A Solution Based on Modeling and Code Generation for Embedded Control System

With the development of computer technology, embedded control system plays an important role in modern industry. For the embedded system, traditional development methods are time-consuming and system is not easy to maintain. Domain-specific modeling provides a solution for the problems. In this paper, we proposed development architecture for embedded control systems based on MIC. GME is used to construct meta-model and application model, model in-terpreter interprets model and stores model information in xml format document. The final cross-platform codes are automatically generated by different templates and xml format document. This development method can reduce time and cost in the lifecycle of system development.

Rate Control Algorithm of Wireless Video Based on Visual Saliency Map Model

In order to further improve the efficiency of video compression, we introduce a perceptual characteristics of Human Visual System (HVS) to video coding, and propose a novel video coding rate control algorithm based on human visual saliency model in H.264/AVC. Firstly, we modifie Itti's saliency model. Secondly, target bits of each frame are allocated through the correlation of saliency region between the current and previous frame, and the complexity of each MB is modified through the saliency value and its Mean Absolute Difference (MAD) value. Lastly, the algorithm was implemented in JVT JM12.2. Simulation results show that, comparing with traditional rate control algorithm, the proposed one can reduce the coding bit rate and improve the reconstructed video subjective quality, especially for visual saliency region. It is very suitable for wireless video transmission.

Model Reduction Methods for High-Rise Buildings with Active Mass Damper Control Systems

To improve the performance of an active mass damper control system,the controller should be designed based on a reduced-order model. An improved method based on balanced truncation method was proposed to reduce the dimension of high-rise buildings,and was compared with other widely used reduction methods by using a framework with ten floors. This optimized method has improvement of reduction process and choice of the order. Based on the reduced-order model obtained by the improved method and pole-assignment algorithm,a controller was designed. Finally,a comparative analysis of structural responses,transfer functions,and poles was conducted on an actual high-rise building. The results show the effectiveness of the improved method.

基于GIT的气象数值模式代码管理平台METCODE

随着气象数值模式的发展完善,已广泛应用于国家级和区域中心,研发力量地理上分散。支撑数值模式运行的高性能计算机系统呈现出异构众核的发展趋势,模式研发的学科交叉衍生性越发明显,分布式模式研发的高效协同共享成为一个亟待解决的问题。本文基于Git建立了一个代码管理协作共享平台METCODE,实现了气象数值模式的代码版本管理、集成协作共享与过程管理,方便地支持分布式团队的合作研发。平台已在气象数值模式的研发中成功应用,应用效益良好。

APPLICATION OF NEURAL NETWORK INVERSE CONTROL SYSTEM IN TURBO DECODING

Adaptive inverse control system can improve the performance of turbo decoding,and modeling turbo decoder is one of the most important technologies. A neural network model for the inverse model of turbo decoding is proposed in this paper. Compared with linear filter with its revi-sion,the general relationship between the input and output of the inverse model of turbo decoding system can be established exactly by Nonlinear Auto-Regressive eXogeneous input (NARX) filter. Combined with linear inverse system,it has simpler structure and costs less computation,thus can satisfy the demand of real-time turbo decoding. Simulation results show that neural network in-verse control system can improve the performance of turbo decoding further than other linear con-trol system.

NOVEL MULTIMEDIA TRAFFIC MODELING BASED CAC SCHEME FOR CDMA COMMUNICATION SYSTEMS

As the radio spectrum is a very scarce resource,the Call Admission Control (CAC) is one of the most important parts in radio resource management. The Code Division Multiple Access (CDMA) based next generation wireless communications systems will support the transmission of multimedia traffic,such as voice,video and data,thus the CAC,which can support the multimedia traffic and guarantee the Quality of Service (QoS) of different traffic,has gained broad attention. In this paper,a novel multimedia traffic modeling method and a corresponding dynamic QoS based CAC are proposed. The analysis and simulation results show that the proposed CAC scheme can guarantee the QoS to different traffic demand,and improve the system performance significantly.

Stabilization of CSTR w ith Self-tuning Sliding Mode Controller Using T-S Fuzzy Linearization

A self-tuning reaching law based sliding mode control(SMC)theory is proposed to stabilize the nonlinear continuous stirred tank reactor(CSTR).T-S fuzzy logic is used to build a global fuzzy state-space linear model.Combing the traits of SMC and CSTR,three fuzzy rules can meet the requirements of controlled system.The self-tuning switch control law which can drive the state variables to the sliding surface as soon as possible is designed to ensure the robustness of uncertain fuzzy system.Lyapunov equation is applied to proving the stability of the sliding surface.The simulations show that the proposed approach can achieve desired performance with less chattering problem.

NUMERICAL ANALYSIS FOR VIBRATION CONTROL OF BEAMS WITH ACTIVE CONSTRAINED LAYER DAMPING TREATMENTS

The finite element method(FEM) is combined with the GHM(Golla Hughes McTavish) model of viscoelastic material to model a cantilever beam with active constrained layer damping (ACLD), which can avoid time consuming iteration for solving modal frequencies, modal damping rations and responses. But the resulting finite element model has too many degress of freedom from the point of control. Furthermore, it is not observable and controllable. So, a new model reduction procedure was proposed. Firstly, an iterativr dynamic condensation is performed in the physical space and Guyan condensation is taken as an initial approximation of the iteration. This results in a reduced order system with suitable size, but it is still not observable and controllable. So a kind of robust model reduction methods is utilized in the state space afterwards. The numerical example shows that the above model reduction procedure can not only reduce the size of the system greatly but also guarantee the stability, controllability and observability of the final reduced order system. Finally, a controller, is designed by LQG (Linear Quadratic Gaussian) method based on the final reduced order model. It shows that the vibration attenuation is obvious.

Variable Bit Rate Fuzzy Control for Low Delay Video Coding

Rate control plays a critical role in achieving perceivable video quality under a variable bit rate,limited buffer sizes and low delay applications.Since a rate control system exhibits non-linear and unpredictable characteristics,it is difficult to establish a very accurate rate-distortion(R-D)model and acquire effective rate control performance.Considering the excellent control ability and low computing complexity of the fuzzy logic in non-linear systems,this paper proposes a bitrate control algorithm based on a fuzzy controller,named the Fuzzy Rate Control Algorithm(FRCA),for All-Intra(AI)and low-delay(LD)video source coding.Contributions of the proposed FRCA mainly consist of four aspects.First,fuzzy logic is adopted to minimize the deviation between the actual and the target buffer size in the hypothetical reference decoder(HRD).Second,a fast lookup table is employed in fuzzy rate control,which reduces computing cost of the control process.Third,an input domain determination scheme is proposed to improve the precision of the fuzzy controller.Fourth,a novel scene change detection is introduced and integrated in the FRCA to adaptively adjust the Group-of-Pictures(GOP)length when the source content fluctuates.The FRCA can be transplanted and implemented in various industry coders.Extensive experiments show that the FRCA has accurate variable bit-rate control ability and maintains a steady buffer size during the encoding processes.Compared with the default configuration encoding under AI and LD,the proposed FRCA can achieve the target bit rates more accurately in various classical encoders.

Efficient Rate Control Algorithm for Hierarchical Video Coding

For rate control (RC) of hierarchical structure coding, an independent rate-quantization (R-Q) model was proposed based on mean absolute differences (MADs) in different temporal levels (TLs). In the proposed R-Q model, a novel MAD model was developed according to the hierarchical structure. The experimental results demonstrate that the proposed algorithm provides better performance, in terms of average peak signal-to-noise ratio (PSNR) and quality smoothness, than the H.264 reference model, JM14.2, under various sequences.

基于自然语言处理的代码指挥建模方法

构建一套高效的且适用的代码指挥体系对于提高指挥控制效率、提升作业效能具有重要意义。基于指挥控制系统的现状和发展方向,分析了代码指挥技术的发展情况,构建了一套文书指挥向代码指挥转化的系统建模方法,并采用依存分析技术和Transformer模型处理自然语言指令,实现了自然语言和指挥代码的转换。原型验证系统试验结果表明,该方法可有效提高指挥控制的效率和准确性。

基于MBD的PLC运动控制系统设计与应用

针对复杂算法在PLC运动控制系统中难以工程实现的问题,该文提出了一种基于MBD(model based design)的系统设计和应用方法。首先,利用MATLAB/Simulink建立控制模型并仿真验证,预留变量接口,正确匹配参数定义和数据类型;然后,基于Simulink PLC Coder将模型转换为符合IEC 61131-3标准的结构化文本ST(structure text)代码,根据集成开发环境CoDeSys定制文件格式;最后,将生成代码以功能块FB(function block)的形式导入CoDeSys,实现算法与应用程序的集成。某型起重机回转控制系统的应用证明了MBD方法可有效解决复杂算法工程实现难的问题。

一种数据库代码自动生成器的设计

介绍了一种数据库代码自动生成器的设计和实现方法,该方法可以自动为SQL Serv-er数据库中的数据表生成用C#或VB.NET语言编写的读写模型控制类代码,也可以将Word中描述的文字型数据字典自动生成SQL Server数据库脚本语言,完成数据库的物理设计。经过验证,这种代码自动生成器的准确率达到95%以上,大大减轻程序员的编程工作量。

基于稀疏编码金字塔模型的农田害虫图像识别

相较于一般物体的图像,农作物害虫图像因具有复杂的农田环境背景,分类与识别更加困难。为提高害虫图像识别的准确率,该文提出一种基于图像稀疏编码与空间金字塔模型相结合的害虫图像表示与识别方法。该方法利用大量非标注的自然图像块构造过完备学习字典,并运用该学习字典实现对害虫图像的多空间稀疏表示。与此同时,结合多核学习,该文设计了一种害虫图像识别算法。通过对35种害虫的识别,试验结果表明:在相同方法下,该文所提特征提取方法可使平均识别精度提高9.5百分点;此外,进一步通过对221种昆虫及20种蝴蝶的识别,试验结果表明:与传统方法相比较,该文所提方法使得平均识别精度提高14.1百分点。

Wyner-Ziv视频编码中无反馈速率控制算法研究

为了避免在分布式视频编码系统中使用反馈信道,提出了一种基于Wyner-Ziv编码的无反馈速率控制算法。首先,利用目标码率和目标帧率进行GOP层码率分配;然后,根据原始图像的帧间相关性动态选择量化因子和量化矩阵来分配每个GOP内关键帧和Wyner-Ziv帧的比特数;接下来,利用系数带级的相关性计算相关噪声模型参数,并选择对应的LDPC校验矩阵,提出Wyner-Ziv帧的无反馈比特面速率控制算法。实验结果表明,在给定目标码率下,所提算法的编码码率误差小于0.57%,且与现有无反馈速率控制算法相比,解码恢复图像的PSNR(峰值信噪比)可以提高1dB。另外,该算法基本没有增加编码端复杂度,可用于实际分布式视频通信系统。

一种面向SVC的码率控制算法

H.264/AVC可伸缩性扩展视频编码系统(JSVM)提供了一种可伸缩视频编码(SVC)的解决方案,然而它本身并没有提供一种有效的码率控制算法.文中基于JSVM的分层预测结构,提出了一种全新的码率控制算法.首先在码率分配方面,考虑到分层B帧预测(或运动补偿时间域滤波(MCTF))结构,给出一种分层的码率分配方案;然后,针对不同类型和不同时间分解层各自的统计特性,分别为它们设计了不同的率失真(R-D)模型.实验结果表明,文中算法能够有效地控制码率,使得目标码率跟实际产生码率之间的偏差最大不超过2%;同时文中算法较大地提高了解码图像的质量,使得峰值信噪比(PSNR)在低码率端可提高1dB;另外,JSVM是通过不断调整量化参数(QP)使得实际产生的码率逐次逼近目标码率,较之这种尝试型的码率控制算法,文中基于模型的码率控制是在一次编码中产生最终的目标码率,从而大大降低了计算复杂度.

一种改进的R-λ模型码率控制算法

码率控制是视频编码系统中的重要模块,用于控制编码器输出特定目标的码率,并使编码视频失真最小。R-λ模型码率控制方法是新一代视频编码标准HEVC中推荐的码率控制算法,其主要包括固定比例比特分配和自适应比率比特分配两种码率控制策略。为了提高R-λ模型码率控制算法的码率控制精度和率失真性能,文中提出了相应的算法改进。首先,根据图像组的编码结构设计了精确的率失真模型参数更新方法;其次,根据率失真依赖关系改进了图像组层的比特分配策略;最后,提出动态的图像组层拉格朗日乘子和编码帧比特权重计算方法。实验结果显示,所提方法在低延迟P帧和B帧配置下,码率相对误差仅为0.006%和0.005%,相比自适应比率比特分配码率控制策略,改进方法的率失真性能提高了1.2%和1.3%。

基于多种群遗传算法的城轨列车节能运行优化研究

通过建立定时约束条件下的最小能量控制模型,采用Pontryagain极小值原理推导了城市轨道列车节能操纵策略的组成。提出一种变长实矩阵编码的多种群遗传算法进行列车节能运行优化:采用多质点的列车牵引仿真器模拟列车运行;对列车运行控制序列采用变长实数矩阵编码;引入基于退火选择的变长算子以增强算法的全局搜索能力;适应值共享保持种群的多样性;多种群并行寻优提高收敛速度,增强寻优过程的稳定性。实例计算结果证实了该方法的有效性和先进性。

基于RTW的2H桥逆变器SPWM目标代码自动生成

提出一种基于实时代码生成工具(RTW)的TMS320F2812型定点DSP控制系统,给出了基于Matlab/RTW的系统设计方法和开发流程。结合该集成一体化控制平台,提出了一种基于嵌入式目标代码自动生成的2H桥级联逆变器SPWM产生方法,利用Matlab/Simulink工具建立了算法模型。仿真验证算法后,给出了以TMS320F2812型定点DSP为目标的SPWM控制模型,并自动生成代码,编译、下载到目标DSP中运行,产生的波形与理论吻合。这种基于模型的设计流程,实现了工程开发过程中从算法设计到最终实现的所有阶段,提高了产品开发效率,降低了成本。

基于直接序列扩频码的图像空间域水印技术

提出了一种基于直接序列扩频码的图像空间域水印方案.在建立数字图像水印的通信模型的基础上,通过生成原图的视觉掩模以充分保证图像的逼真度,在数字图像相应的空间域嵌入扩频码调制水印,同时利用纠错编码技术来进一步增强水印的抗干扰性能.水印的检测通过计算像差图像和原扩频码的相关性来实现.实验表明,该方案提高了数字水印的稳健性和隐蔽性,具有较好的主观效果.