A multi-protocol real-time monitoring and validation system for distributed fieldbus-based automation applications

This work describes BR-Tool (Bus Real-Time Monitoring Tool), an on-line monitoring and validation system to evaluate timing characteristics of automation systems implemented as a distributed network of fieldbus devices. BR-Tool supports several industrial communication protocol standards. It includes a programmable messages logger module and a validation toolset that allows timing requirements specification, validation, and graphical visualization of results. In order to illustrate the main system characteristics, two industrial case studies are presented: a Profibus-DP-based manufacturing system and an energy systems application (a multitap-transformers position control system) based on the CANOpen protocol.     

A hardware supported operating system kernel for embedded hard real-time applications

The concept of the kernel, i.e. the time critical part of a real-time operating system, and its dedicated co-processor, especially tailored for embedded applications, are presented. The co-processor acts as a system controller and operates in conjunction with one or more conventional processors in hard real-time environments. It is composed of three physically and clearly separated layers which vary with regard to implementation, speed and complexity. Correspondingly, the model of the operating system kernel is hierarchically structured, and functions are mapped to these layers, observing the inherent parallelism of recognition and handling of different kinds of events expected in such environments and higher level kernel functions such as tasking operations. The operating system functions are supported by the high level real-time programming language constructs. Since many embedded systems are safety related, the software employed must be highly dependable. Therefore, the kernel was proven correct with formal methods, which represents a major innovation in software technology.     

An efficient motion magnification system for real-time applications

The human eye cannot see subtle motion signals that fall outside human visual limits, due to either limited resolution of intensity variations or lack of sensitivity to lower spatial and temporal frequencies. Yet, these invisible signals can be highly informative when amplified to be observable by a human operator or an automatic machine vision system. Many video magnification techniques have recently been proposed to magnify and reveal these signals in videos and image sequences. Limitations, including noise level, video quality and long execution time, are associated with the existing video magnification techniques. Therefore, there is value in developing a new magnification method where these issues are the main consideration. This study presents a new magnification method that outperforms other magnification techniques in terms of noise removal, video quality at large magnification factor and execution time. The proposed method is compared with four methods, including Eulerian video magnification, phase-based video magnification, Riesz pyramid for fast phase-based video magnification and enhanced Eulerian video magnification. The experimental results demonstrate the superior performance of the proposed magnification method regarding all video quality metrics used. Our method is also 60–70% faster than Eulerian video magnification, whereas other competing methods take longer to execute than Eulerian video magnification.     

A parallel neural processor for real-time applications

Training and testing artificial neural networks can be challenging and time-consuming. Experiments with two real-time applications were performed to compare three approaches for implementing a multilayer perceptron neural network. In both applications, the special-purpose processor performed best     

高速CMOS图像存储与实时显示系统设计

针对遥测系统图像单元存在数据量大、速度快、无法直接存储显示等问题,设计了一种高速图像存储与实时显示系统。系统以Spartan 6系列现场可编程门阵列(FPGA)作为核心处理器,使用Full模式Camera Link接口采集CMOS相机输出的图像数据,利用DDR3乒乓缓存技术将图像数据写入由SATA控制器组成的磁盘阵列中,并且通过千兆以太网接口将处理后的数据上传至计算机;图像数据采用抽帧以及降低分辨率的形式,将其转换为1 024×768像素的VGA分辨率格式,最后通过VGA接口对图像进行实时显示。实验结果表明,该系统能够对分辨率为2 048×2 048像素、帧频为150 f/s的高速图像数据进行长时间存储与实时显示。     

A robust real-time facial alignment system with facial landmarks detection and rectification for multimedia applications

Face detection often plays the first step in various visual applications. Large variants of facial deformations due to head movements and facial expression make it difficult to identify appropriate face region. In this paper, a robust real-time face alignment system, including facial landmarks detection and face rectification, is proposed. A facial landmarks detection model based on regression tree is utilized in the proposed system. In face rectification framework, 2-D geometrical analysis based on pitch, yaw and roll movements is designed to solve the misalignment problem in face detection. The experiments on the two datasets verify the performance significantly improved by the proposed method in the facial recognition task and outperform than those obtained by other alignment methods. Furthermore, the proposed method can achieve robust recognition results even if the amount of training images is not large.

     

A framework for mapping periodic real-time applications onmulticomputers

This short paper presents a framework for periodic execution of task-flow graphs that enables schedulability analysis of the communication requirements. The analysis performs the steps of segmenting messages, assigning the segments to specific links and time intervals, and ordering them within the intervals to generate node switching schedules that provide contention-free message routing at run-time. The analysis is also used to integrate task allocation with message routing using a contention-based objective function. Usefulness of the proposed scheme in ensuring guaranteed communication performance is demonstrated by an appropriate example     

A data collection protocol for real-time sensor applications

The nature of many sensor applications as well as continuously changing sensor data often imposes real-time requirements on wireless sensor network protocols. Due to numerous design constraints, such as limited bandwidth, memory and energy of sensor platforms, and packet collisions that can potentially lead to an unbounded number of retransmissions, timeliness techniques designed for real-time systems and real-time databases cannot be applied directly to wireless sensor networks. Our objective is to design a protocol for sensor applications that require periodic collection of raw data reports from the entire network in a timely manner. We formulate the problem as a graph coloring problem. We then present TIGRA (Timely Sensor Data Collection using Distributed Graph Coloring) — a distributed heuristic for graph coloring that takes into account application semantics and special characteristics of sensor networks. TIGRA ensures that no interference occurs and spatial channel reuse is maximized by assigning a specific time slot for each node. Although the end-to-end delay incurred by sensor data collection largely depends on a specific topology, platform, and application, TIGRA provides a transmission schedule that guarantees a deterministic delay on sensor data collection.     

Tools and applications for large-scale display walls

Increased processor and storage capacities have supported the computational sciences, but have simultaneously unleashed a data avalanche on the scientific community. As a result, scientific research is limited by data analysis and visualization capabilities. These new bottlenecks have been the driving motivation behind the Princeton scalable display wall project. To create a scalable and easy-to-use large-format display system for collaborative visualization, the authors have developed various techniques, software tools, and applications.     

Using Linux for real-time applications

We've selected a topic for practitioners in the embedded and real-time domains, namely how to use Linux for real-time applications. The article is hands-on: it not only summarizes selection criteria and introduction schemes for RTLinux but also shows how Linux was actually integrated in an existing (legacy) architecture. For small and medium-sized businesses to stay competitive, they need communication systems that offer not only excellent telephone service but also Internet and data-handling capability. As a solution to this problem, we have built a comprehensive communication appliance called OmniPCX Office, or OXO - a preconfigured server integrating data, Internet, and voice communication capabilities. Rather than using proprietary software to support the OXO platform, we chose Linux with an RTLinux extension. This column explains why we chose it and how OXO uses it, focusing particularly on architecture and realtime aspects.     

Collaborative real-time traffic information generation and sharing framework for the intelligent transportation system

Real-time traffic information collection and data fusion is one of the most important tasks in the advanced traffic management system (ATMS), and sharing traffic information to users is an essential part of the advance traveler information system (ATIS) among the intelligent transportation systems (ITS). Traditionally, sensor-based schemes or probing-vehicle based schemes have been used for collecting traffic information, but the coverage, cost, and real-time issues have remained unsolved. In this paper, a wiki-like collaborative real-time traffic information collection, fusion and sharing framework is proposed, which includes user-centric traffic event reacting mechanism, and automatic agent-centric traffic information aggregating scheme. Smart traffic agents (STA) developed for various front-end devices have the location-aware two-way real-time traffic exchange capability, and built-in event-reporting mechanism to allow users to report the real-time traffic events around their locations. In addition to collecting traffic information, the framework also integrates heterogeneous external real-time traffic information data sources and internal historical traffic information database to predict real-time traffic status by knowledge base system technique.     

基于FPGA的彩色图像实时采集显示系统设计

设计并实现了一种基于FPGA硬件平台的Bayer到RGB格式图像数据转换实时采集显示系统。该系统能够对前端Camera Link接口的CMOS相机采集的分辨率为1 920×1 080、帧率100 f/s以上的Bayer格式图像进行实时处理,并且将处理得到的RGB彩色图像数据通过DVI显示器以60 f/s的帧率实时显示。根据FPGA并行处理能力强的特点,采用像素矩阵模板实现了Bayer到RGB的彩色图像插值算法,实现了高分辨率、高帧率彩色图像的实时采集显示。     

A design of RFTOG model for distributed real-time applications

In this paper, we design the Real-Time Fault-Tolerant Object Group (RFTOG) model that supports the grouping of distributed objects that are required for distributed application. The proposed model basically provides two services. One is the group management service, which supports both consistency maintenance and transparency of the replicated objects with a variety of replication mechanisms. It also provides the load balancing of distributed applications. The other is real-time service in an object group. When the clients request the service to the service object selected through the load balance, this service guarantees the service execution within deadline for the clients’ requests. We develop the Naval Air Defense System (NADS) simulator for verifying the effectiveness of the services proposed by the RFTOG model.     

A wireless sensor networks MAC protocol for real-time applications

Wireless sensor networks (WSN) are designed for data gathering and processing, with particular requirements: low hardware complexity, low energy consumption, special traffic pattern support, scalability, and in some cases, real-time operation. In this paper we present the virtual TDMA for sensors (VTS) MAC protocol, which intends to support the previous features, focusing particularly on real-time operation. VTS adaptively creates a TDMA arrangement with a number of timeslots equal to the actual number of nodes in range. Thus, VTS achieves an optimal throughput performance compared to TDMA protocols with fixed size of frame. The frame is set up and maintained by a distributed procedure, which allows sensors to asynchronously join and leave the frame. In addition, duty cycle is increased or decreased in order to keep latency constant below a given deadline. Therefore, a major advantage of VTS is that it guarantees a bounded latency, which allows soft real-time applications.

A real-time system for motion retrieval and interpretation

This paper proposes a new examplar-based method for real-time human motion recognition using Motion Capture (MoCap) data. We have formalized streamed recognizable actions, coming from an online MoCap engine, into a motion graph that is similar to an animation motion graph. This graph is used as an automaton to recognize known actions as well as to add new ones. We have defined and used a spatio-temporal metric for similarity measurements to achieve more accurate feedbacks on classification. The proposed method has the advantage of being linear and incremental, making the recognition process very fast and the addition of a new action straightforward. Furthermore, actions can be recognized with a score even before they are fully completed. Thanks to the use of a skeleton-centric coordinate system, our recognition method has become view-invariant. We have successfully tested our action recognition method on both synthetic and real data. We have also compared our results with four state-of-the-art methods using three well known datasets for human action recognition. In particular, the comparisons have clearly shown the advantage of our method through better recognition rates.     

基于DSP的X射线图像实时显示系统设计

研究一种基于高速处理芯片TMS320DM643的X射线图像实时处理及显示系统,针对X射线图像的特点,分析系统整体性能,包括接口电路,A／D、D／A转换芯片、EDMA、二级缓存等。对应用的DSP等主要芯片进行了合理配置,分析运用图像处理算法,选择出适合的算法,编写算法流程图,达到了预期的显示效果。     

Extending Pearl for industrial real-time applications

High-Integrity Pearl, (HI-Pearl) an extension to the Process and Experiment Automation Real-Time language (Pearl) which incorporates several principles from the real-time Euclid language, is described. The requirements of real-time software and components of a real-time language are reviewed. HI-Pearl's mechanisms for concurrency control, synchronization, allocation, time-bounded loops, surveillance of events, parallelism, timing constraints, overload detection and handling, storage management, run tracing, and error detection and handling are discussed. HI-Pearl's schedulability analyzer, an automated tool to predict whether real-time software will adhere to its critical timing constraints, is also discussed     

Evaluating parallel processors for real-time applications

Increasing acceptance of the necessity for high-order parallelism in order to progress digital processing still leaves open the large question of what machine architectures are best for which class of problem.

To help answer this, we are investigating and comparing the use of both SIMD and MIMD architectures for programmable processing in real-time systems. A distributed array machine, Mil-DAP (derived from the original ICL DAP) has been developed and benchmarked on radar, image processing, and on terrain modelling problems. Multi-transputer arrays have been applied to an overlapping set of problems in image processing, FFT and terrain-based computation.

The results are compared and preliminary conclusions drawn.