Search | Korea Science

신현배;이병룡
- Journal of the Korean Society for Precision Engineering
- /
- v.15 no.8
- /
- pp.165-173
- /
- 1998
In this paper, a motion control algorithm is developed by using fuzzy control technique, which makes a robot arm avoid unexpected obstacles when the robot is moving from the start to a goal posture. During the motion, if there exist no obstacles the robot arm moves along the pre-defined path. But if some obstacles are recognized and close to the robot arm, a fuzzy controller is activated to adjust the path of the robot arm. To show the feasibility of the developed algorithm, numerical simulations and experiments are carried out. In the experiments, redundant planar robot arms are considered for the collision avoidance test, and it was proved that the developed algorithm gives good collision avoiding performance.
PDF

Kim, Joong-Wan;Kang, Dae-Ki
- Journal of the Korean Society for Precision Engineering
- /
- v.13 no.2
- /
- pp.76-83
- /
- 1996
We have developed the unconventional robot arm which is composed of the two main parts, one is a ball screw and the other is a robot arm. The dynamic systems of the robot arm and ball screw are unstable systems coupled with each other. The ball screw mechanism is unstable system but controllable system. The robot arm's dynamics is quasi stable system when ball screw's angular position is zero, else, unstable system. Our system has the duality between stability and controllability at the view point of control. This duality causes difficulty to control of the robot arm using normal control law. We have investigated the location of the characteristic roots of the dynamic equation. And we have found out that the best condition for the control of the arm is quasi stable state. In this paper, we have proposed multiple control laws which are consist of three components to guarantee the stability and controllability simultaneously. The computer simulations were carried out based on VSC about the angular position control of the robot arm, and it is confirmed that the good performances could be obtained by using new controller.
PDF

이승룡
- Proceedings of the Korean Society of Precision Engineering Conference
- /
- 1996.04a
- /
- pp.220-226
- /
- 1996
This paper describes the force display system which presents feel information to the operator through manipulating a virtual tool with a master arm in the simulated environment. The movement of a tool grasped by the operator, which is modeled as a circle or a square is displayed in the graphic screen of a computer. When the tool contacts with the virtual environment, the operator is forced to feel contact and the feature of the virtual environment through torque control of the master arm. Contact situations are modeled as close as to the reality considering the friction, and multiple contacts. Several experients are conducted and the effectiveness of the developed system is confirmed.
PDF