• Title/Summary/Keyword: Link-motion

Search Result 267, Processing Time 0.023 seconds

Force control of a structurally flexible robotic manipulator

  • 최병오
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 1992.04a
    • /
    • pp.369-373
    • /
    • 1992
  • Force control of a planar two-link structurally flexible robotic manipulator is considered in this study. The dynamic model is obtained by using the extended Hamilton's principle and the Galerkin criterion. A method is pressented toobtain the linearized equations of motion in Cartesian space for use in designing the control system. The approachto solving the control problem is to use feedforward and feedback control torques. The feedforward torques maneuver the flexible manipulatro along a nominal trajectory and the feedback torques minimize any deviations from the nominal trajectory. The linear quadratic Gaussian/loop transfer recovery (LQG/LTR) design methodology is explotied to design a robust feedback control system that can handle modeling errors and sensor noise, and operates on Cartesian space trajectory errors. The Lqg/LTR compenstaor together with a feedforward ollp is used to control the flexible manipulator. Simulated results are presented for a numerical example.

Code Optimization Techniques to Reduce Energy Consumption of Multimedia Applications in Hybrid Memory

  • Dadzie, Thomas Haywood;Cho, Seungpyo;Oh, Hyunok
    • IEIE Transactions on Smart Processing and Computing
    • /
    • v.5 no.4
    • /
    • pp.274-282
    • /
    • 2016
  • This paper proposes code optimization techniques to reduce energy consumption of complex multimedia applications in a hybrid memory system with volatile dynamic random access memory (DRAM) and non-volatile spin-transfer torque magnetoresistive RAM (STT-MRAM). The proposed approach analyzes read/write operations for variables in an application. Based on the profile, variables with a high read operation are allocated to STT-MRAM, and variables with a high write operation are allocated to DRAM to reduce energy consumption. In this paper, to optimize code for real-life complicated applications, we develop a profiler, a code modifier, and compiler/link scripts. The proposed techniques are applied to a Fast Forward Motion Picture Experts Group (FFmpeg) application. The experiment reduces energy consumption by up to 22%.

A Compliance Control Strategy for Robot Manipulators Under Unknown Environment

  • Kim, Byoung-Ho;Oh, Sang-Rok;Suh, Il-Hong;Yi, Byung-Ju
    • Journal of Mechanical Science and Technology
    • /
    • v.14 no.10
    • /
    • pp.1081-1088
    • /
    • 2000
  • In this paper, a compliance control strategy for robot manipulators that employs a self-adjusting stiffiness function is proposed. Based on the contact force, each entry of the diagonal stiffness matrix corresponding to a task coordinate in the operational space is adaptively adjusted during contact along the corresponding axis. The proposed method can be used for both the unconstrained and constrained motions without any switching mechanism which often causes undesirable instability and/or vibrational motion of the end-effector. The experimental results involving a two-link direct drive manipulator interacting with an unknown environment demonstrates the effectiveness of the proposed method.

  • PDF

Composite Fuzzy Control of a Single Flexible Link Manipulator (단일 유연 링크 매니퓰레이터의 복합 퍼지 제어)

  • 김재승;이수한
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2000.10a
    • /
    • pp.353-353
    • /
    • 2000
  • To control a light weight flexible manipulator, a composite fuzzy controller is proposed. The controller is designed based on two time scaled models. A singular perturbation technique is applied for deriving the models. The proposed controller, however, does not use the complex equilibrium manifold equations, which are usually needed in the controller based on the two time scaled models. The controller for a slow sub-model and a fast sub-model are T-S type fuzzy controllers, which use 3 linguistic variables for each sub-model. A step trajectory is used in simulations as a reference trajectory of joint motions. The results of simulations with the proposed controller show excellent damping of flexible motions compared to a controller with derivative control of flexible motions.

  • PDF

Constrained Structured Sliding Mode Control for Position Tracking-Force Reflection Control of Master-Slave Manipulator (마스터-슬레이브 조작기의 위치추종-힘반영을 위한 제한 구조 슬라이딩모드 제어)

  • Kang, Min-Sig
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.27 no.12
    • /
    • pp.48-58
    • /
    • 2010
  • In this study, position tracking and force reflection control of a master-slave manipulator which will be used for handling objects contaminated by radioactivity has been addressed. Since available measurements concerning on dynamic motion of the master-slave manipulator are restricted, a simple constrained control structure was suggested. In the consideration of the uncertain dynamic behaviors of the slave manipulator which is dependent upon mass and shape of work pieces grasped and dynamic properties of the environment contacted, a simple structured sliding mode control was suggested to guarantee robustness with respect to parameter uncertainties and external disturbances. The proposed control was applied to a 1-DOF master-slave link system. The control performances were verified along with some computer simulation results.

Installation Error Calibration by Using Levenberg-Marquardt Method on a Cubic Parallel Manipulator (Levenberg-Marquardt 방법을 이용한 육면형 병렬기구의 설치 오차 보정)

  • 임승룡;임현규;최우천;송재복;홍대희
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.20 no.2
    • /
    • pp.184-191
    • /
    • 2003
  • A parallel manipulator has high stiffness and all the joint errors on the device are not accumulated at the end -effector unlike a serial manipulator. These are the reasons why the parallel manipulator has been widely used in many fields of industry. In the parallel manipulator, it is very important to predict the exact pose of the end-effector when we want to control the end-effector motion. Installation errors have to be determined in order to predict and control the actual position and pose of the end-effector. This paper presents an algorithm to find the whole 36 joint error components with joint clearance errors and measurement errors considered, when a link length measurement sensor is used and data more than 36 times are acquired for 36 different configurations. A simulation test using this algorithm is performed with a Matlab program which uses the Levenberg-Marquardt method that is known to be efficient for non-linear optimization.

Multi user interference cancellation in satellite to ground uplink system Based on improved WPIC algorithm

  • Qingyang, Guan
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.10 no.11
    • /
    • pp.5497-5512
    • /
    • 2016
  • An improved optimal weights based on parallel interference cancellation algorithm has been proposed to cancel for interference induced by multi-user access satellite to ground uplink system. Due to differences in elevation relative motion between the user and the satellite, as well as access between users, resulting in multi-user access interference (Multi-user Access Interference, MUI), which significantly degrade system performance when multi-user access. By steepest gradient method, it obtained based on the MMSE criterion, parallel interference cancellation adjust optimal weights to obtain the maximum SINR. Compared to traditional parallel interference cancellation (Parallel Interference Cancellation, PIC) algorithm or serial interference cancellation ( Successive interference Cancellation, SIC), the accuracy of which is not high and too many complex iterations, we establish the multi-user access to the satellite to ground up link system to demonstrate that the improved WPIC algorithm could be provided with high accuracy and relatively low number of iterations.

Optimal design of an automatic walking robot based on Jansen's Mechanism (얀센 메커니즘을 이용한 자동주행 보행 로봇의 최적 설계)

  • Kim, Dong-Chan;Kim, Mu-Hwan;Lee, Min-Su;Park, Je-Yeol;Jo, Seong-Uk
    • Proceeding of EDISON Challenge
    • /
    • 2017.03a
    • /
    • pp.540-546
    • /
    • 2017
  • Bipedal robots tend to have greater mobility than conventional treaded or wheeled robots yet they are commonly complicated by instabilities in balance. This paper presents a bipedal robot based upon Jansen's locomotive mechanism which addresses these challenges in stability and efficiency. In order to achieve a functioning robot, we considered a multitude of variables in its motion including, the Ground Score, Drag Score, step size, foot lift, stride, and instantaneous speed of the Jansen mechanism. Matlab and Jansen Opt solver were used to optimize the legs of the robot. A trial and error experimental method was used to determine the best combination of link lengths, and m.Sketch was used to model our results. Finally, we drew the entirety of the robot's figure by using the Edison design.

  • PDF

Study on the moving device of press machine for forming impact reduction (성형충격 저감을 위한 프레스 구동기구에 관한 연구)

  • Kim, Jeong-Eon;Hong, Seok-Kwan;Kim, Jong-Deok;Heo, Young-Moo;Cho, Chong-Du;Kang, Jeong-Jin
    • Design & Manufacturing
    • /
    • v.2 no.4
    • /
    • pp.11-15
    • /
    • 2008
  • In the sheet metal forming using a high speed press machine, driving device, such as crank, link, and knuckle mechanism, has to be designed in consideration of impact at a moment when press die contact with material, because the impact affects a dimensional accuracy of products and a life span of press die. In this study, dynamic analysis was performed using numerical simulation in order to verify the impact reduction effect for proposed double knuckle mechanism by estimating rolling and pitching moment of slide.

  • PDF

Local and Global Isotropy Analysis of Caster Wheeled Omnidirectional Mobile Robot

  • Kim Sung-bok;Moon Byoung-kwon
    • Journal of the Institute of Convergence Signal Processing
    • /
    • v.7 no.1
    • /
    • pp.38-44
    • /
    • 2006
  • The omnidirectional mobility of a mobile robot may lose significance in motion control, unless the isotropy characteristics of the mechanism is maintained well. This paper investigates the local and global isotropy of an omnidirectional mobile robot with three caster wheels. All possible actuations with different number and combination of rotating and steering joints are considered. First, the kinematic model based on velocity decomposition and the algebraic conditions for the local isotropy are obtained. Second, the geometric conditions for the local isotropy are derived and all isotropic configurations are fully identified. Third, the global isotropy index is examined to determine the optimal parameters in terms of actuation set, characteristic length, and steering link length.

  • PDF