平板式压电六维力/力矩传感器的研制

针对弹性体式六维力/力矩传感器存在的技术瓶颈,提出了一种新型平板式压电六维力/力矩传感器.首先,介绍了传感器的结构和工作原理,提出了两种石英晶片组布置方案.然后,推导了两种布置方案的传感器的数学模型,并建立了有限元模型,仿真得到了两种结构传感器输出的电荷灵敏度、维间干扰、固有频率等重要参数,确定了石英晶片组相对合理的布...     

Stewart型六维力传感器弹性体结构的设计

对六维力/力矩传感器弹性体结构进行了分析;提出了基于Stewart平台的球铰接分体式弹性体的设计方案;根据力的叠加原理对传感器分别施加单轴力,分析得到最大受力杆;并利用Matlab软件分析计算系数转换矩阵,得到施加的力与六维力之间的转换方程;调整上下平台夹角α、β及杆长L等参数,对传感器结构参数进行优化设计,得到设计数据表;为Stewart六维力传感器结构参数的选择及优化提供了参考依据。     

预紧式Stewart结构六维力/力矩传感器

针对六维力/力矩传感器测量量程受限问题,提出一种具有分载测量功能的预紧式Stewart结构六维力/力矩传感器.首先,对比传统Stewart结构力/力矩传感器,阐述了预紧式六维力/力矩传感器的结构特点和测量原理.然后,完成了预紧式Stewart结构六维力/力矩传感器的结构设计.建立了传感器的有限元模型,对模型进行了模态分...     

基于六维力传感器的机器人动力学参数辨识

采用基座布置六维力传感器的方式进行机器人动力学参数辨识。以递推牛顿-欧拉方程为基础建立机器人动力学模型，给出六维力传感器输出与机器人关节间动力学关系，分离待辨识动力学参数并确定其最小惯性参数集，最终建立基于基座六维力传感器的机器人辨识模型。为了进一步提高辨识精度，采用两层低通滤波算法推导出加速度替代公式和速度滤波算法，减少加速度和速度噪声的影响。最后，以六自由度协作机器人的前2个关节为对象，设计辨识实验，获得两关节的最小动力学参数集。通过结果逆向验算表明，基座布置六维力传感器方式能以较高的精度辨识出机器人动力学参数。     

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.     

电容式六维力与力矩传感器数据采集系统设计

为实现电容式六维力与力矩传感器测量力与力矩信息的实时采集和显示,针对实验室自主研制的电容式六维力与力矩传感器开发了一套数据采集系统。系统以STM32F103C8T6作为主控芯片,电容信号经AD7147采集并转换为数字信号,转换结果经隔离型SPI通讯传输到主控芯片后,主控芯片通过基于Modbus协议的RS485通讯发送给上位机。上位机采用WinForm界面进行设计,能对数据进行进一步标定计算处理,并最终实现所测量力与力矩值的实时显示与保存。经过实验测试,采集系统的测量值和实际加载的力与力矩值的测量误差低于3%。该系统的采样精度高、开发成本低且上位机功能完善,为电容式六维力与力矩传感器的应用研究提供了重要的信息。     

Y形横梁六维力/力矩传感器的应变分析

设计电阻应变式六维力/力矩传感器的前提是预知其弹性结构的应变分布,而传统的基于几何建模的有限元分析设计方法存在耗时长、效率低等问题。针对Y形横梁六维力/力矩传感器的弹性结构,提出一种高效、精确的解析分析方法。详细考察了该六维力/力矩传感器弹性横梁在各轴力/力矩载荷作用下的变形特征,基于铁木辛柯梁理论建立简化的力学模型,从而解析地得到各轴力/力矩载荷作用下弹性横梁中应变的显式表达式,与有限元模拟进行对比。结果表明:解析模型给出的预测结果与有限元数值解基本吻合,说明了该解析模型的正确性和有效性,从而为Y形横梁六维力/力矩传感器的设计提供了高效、精确的解析手段。     

机器人基座六维力传感器重力补偿研究

机器人基座六维力传感器常受到安装精度和机器人重力影响而出现测量误差。为了解决这一问题,在利用 D-H 法建立机器人位姿模型的基础上,推导出基于最小二乘法的基座六维力传感器静态重力补偿算法。针对算法中需要采集大量机器人位姿数据的问题,采用正交实验法确定样本空间以减少位姿采集量。最后以六自由度协作机器人为例,利用 6 因素 5 水平的正交实验表获取机器人典型位姿,搭建数据采集平台,实现补偿算法所需数据的采集,求解该机器人的基座六维力传感器静态重力补偿矩阵。实验表明,该补偿算法能够有效得到基座六维力传感器测得的误差值。     

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。     

基于快速动力学辨识的机器人力/位混合控制碰撞检测研究

针对机器人力/位混合控制时发生异常碰撞所导致的安全问题,提出一种基于快速动力学辨识的碰撞检测方案.首先,建立机器人快速动力学的辨识模型,基于拉格朗日法整理出机器人关节重力矩的最简三角函数回归矩阵,运用连续摩擦模型建模关节摩擦力;然后,采用最小二乘法分别辨识出机器人关节的重力矩最简参数集和连续摩擦模型参数集;最后,为验证...     

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.     

Optimal synthesis of a wrist-type 6 degree-of-freedom force/ torque sensor using Stewart Platform Structure

The F/T sensor investigated in this study utilizes the Stewart Platform Mechanism Structure. Normally-employed 6-prismatic joints are replaced by 6-prismatic bars, which are extensible and compressible only along the axial direction of the bars. The complete analyses for the design of this kind of F/T sensor are conducted: the position analysis, the first-order and second-order kinematic analyses, and the force-deformation analysis based on the first-order kinematic characteristics of the system. Lastly, a dimensional synthesis for the F/T sensor is performed based on the kinematic isotropic index.     

Dynamic characteristics of piezoelectric six-dimensional heavy force/moment sensor for large-load robotic manipulator

This paper presents research on dynamic characteristics of a piezoelectric six-dimensional heavy force/moment sensor for a large-load robotic manipulator. The theory on dynamic characteristics of the sensor structure is analyzed, and a mathematical model of the sensor dynamics, decoupled into separate vibration modes, is provided. This model is complemented by dynamic mode analysis of the sensor by finite-element modeling (FEM; ANSYS software). A dynamic calibration experiment is designed, and methods and principles for measurements and data analysis are provided. The characteristic dynamic vibration modes of the piezoelectric force/moment sensor are extracted by analyzing experimental data, yielding amplitude frequency and phase frequency curves of the transfer function linking the excitation loads with the output signals of the transducer. The results of the dynamic calibration experiment demonstrate the good dynamic characteristics of the piezoelectric six-dimensional heavy force/moment sensor. The natural frequencies in the three force directions are high, with values close 2000 Hz. This demonstrates the applicability of the presented six-dimensional heavy force/moment sensor to large industrial robotic manipulators.     

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。     

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.     

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.

     

基于MATLAB/Simulink的BLDC直接转矩控制系统仿真

在无位置传感器无刷直流电机直接转矩控制方案中,利用滑模观测器的位置估算法来获取转子位置.观测器以α、β下的定子线电压方程为基础,由电压和电流得到线反电动势,低通滤波后对其过零检测来获得转子位置.系统采用转速和转矩双环结构.利用MATLAB/Simullnk搭建系统仿真模型,仿真结果证明了滑模观测器位置估算法的有效性.引入直接转矩控制策略后,系统能有效抑制电机转矩波动,具有良好的稳态精度和动态性能.