新型红外二氧化碳分析仪

本文介绍一种具有不切光单光束结构的新型红外二氧化碳分析仪。该分析仪基于朗伯——比尔吸收定律，采用光源稳流、温度补偿、单片机数据处理及选用高性能红外探测器等关键技术，能够对二氧化碳气体进行有效准确地测量和分析。该分析仪体积小、重量轻、功耗低、响应速度快、力学性能高，具有广阔的应用前景     

星载光电跟踪系统的组成及其性能指标设计

介绍了星载空间目标光电跟踪系统的组成及工作原理,根据星载环境的特殊性及跟踪系统设计要求,定量分析且提出了跟踪伺服系统的跟踪精度,并对其相关参数及跟踪系统的动态性能指标做了较全面的定性分析和阐述。可以看出,确定系统跟踪性能既要考虑实际系统的工作环境特殊性,又要考虑技术实现的可能性,合理的分析和设计对实现良好的光电跟踪设备总体性能是非常重要的。     

Thermal and mechanical properties of ZrO2-CeO2 plasma-sprayed coatings

The thermal and mechanical properties of ZrC₂-C_{eO 2}plasma-sprayed coatings were evaluated to examine their potential as a thermal barrier coating. ZrO₂-CeO₂ solid-solution powders containing up to 70 mol % CeO₂ are successfully plasma sprayed, but cerium content decreases during spraying due to the vaporization of cerium oxide. Hardness is greatest at 30 mol% CeO₂. With increased CeO₂ content, the thermal conductivity decreases to 0.5 W/m K and the thermal expansion coefficient increases to 12.5 x 10_-6 /K. Increased torch input power causes both the relative density and the hardness to increase monotonically, while the thermal conductivity and the thermal expansion coefficient are not significantly affected. When heated above 1300 K, the coating shrinks considerably due to sintering and its thermal conductivity increases abruptly.     

时滞随机大系统的分散次优镇定

本文基于Ｒｉｃａａｔｉ矩阵方程、采用Ｌｙａｐｕｎｏｖ泛函研究具有时滞的Ｉｔｏ型随机大系统的分散次优镇定，建立了分散次优镇定的判据，给出了确定分散次优控制器的一个算法，这个算法以求解Ｌｙａｐｕｎｏｖ矩阵方程与Ｒｉｃｃａｔｉ矩阵方程为基础。文中命同了数值算例以说明本文算法的用法。     

基于神经网络的多模型同时镇定控制器设计

本文将神经元网络引入多模型同时镇定问题，给出了实现多模型同时镇定的神经网络控制器的设计方法，其特点是方法简练，且不受线性系统的限制。将该方法用于造纸过程定量水分控制系统模型，仿真结果说明了本文所给方法可以为这一不确定时变系统设计出良好的控制器。     

Universal controllers for stabilization and tracking of underactuated ships

We examine the problem of universal control for underactuated surface ships with only surge force and yaw moment. Namely, a single controller is to be designed to achieve stabilization and tracking simultaneously. We propose, in this paper, the first universal controller of which the synthesis is based on Lyapunov's direct method and backstepping technique. Our result is extendible to the input-saturation when the surge and yaw velocities are considered as the controls. Numerical simulations are provided to validate the effectiveness of the proposed controller and to demonstrate its sensitivity with respect to model parameters.     

Buck型变换器固定时间自适应控制

针对Buck型DC/DC变换器系统,提出一种固定时间自适应降压控制方法.首先,针对系统参数已知的情况,设计固定时间滑模面和控制器,保证系统输出电压误差在固定时间内收敛到平衡点,且其收敛时间上界与系统初始状态无关,仅由控制参数决定.针对电阻、电感等参数值受温度及外部干扰影响发生变化且无法准确获取的问题,进一步设计自适应更新律估计系统所有未知参数,并在此基础上设计固定时间自适应控制器,保证输出电压误差在固定时间内收敛到平衡点附近的邻域内.最后通过仿真和实验对比结果验证所提出控制方法的有效性.     

加权最小二乘法与卡尔曼滤波实时稳像技术

无人机和车辆行驶等情况下拍摄的视频受外界影响会造成视频抖动。通过对比现有的电子稳像技术,提出了利用FAST获取特征点的位置信息,再通过光流法结合NCC匹配得到参考帧特征点在当前帧的位置信息,在此基础上,结合RANSAC算法剔除错误匹配的特征点对的改进算法。为了提高运动矢量估计的精度,应用加权最小二乘法得到相邻帧间的刚性变换矩阵,并经过卡尔曼滤波进行运动平滑得到扫描运动矢量并补偿,最终得到实时的稳定视频。实验表明,视频序列稳像后的帧间变换保真度有所提高,并且能够达到实时处理速度。     

Robust Constrained Model Predictive Control for Discrete‐Time Uncertain System in Takagi‐Sugeno's Form

In this paper, we investigate a robust constrained model predictive control synthesis approach for discrete‐time Takagi‐Sugeno's (T‐S) fuzzy system with structured uncertainty. The key idea is to determine, at each sampling time, a state feedback fuzzy predictive controller that minimizes the performance objective function in the infinite time horizon by solving a class of linear matrix inequalities (LMIs) optimization problem. To do this, the fuzzy predictive controller is designed on the basis of non‐parallel distributed compensation (non‐PDC) control law, relaxed stability conditions of the closed‐loop fuzzy system are developed by employing an extended nonquadratic Lyapunov function and introducing additional slack and collection matrices. In addition, the presented approach is capable of ensuring the robust asymptotic stability as well as the recursive feasibility of the closed‐loop fuzzy system. Simulations on a highly nonlinear continuous stirred tank reactor (CSTR) are eventually presented to demonstrate the effectiveness of the developed theoretical approach.     

Exponential Stability and Stabilization for Quadratic Discrete‐Time Systems with Time Delay

In this note, we deal with the exponential stability and stabilization problems for quadratic discrete‐time systems with time delay. By using the quadratic Lyapunov function and a so called ‘Finsler's lemma', delay‐independent sufficient conditions for local stability and stabilization for quadratic discrete‐time systems with time delay are derived in terms of linear matrix inequalities (LMIs). Based on these sufficient conditions, iterative linear matrix inequality algorithms are proposed for maximizing the stability regions of the systems. Finally, two examples are given to illustrate the effectiveness of the methods presented in this paper.