共查询到19条相似文献,搜索用时 125 毫秒
1.
面向未知环境基于智能预测的模糊控制器研究 总被引:4,自引:0,他引:4
提出了一种新的面向未知环境的智能预测算法,并将此算法应用于机器人力跟踪控制中.该方法利用机械手末端与未知受限环境产生的接触轨迹,通过模糊推理智能地预测阻抗控制模型中的参考轨迹,并根据力误差变化用参考比例因子对其进行调节,以适应未知环境刚度的变化.通过对阻抗模型参数进行模糊调节减少受限运动中的力误差,提高了全局的力控制效果.仿真结果证明了此算法的有效性. 相似文献
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基于位置的阻抗控制以位置控制为基础,将它作为整个控制器的内环,附加的外环是阻抗力控制器,其控制效果的好坏取决于位置控制器的精确程度。将轨迹跟踪控制算法构建的位置控制器作为控制内环,同样阻抗参数下,增加了控制的稳定性和柔顺性,减小了超调和跟踪阶段的误差。并给出了基于H IT/DLR灵巧手手指基关节力矩传感器的阻抗控制的实验效果。 相似文献
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机器人多指操作的递阶控制 总被引:1,自引:0,他引:1
为机器人多指协调操作建立一递阶控制系统.给定一操作任务,任务规划器首先生
成一系列物体的运动速度;然后,协调运动规划器根据期望的物体运动速度生成期望的手指
运动速度和期望的抓取姿态变化;同时,抓取力规划器为平衡作用在物体上的外力,根据当前
的抓取姿态,生成各手指所需的抓取力;最后,系统将手指的期望运动速度与为实现期望抓取
力而生成的顺应速度合并,并通过手指的逆雅可比转化为手指关节运动速度后,由手指的关
节级运动控制器实现手指的运动和抓取力的控制.该控制方法已成功应用于香港科技大学
(HKUST)灵巧手控制系统的开发.实验证明该方法不仅能完成物体轨迹的跟踪控制任务,
而且能完成物体对环境的力控制和力与速度的混合控制. 相似文献
4.
四旋翼是一种欠驱动、强耦合的可垂直起降的飞行器,为了实现其能够以设定速度跟踪空间轨迹,设计了一种基于非线性制导算法的轨迹跟踪控制方法。该方法分为了导引与控制两部分组成,导引部分以任务轨迹与期望速度为输入量通过非线性制导算法输出当前四旋翼的期望加速度,控制部分以得到的期望加速度为输入量采用串级PID算法对四旋翼进行姿态控制,从而实现四旋翼保持设定速度对任务轨迹的跟踪。仿真结果表明,所提方法能够实现四旋翼对复杂任务轨迹的精确跟踪,二维复杂轨迹跟踪距离偏差不超过±0.6m,速度偏差不超过2m/s;三维复杂轨迹除了受自身控制力限制的飞行段外,跟踪距离偏差基本控制在±4m以内,速度偏差不超过2m/s。 相似文献
5.
用小波插值方法实现移动机器人的轨迹追踪控制 总被引:2,自引:0,他引:2
基于动力学模型方程,利用小波插值方法,对移动机器人的轨迹追踪控制问题,给出了一种新的方法.该方法在有限时间内,实现了转动速度、前进速度均不为零的期望轨迹追踪.它的突出特点是计算量小、方法简单,期望轨迹可为任意复杂的非线性曲线.在仿真实验里,取得了理想的效果. 相似文献
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基于手指动力学模型建立了速度观测器.该观测器用于欠驱动手的自适应轨迹跟踪,弥补了欠驱动手没有速度传感器的缺点,补偿了手指模型中欠驱动元件(如扭簧)造成的不确定因素.与PID和计算力矩法相比,其跟踪误差更小,动态控制效果更加理想.通过动力学模型建立了基于力的阻抗控制策略,在阻抗控制中使用速度观测器,实现了基关节的动态抓取力跟踪.动态轨迹跟踪与力跟踪相结合,使欠驱动手在抓握时具有良好的动态抓取性能. 相似文献
8.
非完整移动机器人的有限时间跟踪控制算法研究 总被引:5,自引:1,他引:5
对非完整移动机器人的有限时间轨迹跟踪控制问题进行讨论.与基于非连续状态反馈的传统有限时间控制算法相比,基于连续状态反馈的有限时间控制算法更适合于控制工程应用.利用该连续系统有限时间控制技术,设计一种连续的状态反馈跟踪控制算法.使得对角速度为非零常数的期望轨迹,非完整移动机器人能够实现全局跟踪,并能在有限时间内完全跟踪上期望轨迹.仿真结果表明了该方法的有效性. 相似文献
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Robust Sliding Control of Robotic Manipulators Based on a Heuristic Modification of the Sliding Gain
A task space robust trajectory tracking control is developed for robotic manipulators. A second order linear model, which
defines the desired impedance for the robot, is used to generate the reference position, velocity and acceleration trajectories
under the influence of an external force. The control objective is to make the robotic manipulator’s end effector track the
reference trajectories in the task space. A sliding mode based robust control is used to deal with system uncertainties and
external perturbations. Thus, a sliding manifold is defined by a linear combination of the tracking errors of the system in
the task space built from the difference between the real and the desired position, velocity and acceleration trajectories
in comparison with previous works where the sliding manifold was defined by the desired impedance and the external force.
Moreover, the ideal relay has been substituted by a relay with a dead-zone in order to fit in with the actual way in which
a real computational device implements the typical sign function in sliding mode control. Furthermore, a higher level supervision
algorithm is proposed in order to reduce the amplitude of the high frequency components of the output associated to an overestimation
of the system uncertainty bounds. Then, the robust control law is applied to the case of a robot with parametric uncertainty
and unmodeled dynamics. The closed-loop system is proved to be robustly stable with all signals bounded for all time while
the control objective is fulfilled in practice. Finally, a simulation example which shows the usefulness of the proposed scheme
is presented. 相似文献
12.
对步进电机差动驱动轮式机器人的控制算法进行了研究;通过建立轮式移动机器人的运动学模型,提出了基于Lyapunov直接法的控制算法,考虑到步进电机工作特性,建立轮式移动机器人的动力学模型,引入速度和加速度的限制策略对运动学模型控制算法输出的最大速度和最大加速度作必要的限制,最终生成速度与时间的变化关系能更好地满足实际工况;对所设计的控制算法进行仿真,仿真结果表明控制算法对轨迹误差调节快,在调节过程中不会发生速度突变,能稳定跟踪期望轨迹,在轨迹发生变化时能迅速做出反应;采用基于模型的程序设计方法,将控制算法生成的脉冲数据编译下载到STM32F407微控制器进行实验;控制算法收敛迅速,符合步进电机实际工作特性。 相似文献
13.
This paper proposes two simple adaptive control schemes of robot manipulators. The first one is the state feedback control which consists of feedforward from the desired position trajectory, PD feedback from the actual trajectory, and an auxiliary input. The second one is the feedforward/feedback control which consists of a feedforward term from the desired position, velocity, and acceleration trajectory based on the inverse of robot dynamics. The feedforward, feedback, and auxiliary gains are adapted using simple equations derived from the decentralized adaptive control theory based on Lyapunov's direct method, and using only the local information of the corresponding joint. The proposed control schemes are computationally fast and do not require a priori knowledge of the detail parameters of the manipulator or the payload. Simulation results are presented in support of the proposed schemes. The results demonstrate that both controllers perform well with bounded adaptive gains. 相似文献
14.
无人机航迹跟踪控制与仿真 总被引:1,自引:0,他引:1
对于无人机的精确航迹跟踪问题进行了研究。系统分为基本姿态控制器设计和制导系统设计两个部分进行研究。利用多重时间尺度奇异摄动理论,结合非线性动态逆方法设计了基本姿态控制器,包括快逆回路和慢逆回路两部分。由引导飞机沿期望航迹的指令加速度解算出跟踪指令航迹所需要的制导力,求出飞机改变姿态所需的控制指令,作为基本姿态控制器的输入。针对某无人机模型进行了机动航迹跟踪仿真验证,仿真结果显示系统能够较好的跟踪指令机动航迹。证明了该方法的有效性和实用性。 相似文献
15.
Souradip De Soumya Ranjan Sahoo Pankaj Wahi 《Journal of Intelligent and Robotic Systems》2018,92(3-4):521-544
In this paper we present a protocol to track a general trajectory for a multi-agent system in the presence of heterogeneous constant finite input delays. We consider two different multi-agent cases: agents with single-integrator and double-integrator dynamics. For the single-integrator case, we assume that the velocity along the desired trajectory is known to all agents for all time. Similar assumption is made only for the acceleration along the desired trajectory for the double-integrator case. It is assumed that at least one agent has the complete information about the desired trajectory for all time. The tracking strategy comprises of a consensus-based estimator and a simple independent tracking controller for each agent in the system. Only the state estimates are exchanged among the agents. The communication graph for the multi-agent system along with the desired trajectory has a rooted directed spanning tree with the desired trajectory being the root. The proposed tracking strategy ensures asymptotic convergence of the multi-agent system. The controller and estimator gains do not depend on the edge weights of the graph. The chosen controller gains of individual agent are bounded by their respective input delays. We present a particular form of control gains in order to achieve a desired possible exponential convergence rate and maximize the upper bound of the convergence rate for these selective gains. Finally, we present simulation results to substantiate the effectiveness of the proposed methodology. Comparison of the proposed strategy with the existing work in the literature show a better performance. 相似文献
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Abstract: The motion control problem for the finger of a humanoid robot hand is investigated. First, the index finger of the human hand is dynamically modelled as a kinematic chain of cylindrical links. During construction of the model, special attention is given to determining bone dimensions and masses that are similar to the real human hand. After the kinematic and dynamic analysis of the model, in order to ensure that the finger model tracks its desired trajectory during a closing motion, a fuzzy sliding mode controller is applied to the finger model. In this controller, a fuzzy logic algorithm is used in order to tune the control gain of the sliding mode controller; thus, an adaptive controller is obtained. Finally, numerical results, which include a performance comparison of the proposed fuzzy sliding mode controller and a conventional sliding mode controller, are presented. The results demonstrate that the proposed control method can be used to perform the desired motion task for humanoid robot hands efficiently. 相似文献
17.
An optimization approach is proposed in this paper for generating smooth and time-optimal path constrained tool trajectory for Cartesian computer numerical control (CNC) manufacturing systems. The desired smooth time-optimal trajectory generation (STOTG) problem is formulated as a general optimal control problem. And axis jerk (derivative of acceleration with respect to time) constraints are introduced into this problem to remove discontinuities of the acceleration profiles. The desired smoothness of the trajectory can be accomplished by adjusting the values of jerk constraints. A control vector parameterization (CVP) method is applied to convert the optimal control problem into a nonlinear programming (NLP) problem which can be solved conveniently and effectively. The third derivative of the path parameter with respect to time (pseudo-jerk) and jerk act as optimization variables. The pseudo-jerk is approximated as piecewise constant, thus for at least second-order continuous parametric path, the resulted optimized trajectory with respect to time is also at least second-order continuous. Sequential quadratic programming (SQP) method is used to solve the NLP problem, through which numerical solution is obtained. Non-smooth (i.e. without considering jerk constraints) time-optimal trajectory generation (non-STOTG) problem is also considered in this paper for the purpose of comparison. Solutions of time-optimal trajectory generation (TOTG) problems for two test paths are performed to verify the effectiveness of the proposed approach. 相似文献
18.
五坐标数控技术的联动原理 总被引:1,自引:0,他引:1
本文通过对五坐标数控技术的坐标运动规律进行分析研究,揭示了五坐标数控技术的联
动原理.即建立了从CAD中的理想轨迹的几何特性(包括位置、切矢、曲率)和五坐标联动的
运动动力学特性(包括位移、进给速度、各坐标理想速度和加速度)之间的通用数学模型.从
而可根据被加工零件表面的几何形状和机床的进给速度确定联动过程中各坐标的理想速度
和理想加速度. 相似文献
19.
《Control Engineering Practice》2005,13(5):567-576
The proposed filter is placed in front a buffered digital differential analyzer, and is formed by combining three modified moving average filters. It can export the position commands to ensure smooth and accurate motion of a tool with a linear jerk change. These output commands can guarantee contour accuracy despite the error in the chord height. The acceleration and jerk can be designed simply by specifying the number of registers. The filter can be implemented using three circular buffers to simplify the arithmetic and reduce the computation time. The high precision motion commands are confirmed by installing the filtering algorithm in a digital signal processor of a computerized numerical controller. The radius of the command trajectory does not become distorted at high speed 30 m/min. The commands filtered by the linear jerk filter stabilize the beginning and end of the actual motion of the machine table. 相似文献