夹持式扭矩传感器

针对目前录井现场各类在用扭矩传感器存在的安装方便性、精度、稳定性和耐用性差等不足,开发研制了新型夹持式扭矩传感器。在简要分析在用扭矩传感器的优缺点基础上,重点介绍了夹持式传感器的测量原理和电路、样机测试结果及产品特点。与在用各类扭矩传感器相比,夹持式扭矩传感器不仅具有设计思路新颖、重量轻、安装方便、使用寿命长、测量灵敏度高等特点,而且能够获得真扭矩值,可为分析井下钻具工况提供十分有价值的参数。样机测试结果表明,其检测精度高,可靠性好。     

交流电机直接转矩控制系统的MATLAB仿真研究

本文介绍一种基于磁链偏差，转矩偏差和磁链位置来选择直接转矩控制电压矢量开关表，通过对磁链和转矩进行优化设计，提高了直接转矩控制系统的控制性能。应用MATLAB软件对其进行仿真和实验表明：DTC控制具有更好的稳定性，较强的鲁棒性和抑制扰动的能力。     

Steering law for roof type configuration control moment gyro system

A steering law is proposed for a roof type configuration Single Gimbal Control Moment Gyro (SGCMG) system for attitude control of the Large Space Telescope, a payload of the Space Shuttle. Although various steering laws have been developed for SGCMG systems, they have some drawbacks because of singular states of the system. The proposed steering law minimizes the effect of singular states by using a new momentum distribution scheme that makes all the singular states unstable. This scheme is formulated by treating the system as a sampled-data system.     

聚合度和磺化度对油井水泥外加剂SPS性能的影响

本文测定了室内合成聚苯乙烯磺酸钠（ＳＰＳ）样品处理的Ｇ级水泥浆表现粘度、样品抗盐析能力及在Ｇ级水泥上的吸附量，讨论了ＳＰＳ的聚合度和磺化反对ＳＰＳ在水泥浆中减阻效果的影响。ＳＰＳ样品以废旧聚苯乙烯塑料为原料制备。     

A stable friction compensation scheme for motion control systems

In mechanical positioning control systems, friction phenomenon makes undersirable responses. Friction compensation scheme is frequently implemented to the control system together with the friction estimator in order to cancel the effect of the friction. However, the error in the estimation of the friction results in undercompensation or overcompensation, which also makes undesirable responses. In this paper, a new friction compensation scheme is proposed. The stability analysis is performed based on the circle criterion, which provides a sufficient condition for asymptotic stability of a system. For an application example, the scheme is implemented to a mechanical positioning system of a second-order plant with nonlinear friction. The effectiveness of this scheme is illustrated with the time responses obtained by computer simulation.     

Design and fabrication of a six-dimensional wrist force/torque sensor based on E-type membranes compared to cross beams

This paper presents a novel device for measuring components of forces and moments along and about three orthogonal axes based on E-type membranes compared to conventional sensor based on cross beams. After design and analysis of both types of sensors, we chose to fabricate a six-dimensional wrist force/torque sensor based on E-type membranes. Furthermore, the calibration and decoupling based on Neural Network method were performed, and the sensor possesses excellent characteristics such as high measurement sensitivity, overload protection, good linearity, and weak couplings between components. Finally, its maximum interference error and nonlinearity error are 1.6% F.S. and 0.17% F.S., respectively.     

全自动扭矩扳手测试台的设计

概述了扭矩扳手自动测试台的性能、结构和指标。采用了扭矩传感器、变送器对加载到扳手的扭矩进行检测,选用步进电机及其驱动器实现自动加载和卸载,选用30∶1的减速器实现扭矩的变换。通过对扭矩扳手的实际检测,该测试台性能指标达到了用户的要求,实现了检测过程的自动化,减轻了测试人员的劳动强度。     

Evaluation of the real contact area in three-body dry friction by micro-thermal analysis

Many tribological properties and wear mechanisms occurring on the micro-and nanoscale are strongly controlled by the so-called real contact area (A_r) which is a small fraction of the nominal or apparent contact area (A_a). The determination of A_r is often based on either (i) a geometrical approach describing the real geometry of contacting surfaces or (ii) a mechanical approach involving contact mechanics and physical-mechanical properties. In addition some experimental methods have also been attempted but they generally do not take into account the presence of third body at the interface—i.e. the wear debris trapped within the contact. In this paper we propose an experimental approach to estimate the dynamic real contact area from the operating parameters (F_n, v, T) and the tribological responses (μ, F_t) in presence of third body. A scanning thermal microscope (SThM) is used for determining both the thermal conductivity of the third body and the relationship between the contact temperature and the thermal power really dissipated at the micro-asperity level. These results are combined with a thermal model of the macro-tribocontact for computing the real contact area and the real contact pressure. Validation of these results is carried out using a classical Greenwood Williamson model and finite element models built from the real AFM maps.     

基于DSP对永磁同步电机直接转矩控制技术的研究

首先讨论了永磁同步电机的结构、3个坐标系下的数学模型及其变换方法,实现交流电机多变量及其相互作用的解耦,将交流电机化简并等效成直流电机来进行分析.然后基于TMS320F2812,对永磁同步电机直接转矩控制系统的软硬件平台进行了设计,最后对控制效果进行了实验验证.     

基于转矩补偿的双电机驱动消隙控制系统

针对齿轮传动中存在的齿隙非线性,以双电机驱动作为消除齿隙的实现方式,从控制器设计的角度出发,根据所需消隙转矩与负载转矩、运动速度和加速度之间的关系,设计了实时消隙转矩补偿控制器实现系统完全消隙。理论分析和仿真研究结果表明,相对于定常消隙转矩补偿,实时消隙转矩补偿控制器能以较小的控制能量实现系统完全消隙。