一种高性能高清视频编码分像素插值滤波算法

为提高高清晰度视频编码的效率,基于一维立方卷积滤波原理提出了一种新的分像素插值滤波算法.实验结果表明,该插值算法与H.264/AVC标准中规定的6抽头插值滤波相比,在相同码率下,对高清晰度视频的编码信噪比可以提高0.5dB;同时,解码端存储复杂度降低了19%,计算复杂度相当.     

270 MHz Full HD H.264/AVC High Profile Encoder with Shared Multibank Memory‐Based Fast Motion Estimation

We present a full HD (1080p) H.264/AVC High Profile hardware encoder based on fast motion estimation (ME). Most processing cycles are occupied with ME and use external memory access to fetch samples, which degrades the performance of the encoder. A novel approach to fast ME which uses shared multibank memory can solve these problems. The proposed pixel subsampling ME algorithm is suitable for fast motion vector searches for high‐quality resolution images. The proposed algorithm achieves an 87.5% reduction of computational complexity compared with the full search algorithm in the JM reference software, while sustaining the video quality without any conspicuous PSNR loss. The usage amount of shared multibank memory between the coarse ME and fine ME blocks is 93.6%, which saves external memory access cycles and speeds up ME. It is feasible to perform the algorithm at a 270 MHz clock speed for 30 frame/s real‐time full HD encoding. Its total gate count is 872k, and internal SRAM size is 41.8 kB.     

Automatic Synthesis of Motion Estimation Processors Based on a New Class of Hardware Architectures

A new class of fully parameterizable multiple array architectures for motion estimation in video sequences based on the Full-Search Block-Matching algorithm is proposed in this paper. This class is based on a new and efficient AB2 single array architecture with minimum latency, maximum throughput and full utilization of the hardware resources. It provides the ability to configure the target processor within the boundary values imposed for the configuration parameters concerning the algorithm setup, the processing time and the circuit area. With this purpose, a software configuration tool has been implemented to determine the set of possible configurations which fulfill the requisites of a given video coder. Experimental results using both FPGA and ASIC technologies are presented. In particular, the implementation of a single array processor configuration on a single-chip is illustrated, evidencing the ability to estimate motion vectors in real-time.     

基于运动变化的指势行为实时判别方法

提出了一种基于运动变化的实时指势判别方法。根据指势行为特征,跟踪手臂运动区域的运动状态,计算指势视频中每个独立运动序列的连续运动方向,统计其在一定方向范围内的累积运动帧数,当该运动序列在确定方向范围内的累积运动帧数达到预定范围时,根据指势手臂在指向目标时存在片刻停顿,从复杂场景中实时判别指势。实验结果表明,该方法简单、有效。     

Directional notch filters for motion control of flexible structures

A new method to design notch filters for MIMO motion control systems with flexible mechanical structures is proposed. The method involves so-called directional notch filters that work only in the direction of the targeted resonant mode. As a result, only one SISO notch filter is required per mode to suppress a resonance throughout the MIMO system. Compared to the conventional approach where a notch filter is placed and tuned in each of the separate control loops, the new approach reduces the order of the controller significantly and facilitates the design process. The directional notch filter is computed using either the input or output mode shapes of the system. A new numerical optimization method to obtain these mode shapes from frequency response data is described. Experiments on a flexible beam setup demonstrate the feasibility of the proposed method in practice.     

Stability of Motion for Generalized Birkhoffian Systems

The problem on the stability of motion for a generalized Birkhoffian system was studied. The disturbed equations of motion and their first approximation for the system were established. The criterion of stability of motion for the system was set up by using Liapunov’s first approximation theory. Based on the theory of Noether symmetry,the Liapunov’s function was constructed,and the criterion of stability of motion for the system was also set up by using Liapunov’s direct method. Two examples were given to illustrate the application of the results.     

Cross-coupling position command shaping control in a multi-axis motion system

A new structure of a cross-coupling position command shaping controller (CPCSC) for precise tracking in multi-axis motion control is proposed in this paper. This controller feedforwards the cross-coupling terms, based on the geometrical relationship between the tracking and contouring errors, to compensate for the contouring error in real-time. Compared with the conventional multi-axis cross-coupling control (CCC) system, this new structure has the advantage that its compensators in CCC have a simpler design process than conventional ones, as does its stability analysis. The proposed controller is evaluated and compared experimentally with a traditional uncoupled and a conventional CCC controller on a multi-axis positioning system controlled by microcomputer. The experimental results show that the new structure remarkably reduces contour error. In addition, this new controller can be implemented easily on most current systems by reprogramming the reference position command subroutine.     

Data-based spatial feedforward for over-actuated motion systems

For advanced motion systems there is an increasing demand for higher production throughput and accuracy. Traditionally, such systems are designed using a rigid-body design paradigm, which aims at designs with high stiffness. The alternative is to design a lightweight system and deal with the resulting flexibilities by over-actuation and over-sensing. This paper presents a data-based spatial feedforward method based on previous task trials, which aims at reducing the vibrations over the complete structure during motion. The proposed method is experimentally validated on an industrial prototype and compared to standard mass feedforward using rigid-body decoupling.     

CAMC-IP型二轴运动控制电路的功能及应用

CAMC-IP是韩国AXT公司开发的二轴运动控制电路,详细介绍CAMC-IP的主要功能、特点及其内部结构,简要介绍以CAMC-IP为核心的基于PCI总线运动控制卡的设计.     

原子质心运动和场模结构对场熵压缩特性的影响

利用量子信息熵理论,研究了J-C模型中原子质心运动和场模结构及光场的初始平均光子数对场熵压缩特性的影响,结果表明:原子质心运动导致场熵压缩的周期性演化,场模结构参量决定其周期的大小;随着场模结构参量的增大,场熵压缩的演化周期缩短,压缩时间延长;适当选择系统参量,可获得持续的熵压缩效应.