Fuzzy force control of constrained robot manipulators based on impedance model in an unknown environment

To precisely implement the force control of robot manipulators in an unknown environment, a control strategy based on fuzzy prediction of the reference trajectory in the impedance model is developed. The force tracking experiments are executed in an open-architecture control system with different tracking velocities, different desired forces, different contact stiffnesses and different surface figurations. The corresponding force control results are compared and analyzed. The influences of unknown parameters of the environment on the contact force are analyzed based on experimental data, and the tunings of predictive scale factors are illustrated. The experimental results show that the desired trajectory in the impedance model is predicted exactly and rapidly in the cases that the contact surface is unknown, the contact stiffness changes, and the fuzzy force control algorithm has high adaptability to the unknown environment. Translated from Journal of Northeastern University (Natural Science), 2005, 26(8): 766–769 [译自: 东北大学学报 (自然科学版)]     

高速运动机器人动力学分析与研究

当机器人运行于高速条件下时,整个系统将处于一种不稳定的状态。对高速运动条件下的机器人动力学进行了深入的研究。首先,对研制的6自由度搬运机器人平台硬件结构进行了介绍。在此基础上,对高速运动的机器人的动力学表达式式进行了分析,得到了造成机器人高速运动动力学效应的状态参量—机器人的关节角θ、关节角速度θ觶与关节角加速度θ咬,结合机器人样机的PID主控制器,定性探索了机器人的动力学参量与PID控制器参量间的关系规律,为后续的控制器设计提供依据。     

The design and implementation of an accelerometer-assisted velocity observer

This paper presents a dynamically compensated velocity observer (DCVO), in which acceleration measurement is employed to estimate velocity. Its sensitivity to the noise that is associated with the acceleration measurement is formulated and compared with that of a conventional state-space velocity observer (SSVO). Unlike the SSVO, the DCVO is completely insensitive to an accelerometer offset. The DCVO, the SSVO and a common ITM-based estimator are all realized in a linear motion stage, to determine their effectiveness. A sliding-mode controller is also implemented with different velocity observers, and it is shown that the DCVO enables high-frequency switching of the sliding-mode controller and also practically improves the positioning accuracy.     

Operational space trajectory tracking control of robot manipulators endowed with a primary controller of synthetic joint velocity

In this paper, a new control algorithm for operational space trajectory tracking control of robot arms is introduced. The new algorithm does not require velocity measurement and is based on (1) a primary controller which incorporates an algorithm to obtain synthesized velocity from joint position measurements and (2) a secondary controller which computes the desired joint acceleration and velocity required to achieve operational space motion control. The theory of singularly perturbed systems is crucial for the analysis of the closed-loop system trajectories. In addition, the practical viability of the proposed algorithm is explored through real-time experiments in a two degrees-of-freedom horizontal planar direct-drive arm.     

危险作业机器人机械臂设计及其运动学分析

从危险作业机器人的任务需求出发创新设计了一种带有平移自由度的六自由度机械臂,建立了机械臂的虚拟样机模型,机械手工作域的仿真分析表明较好的满足了设计要求。同时,运用D-H法建立机器人的连杆坐标系,进行了正向运动学分析,推导出机械臂的运动学方程以及手爪坐标系相对于基坐标系的位姿矩阵,针对运动学方程的特点,提出了解析法和基于正向运动学分析的可行解估计法相结合的试探搜索算法进行逆运动学求解,实例分析和编程验算表明该方法稳健可靠,计算精度和处理速度能够满足机器人实时在线控制的要求,并且可以应用于机器人轨迹规划和跟踪控制。     

基于双DSP的防爆机器人控制器的设计

给出了防爆机器人控制器的结构，阐述了使用双DSF，对机器人系统进行控制的整体方案，具体介绍了各功能模块的系统组成和结构特点，分析了双DSF，控制器的工作原理。重点介绍了使用双DSF，对防爆机器人进行通信和控制的具体方法。     

基于PLC的中立柱喷胶机器人系统设计

针对汽车内饰件中立柱人工喷胶的缺点,设计了一种基于机、电、气结合适用于普桑与2000两种车型中立柱喷胶生产的机器人及周边设施,介绍了机器人系统的构成及控制的实现方法。     

基于Pro/E和ADAMS的机器人虚拟设计与仿真

用Pro/E建立的机器人虚拟装配模型导入ADAMS中,与机器人末端固结的点MARK-ER_40沿着设定的直线方向直线运动后,进行了机器人逆运动学分析,包括MARKER_40点的速度、加速度的分析以及小臂转轴的角速度、角加速度的分析.通过对机器人的逆运动学问题进行分析,得到的仿真曲线为控制机器人的运动和路径规划提供教据参数.     

Iterative learning control scheme for manipulators including actuator dynamics

This paper presents the iterative learning control for the industrial robot manipulators including actuator dynamics. Motivated by human learning, the basic idea of iterative learning control is to use information from previous execution of a trial in order to improve performance from trial to trial. This is an advantage, when accurate model of the system is not available as friction and actuator dynamics, though present in the system, are not modeled to reduce the computational complexity. In this paper different aspects of ILC including the design schemes and control algorithms are covered. The learning control scheme comprises two types of control laws: a linear feedback law and a feed-forward control law. In the feedback loop, the fixed gain PD controller provides stability of the system and keeps its state errors within uniform bounds. In the feed-forward path, a learning control rule/strategy is exploited to track the entire span of a reference input over a sequence of iterations. Algorithms are verified through detailed simulation results on a two DOF robot manipulator.     

固高工业机器人力/位混合控制

针对固高工业机器人末端主动柔顺控制实现问题,改进并设计了力/位混合控制系统.采用PC+PCI总线采集控制卡的结构,给出了相应的硬件及软件实现方法.实验表明该系统具有良好的稳定性和动态性能.     

一种核管道机器人结构设计与驱动力分析

针对人工方式进行核电管道检测与维护存在效率低的问题,将管道机器人技术应用到核电站管道维护中,代替人工进行现场故障监测、异物探测和清理。设计了直径为300 mm的管道机器人的机械结构,分析了机器人在管道中的受力情况以及驱动特性。同时设计了一种全新的单电机全驱动机构,这种设计使机器人整体结构更为紧凑,提高了机器人行进速度以及驱动负载能力。并利用ADAMS动力学仿真软件对机器人驱动特性进行了研究和分析。结果表明,机器人的驱动能力能够满足实际作业需求,并且其驱动能力与摩擦系数、斜坡度有关;其中驱动力与摩擦系数成正比,即摩擦系数越大机器人的驱动力越大;驱动力与斜坡度成反比,即斜坡度越大驱动力越小。该研究结果可为后续机器人优化设计提供理论依据。     

基于速度方向可操作度的双臂机器人轨迹规划

在双臂机器人速度可操作度椭球的基础上,定义双臂机器人速度方向可操作度,以速度方向可操作度为性能指标,给出了双臂协调运动关节轨迹规划,理论及算例仿真分析结果表明了规划方法的可行性.     

基于模糊自整定PD控制器的机器人计算力矩控制

设计了应用于计算力矩控制方案中的模糊PD控制器(FLC),进一步提出了模糊自整定PD控制器(SFLC).用带有末端执行器的平面3自由度机器人为例进行了动力学仿真,并将采用固定PD控制器、模糊PD控制器和模糊自整定PD控制器的计算力矩控制方案进行了比较.仿真结果表明,采用模糊自整定PD控制器(SFLC)后能有效的克服模型不确定所造成的影响,得到比较小的轨迹跟踪误差,为机器人的实际控制提供了理论基础.     

基于滑动操作模型的履带机器人驱动力设计

履带式结构由于能够提供较大的推进力和良好的复杂环境通过能力,因此被广泛应用于很多的机器人设计当中。基于滑动操作模型详细分析了履带式机器人运动时的运动状态和受力特点,提出了一种履带式机器人力学模型,分析了机器人运动时的驱动力。根据分析结果,对履带式机器人的一些设计问题提出了新的思考。     

排爆机器人PWM调速模块的设计

针对试验中以软件方法实现PWM电机调速的不足,介绍了一种硬件实现PWM调速的方法,该方法成本低,实时性能好,可以消除直流电机在低频信号下的共振现象,从而减小电机的噪音。通过Protel DXP仿真和在排爆机器人样机上的试验,证明了该方法的可行性和优越性。     

Generalized proportional integral control for periodic signals under active disturbance rejection approach

Conventional repetitive control has proven to be an effective strategy to reject/track periodic signals with constant frequency; however, it shows poor performance in varying frequency applications. This paper proposes an active disturbance rejection methodology applied to a large class of uncertain flat systems for the tracking and rejection of periodic signals, in which the possibilities of the generalized proportional integral (GPI) observer-based control to address repetitive control problems are studied. In the proposed scheme, model uncertainties and external disturbances are lumped together in a general additive disturbance input that is estimated and rejected on-line. An illustrative case study of mechatronic nature is considered. Experimental results show that the proposed GPI observer-based control successfully rejects periodic disturbances even under varying speed conditions.     

基于ADAMS的夹持机械手虚拟设计及其结构优化

提出了一种可以精确控制的夹持机械手新结构,并分析了机械手手爪部分的多杆机构各杆件参数与夹持工件半径的关系。在此基础上,着重借助虚拟样机技术软件adams建立了机械手手爪部分多杆机构的参数化模型,并利用adams中的DS(设计研究)、DOE(实验设计),对其进行了分析和优化设计。     

A lane based obstacle avoidance method for mobile robot navigation

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.     

仿人按摩机器人手臂结构设计及改进

仿人按摩机器人手臂是以传统中医按摩理论为基础,结合机器人定位精度高,按摩力量精确可控,动作可准确重复,不会产生疲劳等特点,构建了中医按摩机器人平台。机器人手臂是仿人按摩机器人的关键,在深入研究按摩机器人手臂的工作机理基础上,充分考虑手臂的材料、结构和刚度以及手臂反应的灵活性、稳定性、安全性、拟人化等要求,对大臂、肩关节、肘关节、小臂、手腕等关键环节进行了设计及改进。经过性能对比分析,设计的仿人按摩机器人手臂达到设计要求。     

A double-loop structure in the adaptive generalized predictive control algorithm for control of robot end-point contact force

Robot force control is an essential issue in robotic intelligence. There is much high uncertainty when robot end-effector contacts with the environment. Because of the environment stiffness effects on the system of the robot end-effector contact with environment, the adaptive generalized predictive control algorithm based on quantitative feedback theory is designed for robot end-point contact force system. The controller of the internal loop is designed on the foundation of QFT to control the uncertainty of the system. An adaptive GPC algorithm is used to design external loop controller to improve the performance and the robustness of the system. Two closed loops used in the design approach realize the system?s performance and improve the robustness. The simulation results show that the algorithm of the robot end-effector contacting force control system is effective.