基于Stewart构型的六维力/力矩传感器刚柔度性能研究

刚柔度是传感器的基本特性,是在工作空间中定量衡量其性能与结构参数间关系的重要指标.应用并联机器人机构学理论,对基于Stewart结构六维力传感器的性能指标进行理论推导,定义并分析了其刚度和柔度性能指标,为六维力传感器的优化设计和工程应用提供理论基础.     

新型并联解耦结构五维力传感器性能分析

介绍基于并联4-SPS&1-UPU结构的新型五维力/力矩传感器的结构特点,并分析计算了其力与应变之间的转换关系及其力、力矩各向同性度,为该五维力/力矩传感器的设计和使用提供了理论依据,分析计算结果表明该传感器是力与力矩解耦和力矩各向同性的.该传感器采用弹性球铰替代普通球铰,弹性虎克铰替代普通虎克铰,具有结构灵巧、工艺好等优点,可应用到机器人手指和其他使用多维力/力矩传感器的场合.     

新型解耦和各向同性五维力传感器性能分析

介绍基于并联4-SPS&1-UPU结构的新型机器人五维力与力矩传感器的结构特点,并分析计算了其力与应变之间的转换关系及其力各向同性,为该五维力与力矩传感器的设计和使用提供了理论依据,分析计算结果表明该传感器是力与力矩解耦和各向同性的。该传感器采用弹性铰链替代球铰和虎克铰,具有结构灵巧、工艺好等优点,可应用到机器人手指和其他使用多维力与力矩传感器的场合。     

新型灵巧手指六维力传感器参数设计方法研究

研究机器人力传感器性能与其结构参数关系，对机器人力传感器结构参数的合理选择有重要意义。提出了一种以等平台Stewart机构为原形的新型机器人灵巧手指六维力传感器，基于对其位移刚度椭球和扭转刚度椭球的分析，分别定义了其位移刚度和扭转刚度各向同性性能指标，并以性能图谱的形式给出了性能指标与结构参数关系，为基于各向同性性能的灵巧手指六维力传感器的结构优化设计提供了理论依据。     

并联式轴用压电六维力/力矩传感器

针对巨型重载操作装备极端制造中多维大载荷测量的难题,提出一种利用压电石英作为力敏元件的新型并联式轴用压电六维力/力矩传感器。对比各种力敏元件的性能,选择压电石英作为力敏元件可以实现空间力/力矩的动态测量,分析压电石英晶组不同空间布局方式的测量原理,提出并联式轴用压电六维力/力矩传感器的多点测量原理,分别对其建立空间力学模型,并进行解耦计算。设计出高灵敏度、高刚度、高线性度的非组装整体化六维力/力矩传感器新结构。研究并联式轴用压电六维力/力矩传感器的标定方法,并进行静态和动态标定试验,得到六维力/力矩传感器的标定矩阵和误差矩阵。试验表明,该六维力/力矩传感器可以动态测量空间六维力/力矩,具有量程大、线性好、固有频率高、动态性能好和应用场合多等优点。     

基于6维力/力矩传感器的并联机器人惯性参数辨识方法

提出了基于6维力/力矩传感器的并联机器人惯性参数辨识新方法,这种方法不需要了解关节摩擦和驱动器动力学特性的精确模型,推导了一般并联机器人的惯性参数辨识模型,分析了并联机器人的基惯性参数,提出了并联机器人惯性参数辨识轨迹的选择原则,并给出了两种新型空间并联机器人的分析实例。     

新型过约束正交并联六维力传感器测量模型与静态标定试验

面向航空航天领域对重载大吨位多维测力传感器的急需,通过引入冗余测力分支,提出一种适用于重载测力场合的新型过约束正交并联六维力传感器结构,在提高传感器结构刚度和承载能力的同时有效抑制了关节摩擦对多维力传感器测量精度的影响。基于螺旋理论,推导得到了该并联传感器一阶静力影响系数矩阵,建立理想状态下该新型过约束正交并联六维力传感器测量数学模型。考虑各测量分支的初始预紧力与刚度,基于传感器静力平衡方程与补充建立的位移协调方程,推导建立考虑初始预紧力与分支刚度因素下该新型过约束正交并联六维力传感器测量数学模型。在此基础上,设计并研制该新型过约束正交并联六维力传感器样机,搭建传感器加载标定与信号采集及处理试验系统,对新型过约束正交并联六维力传感器进行了加载标定试验。根据试验结果计算了传感器测量误差矩阵,分析得到了传感器测量精度,从而为重载过约束并联六维力传感器的开发与应用提供了参考。     

过约束平面并联三维力/力矩传感器的研制

针对轴承的故障早期诊断和在线实时监测,提出了一种新型过约束平面并联三维力/力矩传感器。通过采用分支轴线均不过传感器中心的6条对称分布的测力分支,该传感器可同时测量轴承径向载荷和轴向力矩。根据静力学平衡方程,求解了其测量数学模型;基于传感器测量模型与性能指标分析了传感器性能,进而对其各结构参数进行优化设计。研制了传感器样机及其加载标定实验系统,开展了加载标定实验,得到了该传感器的测量精度。标定实验结果显示:传感器径向力测量精度为2.56%,力矩测量精度为0.92%,Ⅰ类误差为2.56%,最大Ⅱ类误差为2.29%。文中所做工作,为将该新型过约束平面并联三维力/力矩传感器应用于在线实时测量轴承径向载荷和轴向摩擦力矩奠定了基础。     

新型3—2—1正交结构机器人六分量腕力传感器设计

基于变异形式的Steewart平台机构,设计了一种新颖的3－2－1正交结构的机器人六分量腕力传感器,应用并联机器人机构学理论,推导出力六分量表达式并对其刚度特性进行分析,为其设计和使用提供理论依据,这种六分量腕力传感器,具有力与力矩解耦和解算简单等优点。     

机器人运动中六维力传感器的重力补偿研究

针对六维力传感器在工业机器人运动过程中,受末端工具重力影响而导致其零位值变化的问题,提出了一种能够对传感器的零位值实时更新的重力补偿算法。首先对机器人连杆结构进行分析,推导出重力补偿算法,然后通过MATLAB软件得到运用该算法进行理论计算的结果曲线,并运用Adams软件对机器人相关运动进行仿真,测得末端工具重力在六维力传感器所在坐标系各力/力矩分量的曲线,最终验证了该重力补偿算法理论推导的正确性。运用该重力补偿算法,可有效提高六维力传感器实际应用中的测量精度。     

A novel parallel sensor with six rigid compliant limbs for measuring six- component force/torque

A novel parallel sensor with six rigid/compliant hybrid limbs and six standard force sensors is developed for measuring the six-component force/torque. The measuring theory and performances are studied. A prototype of the robot hybrid hands with the parallel sensor is developed. A prototype of the parallel sensor is built up and its merits and performances are analyzed. A statics equation among the forces of the standard force sensors and the whole external load and a stiffness model of the parallel sensor are established based on its equivalent parallel mechanism. The force/torque of the parallel sensor is measured under the given external load. The theoretical solutions of the statics model of the parallel sensor are obtained and verified by both the experimental measuring solutions of the prototype of the parallel sensor and the simulation solutions of a FE model.

     

A novel self-decoupled four degree-of-freedom wrist force/torque sensor

Haptic based human–computer interaction (HapHCI) system is currently the frontier of robot research, which is widely used in virtual reality, rehabilitation, entertainment, and so on. The measurement of the multi-dimensional interactive force between human hand and interaction device such as hand-controller, joystick, limb rehabilitation device, etc., becomes an important component of the HapHCI. However, the existing commercial 6 degree-of-freedom (DOF) force sensors are too expensive and often over designed for HapHCI not only in axis but also in bandwidth. In this paper, a novel 4 DOF wrist force/torque sensor suitable for HapHCI is developed, which is self-decoupled without calculating the decoupling matrix. Thus this type of wrist force/torque can be called as direct output force sensor, which is quite different from the conventional ones called as indirect output force sensor. Its elastic body has a simple geometry which is easy to fabricate, and half the number of strain gauges compared to the existing commercial 6 DOF force/torque sensor. So the 4 DOF force/torque sensor is much lower in cost. This paper introduces the elastic body structure of the wrist force/torque sensors, and analyses the self-decoupled principle in detail. A prototype sensor is fabricated, and the calibration test results of the 4 DOF force/torque sensor validate the analysis and demonstrate the advantage of such a sensor.     

正交并联六轴力传感器耦合误差测量模型及实验分析

为解决并联六轴力传感器量程提升受限问题,设计了一种正交构型并联六轴力传感器。正交并联六轴力传感器是基于并联六轴力传感器的一种构型上的改进,具有承载能力强、解耦性能良好的优势,但同时该力传感器的耦合误差输出具有自身的特点。考虑该力传感器测量分支间摩擦以及正交结构自身特点引起的耦合误差输出,建立了正交并联六轴力传感器耦合误差测量模型。基于所建立的测量模型,通过数值算例分析探讨了传感器设计参数与两种耦合误差输出之间的影响关系,据此研制了一种正交并联六轴力传感器。最后对传感器样机进行了实验,得到其误差分布及检验测量精度。实验所得传感器各维力/力矩在各方向误差分别为0.43%/0.31%,0.18%/0.68%,0.80%/1.28%。     

Torque sensor calibration using virtual load for a manipulator

Accurate load sensing of a manipulator becomes increasingly important in performing various tasks involving contact with an environment. Most of the research has been focused on improving the hardware of a force/torque sensor. The torque sensors for a manipulator suffer from crosstalk, which is difficult to compensate for even with sophisticated calibration. This research proposed a novel calibration method composed of two steps. Through the primary calibration, the torque sensor output can be related to the joint torques. The secondary calibration, which is based on a virtual load, is conducted to compensate for the crosstalk of a torque sensor. The virtual load is obtained from the sensed joint torques and manipulator configuration. Using the proposed calibration method, the external load acting on the end-effector of a manipulator can be accurately measured even with relatively low-quality torque sensors. The experimental results showed that the error in the load sensing was significantly reduced by the proposed calibration method.     

Research on force-sensing element's spatial arrangement of piezoelectric six-component force/torque sensor

This paper proposes a novel piezoelectric six-component force/torque sensor with four-point supporting structure, and makes research on force-sensing element's spatial arrangement of the novel sensor. Two kinds of different spatial arrangements are advanced, lozenge and square arrangement. The mathematical models are built and calculated. The influence on using performance of the two kinds of different spatial arrangements of the sensor is analyzed by FEM (ANSYS software). In order to investigate the validity of the proposed method, a prototype of piezoelectric six-component force/moment sensor is developed with two kinds of different spatial arrangements, and characteristic tests of the piezoelectric six-component force/moment sensor are performed. The test shows that both of the different spatial arrangement sensors could be used to measure six-component force/torque, but the square arrangement piezoelectric six-component force/moment sensor is more suitable for measurement of six-component force/torque on axis. The interference errors of square arrangement sensor are less than 5%, which are lower than those of the lozenge arrangement sensor. The natural frequencies in six directions are analyzed and discussed.     

相关小波法在腕力传感器动态特性分析中的研究

在机器人腕力传感器的动态特性分析中，最关键的步骤之一是从传感器输入输出信号中提取精确的脉冲响应函数和频响函数。介绍了一种新的提取腕力传感器脉冲响应函数的方法——相关小波法。在建立腕力传感器的简化动力学模型的基础上，模拟了机器人与环境相互碰撞及机器人在强噪声环境中的典型工作条件，用相关小波法提取了模型系统的脉冲响应函数和频响函数，并与传统的FFT方法进行了比较。结果表明，相关小波法比FFT方法具有更明显的优势，获得了更高精度的脉冲响应函数和频响函数的提取。相关小波法为腕力传感器，同时也为其他传感器的动态特性分析提供了一种新的、有效的方法。