基于PC+控制卡的机器人手势容错控制系统设计

当前机器人手势容错控制系统,手臂控制灵活性较差,难以达到人们提出的要求。为解决上述问题,设计了一种新的机器人手势容错控制系统,设定“PC+控制卡” 为总体架构,加入主站和总站控制器增强系统的可扩展性,同时采用无冗余和冗余两种方式连接发生故障的线缆,提高系统的容错能力。使用最新的EtherCAT从站芯片设计了硬件的从站系统,LAN9252与外围电路连接形成ESC通信卡和外围电路组成ESC通信卡,引用八轴伺服控制卡作为核心部件,兼容两种从站要求,采用决策系统和原始数据加工处理算法设计了传感器控制。根据硬件设定驱动程序,分别包括从PC端向EtherCAT Master开源主站的驱动程序、从伺服控制卡到主控器的驱动程序、从传感器到伺服控制卡的驱动程序。实验结果表明,基于PC+控制卡的机器人手势容错控制系统最大跟随误差比传统系统误差缩短了24.33%,测试结果能够达到与其要求。     

An adaptive arm’s mechanical impedance estimator for rehabilitation robots without force and acceleration sensors

The mechanical impedance of the human arm can be measured to quantitatively assess the motor function. In this paper, an adaptive least square estimation method is proposed for online measurement of the mechanical impedance of the arm, without force or acceleration sensors, which extremely reduces the expenses and complexity of rehabilitation robots. The proposed strategy may also be used for monitoring the dynamic changes of the mechanical impedance. Estimation of time-varying force is also the other capability of the algorithm. The closed-loop stability of the system is analytically shown using the Lyapunov stability theorem. To show the applications of the proposed scheme, two main scenarios are described which can be used for the rehabilitation robots to assess the motor recovery of the patients undergoing the rehabilitation sessions. To validate the scheme, a 2-DOF manipulator is adopted to illustrate the accuracy of the impedance and force estimations in noiseless and noisy conditions.     

User evaluation of a novel eye-based control modality for robot-assisted object retrieval

In recent years, great efforts have been put into the investigation of assistive robotics. However, rapid growth in robot functionality has caused control of these robots to become more complex. Natural interaction interfaces between the user and robot systems are highly desired to promote the usability of these robots in practical applications. This paper presents a novel intuitive gaze-based system, which enables a user to effectively command an assistive robot with his/her gaze. This system has the potential to help those, who have limited mobility and/or are confined in bed, with their daily living. Using this system, the object that needs to be manipulated can be directly identified and localized by simply looking at it by the user. Then the assistive robot is activated to perform appropriate manipulation of the object. In the experiments, participants were able to successfully accomplish the object retrieval tasks using the presented system. Moreover, results from subjective evaluation showed high usability of the presented system.     

基于全身力矩控制的双腿轮机器人跳跃方法研究

双腿轮机器人由于内在不稳定性以及强耦合非线性特性, 其运动控制尤其是高动态运动控制非常困难. 为此, 提出基于最优力分配的全身力矩控制框架, 可同时实现双腿轮机器人的自平衡与躯干位姿控制; 为提高双腿轮机器人在高速运动时跨越垂直障碍物的能力, 提出应对垂直障碍的跳跃动作规划方法, 并基于全身力矩控制框架进行控制与实现; 通过分析简化的轮式倒立摆模型, 得到腾空时飞轮转动对俯仰姿态的动力学影响, 实现腾空阶段俯仰姿态的调整. 设置连续跳跃仿真实验与有无飞轮调整的俯仰姿态对比实验, 其仿真结果证明所提方法的有效性与鲁棒性.     

超冗余度机械手自律分散控制算法

本文介绍了一种超冗余度机械手的控制算法,它采用自律分散控制方法来指导冗余度机械手末端执行器的运动,实现做功最小,从而避免采用需复杂计算的求逆解的方法,大大简化了机械手的算法和控制,具有高度的“鲁棒性”和“容错性”．     

空间多维力/力矩传感器关键技术研究综述

空间多维力/力矩传感器安装在空间机械臂的关节部位,随航天器一起发射进入太空,面临强振动、高冲击和大温差等复杂的恶劣环境,普通地面使用的多维力/力矩传感器要突破这些恶劣环境的限制方可使用.介绍了空间多维力/力矩传感器的研究发展现状,对空间多维力/力矩传感器在弹性体结构设计、过载保护、容错和温度补偿等方面的关键技术研究现状...     

基于六维力传感器的工业机器人末端负载受力感知研究

针对工业机器人末端负载与外界环境接触力的感知需求,在机器人法兰与负载之间设置六维力传感器,并研究一套标定与计算方法,综合考虑负载重力作用、传感器零点、机器人安装倾角等因素,利用不少于3个机器人姿态下的力传感器数据,可求得传感器零点、机器人安装倾角、负载重力大小、负载重心坐标等参数,进一步可消除传感器零点及负载重力对受力感知的影响,精确得到机器人末端负载所受的外部作用力与力矩.实验得到对于重量从320N到1917N的负载,在静态条件下,感知外力的误差在负载重力的0.28%以内,感知外力矩的误差在负载对传感器力矩的0.59%以内.     

康复辅助机器人及其物理人机交互方法

面对中国社会快速老龄化现状和庞大的残疾人群,康复辅助机器人研究具有重要学术价值和广阔的应用前景.康复辅助机器人研究涉及神经科学、生物力学、机器人自动控制等领域知识,是机器人最具挑战性和最受关注的研究领域之一.与其他机器人不同,康复辅助机器人的作用对象是人,存在人与机器人的信息交流和能量交换,物理人机交互控制方法是其研究核心和关键技术.本文以神经康复机器人、穿戴式外骨骼、智能假肢等应用为例,介绍当前的研究现状,并重点介绍人体运动意图识别方法和交互控制方法等研究重点和难点.最后展望该领域的未来技术发展方向.     

Design of a slave arm of a surgical robot system to estimate the contact force at the tip of the employed instruments

Acquisition of the contact force at the instrument tip can enable better performance, e.g. transparency of the haptic feedback in the surgical robot systems. It is, however, difficult to measure the contact force directly due to technical limitations in attaching sensors to the tip of the instruments. This paper proposes a method to estimate the forces by installing the sensors away from the instrument tip. The proposed method employs specially designed mechanical parts of the slave robot, i.e. a slider cover plate for the z-axis translational force along the insertion direction, and docking clamps for the rotational pivot torques around the fulcrum point. Strain gauges are attached to specially designed places with enhancing shapes. The simulation results of the force estimation are presented to confirm the strain concentration area. The proposed method is validated with quantitative experimental results. Calibrated weights are determined upon the comparison of the strain value with a calibrated 6-axis force/torque sensor. The percentage error in the force calibration is about 5~8% calculated by the root mean square error (RMSE) of force-sensing performance. In addition, it can be computed by considering only the bending phase of each sensor although the hysteresis is observed from the calibration graph.     

一种低成本汽车电动车窗防夹控制系统

针对汽车控制系统减少线束和降低成本的要求,提出了以集成CAN控制器的PIC18F258单片机为核心设计而成的汽车电动车窗控制系统,给出了系统主要硬件结构和软件设计流程.通过对车窗运行时间和采样电流的处理,判断车窗是否遇到障碍物,从而实现车窗的防夹功能.相对于传统的点对点控制方式,不仅减少了车内的线束,降低了成本,而且控...     

Manipulating Deformable Linear Objects: Fuzzy-Based Active Vibration Damping Skill

Human can handle a deformable object and damp its vibration with recognized skill. However, for an industrial robot, handling a deformable object with acute vibration is often a difficult task. This paper addresses the problem of active damping skill for handling deformable linear objects (DLOs) by using a strategy inspired from human manipulation skills. The strategy is illustrated by several rules, which are explained by a fuzzy and a P controller. A proportional-integral-derivative (PID) controller is also employed to explain the rules as a comparison. The interpretations from controllers are translated into high level commands in a robotic language V+. A standard industrial robot with a force/torque sensor mounted on the wrist was employed to demonstrate the skill. Experimental results showed the fuzzy based damping skill is quite effective and stable even without any previous acknowledge of the deformable linear objects.Category (5)     

基于计算力矩的微创手术机器人控制

针对微创手术机器人通常采用的独立PD控制或基于重力补偿的PD控制,都必须预先设定好相应的PD常数,不能随刀具所受有效外载荷而进行自适应调节,从而影响了机器人的定位精度的问题.提出了一种基于计算力矩的控制模型,在拉格朗日动力学模型基础上引进控制量使机器人系统线性化,并且将静力学分析结果作为反馈信号,完成外载荷作用下的轨迹...     

Improved stability of haptic human–robot interfaces using measurement of human arm stiffness

Necessary physical contact between an operator and a force feedback haptic device creates a coupled system consisting of human and machine. This contact, combined with the natural human tendency to increase arm stiffness to attempt to stabilize its motion, can reduce the stability of the system. This paper proposes a method to increase stability on demand while maintaining speed and performance. Operator arm stiffness is not directly measurable, so controllers cannot typically account for this issue. The causes of arm end-point stiffness are examined as related to system stability, and a method for estimating changes in arm stiffness based on arm muscle activity was designed to provide a robotic controller with additional information about the operator. This was accomplished using electromyograms (EMGs) to measure muscle activities and estimating the level of arm stiffness, which was used to adjust the dynamic characteristics of an impedance controller. To support this design, the correlation between EMGs and arm stiffness was validated experimentally. Further experiments characterized the effects of the designed system on operator performance. This showed increased stability and faster, more accurate movements using the compensating system. Such a system could be used in many applications, including force assisting devices in industrial facilities.     

面向应用需求的力／力矩传感器技术发展动向

本文论述了面向应用需求的力/力矩传感器发展现状和趋势，从机器人学、特种机器 人及机器人化机器几个方面讨论了力传感器研究的现状和应用需求，并指出力传感技术发展 的总趋势为利用新材料、新工艺实现微型化、集成化，利用新原理、新方法实现更多种类的 信息获取，再辅以先进的信息处理技术提高传感器的各项技术指标，以适应更广泛的应用需 求．     

洁净机器人反应转矩观测与碰撞保护研究

提出一种基于反应转矩观测器的机器人碰撞保护方法;机器人的反应转矩由基于模型的干扰观测器估值得到,模型的建立包括电机系统转矩模型与机器人系统动力学模型两部分;由于洁净机器人特殊的构型及关节耦合关系,机器人的动力学建模被大大简化,同时对简化后的模型采用最小二乘法对惯性参数和摩擦参数进行辨识,提高了模型的精度;根据永磁同步电机的转矩模型与机器人动力学模型,可以得到基于电机电流的机器人关节转矩;机器人与外界环境接触时,关节转矩的增加量即为反应转矩;通过设计反应转矩观测器并采用力/位混合控制结构,实现基于电流的机器人主动柔顺控制功能,并在洁净机器人进行碰撞保护实验,实际运行结果验证了该方法的有效性。     

辅助型康复机器人技术的研究与发展

较详细地阐述了辅助型康复机器人的发展过程,对主要类型进行分类介绍,分析了涉及的关键技术并探讨了未来的发展趋势．     

基于实时优化遗传算法的磨削机器人阻抗控制方法研究

针对机械臂与环境接触时恒力跟踪动态响应速度慢的问题,提出了基于实时优化遗传算法的阻抗控制方法。在研究过程中,依据机械臂恒力跟踪的响应速度和控制精度的综合性能指标,改进了离线优化中遗传算法的交叉、变异和计算适应度值等操作算子的处理方式,实现了阻抗控制方法中的控制参数的实时优化。仿真结果表明：与传统控制方法相比,该方法可以在保证控制精度的前提下,提高了机械臂与环境接触力的动态响应速度,降低了控制过程超调量,获得了较好的调节品质。     

一种基于肌电信号的自适应人机交互控制方法

针对踝关节康复机器人运动过程中的人机交互性问题,本文提出一种基于肌电信号的鲁棒自适应人机交互控制方法.针对患者难以保持某一动作、肌电信号微弱等特点,提出一种新的关节角度估计方法.该方法充分利用了踝关节运动时胫骨前肌与腓肠肌的拮抗关系,将踝关节的动作类型与单个肌肉群的收缩进行关联,利用归一化的特征值完成运动意图的辨识和运动角度的估计.为了保证人机交互的安全性,提出一种刚度、阻尼参数在线自适应调节的阻抗控制算法.基于交互力矩对机器人末端的运动角度与运动速度实时进行调节,使其对外表现出等效柔性.实验研究表明所提出的人机交互控制方法是有效的,并具有一定应用前景.     

机器人计算力矩不确定性的神经网络补偿控制

提出一种由计算力矩控制器和神经网络补偿控制器相结合的控制方案,探讨了用神经网络补偿机器人计算力矩不确定性的方法,推导了网络权值的自适应调整律,并证明了系统的稳定性和误差的收敛性.该方案结构简单、鲁棒性强,且神经网络补偿器有较好的适应性,无须事先知道机器人动力学参数和结构的精确值.对机器人轨迹跟踪的仿真结果表明,所提方案具有很好的鲁棒性和抗干扰能力.