具有震颤抑制的微创机器人主从控制系统设计

详述了一种用于抑制微创手术机器人震颤现象的主从控制系统，提出了针对人手生理震颤的新型零相位滤波方法及针对从操作臂关节“粘滑行为”的前馈补偿PD伺服算法。新型零相位滤波避免了传统低通滤波器容易造成延时和传统零相位滤波无法在线使用的缺点，前馈补偿PD伺服算法通过摩擦补偿克服了非线性摩擦对从操作臂运动造成的影响。最后，对系统进行仿真及实验，结果表明该方法能有效地抑制机器人手术工具末端的震颤现象。     

Performance of a pavement foundation system based on the partial compensation of masses method

The system of the partial compensation of masses in the lacustrine zone of the Mexico Basin has been conceptualized, developed, used and improved over the past five decades as a foundation alternative for different types of roadways. This kind of foundation has been used in highways and runways built on lacustrine soils to reduce the settlement that can affect the service and operation conditions of those structures. In the construction of the new Mexico City International Airport in the Texcoco Lake area, various alternatives for runway foundations were evaluated through different test sections that were constructed to identify which of them would yield an adequate transfer of stress and prevent excessive total and differential deformations of the soil deposits. In this work, the behavior of the test section of the system of the partial compensation of masses, built in the Texcoco Lake area, is studied. An exploration campaign was performed; it consisted of different field and laboratory tests to determine the stratigraphic profile and the index and mechanical properties of the soil strata. Numerical models were applied using the finite element software PLAXIS 2D to analyze the behavior of the test section and to determine the maintenance frequency required to preserve the functionality of future runways. To validate the capability of the numerical models to properly simulate the stress-strain behavior of the test section, a comparative analysis was performed between the data obtained from the instrumentation installed on the test section and the results obtained from the finite element software. Once the numerical models were calibrated, the medium- and long-term behaviors of the test section were predicted, and the evolution over time of its surface geometry and transverse slopes were obtained.     

补偿强反光体表面红外测温误差的算法研究

针对运动强反光体表面温度实时测量困难、精度低这一难点,本文从红外测温原理入手,分析并揭示了红外测温精度易受到被测物体反射率、测量距离、测量环境、红外入射角等因素的影响。根据铝板材加工设备轧辊表面测温实际需要设计了一种利用红外传感器实现对强反光体表面温度点对点测量的方案。通过对测量数据的研究分析建立了一种基于斯忒藩定律的红外入射角度补偿算法,以此减小因红外入射角度变化产生的测温误差。实验结果证明本方法能较好地弥补红外入射角度变化产生的测温误差,提高测温精度。该补偿算法运算简单,适应性强,为改善入射角度变化对测温精度影响提供了新的方法。     

采用一维物理光学法的天线罩瞄准误差补偿

针对雷达天线罩瞄准误差的补偿问题，提出了一种适用于各向同性的天线罩瞄准误差修正方法。构建了基于一维物理光学法的天线罩瞄准误差的数学模型，推导了雷达导引头测量目标角度和角速度的误差修正公式。试验结果表明，该方法有效降低了天线罩瞄准误差对目标角速度性能的影响。     

Realization of direct flow control with load pressure compensation on a load control valve applied in overrunning load hydraulic systems

This paper presents the realization of direct proportional flow control with load pressure compensation feature on a LCV (load control valve). Proportional flow control performance means the flow through the LCV is proportional to the pilot pressure in the control stroke. Proportional flow control decides the overrunning load lowering speed control performance of the whole system. The load pressure compensation feature means when the load pressure is too high, the flow of the LCV can be restricted about the maximum rated flow. The load pressure compensation feature is important to the safety of the system. That is because large flow means undesired fast lowering speed, which will cause accident in applications, especially those large mass overrunning load systems. In this paper, the flow control performance was simulated and the parameter relationship of the orifices was derived, which is the base for the optimizing of the compensation orifice. In addition, load pressure compensation feature was simulated and the compensation orifice size was optimized. Finally, an LCV built according to above methods was tested on a test rig. Experiment data validates the methods presented and the realization of direct flow control with load pressure compensation feature gives guidance for the direct flow control performance development of other valves.     

关于计算机数据库的弱点研究

目前,有关计算机技术已经开始研究计算机数据库的弱性问题,以发挥弱点数据库的重要作用,提高计算机系统的安全性、可靠性、机密性。分析并阐述了计算机弱点数据库的价值与原则,提出计算机弱点数据库的实现方式。     

轧机开卷卷取直流电机工作电流分析

对直流驱动开卷卷取机工作过程进行分析,按照励磁磁通饱和,和励磁弱磁两种工况分别考虑,计算出张力转矩和动态补偿转矩与料卷卷径的关系,从而求出在一道次轧制过程中的电机最大电流     

Friction compensation in control valves: Nonlinear control and usual approaches

This work presents different approaches to reduce the control valve friction effect on a process. One is to use the sliding mode control in different conditions and then to compare this controller to widely used algorithms and devices that reduce the control loop variability. The experiments were performed in the Flow Pilot Plant of Polytechnic School of the University of São Paulo with a pneumatic control valve with high friction in a flow control loop. The sliding mode controller yielded promising results, which can represent new horizons with respect to friction compensation in control valves.     

AN ALTERNATIVE PERSPECTIVE ON FUZZY SET-BASED APPROXIMATE REASONING

Abstract

On the subject of fuzzy set-based approximate reasoning, this paper attempts to present a perspective that is both rigorously stated and different from the standard approach as stated by Mamdani and many others. Functionally speaking, this alternative perspective produces results essentially the same as the standard one, and in fact we intend to prove that subject to certain assumptions the results will be exactly die same. We feel however that the alternative perspective offers advantages in that it makes a more appropriate and more understandable use of such concepts as fuzzy relations, the extension principle, and fuzzy composition. If indeed it can lead to a clearer and more widespread understanding of the approximate reasoning formalism then this could conceivably spark broader interest in fuzzy control and other applications.