A shared memory based interface of MARTe with EPICS for real-time applications

The Multithreaded Application Real-Time executor (MARTe) is a multi-platform C++ middleware designed for the implementation of real-time control systems. It currently supports the Linux, Linux + RTAI, VxWorks, Solaris and MS Windows platforms. In the fusion community MARTe is being used at JET, COMPASS, ISTTOK, FTU and RFX in fusion [1].The Experimental Physics and Industrial Control System (EPICS), a standard framework for the control systems in KSTAR and ITER, is a set of software tools and applications which provide a software infrastructure for use in building distributed control systems to operate devices.For a MARTe based application to cooperate with an EPICS based application, an interface layer between MARTe and EPICS is required. To solve this issue, a number of interfacing solutions have been proposed and some of them have been implemented. Nevertheless, a new approach is required to mitigate the functional limitations of existing solutions and to improve their performance for real-time applications.This paper describes the design and implementation of a shared memory based interface between MARTe and EPICS.     

A Timed-Token Based Network for the ITER Poloidal Field Converter Control System

The control system for poloidal field (PF) in ITER is running in a cluster of distributed controller nodes connected by a soft real-time network. The non-functional performance of network communication, such as latency and jitter, plays an important role in the control system. We analyze the essential of network communication for PF converter control system with stringent real-time requirement and identify the feasibility of the conventional time division method at the request of current data size. However, in order to meet the increased demand for communication data size, we present the design of a timed-token based method and its network scheduler. A test scenario involving a cluster of local control cubicles has been set up to verify the method. The test result shows the timed-token method is more competent to the conventional method and more qualify to the networked control system of PF converter. Meanwhile, in other network with similar architecture, implementation of the timed-token method can guarantee real-time performance as well.     

Multiprocessor data acquisition system for high event rates at theHeidelberg/Darmstadt crystal ball

The Heidelberg/Darmstadt crystal ball detector uses a distributed data acquisition system consisting of a FASTBUS/CAMAC front-end, the Heidelberg Polyp multiprocessor system with thirty processor modules, and an online VAX. For this heterogeneous multicomputer system a distributed real-time operating system, which allows for even rates up to 2×10⁴ events/s, was developed. It is managed user-transparently and fault-tolerantly. An overview of the system is given. The operating system is discussed, covering its general organization, event management, and control and communication. The data acquisition software is described     

Software integration for monitoring systems with high flexibility

A new scheme of software integration methodology is applied to the implementation of a neural-network-based real-time monitoring aid system. In this scheme, the data communication between modules is established by means of connecting a standard I/O stream of a module to that of another. The methodology enables easy coupling of software modules with the least modifications of existing source code, and it can make distributed software systems highly flexible, portable and testable.     

Pre-Results of the Real-Time ODIN Validation on MARTe Using Plasma Linearized Model in FTU Tokamak

MARTe is a modular framework for real-time control aspects. At present time there are several MARTe systems under development at Frascati Tokamak Upgrade (Boncagni et al. in First steps in the FTU migration towards a modular and distributed real time control architecture based on MARTe and RTNet, 2010) such as the LH power percentage system, the gas puffing control system, the real-time ODIN plasma equilibrium reconstruction system and the position/current feedback control system (in a design phase) (Boncagni et al. in J Fusion Eng Design). The real-time reconstruction of magnetic flux in FTU tokamak is an important issue to estimate some quantities that can be use to control the plasma. This paper addresses the validation of real-time implementation of that task on MARTe.     

EPICS在RTEMS上的实现

EPICS是用于开发分布式实时控制系统的软件工具包,广泛应用于粒子加速器、高能物理实验、天文望远镜等大型科学实验设备的控制系统的开发。阐述了EPICS在RTEMS上实现的原理和方法,介绍了以RTEMS作为前端IOC的实时操作系统而实现的EPICS样机系统,为EPICS的研究和EPICS在实际项目中的应用提供了一种新的IOC操作系统平台。     

BESIII在线软件中的分布式进程通信框架

新一代北京谱议(BESIII)数据获取系统(DAQ)是北京正负电子对撞机(BEPC)上的大型高能物理探测器的关键组成部分,分布式环境下软件的进程通信是设计和实现的关键技术之一.介绍了数据获取系统中所使用的一种分布式进程通信(IPC,Inter Process Communication)框架,该框架基于CORBA系统进行开发.着重描述了该框架在数据获取系统在线软件中的设计、实现及应用.     

Software design of the hybrid robot machine for ITER vacuum vessel assembly and maintenance

A specific software design is elaborated in this paper for the hybrid robot machine used for the ITER vacuum vessel (VV) assembly and maintenance. In order to provide the multi-machining-function as well as the complicated, flexible and customizable GUI designing satisfying the non-standardized VV assembly process in one hand, and in another hand guarantee the stringent machining precision in the real-time motion control of robot machine, a client–server-control software architecture is proposed, which separates the user interaction, data communication and robot control implementation into different software layers. Correspondingly, three particular application protocols upon the TCP/IP are designed to transmit the data, command and status between the client and the server so as to deal with the abundant data streaming in the software. In order not to be affected by the graphic user interface (GUI) modification process in the future experiment in VV assembly working field, the real-time control system is realized as a stand-alone module in the architecture to guarantee the controlling performance of the robot machine. After completing the software development, a milling operation is tested on the robot machine, and the result demonstrates that both the specific GUI operability and the real-time motion control performance could be guaranteed adequately in the software design.     

EPICS系统中CORBA接口技术的研究

介绍了被称为软总线的中间件(Middleware)CORBA与分布式控制系统软件工具EPICS的接口技术。CORBA接口技术能极大地改善大型实验物理装置的系统建模、仿真和机器运行等高层物理应用软件的开发环境，提高软件可重用性、可维护性以及可移植性。     

The development of data acquisition and processing application system for RF ion source

As the key ion source component of nuclear fusion auxiliary heating devices, the radio frequency(RF) ion source is developed and applied gradually to offer a source plasma with the advantages of ease of control and high reliability. In addition, it easily achieves long-pulse steady-state operation. During the process of the development and testing of the RF ion source, a lot of original experimental data will be generated. Therefore, it is necessary to develop a stable and reliable computer data acquisition and processing application system for realizing the functions of data acquisition, storage, access, and real-time monitoring. In this paper, the development of a data acquisition and processing application system for the RF ion source is presented. The hardware platform is based on the PXI system and the software is programmed on the Lab VIEW development environment. The key technologies that are used for the implementation of this software programming mainly include the long-pulse data acquisition technology, multithreading processing technology, transmission control communication protocol, and the Lempel–Ziv–Oberhumer data compression algorithm. Now, this design has been tested and applied on the RF ion source. The test results show that it can work reliably and steadily. With the help of this design, the stable plasma discharge data of the RF ion source are collected,stored, accessed, and monitored in real-time. It is shown that it has a very practical application significance for the RF experiments.     

Virtual plasma chamber integrated multi-physics simulation: Status and next steps

A modest approach to develop the ISPC enabling tool for fusion plasma chamber systems has been achieved. This high performance computing simulation addresses 3D physical phenomena in a complex and heterogeneous virtual fusion plasma chamber system and opens a new way for how one, such as DEMO/FNSF, ought to be designed and modeled. In the current approach, complex FNST scenarios were simulated and modeled through a community-built reflective middleware for simulation integrations involving multiple simulators. Example advancements are presented while issues and ideas are discussed to further expand the development of such a tool.     

ASDEX Upgrade Discharge Control System—A real-time plasma control framework

ASDEX Upgrade is a fusion experiment with a size and complexity to allow extrapolation of technical and physical conditions and requirements to devices like ITER and even beyond. In addressing advanced physics topics it makes extensive use of sophisticated real-time control methods. It comprises real-time diagnostic integration, dynamically adaptable multivariable feedback schemes, actuator management including load distribution schemes and a powerful monitoring and pulse supervision concept based on segment scheduling and exception handling. The Discharge Control System (DCS) supplies all this functionality on base of a modular software framework architecture designed for real-time operation. It provides system-wide services like workflow management, logging and archiving, self-monitoring and inter-process communication on Linux, VxWorks and Solaris operating systems. By default DCS supports distributed computing, and a communication layer allows multi-directional signal transfer and data-driven process synchronisation over shared memory as well as over a number of real-time networks. The entire system is built following the same common design concept combining a rich set of re-usable generic but highly customisable components with a configuration-driven component deployment method.We will give an overview on the architectural concepts as well as on the outstanding capabilities of DCS in the domains of inter-process communication, generic feedback control and pulse supervision. In each of these domains, DCS has contributed important ideas and methods to the on-going design of the ITER plasma control system. We will identify and describe these essential features and illustrate them with examples from ASDEX Upgrade operation.     

Software fault detection and recovery in critical real-time systems: An approach based on loose coupling

Remote handling (RH) systems are used to inspect, make changes to, and maintain components in the ITER machine and as such are an example of mission-critical system. Failure in a critical system may cause damage, significant financial losses and loss of experiment runtime, making dependability one of their most important properties. However, even if the software for RH control systems has been developed using best practices, the system might still fail due to undetected faults (bugs), hardware failures, etc. Critical systems therefore need capability to tolerate faults and resume operation after their occurrence. However, design of effective fault detection and recovery mechanisms poses a challenge due to timeliness requirements, growth in scale, and complex interactions. In this paper we evaluate effectiveness of service-oriented architectural approach to fault tolerance in mission-critical real-time systems. We use a prototype implementation for service management with an experimental RH control system and industrial manipulator. The fault tolerance is based on using the high level of decoupling between services to recover from transient faults by service restarts. In case the recovery process is not successful, the system can still be used if the fault was not in a critical software module.     

An integrated architecture for the ITER RH control system

The ITER remote handling (RH) system has been divided into 7 major equipment system procurements that deliver complete systems (operator interfaces, equipment controllers, and equipment) according to task oriented functional specifications. Each equipment system itself is an assembly of transporters, power manipulators, telemanipulators, vehicular systems, cameras, and tooling with a need for controllers and operator interfaces.From an operational perspective, the ITER RH systems are bound together by common control rooms, operations team, and maintenance team; and will need to achieve, to a varying degree, synchronization of operations, co-operation on tasks, hand-over of components, and sharing of data and resources. The separately procured RH systems must, therefore, be integrated to form a unified RH system for operation from the RH control rooms.The RH system will contain a heterogeneous mix of specially developed RH systems and off-the-shelf RH equipment and parts. The ITER Organization approach is to define a control system architecture that supports interoperable heterogeneous modules, and to specify a standard set of modules for each system to implement within this architecture. Compatibility with standard parts for selected modules is required to limit the complexity for operations and maintenance. A key requirement for integrating the control system modules is interoperability, and no module should have dependencies on the implementation details of other modules.The RH system is one of the ITER Plant systems that are integrated and coordinated through the hierarchical structure of the ITER CODAC system. It is distinguished from other Plant systems by the man-in-the-loop nature of RH operations and the need for control rooms at a level below the main control room. The RH control system architecture has been designed to also support the central monitoring and coordination of the RH activities.     

基于ARM的通信接口测试系统的开发

分布式数据采集系统各子系统间的连接测试,需要专门的接口测试工具。随着私有协议的广泛使用,设备生产、维修中的调试测试问题也大大增加。这些问题往往无法使用传统的通用协议测试仪器进行测试,本文提出一种由测试模块加PC机方式构成专用接口测试系统的开发策略,并且重点介绍基于ARM的测试模块设计实现方法。文章分析了测试模块的接口特性、基本结构和软件流程,随后探讨了其与PC组成测试系统的应用方法。实验结果表明,该测试系统较好地满足了专用接口测试需求。这种测试模块加PC机构成简便系统的开发思路,为此类专用接口测试系统的快速开发提供了一种途径。     

数据块并行处理的实现策略及评价方法的研究

提出了一种针对高速、大容量测试数据的多DSP实时并行处理方法。其中DSP采用了环形的互联方式对数据按块处理。在分析了处理系统中数据I／O、DSP的运算与通信等过程相关性的基础上,提出了如何在给定数据吞吐率下,确定系统工作参数的方法,并给出了具体的算法评价指标,最后以FIR滤波算法为例,给出了详细的实施方法、评价指标和实际验证结果。     

Upgrade of the COMPASS tokamak real-time control system

The COMPASS plasma control system is based on the MARTe real-time framework. Thanks to MARTe modularity and flexibility new algorithms have been developed for plasma diagnostic (plasma position calculation), control (shaping field control), and protection systems (central solenoid protection). Moreover, the MARTe framework itself was modified to broaden the communication capabilities via Aurora.This paper presents the recent upgrades and improvements made to the COMPASS real-time plasma control system, focusing on the issues related to precision of the real-time calculations, and discussing the improvements in terms of discharge parameters and stability. In particular, the new real-time system has given the possibility to analyze and to minimize the transport delays of each control loop.