Underactuated fingers controlled by robust and adaptive trajectory following methods

Choosing an appropriate control scheme to alleviate nonlinearities and uncertainties is not a trivial task, especially when models are not easily available and practical evaluation provides the only means for actual performance assessment. Various factors can contribute to these nonlinearities and uncertainties, such as friction and stiction. Thus, this article investigates four different control schemes, namely PID, adaptive, conventional sliding mode control (SMC) and integral sliding mode control (ISMC) which are implemented in the Bristol Elumotion Robot Hand (BERUL) to analyse and overcome the aforementioned problems. The hand has five fingers with 16 joints and all fingers are underactuated. The implementation of the proposed control schemes are challenging since the BERUL fingers have significant friction, stiction and unknown parameters. The fingers are light in weight and fragile. Comparative performance characteristics have shown that the ISMC is the most suitable candidate to provide good experimental trajectory following and positioning control for underactuated BERUL fingers.     

H.264/SVC mode decision based on mode correlation and desired mode list

Design of video encoders involves implementation of fast mode decision (FMD) algorithm to reduce computation complexity while maintaining the performance of the coding. Although H.264/scalable video coding (SVC) achieves high scalability and coding efficiency, it also has high complexity in implementing its exhaustive computation. In this paper, a novel algorithm is proposed to reduce the redundant candidate modes by making use of the correlation among layers. A desired mode list is created based on the probability to be the best mode for each block in base layer and a candidate mode selection in the enhancement layer by the correlations of modes among reference frame and current frame. Our algorithm is implemented in joint scalable video model (JSVM) 9.19.15 reference software and the performance is evaluated based on the average encoding time, peak signal to noise ration (PSNR) and bit rate. The experimental results show 41.89% improvement in encoding time with minimal loss of 0.02 dB in PSNR and 0.05% increase in bit rate.     

关于中压电缆网双环接线方式供电能力的分析

结合北京地区现阶段对相关技术的规定,以实际供用电方案为例,对中压电缆网双环接线方式的供电能力进行深入讨论。通过设计环网单元划分,发现某些条件下双环网供电能力可以得到进一步提升。     

关于软件对字符编码方式误判的研究

针对目前字符编码方式众多的现状,应用软件如何更好的判断文件编码属于何种字符集,并将其正确的解码成为不容忽视的问题。针对Windows记事本不能正常显示"联通"二字的Bug进行分析,利用Winhex软件解析文件获得16进制编码,根据得到的编码分析误判原因,通过注释记事本IsTextUTF8函数对分析得到的误判原因进行证实,进一步找到了更多Windows记事本无法正常显示的汉字。     

陕西秦岭山地体育旅游资源特征及开发模式分析＊

体育旅游作为一种新兴的旅游产品,正在慢慢走近人们的生活中。它将体育与旅游结合起来,在满足了人们休闲旅游需求的同时,也锻炼了身体,因此,受到了许多人的青睐。特别是山地体育旅游,它已经成为了广大旅游者的首要选择。在山地体育旅游蓬勃发展的大背景下,着重研究了陕西秦岭的山地体育旅游资源,分析了它的优势,并提出了合理的建议,以促进山地体育旅游的发展。     

大学论文评审系统的设计与实现

详细介绍了大学论文评审系统的应用开发背景、系统开发方案、系统功能结构设计、数据库设计以及系统功能的实现。系统基于B/S模式,采用DreamWeaverCS3、ASP和Access数据库开发,实现了用户登录验证,学生在线提交论文、查询论文评审信息、发表留言,专家在线查询、下载和评审论文以及回复留言,管理员后台数据管理等功能,提高了大学论文评审的效率,实现了大学论文评审和管理的高效性、数字化和网络化。     

“3+1”人才培养模式企业实践教学研究——应用技术大学的教学改革

针对目前"3+1"人才培养模式中企业教学内容构建还不完善、达不到教学目的等问题,根据应用技术大学的人才培养目标要求,以人才的素质培养和专业能力培养为目的,研究和探索企业实践教学对人才培养的意义。     

服务于教学实践和创业实训的校园电子商务模式研究

将电子商务引入校园生活,可以很好地突破时间和空间的限制,最大限度地发挥其优势,给校园师生提供方便。我国的校园电子商务目前只处于起步阶段,这方面的研究也比较少。本文在分析国内高校电子商务教学和创业教育存在的主要问题基础上,对我国高校的校园电子商务常见模式进行归纳、分析和比较,并结合我校的实际优势,提出一种服务于教学实践和创业实训的校园电子商务模式并加以介绍。     

基于DedeCMS的视频点播模块实现与比较

对视频点播方法进行研究和探讨,将DedeCMS为基础的视频模块与流媒体服务、FTP服务的视频点播形式进行对比。     

Sliding‐Mode Velocity Control of a Two‐Wheeled Self‐Balancing Vehicle

Underactuated vehicles are those in which the number of control inputs is less than the degrees of freedom to be controlled. Using actuated wheels, velocity control of the two‐wheeled self‐balancing vehicle drives the vehicle at a desired speed and balances the body of the vehicle. First, we investigate the effects of friction on the wheel and derive the hybrid model of rolling and slipping. Second, we propose a nonlinear sliding mode velocity control scheme for the pure rolling model of the two‐wheeled vehicle. We present the design of the corresponding sliding surfaces and internal dynamics of the two‐wheeled vehicle. Our stability analysis reveals that the proposed sliding mode method can guarantee the asymptotic stability of the error dynamics for velocity control of the underactuated vehicle. Compared to linear optimal control, our numerical simulations demonstrate that the proposed sliding mode schemes can effectively control the velocity under the circumstances of parametric variations, emergency braking, and rapid acceleration in slippery road conditions. The proposed velocity control and the simulation improve our understanding on designing velocity control of the two‐wheeled self‐balancing vehicle.