• 제어로봇시스템학회:학술대회논문집
• /
• 1993.10a
• /
• pp.440-444
• /
• 1993

• Physical Therapy Korea
• /
• v.6 no.4
• /
• pp.36-42
• /
• 1999

본 연구의 목적은 운동제어/학습 또는 운동역학을 연구하는데 중요한 역할을 하는 근전도의 사용과 근전도와 등척성 수축력과의 관계에 나타나는 문제점과 제안점을 조사하는 것이다. 선행연구를 분석한 결과, 등척성 힘의 증가에 따른 근전도의 증가 관계가 선형적 모양으로 나타나지는 않았다. 또한, 선행연구에서 근전도와 등척성 힘 관계를 연구하는데 몇 가지 문제점들이 발견되었다. 이러한 문제점은 선행 연구실험들의 절차상에 차이가 나타났고, 근육의 생리학적인 또는 해부학적인 성질에서 문제점이 논의되었다. 결론적으로, 이러한 문제점들이 해결되지 않는 한 근전도와 등척성 수축력과의 관계는 불분명하게 남아있을 것이다.

• 제어로봇시스템학회:학술대회논문집
• /
• 1996.10b
• /
• pp.552-555
• /
• 1996

In this paper, we present a force control of a five-axes robot, using an impedance model. Tasks such as assembly, grinding, and deburring, which involve extensive contact with the environment, are better handled by controlling the forces of interaction between the manipulator and the environment. The five-link articulated robot is equipped with a wrist force sensor which consists of an array of strain gauges and can delineate the three components of the vector force along the three axes of the sensor coordinate frame, and the three components of the torque about these axes. For the precise control of the contact force, impedance models of a robot and the environment are defined. Experimental results are shown.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.18 no.9
• /
• pp.2284-2296
• /
• 1994

Force control of robotic mechanisms continues to be a challenging area. Previous implementation have seldom produced satisfactory results, and researchers in the past have experienced significant instability problems associated with their force controllers. In this study, a new stability factor in force control will be pointed out. When a manipulator is constrained to an environment(force-controlled), geometric instability due to the relationship between the manipulator configuration and the force-controlled direction is shown to be a significant factor in overall system stability. This exploratory study points out a rather intuitive, geometrically based stability factor in terms of an effective system stiffness and analyzes the phenomenon both analytically and graphically. Also, a stiffness control algorithm using the kinematic redundancy of a kinematically redundant manipulator is proposed to improve the overall stability in force control.

• Journal of the Korean Society for Precision Engineering
• /
• v.19 no.10
• /
• pp.114-119
• /
• 2002

The aim of this paper is to clarify the structural compliance of the constrained flexible manipulator and to develop the force control algorithm by using the compliance of the links. The proposed structural compliance control consists of the position control to utilize a flexible manipulator model (considering the compensation for the elastic deflection of links) and the passive force control to utilize the rigid manipulator model (without considering the compensation for the elastic deflection of links). We present the experimental results for the case when applying the only position control, and when applying the structural compliance control. Finally, a comparison between these results is presented to show the performance of our method.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.3
• /
• pp.1296-1301
• /
• 2012

This paper deals with development of the driving-will control system in power-assisted electric wheelchair. Nowadays, population of elderly people has been increased rapidly, and also an electric wheelchair has been considered as the device for the elderly. Especially, power-assisted electric wheelchair can overcome problems that a conventional electric wheelchair holds, such as lack of movement of wheelchair user. In this paper, we propose the sensors system to measure the driving-will force and perform the control action for a power-assisted electric wheelchair. And motion performance of the proposed system is verified through the experiment.

• Journal of Korean Society of Transportation
• /
• v.21 no.4
• /
• pp.79-90
• /
• 2003

Internal metering policy(IMP) is a control strategy to improve the quality of traffic flow within a network by avoiding queue spillback or intersection blockage. It is a more aggressive control strategy than the current control strategy employed in COSMOS. A preliminary study was made to incorporate the IMP logic within the COSMOS system to improve its' functionality at oversaturated conditions. From the study results, a set of guideline for real implementation was recommended : traffic conditions, detector configurations, and control procedures, etc. A simulation study was performed to evaluate the effectiveness of the proposed guidelines. It was shown that the occurrence of queue spillback was minimized. and overall network performance was also improved by applying IMP logic as compared to COSMOS control onl.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.18 no.10
• /
• pp.2554-2566
• /
• 1994

Robot position/force control has been a difficult task owing to the interaction between a robot and an environment with a rather high stiffness. In addition to the dynamic instability, the interaction causes the following problem : 1) chattering at steady-state, 2) dynamic coupling effect of robot, and 3) performance degradation due to a titled environment. To solve the problem, the Time Delay Control(TDC), which has been known to be quiet robust to plant uncertainties and disturbances, has been applied. In conjunction to TDC, the following three ideas were also used : 1) To reduce the amplitude of the chattering at the steady state, a novel scheme was adopted to enhance the resolution type solution of A/D conversion for the force sensor. 2) To reduce the dynamic coupling, a trajectory type position command was tried on a comparative basis to the step command, as well as a more accurate mass matrix was used instead of the constant mass matrix. 3) And finally to improve the performance in the tilted environment, force derivatives instead of position derivatives were used in the TDC law. Computer simulations and experiments resulted in obvious improvements on the quality of the hybrid control, thereby clearly demonstrating the effectiveness of TDC with the proposed ideas.

• Proceedings of the IEEK Conference
• /
• 2002.06e
• /
• pp.33-36
• /
• 2002

본 논문은 고정 및 이동물체와의 효율적인 충돌회피 알고리즘으로 적응임피던스제어 알고리즘을 제안하였다. 일반적인 충돌회피 알고리즘은 이동로봇의 동적 특성을 고려하지 않고 최적의 경로생성에만 관심을 둠으로써 실제 이동로봇이 추종하기 어려운 경로를 생성하기 쉽다. 그러므로 이동로봇의 동적 특성을 고려한 충돌회피 알고리즘을 위해, 이동로봇과 장애물과의 상호작용관계를 가상의 힘으로 정의한 임피던스제어 알고리즘을 사용하였다. 하지만 이런 단순 임피던스제어 알고리즘만으로는 갑작스런 장애물의 출현 시 이동로봇의 속도가 증가하고 장애물이 사라지면 속도가 감소하는 비효율적인 속도제어라는 문제점을 가지고 있다. 그러므로 충돌 가능성에 따른 새로운 속도제어 방식을 고려한 적응임피던스제어 알고리즘을 제안하고 검증하고자 한다.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.4 no.5
• /
• pp.455-461
• /
• 1999

In this paper, we present the 3DOF force-rei1ecting interface which allows to acquire force of objc'Ct within a a virtual environment. This system is comlxlsed of device, virtual environment model, and force-rei1ecting r rendering algorithm. We design a J DOF force reflecting device using the pc$\alpha$allel linkage, torque shared by W wire, and the controller of system applied by impedance control algorithm. The force reflecting behaviour i implemented as a function position is equivalent to controlling the mechanical impedance felt by the user. E Especially how force should be supplied to user, we know using a God-Object algorithm As we experiment a system implement$\varepsilon$d by the interface of 3D virtual object and 3DOF force reJll'Cting i interface, we can feel a contact, non contact of :)D virtual object surface and sensin앙 of push button model.utton model.