一种辨识Hammerstein模型的新方法

本文结合参数估计理论和函数逼近论中的一些理论结果,提出了一种开环辨识Hammerstein 模型的新方法.这种方法能够克服目前广泛采用的辨识Hammerstein模型的方法中的 缺点,获得模型线性动态部分参数的渐近无偏估计及无记忆非线性特性,具有接近最佳逼近 效果和较好收敛性的逼近多项式.  

半被动双足机器人的准开环控制

目前的被动行走机器人还只能完成单一的步态，且非常容易摔倒，为此对半被动双足机器人的稳定行走控制问题进行了研究．通过结合被动行走和主动控制两种原理的优点，提出了一种准开环的行走控制方法．通过检测安装在机器人足底和髌骨处的接触开关信号，在髋关节处施加一个间断的、微小的开环振荡力矩，进而实现高效的稳定步行．仿真结果表明，当控制参数在较大范围内变化时，双足机器人仍可实现稳定行走，且步行能耗特性与人类相似；通过调节振荡力矩的参数，机器人可实现稳定的行走模式转换．  

一种新的相平面分区控制器的分析与仿真

通过对相平面分区控制方式的分析,为扩大控制器适用范围和降低系统参数整定难度,提出了控制器的一种改进措施,引入分段相平面分区控制方法.采用了控制力的确定方法以及改进相平面分区控制器参数整定原则,并对系统稳定性进行了分析.通过高阶系统仿真示例,分析了改进相平面分区控制系统中的第一控制器参数、第二控制器参数、作用时间这三类控制参数对系统性能的影响.仿真结果表明,该方法能较好的兼顾系统的动态、稳态特性,并具有较好的抗干扰能力.  

一种基于H.264的混合视频转码方法*

为了提高比特率缩减的H.264视频转码速度，提出了一种混合型视频转码（mixtue video transcode，MVT）方法。该方法选择串联结构对intra帧进行转换编码，选择开环结构对inter帧进行转换编码，同时对inter帧进行部分误差消除操作。对intra帧，转换编码操作后可以得到无误差的intra帧；对于inter帧，转码后图像质量的损失大于串联结构，但因为进行了消除误差漂移的操作，这一损失可以控制在可接受的最小范围内。实验结果表明，提出的混合型视频转码结构在转码速度上远远高于串联结构，转  

Real-time edge-enhanced dynamic correlation and predictive open-loop car-following control for robust tracking

We present a robust framework for a real-time visual tracking system, based on a BPNN-controlled fast normalized correlation (BCFNC) algorithm and a predictive open-loop car-following control (POL-CFC) strategy. The search for the target is carried out in a dynamically generated resizable search-window. In order to achieve the robustness, we use some edge-enhancement operations before the correlation operation, and introduce an adaptive template-updating scheme. The proposed tracking algorithm is compared with various correlation-based techniques and (in some cases) with the mean-shift and the condensation trackers on real-world scenarios. A significant improvement in efficiency and robustness is reported. The POL-CFC algorithm approximates the current velocity of an open-loop pan-tilt unit, computes the predicted relative-velocity of the object using Kalman filter, and generates the precise control signals to move the camera accurately towards the maneuvering target regardless of its changing velocity. The proposed system works in real-time at the speed of 25–200 frames/ second depending on the template size, and it can persistently track a distant or near object even in the presence of object fading, low-contrast imagery, noise, short-lived background clutter, object-scaling, changing object-velocity, varying illumination, object maneuvering, multiple objects, obscuration, and sudden occlusion.  

A differential game of international pollution control

Pollution is an inevitably by-product of production and damages the environment. The trade-off between production as a good and pollution as a bad over time can be analysed in the framework of a control model, which yields a path of emission charges that force the producers to behave in associally optimal way. Pollution that crosses national borders calls for international coordination of emission charges. In order to estimate the benefits of coordination one must use a realistic non-cooperative equilibrium concept. A natural extension of the control model implies unrealistic assumptions on information and commitment, and under-estimates the damage to the environment of not coordinating emission charges. In this note the more realistic subgame-perfect non-cooperative equilibrium is derived, which reinforces the case for international agreement og on pollution control.  

Automation in forming processes

Whereas the extent of automation in plants relative cutting machine tools is rather large, automation with respect to forming machines is still rather limited. Due to the large number of varying parameters for formed materials, an automation tool of high flexibility is required. The variety of currently available microcomputers offers powerful such automation tools. The present paper surveys some of the forming processes that have become automated in the past few years, and others that are to be automated in the future.  

Adaptive input shaping for single-link flexible manipulators using an algebraic identification

This work proposes an adaptive control scheme applied to single link-flexible manipulators, which combines a feedback controller of the joint angle with an adaptive input shaper updated by an algebraic non-asymptotic identification. The feedback controller is designed to guarantee trajectory tracking of the joint angle, simplifying thus the input shaper, which can be designed for the arm dynamics only. The input shaper is updated by an algebraic identification of the natural frequency corresponding to the first vibration mode of the arm. In addition, the influence of the assumptions adopted to derive the algebraic identification on the performance of the estimation is studied. Finally, the proposed adaptive control strategy is implemented in practice.  

隔离放大器的测试方法研究

近年来隔离放大器的指标在不断提高,性能也在不断提升,应用范围越来越广,伴随着隔离放大器的发展,对用来考核放大器指标的测试技术也提出了相应的要求。论文针对常用的隔离运算放大器AD204,结合测试标准,研究其测试方法、设计了测试电路,提出了提高测试参数准确性的几项措施,实现了对AD204重要参数指标的测试。