面向操作可靠性提升的复合工业机器人运动规划

复合工业机器人的应用能够有效提升智能制造车间生产效率。而在其运动规划问题中,基于移动平台调整的机械臂初始站姿直接决定了目标任务是否能够可靠执行。为解决以上问题,提出一种考虑机械臂初始站姿的运动规划优化方法。基于前期基础,采用旋量描述和切片表征方法分别解决了复合工业机器人运动学建模和最小避障距离建模问题,为进行轨迹优化提供了模型基础;建立了最小化耗能当量和运动时间的运动规划优化模型,通过考虑初始站姿影响设计了包括移动运动参数、冗余关节角度和机械臂运动参数在内的混合优化变量集,同时考虑运动学约束和避障约束条件保证机械臂运动平稳性和安全性;结果表明,基于规划优化的复合工业机器人具有较高的操作可靠性。     

Load transportation by dual arm robot using sliding mode control

In this study, a sliding mode controlled dual arm robotic system was designed. Such multi-arm, collaborative and synchronous robots typically are employed in hazardous situations such as radioactive materials transport explosives disposal and industrial applications. In the present study, a high performance, robust, non-chattering sliding mode controller (SMC) was developed for the purpose of safe load handling, transportation and trajectory realization. First, dynamic equations of robot/load interaction were derived. Then, the robust SMC was designed for the dual arm robotic system. In order to test the robustness of the proposed SMC, parameter variations and external disturbances were introduced to the system. Furthermore, for comparative purposes, the conventional and widely used, PID controller was also applied to the dual arm robot. Significantly, it was found that the SMC made smaller trajectory tracking errors than the PID controller. An overall analysis of the numerical results confirmed that the dual-arm robotic systems with the proposed SMC can safely and effectively be used in hazardous applications.     

机械臂控制实验系统研究

针对机械臂在教学实验方面的应用相对欠缺这个问题,介绍了一种实验用多自由度机械臂计算机控制系统。系统由上下位机两级组成,下位机实现关节电机伺服控制、机械臂运行参数自动检测及与上位机的通信。上位机通过视频图像识别技术来规划运动路径,下传命令至下位机,实现自动循迹、工作状态实时显示、指定颜色或形状物体自动抓取等功能。实验结果表明,该系统达到了预期功能。     

考虑柔性关节的仿袋鼠跳跃机器人落地稳定性研究

对具有柔性关节的仿袋鼠跳跃机器人落地稳定性进行了研究。用拉格朗日方法建立了机构在着地阶段的动力学方程。结合实例,运用Matlab和Adams软件对机器人进行仿真分析,给出了机器人在着地阶段的各关节转角、关节驱动力矩、着地压力及ZMP随时间的变化规律。分析结果表明:膝关节,特别是踝关节引入柔性关节,不仅能显著地吸收落地能量而获得落地缓冲能力和降低关节输入力矩峰值而减小驱动元件的功率,而且能有效地提高跳跃机构的弹跳能力和落地稳定性。     

碰撞下PMSM电机驱动机器人关节速度滑模控制

碰撞引起负载突变情况下速度的快速响应和精确控制是机器人研究重点.根据永磁同步电机的原理,建立了状态空间方程,并利用矢量控制方法,进行了解耦.为抗碰撞影响,设计了转动关节速度的滑模控制算法,建立了二维滑模函数,分析了算法稳定条件,给出了滑模控制算法参数选择原则.用Matlab/Simulink建立了速度控制仿真平台.针对碰撞突加负载和变参数情况下的速度平稳控制,对滑模和PI两种控制算法进行了仿真,对转矩和速度响应进行了对比分析.仿真结果表明所设计的滑模控制方法响应速度快、无超调、对负载和系统参数变化的鲁棒性好,是碰撞工况下机器人关节速度稳定控制的可选方法.     

基于Bang-Bang控制的足球机器人运动控制研究

针对Roboocup小型组足球机器人运动控制要求实时、准确、稳定等特点,采用了基于时间最优的bang-bang控制算法来进行机器人的运动控制,解决了机器人在高速的比赛中因为其自身的特性而不能实时、准确的跟踪路径规划程序生成的轨迹这一问题.仿真实验的结果和在实际足球机器人平台上的应用表明,该算法能准确有效的实现机器人的运动控制.     

基于惯量估计的工业机器人关节伺服系统变增益自抗扰控制* .txt

摘要：针对工业机器人关节伺服系统存在时变负载和模型不确定性问题,提出了基于惯量估计的变增益自抗扰控制策略。首先,建立了关节伺服系统数学模型,并通过频域分析,得到了关节伺服系统二阶状态方程。为了削弱扰动和不确定参数的影响,设计了线性扩张状态观测器,利用自适应的方法估计惯量,同时结合鲁棒和滑模控制以保持系统稳定性,并对该控制策略进行了仿真和实验研究。实验结果表明,在该控制策略下,电机端正弦信号跟踪误差小于02 rad,在负载扰动下位置误差小于003 rad,较之单一自抗扰控制误差大约减小了40%,具有较强的抗扰动性,提高了关节伺服系统的控制精度和动态性能。 .txt     

六自由度机械臂参数校准不确定度评定方法

六自由度机械臂的结构参数校准对其定位精度影响较大,为了评价其参数化校准效果,采用蒙特卡洛法建立了六自由度机械臂参数校准不确定度评定模型。首先,根据空间坐标系的几何转换关系建立六自由度机械臂结构参数校准模型,分析主要误差来源对校准参数的影响,建立各校准参数的不确定度分量的函数关系;其次,采用现场校准数据集的抽样统计,分析各不确定度分量的概率密度函数,获得真实分布规律;最后,采用蒙特卡洛法建立各校准参数的不确定度分量与机械臂模型之间的数学关系,通过大规模随机数值模拟,实现机械臂校准不确定度的评定。为了验证本文方法的有效性,利用激光跟踪仪对六自由度机械臂进行了校准实验。结果表明,当采用正则化方法进行机械臂校准时,各坐标轴的相对扩展不确定度分别优于0.542 2%,1.325 9%, 0.015 4%。     

基于关节阻尼的6自由度工业机器人优化分析

首先,考虑工业机器人末端振型的变化,基于“转子-扭簧”模型和有限元理论,推导出机器人柔性关节和刚柔耦合杆件部分的动力学模型,探讨关节阻尼与机器人末端振动位移之间的关系,建立关节阻尼的优化设计数学模型;然后,以机器人末端振幅为设计目标,以机器人的驱动关节阻尼为设计变量进行优化;最后,借助ADAMS软件应用该优化模型对刚柔耦合的六自由度串联工业机器人进行优化设计,并对优化结果进行比较分析,验证了关节阻尼抑制末端振动的效果,为工业机器人关节阻尼抑制末端振动提供了理论依据.     

Dynamic optimization of robot arm based on flexible multi-body model

This paper examines the effect mechanism of torsional stiffness on flexible joints and the dynamic optimization of a six Degree-of-freedom industrial robot arm. The design optimization of the robot arm is investigated based on the rotor-torsional spring model and finite element method. The flexible multi-body dynamic model of the robot arm are established by considering the flexible characteristics of arms and joints, and the natural frequencies of a robot arm are calculated to obtain the torsional stiffness of the flexible joints. Natural frequency results gradually increased with joint stiffness improvement. Using the established dynamic model, the topology optimization on the robot arm is carried out by regarding lightweight as design goal and total displacement as constraints. The tare-load ratio and dynamic performance of the optimized robot arm are significantly enhanced compared with the original design model. This research can provide the theoretical basis for the dynamic optimization and upgrade of lightweight robot arm.     

基于解耦型球关节的工业机器人控制系统研究初探

解耦型球关节能实现运动解耦,基于该关节所构造的工业机器人将具有灵巧及易于控制的特点。通过对现有国内外各种机器人控制系统的分析,探讨了解耦型球关节工业机器人控制系统的初步方案。     

轮式移动机器人的运动及定位分析

对机器人的结构组成和功能进行了介绍,这是对机器人进行路径规划的基础.而具体的规划策略首先取决于机器人的运动机构,故对其进行运动分析.还对机器人的方位确定问题进行了论述,在电机码盘作为传感器的条件下,对机器人的方位确定进行了具体的推导.这些都是为以后机器人的路径规划所作的准备.     

Set-point control of elastic joint robots using only position measurements

Motivated by the dynamic output feedback passification results, point-to-point control laws for an elastic joint robot are presented when only the position measurements are available. The proposed method makes a parallel connection of the robot system and an input-dimensional linear system which obtains the effect of the desired differentiators. It is shown that the closed-loop nonlinear robot system can be rendered output strictly passive and the regulation of the system is achieved in the end. Robustness analysis is also given with regard to uncertainties on the robot parameters. Performance of the proposed control law is illustrated in the simulation studies of a manipulator with three revolute elastic joints.     

Contour-following of a force-controlled industrial robot using preview control

A contour-following system using accommodation force control is modeled in the discrete-time domain. One of the fundamental problems in the contour-following control of a robot is that the unexpected workpiece disturbances that degrade the system performance. If the information about the future as well as the present contour shape is utilized in the edge-following controller, better performance may be expected. This type of control is called preview control. A general method for developing a preview controller is given. A Kalman filtering algorithm is applied to reconstruct the system states and to filter noisy force measurements. The force controller designed by the preview control method is implemented on a VME-based computer, and experimentation using a PUMA 560 industrial robot is presented. Experimental results verify that the preview control is a very useful tool for robot force control showing the superior performance to the conventional nonpreview control system.     

Intelligent phase plane switching control of a pneumatic muscle robot arm with Magneto-Rheological Brake

Pneumatic cylinders are one kind of low cost actuation sources which have been applied in industrial and robotics field, since they have a high power/weight ratio, a high-tension force and a long durability. To overcome the shortcomings of conventional pneumatic cylinders, a number of newer pneumatic actuators have been developed such as McKibben Muscle, Rubber Actuator and Pneumatic Artificial Muscle (PAM) Manipulators. However, some limitations still exist, such as the air compressibility and the lack of damping ability of the actuator bring the dynamic delay of the pressure response and cause the oscillatory motion. In addition, the nonlinearities in the PAM manipulator still limit the controllability. Therefore, it is not easy to realize motion with high accuracy and high speed and with respect to various external inertia loads. To overcome these problems, a novel controller which harmonizes a phase plane switching control method (PPSC) with conventional PID controller and the adaptabilities of neural network is newly proposed. In order to realize satisfactory control performance a variable damper, Magneto-Rheological Brake (MRB), is equipped to the joint of the robot. The mixture of conventional PID controller and an intelligent phase plane switching control using neural network (IPPSC) brings us a novel controller. The experiments were carried out in a robot arm, which is driven by two PAM actuators, and the effectiveness of the proposed control algorithm was demonstrated through experiments, which had proved that the stability of the manipulator can be improved greatly in a high gain control by using MRB with 1PPSC and without regard for the changes of external inertia loads.     

基于BLDC的新型五自由度并联机器人运动控制

在自主研制的新型五自由度并联机器人的基础上,设计完成了以微机、无刷直流电机、PCI接口测控卡为基础的控制系统硬件部分,应用ADAMS软件求解了机构的位置反解曲线,利用C 语言编写了机器人系统的控制软件,实现了并联机构连续轨迹运动.实验结果验证了本并联机构及其控制系统的可行性.     

Feasibility analysis of using a two-stage nutation drive as joint reducer for industrial robots

Nutation drive claims the advantages of high load capacity, large transmission ratio, desirable stability, low noise, and compact volume, which makes it an excellent alternative to typical joint reducers used in industrial robots. This paper proposes a novel two-stage nutation drive as a joint reducer for the industrial robot. The working principle of the nutation movement is first introduced followed by an analysis of transmission characteristics. The transmission ratio, the transmission efficiency as well as the structural schematic of the proposed nutation drive are presented. Finite element analysis of the main components, including nutation sleeve and bevel gears, was performed. Finally, a prototype was designed, manufactured and tested to verify the feasibility of applying the nutation drive as a joint reducer for industrial robots.

     

基于运动趋势分析型论域自调整模糊控制算法的移动机器人运动控制

针对非完整约束轮式移动机器人的运动控制问题,综合考虑移动机器人运动控制精确性、实时性和自适应性的要求,提出了一种运动趋势分析型论域自调整的模糊控制算法.该算法以位置偏差和速度偏差为输入,以PWM波形的占空比为输出,通过实时地改变输入/输出论域,提高了控制精度;引入对运动趋势的分析,实时地改变模糊规则,提高了算法的自适应性.仿真及实验结果表明,该算法具有简单、有效的特点,能基本满足移动机器人运动控制的要求.     

柔性臂空间机器人的神经网络自适应控制及振动模态分级模糊控制

由于太空中的在轨作业一般要求空间机器人具有手臂长、负载大,对空间机器人动力学及控制进行分析时必须考虑到机械臂杆件的柔性问题。为此探讨了参数未知柔性臂空间机器人载体姿态、关节协调运动控制及柔性振动抑制问题。由系统动量守恒关系及假设模态法,利用Lagrange方法建立了漂浮基柔性臂空间机器人的系统动力学方程。运用奇异摄动理论的双时间刻度分解,导出了适用于控制系统算法设计的奇异摄动数学模型。利用该模型,针对慢时标子系统——等价刚性空间机械臂,设计了系统参数不确定情况下的径向基函数神经网络补偿控制算法,以控制柔性臂空间机器人的载体姿态及机械臂关节铰协调地来完成各自在关节空间的期望运动;神经网络控制算法的研究目的是基于神经网络良好的在线自学习能力,大大提高整个系统的控制精度。针对快时标子系统——柔性臂的振动,设计了分级模糊控制算法来主动抑制柔性杆的振动。分级模糊控制算法的研究目的是为了减少模糊规则库的大小,有效提高模糊控制器的计算效率。通过计算机仿真验证了提出方法的有效性和可行性。     

网络机器人控制系统中异构机器人接入技术的研究

网络控制机器人是传统机器人和网络技术的结合.研究了异构机器人接入网络机器人控制系统的要求和途径.采用多态和模板的设计方法,实现了一种异构机器人动态接入方法.