• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2003년도 ICCAS
• /
• pp.1190-1195
• /
• 2003

In this paper, it is shown how a robot with n passive trailers can be controlled in backward direction. When driving backward direction, a kinematic model of the system is represented highly nonlinear equations. The problem is formulated as a trajectory following problem, rather than control of independent generalized coordinates. Also, the state and input saturation problems are formulated as a trajectory generation problem. The trajectory is traced by a rear hinge point of the last trailer, and reference trajectories include line segments, circular shapes and rectangular turns. Experimental verifications were carried out with the PSR-2(public service robot $2^{nd}$ version) with three passive trailers. Experimental result showed that the backward motion control can be successfully carried out using the proposed control scheme.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2007년도 춘계학술대회A
• /
• pp.1120-1125
• /
• 2007

Experimental study on the control of randomly disturbing system is conducted. External and internal disturbances are imposed to the system in combined manner. A vertical propeller system exposed horizontal weak turbulent air flow is chosen as an experimental model. The aim of the control system is to maintain the angular position of vertical propeller in parallel to air flow. Trajectory Tracking Stochastic Controller (TTSC) is designed to ensure system's stability while following system command. The Trajectory Tracking Stochastic Controller is composed of two controller, one is stochastic controller to suppress internal random noise and the other one is trajectory-tracking controller to follow the command having random noise. The proposed hybrid controller, TTSC, shows remarkable performance in pitch control of vertical propeller system in wind-tunnel test

• 한국생산제조학회지
• /
• 제24권4호
• /
• pp.374-385
• /
• 2015

In this paper, effective and user friendly CAM software is presented that automatically generates any three dimensional complex toolpaths according to a CAD drawing. In advanced manufacturing, often it is essential to scan the sample following a complex trajectory which consists of short (few microns) and multidirectional moves. The reported CAM software offers constant velocity for all short trajectory elements and provides an efficient shift of tool path direction in sharp corners of a tool trajectory, which is vital for any laser, based precision machining. The software also provides fast modification of tool path, automatic and efficient sequencing of path elements in a complicated tool trajectory, location of reference point and automatic fixing of geometrical errors in imported drawing exchange files (DXF) or DWG format files.

• EDISON SW 활용 경진대회 논문집
• /
• 제6회(2017년)
• /
• pp.528-532
• /
• 2017

The Theo Jansen mechanism using 1 degree of freedom is special system of walking robot. The trajectory made by the point of ground position is similar to other walking robot using many degrees of freedom. Because of diversity of design parameter of the Jansen mechanism, it makes a lot of trajectory and takes possibilities of optimization. However this research doesn't focus on the optimization of trajectory, but it focused on comprehensive design of the robot using well-known trajectory and line tracer logic to go fast and accurate along the line. The logic to follow a line has many kinds of possibility of algorithm. To eliminate uncertainty about recognizing a line, I divide the case of line following situation and make optimized logic.

• 한국지능시스템학회논문지
• /
• 제23권1호
• /
• pp.29-34
• /
• 2013

본 논문은 애드혹 통신을 기반으로 아이폰의 가속도 센서를 사용하여 이동로봇을 무선 제어하는 연구에 대하여 다룬다. 이동로봇을 아이폰으로 무선제어하기 위한 방법으로 사용자 원격제어와 자율제어 방법이 제안되었다. 궤적 추종제어 알고리즘의 효율성을 평가하기 위하여 아이폰의 인터페이스를 기반으로 모니터에 그려진 궤적을 가상로봇이 추종하는 시뮬레이터를 개발하였다. 제안된 시뮬레이터에서는 궤적 추종제어를 위해 이동로봇을 제어할 때 컴퓨터에서 해당 알고리즘을 이용하여 미리 시뮬레이션이 가능하며 사용자에 의한 원격제어와의 결과 비교도 보여준다. 연구의 결과로 제안된 시뮬레이터가 이동로봇에 자율이동제어 방법을 사용할 때, 자율추종 알고리즘의 적합성과 효율성을 미리 검사 하는데 사용될 수 있음을 보여준다.

• 한국통신학회논문지
• /
• 제39C권1호
• /
• pp.47-59
• /
• 2014

본 논문은 실내 환경에서의 엔터테인먼트 활용을 목적으로 쿼드로터형 비행체를 위한 비전 기반의 궤적 추종제어 시스템을 다룬다. 항공촬영 및 감시 등의 특수임무를 완수하기 위해 자율성이 강조되는 실외 비행체와 비교할 때, 엔터테인먼트를 목적으로 하는 실내 환경에서의 비행체를 위해서는 안정성 및 정밀성이 특히 고려된 호버링 및 궤적추종 기능 등이 요구된다. 이에, 본 논문은 동작생성, 자세추정, 궤적추종 모듈로 구성된 궤적추종 제어시스템을 제안한다. 동작생성 모듈은 매 시간에서의 3차원 자세로 기술되는 동작들에 대한 연속적인 시퀀스를 생성한다. 자세추정 모듈은 비행체에 장착된 원형 링 패턴의 인식을 통해 쿼드로터의 3차원 자세정보를 추정한다. 궤적추종 모듈은 동작생성 모듈과 자세추정 모듈로부터 제공되는 정보를 이용하여 쿼드로터 비행체의 3차원 위치를 실시간적으로 제어한다. 제안된 시스템의 성능은 단일 점 추종, 다점 추종, 곡선궤적 추종에 대한 실험을 통해 평가된다.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국제학술편); Seoul National University, Seoul; 20-22 Oct. 1993
• /
• pp.230-233
• /
• 1993

This paper described a relationship between motion speed and working accuracy of industrial articulated robot arms. Working accuracy of the robot arm deteriorates at high speed operation caused by a nonlinear transformation of the kinematics and the time delay of the robot arm dynamic. The deterioration of the following trajectory was expressed as a linear function of the squares of the robot arm motion speed, depending upon a posture of the robot arm and division interval of the objective trajectory.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1988년도 한국자동제어학술회의논문집(국내학술편); 한국전력공사연수원, 서울; 21-22 Oct. 1988
• /
• pp.67-71
• /
• 1988

We present an algorithm that uses trajectory following errors to improve a feedforward command to a robot in the iterative manner. It has been shown that when the manipulator handles an unknown object, the P-type learning algorithm can make the trajectory converge to a desired path and also that the proposed learning control algorithm performs better than the other type learning control algorithm. A numerical simulation of a three degree of freedom manipulator such as PUMA-560 ROBOT has been performed to illustrate the effectiveness of the proposed learning algorithm.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2011년도 제42회 하계학술대회
• /
• pp.1770-1771
• /
• 2011

In mission planning of UAV applications, especially for the missions requiring height transitions, it is required to generate reference flight trajectories considering the performances of the engine installed in the UAV. Even though the vertical line following guidance based height transition trajectory generation method has been developed to build reference height transition trajectories easily, it is not adequate for considering engine performances effectively since many engine characteristics and performances have conventionally been described in the V-H(speed-height) plane which is not the very space where the UAVs are actually flying. In this paper, we derive the trajectories in V-H plane for the vertical line following flights. And based on the results, a new algorithm to design the reference height transition trajectories for UAV applicaions. Simulation results demonstrate that the proposed algorithm is very effective and easily applicable.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제18권7호
• /
• pp.1726-1748
• /
• 2024

Trajectory planning is vital for autonomous systems like robotics and UAVs, as it determines optimal, safe paths considering physical limitations, environmental factors, and agent interactions. Recent advancements in trajectory planning and future location prediction stem from rapid progress in machine learning and optimization algorithms. In this paper, we proposed a novel framework for Spatial-temporal transformer-based feed-forward neural networks (STTFFNs). From the traffic flow local area point of view, skip-gram model is trained on trajectory data to generate embeddings that capture the high-level features of different trajectories. These embeddings can then be used as input to a transformer-based trajectory planning model, which can generate trajectories for new objects based on the embeddings of similar trajectories in the training data. In the next step, distant regions, we embedded feedforward network is responsible for generating the distant trajectories by taking as input a set of features that represent the object's current state and historical data. One advantage of using feedforward networks for distant trajectory planning is their ability to capture long-term dependencies in the data. In the final step of forecasting for future locations, the encoder and decoder are crucial parts of the proposed technique. Spatial destinations are encoded utilizing location-based social networks(LBSN) based on visiting semantic locations. The model has been specially trained to forecast future locations using precise longitude and latitude values. Following rigorous testing on two real-world datasets, Porto and Manhattan, it was discovered that the model outperformed a prediction accuracy of 8.7% previous state-of-the-art methods.