• Title/Summary/Keyword: velocity control algorithm

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Trajectory tracking control of underactuated USV based on modified backstepping approach

  • Dong, Zaopeng;Wan, Lei;Li, Yueming;Liu, Tao;Zhang, Guocheng
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.7 no.5
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    • pp.817-832
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    • 2015
  • This paper presents a state feedback based backstepping control algorithm to address the trajectory tracking problem of an underactuated Unmanned Surface Vessel (USV) in the horizontal plane. A nonlinear three Degree of Freedom (DOF) underactuated dynamic model for USV is considered, and trajectory tracking controller that can track both curve trajectory and straight line trajectory with high accuracy is designed as the well known Persistent Exciting (PE) conditions of yaw velocity is completely relaxed in our study. The proposed controller has further been enriched by incorporating an integral action additionally for enhancing the steady state performance and control precision of the USV trajectory tracking control system. Global stability of the overall system is proved by Lyapunov theory and Barbalat's Lemma, and then simulation experiments are carried out to demonstrate the effectiveness of the controller designed.

Design and Analysis of Fuzzy PID Controller for Control of Nonlinear System (비선형 시스템 제어를 위한 퍼지 PID 제어기의 설계 및 해석)

  • Lee, Chul-Heui;Kim, Sung-Ho
    • Journal of Industrial Technology
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    • v.20 no.B
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    • pp.155-162
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    • 2000
  • Although Fuzzy Logic Controller(FLC) adopted three terms as input gives better performance, FLC is in general composed of two-term control because of the difficulty in the construction of fuzzy rule base. In this paper, a three-term FLC which is similar to PID control but acts as a nonlinear controller is proposed. To reduce the complexity of the rule base design and to increase efficiency. a simplified fuzzy PID control is induced from a hybrid velocity/position type PID algorithm by sharing a common rule base for both fuzzy PI and fuzzy PD parts. It is simple in structure, easy in implementation, and fast in calculation. The phase plane technique is applied to obtain the rule base for fuzzy two-term control and the resultant rule base is Macvicar-Whelan type. And the membership function is a Gaussian function. The frequency response information is used in tuning of the membership functions. Also a tuning strategy for the scaling factors is proposed based on the relationship between PID gain and the scaling factors. Simulation results show better performance and the effectiveness of the proposed method.

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Development of Fast Side-impact Sensing Algorithm (고속 측면 충돌 감지 알고리즘의 개발)

  • 박서욱;김현태
    • Transactions of the Korean Society of Automotive Engineers
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    • v.8 no.3
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    • pp.163-170
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    • 2000
  • Accident statistics shows that the portion of fatal occupant injuries due to side impacts is considerably high. The side impact usually leads to a severe intrusion of side structure into the passenger compartment. Furthermore, the safety zone for the side impact is relatively small compared to the front impact. Those kinds of physics for side impact frequently result in a fatal injury for the occupant. Therefore, NHTSA and EEVC are trying to intensify the regulation for the occupant protection against side impact. Both the regulation and recent market trends are asking for an installation of side airbag. There are several types of system configuration for side impact sensing. In this paper, we adopt the acceleration-based remote sensing method for the side airbag control system. We mainly focus on the development of hardware and crash discrimination algorithm of remote sensing unit. The crash discrimination algorithm needs fast decision of airbag firing especially for high-speed side impact such as FMVSS 214 and EEVC tests. It is also required to distinguish between low-speed fire and no-fire events. The algorithm should have a sufficient safety margin against any misuse situation such as hammer blow, door slam, etc. This paper introduces several firing criteria such as acceleration. velocity and energy criteria that use physical value proportional to crash severity. We have made a simulation program by using Matlab/Simulink to implement the proposed algorithm. We have conducted an algorithm calibration by using real crash data for 2,500cc vehicle. The crash performance obtained by the simulation was verified through a pulse injection method. It turned out that the results satisfied the system requirements well.

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Design and Control of Hybrid a Powered Wheelchair for the Elderly (고령자를 위한 하이브리드형 전동 휠체어의 설계 및 제어)

  • Yoon, Tae-Su;Ann, Sung-Jo;Kim, Sang-Min;Han, Young-Bin;Kim, Jung-Yup
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.40 no.12
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    • pp.1067-1076
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    • 2016
  • This paper describes the development of a hybrid-powered wheelchair (HPW) for the elderly. The proposed HPW has novel mechanical and control features compared with conventional powered wheelchairs. An ergonomic back-braking mechanism was designed in order to stop the wheels easily. In terms of control features, the HPW remarkably reduces the muscle power required by combining various assistive functions, such as wheel torque assistance, friction/inertia compensation, gravity compensation, and the one-hand driving algorithm. For wheel torque assistance, strain gauges were attached to the hand-rim in order to measure the wheel torque applied by a human. Gyroscopes and an accelerometer were attached to the wheel and chair respectively for friction and inertia compensation. An inclinometer was attached for gravity compensation and the one-hand driving algorithm was included for patients who can only use one hand. The one-hand driving algorithm controls the angular velocity of the uncontrolled wheel by using a gyroscope and pressure sensors attached to the bottom of the seat. Finally, the performance of the proposed motion assisted algorithm was verified through various experiments.

GPS/INS Integration using Fuzzy-based Kalman Filtering

  • Lim, Jung-Hyun;Ju, Gwang-Hyeok;Yoo, Chang-Sun;Hong, Sung-Kyung;Kwon, Tae-Yong;Ahn, Iee-Ki
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.984-989
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    • 2003
  • The integrated global position system (GPS) and inertial navigation system (INS) has been considered as a cost-effective way of providing an accurate and reliable navigation system for civil and military system. Even the integration of a navigation sensor as a supporting device requires the development of non-traditional approaches and algorithms. The objective of this paper is to assess the feasibility of integrated with GPS and INS information, to provide the navigation capability for long term accuracy of the integrated system. Advanced algorithms are used to integrate the GPS and INS sensor data. That is fuzzy inference system based Weighted Extended Kalman Filter(FWEKF) algorithm INS signal corrections to provided an accurate navigation system of the integrated GPS and INS. Repeatedly, these include INS error, calculated platform corrections using GPS outputs, velocity corrections, position correction and error model estimation for prediction. Therefore, the paper introduces the newly developed technology which is aimed at achieving high accuracy results with integrated system. Finally, in this paper are given the results of simulation tests of the integrated system and the results show very good performance

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Control and VR Navigation of a Gait Rehabilitation Robot with Upper and Lower Limbs Connections (상하지가 연동된 보행재활 로봇의 제어 및 VR 네비게이션)

  • Novandy, Bondhan;Yoon, Jung-Won
    • Journal of Institute of Control, Robotics and Systems
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    • v.15 no.3
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    • pp.315-322
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    • 2009
  • This paper explains a control and navigation algorithm of a 6-DOF gait rehabilitation robot, which can allow a patient to navigate in virtual reality (VR) by upper and lower limbs interactions. In gait rehabilitation robots, one of the important concerns is not only to follow the robot motions passively, but also to allow the patient to walk by his/her intention. Thus, this robot allows automatic walking velocity update by estimating interaction torques between the human and the upper limb device, and synchronizing the upper limb device to the lower limb device. In addition, the upper limb device acts as a user-friendly input device for navigating in virtual reality. By pushing the switches located at the right and left handles of the upper limb device, a patient is able to do turning motions during navigation in virtual reality. Through experimental results of a healthy subject, we showed that rehabilitation training can be more effectively combined to virtual environments with upper and lower limb connections. The suggested navigation scheme for gait rehabilitation robot will allow various and effective rehabilitation training modes.

Improved Sensorless Control of Induction motor by Rotor Resistance Compensation (슬립각속도를 사용하는 회전자 저항 보정에 의한 유도전동기의 센서리스 속도제어 개선)

  • Park, Kang-Hyo;Kwon, Young-Ahn
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.15 no.4
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    • pp.886-890
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    • 2011
  • Induction motors are relatively cheap and rugged machines. For the vector control of induction motors, a position or speed sensor is needed. But a speed sensor increases motor cost and reduces reliability in harsh environment. Recently, many studies have been performed for sensorless speed control. This paper investigates an improved flux observer with the parameter error compensation for a sensorless induction motor. The proposed algorithm is verified through simulation and experiment.

Anti-sway and Position 3D Control of the Nonlinear Crane System using Fuzzy Algorithm

  • Lee, Tae-Young;Lee, Sang-Ryong
    • International Journal of Precision Engineering and Manufacturing
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    • v.3 no.1
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    • pp.66-75
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    • 2002
  • The crane operation used fur transporting heavy loads causes a swinging motion with the loads due to the crane\`s acceleration and deceleration. This sway causes the suspension ropes to leave their grooves and can cause serious damage. Ideally, the purpose of a crane system is to transport loads to a goal position as soon as possible without any oscillation of the rope. Currently, cranes are generally operated based on expert knowledge alone, accordingly, the development of a satisfactory control method that can efficiently suppress object sway during transport is essential. The dynamic behavior of a crane shows nonlinear characteristics. When the length of the rope is changed, a crane becomes a time-varying system thus the design of an anti-sway controller is very difficult. In this paper, a nonlinear dynamic model is derived for an industrial overhead crane whose girder, trolley, and hoister move simultaneously. Furthermore, a fuzzy logic controller, based on expert experiments during acceleration, constant velocity, deceleration, and stop position periods is proposed to suppress the swing motion and control the position of the crane. Computer simulation is then used to test the performance of the fuzzy controller with the nonlinear crane model.

Design, Implementation and Navigation Test of Manta-type Unmanned Underwater Vehicle

  • Kim, Joon-Young;Ko, Sung-Hyub;Cho, So-Hyung;Lee, Seung-Keon;Sohn, Kyoung-Ho
    • International Journal of Ocean System Engineering
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    • v.1 no.4
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    • pp.192-197
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    • 2011
  • This paper describes the mathematical modeling, control algorithm, system design, hardware implementation and experimental test of a Manta-type Unmanned Underwater Vehicle (MUUV). The vehicle has one thruster for longitudinal propulsion, one rudder for heading angle control and two elevators for depth control. It is equipped with a pressure sensor for measuring water depth and Doppler Velocity Log for measuring position and angle. The vehicle is controlled by an on-board PC, which runs with the Windows XP operating system. The dynamic model of 6DOF is derived including the hydrodynamic forces and moments acting on the vehicle, while the hydrodynamic coefficients related to the forces and moments are obtained from experiments or estimated numerically. We also utilized the values obtained from PMM (Planar Motion Mechanism) tests found in the previous publications for numerical simulations. Various controllers such as PID, Sliding mode, Fuzzy and $H{\infty}$ are designed for depth and heading angle control in order to compare the performance of each controller based on simulation. In addition, experimental tests are carried out in a towing tank for depth keeping and heading angle tracking.

Anti-sway and 3D position Control of the Nonlinear Crane System using Fuzzy Algorithm (퍼지 알고리즘을 이용한 비선형 크레인 시스템의 진동방지 및 3차원 위치제어)

  • Lee, Tae-Young;Lee, Sang-Ryong
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.8
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    • pp.193-202
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    • 1999
  • Crane operation for transporting heavy loads causes swinging motion at the loads due to crane's acceleration and deceleration. This sway causes the suspension ropes to leave their grooves and leads to possibility of serious damages. So, this swing of the objects is a serious problem and the goal of crane system is transporting to a goal position as soon as possible without the oscillation of the rope. Generally crane is operated by expert's knowledge. Therefore, a satisfactory control method to supress object sway during transport is indispensible. The dynamic behavior of the crane shows nonlinear characteristics. when the length of the rope is changed the crane is time varying system and the design of anti-sway controller is very difficult. In this paper, the nonlinear dynamic model for the industrial overhead crane whose girder, trolley and hoister move simultaneously is derived. and the Fuzzy logic controller based on the expert experiments during acceleration, constant velocity, deceleration and stop position period is proposed to supress the swing motion and control the position of the crane. The performance of the fuzzy controller for the nonlinear crane model is simulated on the personal computer.

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