共查询到20条相似文献,搜索用时 343 毫秒
1.
This paper proposes an adaptive controller for partially known system and applies to a two-wheeled Welding Mobile Robot (WMR)
to track a reference welding path at a constant velocity of the welding point. To design the tracking controller, the errors
from WMR to steel wall is defined, and the controller is designed to drive the errors to zero as fast as desired. Additionally,
a scheme of error measurement is implemented on the WMR to meet the need of the controller. In this paper, the system moments
of inertia are considered to be partially unknown parameters which are estimated using update laws in adaptive control scheme.
The simulations and experiments on a welding mobile robot show the effectiveness of the proposed controller. 相似文献
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Wall-following control problem for a mobile robot is to move it along a wall at a constant speed and keep a specified distance
to the wall.This paper proposes wall-following controllers based on Lyapunov function candidate for a two-wheeled mobile robot (MR) to
follow an unknown wall. The mobile robot is considered in terms of kinematic model in Cartesian coordinate system. Two wall-following feedback controllers
are designed: full state feedback controller and observer-based controller. To design the former controller, the errors of
distance and orientation of the mobile robot to the wall are defined, and the feedback controller based on Lyapunov function
candidate is designed to guarantee that the errors converge to zero asymptotically. The latter controller is designed based
on Busawon’s observer as only the distance error is measured. Additionally, the simulation and experimental results are included
to illustrate the effectiveness of the proposed controllers. 相似文献
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This paper presents a motion control method and its simulation results of a mobile robot for a lattice type welding. Its dynamic equation and motion control methods for welding speed and seam tracking are described. The motion control is realized in the view of keeping constant welding speed and precise target line even though the robot is driven for following straight line or curve. The mobile robot is modeled based on Lagrange equation under nonholonomic constraints and the model is represented in state space form. The motion control of the mobile robot is separated into three driving motions of straight locomotion, turning locomotion and torch slider control. For the torch slider control, the proportional-integral-derivative (PID) control method is used. For the straight locomotion, a concept of decoupling method between input and output is adopted and for the turning locomotion, the turning speed is controlled according to the angular velocity value at each point of the corner with range of 90° constrained to the welding speed. The proposed control methods are proved through simulation results and these results have proved that the mobile robot has enough ability to apply the lattice type welding line. 相似文献
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W. P. Gu Z. Y. Xiong W. Wan 《The International Journal of Advanced Manufacturing Technology》2013,69(1-4):451-460
Automatic welding technology is a solution to increase welding productivity and improve welding quality, especially in thick plate welding. In order to obtain high-quality multi-pass welds, it is necessary to maintain a stable welding bead in each pass. In the multi-pass welding, it is difficult to obtain a stable weld bead by using a traditional teaching and playback arc welding robot. To overcome these traditional limitations, an automatic welding tracking system of arc welding robot is proposed for multi-pass welding. The developed system includes an image acquisition module, an image processing module, a tracking control unit, and their software interfaces. The vision sensor, which includes a CCD camera, is mounted on the welding torch. In order to minimize the inevitable misalignment between the center line of welding seam and the welding torch for each welding pass, a robust algorithm of welding image processing is proposed, which was proved to be suitable for the root pass, filling passes, and the cap passes. In order to accurately track the welding seam, a Fuzzy-P controller is designed to control the arc welding robot to adjust the torch. The Microsoft Visual C++6.0 software is used to develop the application programs and user interface. The welding experiments are carried out to verify the validity of the multi-pass welding tracking system. 相似文献
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差速驱动式移动焊接机器人动力学建模 总被引:4,自引:1,他引:3
采用牛顿-欧拉法,分析差速驱动式移动焊接机器人系统的左右驱动轮和机器人本体对焊炬点的动力学行为.为了实现机器人本体和滑块的联合控制,进一步研究滑块的动力学行为,建立了移动焊接机器人系统完整的动力学模型.由于模型的复杂性和不确定影响因素,基于动力学模型进行控制器的设计是不切实际的.为便于控制器的设计,最后结合实际应用情况对模型进行合理简化,并转化为状态空间方程.应用Matlab对移动焊接机器人进行动力学仿真建模,模型的建立为差速驱动式移动焊接机器人的机构设计、稳定性分析以及控制器设计提供了理论依据. 相似文献
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This paper focuses on the two-robot welding coordination of complex curve seam which means one robot grasp the workpiece, the other hold the torch, the two robots work on the same workpiece simultaneously. This paper builds the dual-robot coordinate system at the beginning, and three point calibration method of two robots’ relative base coordinate system is presented. After that, the non master/slave scheme is chosen for the motion planning, the non master/slave scheme sets the poses versus time function of the point u on the workpiece, and calculates the two robot end effecter trajectories through the constrained relationship matrix automatically. Moreover, downhand welding is employed which can guarantee the torch and the seam keep in good contact condition all the time during the welding. Finally, a Solidworks-SimMechanics simulation platform is established, and a simulation of curved steel pipe welding is conducted. The results of the simulation illustrate the welding process can meet the requirements of downhand welding, the joint displacement curves are smooth and continuous and no joint velocities are out of working scope. 相似文献
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Robot welding seam tracking method based on passive vision for thin plate closed-gap butt welding 总被引:1,自引:1,他引:0
Hongbo Ma Shanchun Wei Zhongxi Sheng Tao Lin Shanben Chen 《The International Journal of Advanced Manufacturing Technology》2010,48(9-12):945-953
A passive vision sensor is added to a teaching and playback welding robot for pulsed gas tungsten arc welding, which is normally used in the welding of thin plate closed-gap butts. This paper presents a seam tracking method based on this sensor through period visual measurement of the offset between the torch and the seam center. A robust image processing algorithm is developed to extract the seam center. A kind of ARX(auto-regressive with exogenous input) model is studied to describe the relationship between the rectifying voltage and the offset. The fuzzy PID(proportional-integral-derivative) seam tracking controller is analyzed and designed in consideration of various offsets based on the ARX model. The experimental results on straight line weld display a good seam tracking capability of the proposed method. 相似文献
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移动机械臂的输出跟踪控制 总被引:2,自引:0,他引:2
移动机械臂通常由移动机器人和装在移动机器人上的机械臂组成。它既具有移动机器人的可移动性又具有机械臂的操作灵活性,有极高的实际应用价值。本文针对由二轮驱动的移动平台和二连杆机械臂组成的移动机械臂的输出跟踪问题,利用滑模控制原理为其设计了动态滑模控制器。首先给出了移动机械臂的简化动态模型,然后通过微分同胚和输入变换将其分解为4个低阶子系统,并给出了其输出跟踪的动态滑模控制器的设计方法。仿真实验表明,所设计的动态滑模控制器不仅能很好地跟踪给定轨迹,而且能有效地削弱滑模控制系统的抖振。 相似文献
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基于FTA的焊接机器人故障诊断技术研究 总被引:1,自引:0,他引:1
焊接机器人作为一种大型复杂系统,主要从事焊接、切割与喷涂作业,因其控制对象复杂、处理任务繁多,所以出故障机率较大、诊断难度较高。为了解决焊接机器人故障诊断的盲目性问题,提高诊断效率及运行可靠性,在结合分析焊接机器人故障模式及故障树分析法特点的基础上,将故障树分析法应用于焊接机器人故障诊断中。根据维修经验找出系统可能发生的各种故障原因,由总体至部分,按树枝状结构,采用自上而下逐层细化的分析方法,探讨了新型焊接机器人机械及电气控制系统的故障树模型。并以焊接机焊枪姿态和悬浮高度设置系统故障为例,研究了系统故障树模型的建立,并对此进行定性和定量分析,找出系统的薄弱环节,及时确定故障源。计算结果表明,该方法直观简单,可操作性强,具有很好的实际应用价值。 相似文献
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De Xu Zaojun Fang Haiyong Chen Zhiguo Yan Min Tan 《The International Journal of Advanced Manufacturing Technology》2012,62(9-12):1157-1167
In this paper, a visual control system is proposed to locate the start welding position and track the narrow butt welding seam in container manufacturing. It estimates the error between the welding torch and the welding seam with a camera and a panel computer. It adjusts the torch’s position via a stepper motor to eliminate the error. A decision controller with three gates is designed to decide the working procedure. Feature extraction algorithms are designed according to the seams and pre-weld spots. The seam line and the position of the pre-weld spot are detected to locate the start welding position in initial aligning. Then the torch is aligned to the seam. In the welding stage, the reference feature is determined with many frames of images based on their statistical property. The current estimated feature is checked to ensure only normal features to be used for welding seam tracking. Experiments are well conducted to verify the effectiveness of the proposed system and methods. 相似文献
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Tuan Dinh Viet Phuc Thinh Doan Nguyen Hung Hak Kyeong Kim Sang Bong Kim 《Journal of Mechanical Science and Technology》2012,26(7):2197-2211
This paper proposes a tracking control method for a three-wheeled omnidirectional manipulator system (OMMS) with disturbance and friction. The OMMS is separated into two subsystems, a three-wheeled omnidirectional mobile platform (OMP) and a selective compliant articulated robot for assembly (SCARA) type of manipulator. Therefore, two controllers are designed to control the OMP and the manipulator system. Firstly, based on a kinematic modeling of the manipulator, a kinematic controller (KC), combined with an integral sliding mode controller (ISMC), is designed for the end-effector of the manipulator to track a desired trajectory with the desired angular velocity vector of links. Secondly, a differential sliding mode controller (DSMC) based on a dynamic modeling of the OMP with force external disturbances is proposed to obtain control inputs moving the OMP so that the manipulator tracks the desired posture without singularity. The system stability is proven using Lyapunov stability theory. The simulation and experimental results are presented to illustrate the effectiveness of the proposed controllers in the presence of disturbance and friction. 相似文献
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对两轮自平衡机器人的运动控制过程中相对定位的问题进行了研究.根据两轮自平衡车的特点,对诸如车轮打滑、碰撞、越障及转向等运动情况下的位置传感器和姿态传感器的信号进行了分析,提出了将光电码盘、MEMS陀螺仪与MEMS加速度计数据融合的方法,对机器人的位姿进行检测估计,从而解决了采用传统的单一位置传感器对机器人测程不准确的问题.同时也降低了陀螺仪、加速度计固有漂移的不利影响,提高了两轮自平衡机器人的定位精度.通过对两轮机器人分别进行直线运动实验、越障实验和异常碰撞试验,验证了两轮自平衡机器人组合定位方法的合理性和有效性. 相似文献
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Tan Tung Phan Tan Lam Chung Manh Dung Ngo Hak Kyeong Kim Sang Bong Kim 《Journal of Mechanical Science and Technology》2005,19(3):756-767
This paper presents a decentralized motion control method of welding mobile manipulators which use for welding in many industrial
fields Major requirements of welding robots are accuracy, robust, and reliability so that they can substitute for the welders
in hazardous and worse environment To do this, the manipulator has to take the torch tracking along a welding trajectory with
a constant velocity and a constant heading angle, and the mobile-platform has to move to avoid the singularities of the manipulator
In this paper, we develop a kinematic model of the mobile-platform and the manipulator as two separate subsystems With the
idea that the manipulator can avoid the singularities by keeping its initial configuration in the welding process, the redundancy
problem of system is solved by introducing the platform mobility to realize this idea Two controllers for the mobile-platform
and the manipulator were designed, respectively, and the relationships between two controllers are the velocities of two subsystems
Control laws are obtained based on the Lyapunov function to ensure the asymptotical stability of the system The simulation
and experimental results show the effectiveness of the proposed controllers 相似文献
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This paper addresses the problem of finite-time tracking controller design for nth-order chained-form non-holonomic systems in the presence of unknown disturbances. To this aim, a generalized disturbance observer based controller is proposed and combined with a recursive terminal sliding mode approach which guarantees finite-time convergence of the disturbance observer dynamic. By introducing a time-varying transformation and introducing a new control law, the existence of the sliding around the recursive terminal sliding mode surfaces is guaranteed. Finally, the proposed approach is applied for a wheeled mobile robot with a fourth-order chained-form non-holonomic model. The simulation results demonstrate the desirable and robust tracking performance of the proposed approach in the presence of unknown disturbance. 相似文献