• Proceedings of the KIEE Conference
• /
• 1998.07g
• /
• pp.2348-2350
• /
• 1998

The hybrid control system for a wheeled mobile robot with nonholonomic constraints to perform a cluttered environment maneuver is proposed. The proposed hybrid control system consists of a continuous state system for the trajectory control, a discrete state system for the motion and orientation control, and an interface control system for the interaction process between the continuous dynamics and the discrete dynamics The continuous control systems are modeled by the switched systems with the control of driving wheels, and the digital automata for motion control are modeled and implemented by the abstracted motion of mobile robot. The motion control tasks such as path generation, motion planning, and trajectory control for a cluttered environment are investigated as the applications by simulation studies.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.25 no.12
• /
• pp.1601-1609
• /
• 1988

In the control of the robotic manipulators, the variable structure control method for the set point Regualation has an advantage of the insensitivity about parameter variations and disturbances. When the robotic manipulatores are controlled by a point-to-point scheme, no path constraint is considered. Thus, the variable structure control method will be effectively applied only if the trajectory of the robot hand is estimated precisely. In this paper, the joint trajectories in the joint space and the hand trajectory in the cartesian space are calculated by the variable structure control method, and an algorithm is suggested to elaborate the deviation error of the robot hand from a straight line path. The result of this study will become a base of the effective path planning about robotic manipulators with the variable structure control concept.

• Journal of the Korean Society for Precision Engineering
• /
• v.10 no.1
• /
• pp.52-61
• /
• 1993

Developed in this research is a CAM system for 5-axis NC Machining of sculptured surfaces. We identify problems in generating 5-axis NC data and propose methods of overcoming them. Issues discussed in this paper are: kinematic modelling of NC machines; determination of cutter position (location and orientation); check of machine work-range; linear trajectory plann- ing ; calculation of feedrate number. The proposed system has been implemented in FORTRAN77 on the Personal IRIS EWS, and it also constitutes a module of the CAD/CAM system 'CASSET' developed in KIST CAD/CAM lab.

• International Journal of Computer Science & Network Security
• /
• v.24 no.1
• /
• pp.17-22
• /
• 2024

The objective of this work is to design a low cost yet fully functional 4-DOF articulate manipulator for educational applications. The design is based on general purpose, programmable smart servo motors namely the Dynamixel Ax-12. The mechanism for motion was developed by formulating the equations of kinematics and subsequent solutions for joint space variables. The trajectory of end-effector in joint variable space was determined by interpolation of a 3rd order polynomial. The solutions were verified through computer simulations and ultimately implemented on the hardware. Owing to the feedback from the built-in sensors, it is possible to correct the positioning error due to loading effects. The proposed solution offers an efficient and cost-effective platform to study the trajectory planning as well as dynamics of the manipulator.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.9 no.2
• /
• pp.30-41
• /
• 2006

This paper proposes an e-logistics system supporting efficient vehicle moving trajectory management. Recent advances in wireless communications have given rise to a number of location-based services including logistics vehicle tracking, cellular phone user's location finding, and location-based commerce. Logistics systems typically entail tracking vehicles for purposes of the logistics center knowing the whereabouts of the vehicles and/or consignments. Moreover, storing and managing location trajectory of continuously moving vehicles and consignments is necessary for supporting efficient logistics plan and consignment. The proposed system is able to manage spatial objects in GIS as well as logistic information in the mobile environment. And for the efficiently managing and retrieving of transporting trajectory of logistics, we extend previous moving object indexing method, TB-Tree, to use multi-version framework and evaluate data updating performance. It is able to apply the proposed method to develop mobile contents services based on continuously changing location of moving object in the mobile environment.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.13 no.1
• /
• pp.18-23
• /
• 2003

This paper presents new algorithms of path planning and obstacle avoidance for an autonomous mobile robot to navigate under unknown environments in the real time. Temporary targets are set up by distance variation method and then the algorithms of trajectory planning and obstacle avoidance are designed using fuzzy rules. It is shown by computer simulation that these algorithms are working well. Furthermore, an autonomous mobile robot was constructed to implement and test these algorithms in the real field. The experimental results are also satisfactory just like those of computer simulation.

• Journal of Institute of Control, Robotics and Systems
• /
• v.17 no.5
• /
• pp.405-411
• /
• 2011

This paper presents a hierarchical trajectory planning method which can handle a collision-free of the planned path in complex and dynamic environments. A PV (Path & Velocity profile) planning method minimizes a sharp change of orientation and waiting time to avoid a collision with moving obstacle through detour path. The path generation problem is solved by three steps. In the first step, a smooth global path is generated using $A^*$ algorithm. The second step sets up the velocity profile for the optimization problem considering the maximum velocity and acceleration. In the third step, the velocity profile for obtaining the shortest path is optimized using the fuzzy and genetic algorithm. To show the validity and effectiveness of the proposed method, realistic simulations are performed.

• Proceedings of the KIEE Conference
• /
• 1999.11c
• /
• pp.661-663
• /
• 1999

본 논문에서는 새로운 경로 계획 방법으로 중심 이등에 의한 경로 알고리즘을 제안한다. 제안된 알고리즘을 사용하여 곡률 반경을 이용한 경로 계획의 문제점인 각도오차가 커질수록 우회하는 현상을 보다 효율적으로 해결함을 시뮬레이션을 통하여 보인다. 또한 제안된 경로 알고리즘에 칼만 필터를 이용한 예측기를 적용시켜 로봇이 공을 추정하는데 발생할 수 있는 잡음에 강인함을 보이며 신뢰성 있는 결과를 확인한다.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.26 no.10
• /
• pp.1471-1478
• /
• 1989

The optimal-time control of the coordinated motion of two robot manipulators may be of consequence in the industrial automation. In this paper two robot manipulators garsping a common object are assumed to travel a specified Cartesian path and the method how to derive the optimal-time solution is explained. This approach is based on parameterizing the corresponding patn and utilizing the phase-plame technique in the trajectory planning. Also the torques supplied by the actuators are assumed to have some constant bounds. The effectiveness of this approach is demonstrated by a computer simulation using a PUMA 560 manipulator.

• 제어로봇시스템학회:학술대회논문집
• /
• 1991.10a
• /
• pp.1052-1056
• /
• 1991

페인팅작업에의 로보트응용은 열악환경의 극복, 자동화, 품질의 향상수단으로서 강력한 대안책이며 이에 관한 관심이 국내외에 고조되고 있다. 본 논문에서는 이전에 제시한 바있는 자동동작계획의 개념을 확장하여 통합페인팅시스템을 위한 Extended ATPS(Automatic Trajectory Planning System)를 개발하고, 이의 구현 및 검증을 위한 하드웨어 시스템의 개발현황을 소개한다. 개발될 시스템은 하드웨어 및 소프트웨어가 일식화된 로보틱페인팅 시스템으로서 동작계획의 자동화 뿐만아니라 측정 및 제어기능을 소프트웨어에서 일관처리하는 새로운 방식이다.