors to measure user's power. In this paper, we don't design the rim to measure the man power. To predict the man power, we propose a control algorithm of the in-wheeled electric wheelchair by using torque estimation from the wheel. First, we measure the wheel velocity and voltage at the in-wheel electric wheelchair. And then we extract driving will forces by using proposed mathematical model. Also they are applied at the controller as the control input, we verify to be able to control in-wheel type smart wheelchair by using simulation

Power-Assisted Wheelchair with Gravity Compensation

Soon-Wook Hwang,Chang-Hyuk Lee,Young-bong Bang 제어로봇시스템학회 2012 제어로봇시스템학회 국제학술대회 논문집 Vol.2012 No.10

To overcome disadvantages of conventional manual or motorized wheelchairs, the push-rim activated power assisted wheelchair (PAPAW) has been developed. Though with the help of PAPAW the rider can climb slopes without much exertion, PAPAW cannot be finely position-controlled on the slopes, and the rider’s hands are not free while pausing on the slopes. In order to solve these problems, the gravitation-compensating power-assisted wheelchair (GCPAW) is suggested in this paper. When the wheelchair is manually moved, the wheel and the driving mechanism (motor and reduction gears) should be disconnected to avoid generating a friction force. For this purpose, an electromagnetic clutch is used in the driving mechanism. In addition, friction compensation during the power-assistive mode is suggested. As a preliminary work, experiments for gravity and friction compensation were performed. The rider could feel like riding an ordinary manual wheelchair on the flatland, even on slopes.

A Control Method for Power-Assist Devices using a BLDC Motor for Manual Wheelchairs

Dong-Youn Kim,Yong-Hyu Kim,Kwang-Sik Kim,Jang-Mok Kim 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.2

This paper proposes a new operation and control strategy for Power-Assisted Wheelchairs (PAW) using one brushless DC (BLDC) motor. The conventional electrical wheelchairs are too heavy and large for one person to move because they have two electric motor wheels. On the other hand, the proposed PAW system has a small volume and is easy to move due to the presence of a single wheel motor. Unlike the conventional electric wheelchairs, this structure for a PAW does not have a control joystick to reduce its weight and volume. To control the wheelchair without a joystick, a special control system and algorithm are needed for proper operation of the wheelchair. In the proposed PAW system uses only one sensor to detect the acceleration and direction of PAW’s movement. By using this sensor, speed control can be achieved. With a speed control system, there are three kinds of operations that can be done on the speed of a PAW: the increment of PAW speed by summing external force, the decrement of PAW speed by subtracting external force, and emergency breaking by evaluating the time duration of external force. The validity of the proposed algorithm is verified through experimental results.

A Control Method for Power-Assist Devices using a BLDC Motor for Manual Wheelchairs

Kim, Dong-Youn,Kim, Yong-Hyu,Kim, Kwang-Sik,Kim, Jang-Mok The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.2

This paper proposes a new operation and control strategy for Power-Assisted Wheelchairs (PAW) using one brushless DC (BLDC) motor. The conventional electrical wheelchairs are too heavy and large for one person to move because they have two electric motor wheels. On the other hand, the proposed PAW system has a small volume and is easy to move due to the presence of a single wheel motor. Unlike the conventional electric wheelchairs, this structure for a PAW does not have a control joystick to reduce its weight and volume. To control the wheelchair without a joystick, a special control system and algorithm are needed for proper operation of the wheelchair. In the proposed PAW system uses only one sensor to detect the acceleration and direction of PAW's movement. By using this sensor, speed control can be achieved. With a speed control system, there are three kinds of operations that can be done on the speed of a PAW: the increment of PAW speed by summing external force, the decrement of PAW speed by subtracting external force, and emergency breaking by evaluating the time duration of external force. The validity of the proposed algorithm is verified through experimental results.

Power-Assist Transportation Based on Virtual Impedance Control for Self-Balancing Robotic Cart

Taisei Hayashi,Fumiatsu Matsukawa,Seonghee Jeong 제어로봇시스템학회 2013 제어로봇시스템학회 국제학술대회 논문집 Vol.2013 No.10

In this study, we proposed an efficient power-assist transportation method of a heavy object with a high center of mass using a self-balancing robotic cart. We introduced a virtual impedance between the robot and an operator during a transportation task. This will improve the operability since the operator can feel some physical reaction force from the robot while moving it. Moreover, it is not necessary to remove the position control from general state feed back controller. Through simulations and experiments, it was found that adopting the impedance control was to allow operator to smoothly accelerate, move, and then decelerate the robot.