• 제어로봇시스템학회:학술대회논문집
• /
• 2004.08a
• /
• pp.1245-1248
• /
• 2004

This paper presents a new technique to analyze data on the coordinate x, y, z and apply these data to design the motion control to improve the efficiency of the engraving machine so that it can engrave accordingly in 3 dimensions. First, the tool path on the x-y plane is analyzed to be synchronized with the z-axis. The digital data is then sent to the motion control to guide the movement of the engrave point on the x-y plane. Tool path moves along the x-axis with zero degree and different values of the y-axis according to the coordinate of the digital data and the analysis along z-axis to determine the depth for engraving. The depth can be specified from the gray level with the 256 levels of resolution. The data obtained includes the distances on x-axis, y-axis, and z-axis, the acceleration of the engrave point's movement, and the speed of the engrave point's movement. These data is then transfered to the motion control to guide the movement of the engrave point along the z-axis associated with the x-y plane. The results indicate that engraving using this technique is fast and continuous. The specimen obtained looks perfect in 3D view.

• Journal of Institute of Control, Robotics and Systems
• /
• v.1 no.1
• /
• pp.58-62
• /
• 1995

Necessarily, it is required to analyze interfacial mechanism between tire and road for understanding tire wear, vehicle tracking and breaking. Therefore, there have been some efforts to measure 3-axis pressure and 2-axis displacement on tire road interface. But it was so hard to couple precisely measuring sensor and desired point on tire tread pattern block that it was impossible to analyze the mechanism on commercial tire with tread pattern. To overcome such a problem, a on-line measurement system is proposed in this paper. And an automatic control system is designed to test the tire with similar configuration of real vehicle driving.

• Journal of Institute of Control, Robotics and Systems
• /
• v.15 no.3
• /
• pp.300-305
• /
• 2009

This paper describes the intelligent robot's hand with three-axis finger force sensors for an intelligent robot. In order to grasp an unknown object safely, it should measure the mass of the object, and determine the grasping force using the mass, then control the robot's fingers with the grasping force. In this paper, the intelligent robot's hand for an intelligent robot was developed. First, the three-axis finger force sensors were designed and manufactured, second, the intelligent robot's hand with three-axis finger force sensors were designed and fabricated, third, the high-speed control system was designed and manufactured using DSP( digital signal processor), finally, the characteristic test to grasp an unknown object safely was carried out. It was confirmed that the developed intelligent robot's hand could grasp an unknown object safely.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.17 no.3
• /
• pp.40-46
• /
• 2008

This paper presents the optimal motion control for 3-axis SCARA robot by using $LabVIEW^{(R)}$. Specifically, for optimal motion control of 3-axis SCARA robot, we study velocity profile based on finite jerk(the first derivative of acceleration) and optimal gain tunig based on frequency response method by using $LabVIEW^{(R)}$. The velocity optimization with finite jerk aims at generating the smooth velocity profile of robot. Velocity profile based on finite jerk is acquired and applied to 3-axis SCARA robot by using $LabVIEW^{(R)}$. DSA(Dynamic Signal Analyzer) for frequency response method is programed by using $LabVIEW^{(R)}$. We obtain the bode plot of transfer function about 3-axis SCARA robot by using DSA, and perform the gain tuning considering dynamic characteristic based on the bode plot. These experiments have shown that the proposed motion control can reduce vibration displacement and response error rate each 33.7% and 51.7% of 3-axis SCARA robot.

• The Journal of Korean Academy of Prosthodontics
• /
• v.29 no.3
• /
• pp.121-140
• /
• 1991

Fifteen dental college students of Chosun University without the abnormal occlusion, the history and symptom of temporomandibular dysfunction(TMD), and who had all permanent teeth except third molar and the fifteen moderate group and the fifteen severe group classified according to Helkimo's dysfunction index among patients on the basis of the symptom of TMD were selected. The occlusal contact, occlusal force and occlusal interference in eccentric movement was studied and analyzed using T-Scan system. The result were as follows : 1. The TLR centering around midsagittal axis was located at $1.42{\pm}0.82mm$ in control group, $3.36{\pm}1.45mm$ in severe group, and as TMD was heavier, occlusal contact was located at the farther point from midsagittal axis. 2. The PLR from the first contact to the fifth contact centering around midsagittal axis was located at $1.73{\pm}1.78mm$ in control group, $3.36{\pm}1.41mm$ in moderate group, and $5.39{\pm}4.32mm$ in severe group, and as TMD was heavier, occlusal contact was located at the farther point from midsgittal axis. 3. The TFB, PFB, RFB and LFB of occlusal contact centering around incisal axis had no significant difference statistically among control group, moderate group, and severe group, and it was located at first molar. 4.The LF and RF was smaller in TMD group than in control group. 5. The LR moment of occlusal force centering around midsagittal axis was located at $178.51{\pm}139.81N.mm$ in control group, $466.25{\pm}296.47N.mm$ in moderate group, and $749.18{\pm}588.18N.mm$ in severe group. And as TMD was heavier, it was located at the farther point from midsagittal axis. 6. The RL and LL of occlusal force centering around incisal axis had not-significance statistically among control group, moderate group, and severe group, and it was at the first molar. 7. The number of occlusal interference of the eccentric movement was increased in the patients of TMD.

• 제어로봇시스템학회:학술대회논문집
• /
• 1993.10a
• /
• pp.793-798
• /
• 1993

In this study the attitude control of the KOREASAT is investigated. The KOREASAT is a geostationary satellite and its 3 attitude angles, namely, roll, pitch and yaw angles, are stabilized by using the 3-axis stabilization technique. In the pitch control loop, the pitch attitude angle received from the earth sensor is processed in the attitude processing electronics by using PI type control logic, and the control command is sent to the momentum wheel assembly to generate the control torque by varying the wheel rate. The roll/yaw attitude control is performed by activating a magnetic torquer or by firing appropriate thrusters. The magnetic torquer interacts with the earth magnetic field to produce the control torque, and the thrusters are used to control the larger roll attitude errors. In this study dynamic modelling of the satellite is performed. And the earth sensor, the momentum wheel, and the magnetic torquer are mathematically modelled. The 3-axis attitude control logic is implemented to make the closed-loop system and simulations are carried out to verify the implemented control laws.

• Journal of Institute of Control, Robotics and Systems
• /
• v.22 no.3
• /
• pp.226-232
• /
• 2016

This paper describes the design of a smart three-axis force sensor for measuring forces Fx, Fy and Fz. The smart three-axis force sensor is composed of a three-axis force sensor, a force-measuring device, housing and a cover, where the three-axis force sensor and the force-measuring device are inside the housing and the cover. The measuring device measures forces Fx, Fy and Fz from the three-axis force sensor, and calculates the resultant force using the measured forces, and then sends the resultant force and forces to a PC or other controller using RS-485 communication. The repeatability error and the non-linearity error of the smart three-axis force sensor are less than 0.03%, and the interference error of the sensor is less than 0.87%. It is thought that the sensor can be used for measuring forces in a robot, automatic systems and so on.

• The KSFM Journal of Fluid Machinery
• /
• v.11 no.3
• /
• pp.43-49
• /
• 2008

The pump control valve is a butterfly valve that has an eccentric rotating axis. It is not only used as a butterfly valve to control the flow rate or pressure, but also as a check valve to prevent backward flow. A new design method of eccentric rotating axis is proposed to design the valve. The height of the rotating axis is determined through flow field analysis. A general purpose of computational fluid dynamics software system, Fluent is used to simulate the fluid flow. Flow field analysis is performed for various heights of the rotating axis and different opening angles of the valve. A characteristic function is defined for estimating the flow characteristics based on the results of flow field analysis. The characteristic function is defined in order to determine the height of the rotating axis. An optimization problem with a characteristic function is formulated to determine the amount of eccentricity. The height of the Totaling axis of the valve is determined through solving the optimization problem.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.31 no.2
• /
• pp.63-71
• /
• 2003

This paper presents a robust slewing control of a flexible space structure based on sliding surface design. A sliding surface is designed for a single-axis rest-to-rest slewing in view of target angle, target angular velocity, and root monent of the flexible appendage. In comparison with the Lypunov control law, both controllers guarantee the stability and command tracking capabilities for nominal system. It is also shown that the designed control law provides further robustness to internal/external uncertainties. Extending the results of a single-axis maneuver, a sliding mode control law was sought for an arbitrary three-axis maneuver. Quaternion was used to determine the attitude of a space structure and sliding surfaces were designed for each axis, thereby a robust control law was derived considering the coupling effects between each rotational axis during the maneuver. Several numerical examples were demonstrated to show the effectiveness of the designed control law.

• 제어로봇시스템학회:학술대회논문집
• /
• 1986.10a
• /
• pp.341-345
• /
• 1986

In the course of robot control system building, there are problems in the position control loop of 3rd axis of robot manipulator. The problems are summerized as two: one is uncontrollability of position and the other is oscillation. And these problems are analyzed through experiment, and it is known that the cause of problems in torsional vibration of 3rd axis. So that these two problems are solved by noise immunity enhancement and lowering of PI controller gain.