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1.
为了辨识具有谐波减速器的柔性关节模型的关键参数,设计了一套基于多传感器融合的离线辨识方法,根据电机的位置传感器、电流传感器和关节力矩传感器的实验数据完成柔性关节模型关键参数的辨识.首先,建立采用谐波减速器柔轮输出的柔性关节模型;然后,使用正反转加载力矩的方法辨识出电机的力矩系数;并在空载的情况下,由关节力矩和电机输出力矩分别辨识出关节端和电机端的摩擦力;最后,采用敲击法初步辨识出关节的刚度和阻尼后,在关节位置受限条件下,逐渐增加电机输出力矩,得到柔性关节刚度和关节力矩的非线性关系.多次实验的结果显示,辨识出的参数具有较高的重复性,验证了该方法的有效性.  相似文献   

2.
当机械臂的质量很轻,尤其是空间应用场合,机器人系统将受到高度柔性限制并且不可避免地产生机械振动.本文为了证实提出的控制不期望残余振动的方法,设计并建立了柔性机器人实验平台.控制方案采用交流伺服电机通过谐波齿轮减速器驱动柔性机械臂,利用粘贴在柔性臂上的压电陶瓷片(PZT)作为传感器来检测柔性臂的振动.对由于环境激励,尤其是在电机转动(机动)时由于电机力矩产生的振动,采用了几种主动振动控制器包括模态PD控制,软变结构控制(VSC)和增益选择变结构方法,进行柔性臂的振动主动控制实验研究.通过实验比较研究,结果表明采用的控制方法可以快速抑制柔性结构的振动,采用的控制方法是有效的.  相似文献   

3.
当前,苹果采摘机器人大多选用工业机械臂,关节控制采用电机加减速装置来提高控制精度、增大驱动力矩,这无疑会增加系统的复杂性、成本以及降低系统控制性能;为改善这种情况,给出一种基于直流力矩电动机加谐波减速器的苹果采摘机器人关节控制方案,系统可大大减小驱动机构体积,提高系统刚性,实现低速稳定的精准控制;MATLAB环境下仿真结果表明,在0.5°和60°的阶跃给定下,系统超调量和稳态误差均为0;在幅值为5°,频率为3.14rad/s正弦信号输入下,系统输出能够完全跟随输入;系统控制精度达到了苹果采摘要求,为后续简化采摘机器人机械臂结构、甚至实现直接驱动提供了有力的理论支持。  相似文献   

4.
针对串联机器人,提出了一种改进的机器人关节模型,并采用该模型开展了机器人动力学建模与辨识工作。建立了机器人动力学模型,对机器人关节结构进行分析,改进了关节模型,并通过谐波减速器的输入力矩近似估计其摩擦力矩。选取傅里叶级数为激励轨迹并优化其参数,通过控制关节按照所得轨迹运动,采集并处理相关数据,并基于加权最小二乘法分别辨识机器人关节模型参数与连杆动力学参数。通过关节预测力矩对所得参数进行验证,结果表明,基于改进关节模型的机器人动力学模型精度得到明显提升。  相似文献   

5.
基于碰撞检测的护理型操作臂的安全性设计与实现   总被引:2,自引:0,他引:2  
针对与人近距离交互的护理型操作臂的安全性问题,提出并实现了一种基于碰撞检测的安全性设计方法,它根据由动力学模型计算获得的参考输出力矩与力矩传感器测得的实际输出力矩间的偏差实现碰撞检测.在关节力矩传感器设计中,采用有限元分析方法来优化应变片的位置布置,并开发了高抗干扰能力的信号处理电路.根据护理型操作臂的低速特点,提出了...  相似文献   

6.
何广平  孙汉旭 《机器人》1997,19(6):464-467
给了了一种考虑关节速度极限的柔性冗余度机器人动力学算法,不仅可以使机器人臂的振动得到良好的抑制,同时改善关节力矩的分配,而且能保证关节角不超过极限值,实现了运动学和动力学优化的同时进行。仿真结果证明了算法的合理性及有效性。  相似文献   

7.
为实现人身和机器人交流时的运动同步,首先提出了一类非线性多关节神经振动子运动控制算法,其输入为机器人和人相互作用所产生的关节扭矩信号,输出为机器人关节期望角度;然后对具有代表性的二关节神经振动子控制算法中各参数的耦合特性进行了分析;最后,基于7自由度机器人臂平台对该神经振动子控制算法的有效性进行实验.实验结果表明,该控制算法能够实现人和机器人相互运动的同步,通过调节神经振动子的增益参数,同步的程度能够被改变.  相似文献   

8.
针对主从式上肢外骨骼康复机器人主臂信息获取、从臂快速响应等问题,提出了基于关节位姿、速度和力/力矩等信息的运动意图建模方法及基于模糊补偿的康复训练控制策略.根据人体工程学原理,提出了一种同构同型的主从式双臂康复机器人新型结构;利用D-H算法给出了笛卡儿空间的主从臂运动学模型,建立了患者健肢运动意图信息和从臂各关节动作的人机协作映射关系;以患者运动意图力矩作为输入,基于模糊补偿算法提出了患者-主臂-从臂协作控制策略,并利用李亚普诺夫定理证明了该控制系统的稳定性.仿真结果表明,康复机器人从臂可以根据患者运动意图跟随主臂运动,能有效地防止抖动误动,可避免对患肢的二次伤害.实验结果表明从臂运动轨迹平滑,无剧烈波动,控制轨迹跟踪主臂效果好.  相似文献   

9.
李肖  李世其  韩可  李卓  熊友军  谢铮 《信息与控制》2023,(2):211-219+234
为解决双臂机器人运动过程中的自碰撞问题,提出了一种面向实时自避碰的双臂机器人力矩控制策略。利用机械臂正向运动学构建双臂机器人动态骨架包围盒,用于简化计算关节间最小距离;根据机械臂关节空间阻抗控制规则,设计了基于关节间距离的力矩控制算法,将运动中各关节间距离转换为避碰力矩,并将避碰力矩和其他任务的期望力矩相加,从而得到控制双臂机器人运动的实际力矩。实验表明:当双臂机器人的设定杆件相互靠近且达到避碰距离时,本研究所提出的自避碰策略能够及时对机器人的运动关节产生一组平滑的避碰力矩,避免了机器人自身发生碰撞,验证了所提算法的有效性及实用性。  相似文献   

10.
徐凯  陈恳  刘莉  杨东超 《机器人》2006,28(2):213-218
为实现仿人机器人的稳定行走,提出一种根据其足底六维力/力矩传感器信息、针对关节力矩的步态补偿算法.利用直流伺服电机的过载能力,来改善仿人机器人关节在大负载扰动下的动态性能.行走实验证明了该算法在离线实施过程中的有效性.  相似文献   

11.
Conventional robot manipulators actuated by motors with conventional speed reducers such as the harmonic drive or RV have weakness in the load capacity since the speed reducers are not stiff enough. To overcome this, we propose a four‐bar‐link actuator driven by the ball screw, which has a high stiffness and high torque transmission ability, and propose a new type of four degree‐of‐freedom revolute robot manipulator adapting the proposed actuators. The base joint of the robot is actuated by the motor with the conventional speed reducer, and the other joints are actuated by the proposed actuators. The kinematics and dynamics of the robot are analyzed in the joint coordinate and in the Cartesian coordinate. For the performance tests of the robot, a four degree‐of‐freedom revolute robot was built. Through the performance tests, the results of superior load capacity and positioning accuracy are presented. © 2005 Wiley Periodicals, Inc.  相似文献   

12.
A safe robot arm with safe joints and gravity compensator   总被引:1,自引:0,他引:1  
This study presents a robot arm equipped with safe joints and multi DOFs gravity compensators. The safe joint, also referred to as “Spring-clutch”, is simple passive mechanism that consist of a spring, a cam, and a joint torque sensor. When the torque applied is lower than a pre-set threshold, the Spring-clutch serves as a rigid joint between the input and output. When the applied torque exceeds the threshold, the Spring-clutch is released and is free to rotate like a revolute joint, which significantly reduces the collision force to avoid damage to the robot, as well as to humans. In addition, a compact joint torque sensor is installed in the Spring-clutch to measure the torque at the joint. Also, the analysis of energy and torque shows that the proposed mechanism can function as a gravity compensator capable of static balancing. Since joint torques vary in accordance with the pose of a manipulator (i.e., rotation angles), a Spring-clutch with a constant threshold torque cannot always guarantee the maximum collision torque in some poses of a manipulator. To overcome this limitation, a gravity compensator is adopted to eliminate the gravitational torque. In this research a bevel gravity compensator is applied which can perform static balancing completely. This paper describes the design principles and fabrication of the safety mechanisms and the robot arm.  相似文献   

13.
This paper discusses cooperative control of a dual-flexible-arm robot to handle a rigid object in three-dimensional space. The proposed control scheme integrates hybrid position/force control and vibration suppression control. To derive the control scheme, kinematics and dynamics of the robot when it forms a closed kinematic chain is discussed. Kinematics is described using workspace force, velocity and position vectors, and hybrid position/force control is extended from that on dual-rigid-arm robots. Dynamics is derived from constraint conditions and the lumped-mass-spring model of the flexible robots and an object. The vibration suppression control is calculated from the deflections of the flexible links and the dynamics. Experiments on cooperative control are performed. The absolute positions/orientations and internal forces/moments are controlled using the robot, each arm of which has two flexible links, seven joints and a force/torque sensor. The results illustrate that the robot handled the rigid object damping links' vibration successfully in three-dimensional space.  相似文献   

14.

针对受外界动态约束的谐波传动式可重构模块机器人轨迹跟踪问题, 提出一种基于关节力矩反馈的分散积分滑模控制方法. 在无力/力矩传感器且存在耦合模型不确定性的条件下即能获得良好的控制品质. 基于谐波传动模型, 仅采用位置测量数据估计关节力矩, 并建立机器人子系统动力学模型. 基于可变增益超螺旋算法(VGSTA) 设 计分散积分滑模控制器, 补偿模型不确定性并削弱控制器抖振. 采用Lyapunov 理论对系统的渐近稳定性进行了证明. 值仿真结果验证了所设计的控制器的优越性.

  相似文献   

15.
针对协作机器人对高载荷自重比和高精度速度控制的需求,设计了基于双定子永磁同步电机和谐波减速器的关节模块,利用双定子结构提升了电机的转矩密度。为了提高关节速度控制精度,将摩擦等低频非线性因素、电机转矩波动和谐波减速器传递误差对关节速度波动的影响等效为关节系统的输入力矩干扰,并对其进行补偿以抑制关节速度波动。为提高干扰估测精度,提出一种基于双干扰估测器与自适应算法的方法。双定子电机性能测试结果表明,相较于单定子结构,本文的双定子电机转矩密度提升11%。关节速度控制实验表明,与单纯的比例-积分速度控制器相比,采用本文方法,关节的低速稳态波动误差的均方根减小约40%~60%,中、高速稳态波动误差的均方根减小约30%~40%,速度控制精度提升。  相似文献   

16.
Future space systems will use teleoperated robotic systems mounted on flexible bases such as the Shuttle Remote Manipulator System. Due to dynamic coupling, a major control issue associated with these systems is the effect of flexible base vibrations on the performance of the robot. If uncompensated, flexible vibrations can lead to inertial tracking errors and an overall degradation in system performance. One way to overcome this problem is to use kinematically redundant robots. Thus, this article presents research results obtained from locally resolving kinematic redundancies to reduce or damp flexible vibrations. Using a planar, three-link rigid robot example, numerical simulations were performed to evaluate the feasibility of three vibration damping redundancy control algorithms. Results showed that compared to a zero redundancy baseline, the three controllers were able to reduce base vibration by as much as 90% in addition to decreasing the required amount of joint torque. However, similar to locally optimizing joint torques, excessive joint velocities often occurred. To improve stability, fixed weight, multi-criteria optimizations were performed. © 1995 John Wiley & Sons, Inc.  相似文献   

17.
With the development of space technology, lighter and larger space manipulators will be born, of which flexible characteristics are more obvious. The manipulator vibration caused by the flexibility not only reduces the efficiency of the manipulator but also affects the accuracy of the operation. The flexibility of space manipulator mainly comes from structural flexibility of links and transmission flexibility of harmonic gear reducer in joints. The vibrations generated by these two kinds of flexibility are coupled and transformed mutually, making the dynamics characteristics of space manipulator system complicated. Therefore it is difficult to assess respective effects of these flexibilities on vibrations of the manipulator tip. And the characteristics of integrated vibration of manipulator tip with different link and joint stiffnesses are not very clear. In this paper, the dynamic equations of multi-link multi-DOF flexible manipulator are established. Then, vibration responses of the tip under different elastic modulus, damping and joint stiffness were studied, and vibration characteristics of the tip with both link and joint were also analyzed. Moreover, the effects of motion planning on the vibration of the tip were analyzed. Finally, the vibration characteristics of the manipulator with flexible joints and links are verified by a two-degree-of-freedom manipulator experimental system. Dynamics analysis results presented some useful rules for the path planning and control to suppress the vibration of the flexible space manipulator.  相似文献   

18.
《Advanced Robotics》2013,27(11):1155-1180
The purpose of this paper is to present our results on experimental investigations on Cartesian impedance control and nonlinearity compensation for our harmonic drive robot based on joint torque sensors. The imperfection of the cubic model for harmonic drive friction is detected according to friction identification experiments. In addition, five different Cartesian impedance control schemes are considered and four of them are tested by corresponding experiments with/without friction compensation. Experimental results tell us that the force-based impedance control strategy is more suitable than the position-based strategy for the harmonic drive robot based on joint torque feedback.  相似文献   

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