• Title/Summary/Keyword: Velocity Command

Search Result 109, Processing Time 0.024 seconds

Control Method of Mobile Robots for Avoiding Slip and Turnover on Sloped Terrain Using a Gyro/Vision Sensor Module (Gyro/Vision Sensor Module을 이용한 주행 로봇의 미끄러짐 및 넘어짐 회피 제어 기법)

  • Lee Jeong-Hee;Park Jae-Byung;Lee Beom-Hee
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.11 no.8
    • /
    • pp.669-677
    • /
    • 2005
  • This acticle describes the control method of mobile robots for avoiding slip and turnover on sloped terrain. An inexpensive gyro/vision sensor module is suggested for obtaining the information of terrain at present and future. Using the terrain information and the robot state, the maximum limit velocity of the forward velocity of the robot is defined fur avoiding slip and turnover of the robot. Simultaneously the maximum value of the robot velocity is reflected to an operator in the form of reflective force on a forte feedback joystick. Consequently the operator can recognize the maximum velocity of the robot determined by the terrain information and the robot state. In this point of view, the inconsistency of the robot movement and the user's command caused by the limit velocity of the robot can be compensated by the reflective force. The experimenal results show the effectiveness of the suggested method.

Design Problem of Automated Warehouse Systems Subject to Minimum Cost and Maximum Throughput

  • Ro, In Kyu;Lee, Hyoung Seok
    • Journal of Korean Society for Quality Management
    • /
    • v.16 no.2
    • /
    • pp.99-110
    • /
    • 1988
  • This study is concerned with a design algorithm to minimize the investment as well as maximize the throughput in automated warehouse system. A simulation model is designed and a solution methodology is proposed. The experiment, are conducted for the cases with 100, 90, 80, 70, 60, 50 and 0 % dual command policies in terms of the important factors such as the crane velocity, the height of system and the rack utilization. The results indicate that the throughput is slightly decreased when the ratio of dual command is decreased and the other characteristics however are not affected. The result also shows that the optimal rack should be designed for a crane to take the same amount of travel time for horizontal and vertical movement.

  • PDF

Relative Motion Control Methodology Using the Minimum Relative Error Between Two Systems (두 시스템간의 편차 최소화를 적용한 상대적 동작제어 방법)

  • 김성권
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.9 no.12
    • /
    • pp.994-1000
    • /
    • 2003
  • A new relative motion control methodology for a following system to an independent leading system is proposed for controlling relative position, velocity, and tension etc. It is based on maintaining minimum relative error between two independent systems. The control command of the following system to a leading system is generated by adding the current command and the output of the relative error compensation. The proposed control method is implemented on the experimental equipment which is a wire winding-unwinding system to control the tension of the line. The results show the unwinding system(follower) following the independent motion of the winding system(leader) to control the constant tension of the line in order to keep the roller dancer in reference position. The relative motion control method proposed in this paper can be applied to high precision equipment for unwinding and winding fine wire, fine fiber, and tape etc.

Controller Design for a Robot's Safe Contact on an Object (원격조종 로봇의 안전한 물체 접근을 위한 제어기 구성)

  • Shin Wan-Jae;Park Jahng-Hyon
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.23 no.4 s.181
    • /
    • pp.83-90
    • /
    • 2006
  • A robot manipulator is usually operated in two modes: free and constrained motion modes, depending on whether the robot is in contact with an environment or not. At the moment of contact, an impact occurs and can exert harmful effects to the robot or the object. In case of teleoperation, since a user may give an inadequately excessive velocity command to the slave due to insufficient visual information, the robot nay collide the object with an excessive speed and it possibly deteriorates the robot's performance causing vibrations and at worst, shortens its lifetime by its fracture. In this article, a new algorithm is proposed by introducing a command signal modification method on the basis of impedance control and validity of the proposed algorithm is demonstrated by performing simulations and experiments.

UAV Formation Wight Control Law Utilizing Energy Maneuverability

  • Choi, Jong-Ug;Kim, You-Dan;Moon, Gwan-Young
    • International Journal of Aeronautical and Space Sciences
    • /
    • v.9 no.1
    • /
    • pp.31-41
    • /
    • 2008
  • This paper deals with the energy saving problem of the follower aircraft in the loose leader-follower formation geometry in which the lateral separation between formation members is more than a wingspan of the leader aircraft. This formation geometry offers no drag benefit, but has a strategic advantage. In the case of loose formation flight, the follower aircraft usually consumes more energy than the leader aircraft because the follower aircraft should use more thrust to maintain given formation geometry, especially during the turning phase from the outside of the leader"s flight path or join-up phase. A formation control scheme based on the energy maneuverability is proposed in this paper. To design the proposed control law, the velocity command is designed using feedback linearization for the horizontal formation geometry and then coverts it to the altitude command using the energy equation. Numerical simulation is performed to verify the effectiveness of the proposed controller.

A Lane Based Obstacle Avoidance Method for Mobile Robot Navigation

  • Ko, Nak-Yong;Reid G. Simmons;Kim, Koung-Suk
    • Journal of Mechanical Science and Technology
    • /
    • v.17 no.11
    • /
    • pp.1693-1703
    • /
    • 2003
  • This paper presents a new local obstacle avoidance method for indoor mobile robots. The method uses a new directional approach called the Lane Method. The Lane Method is combined with a velocity space method i.e., the Curvature-Velocity Method to form the Lane-Curvature Method (LCM). The Lane Method divides the work area into lanes, and then chooses the best lane to follow to optimize travel along a desired goal heading. A local heading is then calculated for entering and following the best lane, and CVM uses this local heading to determine the optimal translational and rotational velocities, considering some physical limitations and environmental constraint. By combining both the directional and velocity space methods, LCM yields safe collision-free motion as well as smooth motion taking the physical limitations of the robot motion into account.

A Stable Locomotion Control Method for an Autonomous Mobile Robot (자율 이동 로보트를 위한 안정한 주행 제어 방법)

  • Shim, Hyun-Sik;Kim, Jong-Hwan
    • Proceedings of the KIEE Conference
    • /
    • 1992.07a
    • /
    • pp.374-376
    • /
    • 1992
  • This paper proposes a stable locomotion control rule for non-holonomic mobile robot. Stability of the rule is proved through the use of a Liapunov function. We have two controller for locomotion control. One is velocity controller, the other is position controller. The proposed controller is position controller whose input to robot are a reference posture and reference velocities. The major objective of this paper is to propose a control rule to find a reasonable velocity command under a assumption which is velocity controller is ideal controller.

  • PDF

Development of a Aerostatic Guideway Driven by the Linear Motor (리니어모터를 이용한 초정밀 공기정압안내면 개발)

  • 박종하;황주호;박천홍;홍준희
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
    • /
    • 2003.10a
    • /
    • pp.36-40
    • /
    • 2003
  • In order to discuss the availability of aerostatic guideways driven by the coreless linear motor to ultra precision machine tools, a prototype of guideway is designed and tested in this research. A coreless linear DC motor with the continuous force of 156N and a laser scale with the resolution of $0.01\mu\textrm{m}$ are used as the feeding system. The experiments are performed on the static stiffness, motion accuracy, positioning accuracy, microstep response and variation of velocity. The guideway also has $0.21\mu\textrm{m}$ of positioning error and $0.09\mu\textrm{m}$ of repeatability, and it shows the stable response against the $0.01\mu\textrm{m}$ resolution step command. The velocity variation of feeding system is less than 0.6%. From these results, it is confirmed that the aerostatic guideway driven by the coreless linear motion is very useful for the ultra precision machine tools.

  • PDF

Improvement of elevator position control performance in unified control system (통합 제어 시스템에서의 엘리베이터 위치 제어 성능 개선)

  • Ryu, Hyung-Min;Sul, Seung-Ki
    • Proceedings of the KIEE Conference
    • /
    • 2002.04a
    • /
    • pp.34-36
    • /
    • 2002
  • This paper addresses an elevator position control scheme in unified control system. Conventional systems have employed independent micro-processors for speed, car, and group control respectively and the car controller generates a velocity command by combining the time-based and distance-based velocity pattern. In this scheme, it is inevitable that an elevator creeps in the vicinity of target floor, or stops abruptly. The proposed control system employs only one high-performance micro-processor, which can execute the car and group control as well as the speed control. It simply generates the desired position trajectory based on time and on-line corrects a velocity pattern to make the position error be zero. Experimental results show the feasibility of the proposed control scheme.

  • PDF

Nonlinear Adaptive Velocity Controller Design for an Air-breathing Supersonic Engine

  • Park, Jung-Woo;Park, Ik-Soo;Tahk, Min-Jea
    • International Journal of Aeronautical and Space Sciences
    • /
    • v.13 no.3
    • /
    • pp.361-368
    • /
    • 2012
  • This paper presents an approach on the design of a nonlinear controller to track a reference velocity for an air-breathing supersonic vehicle. The nonlinear control scheme involves an adaptation of propulsive and aerodynamic characteristics in the equations of motion. In this paper, the coefficients of given thrust and drag functions are estimated and they are used to approximate the equations of motion under varying flight conditions. The form of the function of propulsive thrust is extracted from a thrust database which is given by preliminary engine input/output performance analysis. The aerodynamic drag is approximated as a function of angle of attack and fin deflection. The nonlinear controller, designed by using the approximated nonlinear control model equations, provides engine fuel supply command to follow the desired velocity varying with time. On the other hand, the stabilization of altitude, separated from the velocity control scheme, is done by a classical altitude hold autopilot design. Finally, several simulations are performed in order to demonstrate the relevance of the controller design regarding the vehicle.