A day in an astronaut's life: reflections on advanced planning and scheduling technology

The day in a Space Station astronaut's life starts a year before his or her mission (or increment, in NASA-ese), when the mission planning and scheduling begins. The mission controllers refine and review the mission plan until execution time, when they upload it to the Space Station as an onboard short-term plan (OSTP). This installment of the AI in Space department looks at the process NASA uses to plan and execute an astronaut's "day in the life". It examines new planning and scheduling technologies presented at the Third International NASA Workshop on Planning and Scheduling for Space and show how they might affect future Space Station astronauts.     

OPTIMUM-AIV: A planning and scheduling system for spacecraft AIV

This paper presents a project undertaken for the European Space Agency (ESA). The project is developing a knowledge based system for planning and scheduling of activities for spacecraft assembly, integration and verification (AIV). The system extends to the monitoring of plan execution and the plan repair phases.

The objectives of the contract are to develop an operational kernel of a planning, scheduling and plan repair tool, called OPTIMUM-AIV, and to provide facilities which will allow individual projects to customize the kernel to suit its specific needs. The kernel shall consist of a set of software functionalities for assistance in the initial specification of the AIV plan, in the verification and generation of valid plans and schedules for the AIV activities, and in interactive monitoring and execution problem recovery for the detailed AIV plans. Embedded in OPTIMUM-AIV are external interfaces which allow integration with alternative scheduling systems and project databases.

The current status of the OPTIMUM-AIV project, as of May 1991, is that the architectural design of the system has been agreed on by ESTEC/ESA and detailed design and implementation is now underway, expecting a final delivery in October of 1991.     

The Onboard Algorithm for Averaging the Orbital Motion Parameters of the International Space Station in the ICARUS Experiment

This paper describes the algorithm for averaging the orbital parameters of the International Space Station (ISS), which was implemented for the International Cooperation for Animal Research Using Space (ICARUS) experiment aboard the ISS. Based on the ballistic and navigational information received from the control system, the algorithm aboard the station calculates the orbital motion parameters in the Two Line Elements format. The acquired data are averaged using the least-square method. To ensure the algorithm’s execution on the platform of the ISS onboard computer in a realtime system, the process of calculations is distributed over computational cycles. The efficiency of the proposed algorithm is demonstrated using the results of mathematical simulation.     

An Autonomous Spacecraft Agent Prototype

This paper describes the New Millennium Remote Agent (NMRA) architecture for autonomous spacecraft control systems. The architecture supports challenging requirements of the autonomous spacecraft domain not usually addressed in mobile robot architectures, including highly reliable autonomous operations over extended time periods in the presence of tight resource constraints, hard deadlines, limited observability, and concurrent activity. A hybrid architecture, NMRA integrates traditional real-time monitoring and control with heterogeneous components for constraint-based planning and scheduling, robust multi-threaded execution, and model-based diagnosis and reconfiguration. Novel features of this integrated architecture include support for robust closed-loop generation and execution of concurrent temporal plans and a hybrid procedural/deductive executive.We implemented a prototype autonomous spacecraft agent within the architecture and successfully demonstrated the prototype in the context of a challenging autonomous mission scenario on a simulated spacecraft. As a result of this success, the integrated architecture has been selected to fly as an autonomy experiment on Deep Space One (DS-1), the first flight of NASA';s New Millennium Program (NMP), which will launch in 1998. It will be the first AI system to autonomously control an actual spacecraft.     

An approach to creating concretized test scenarios within test automation technology for industrial software projects

The paper describes an approach for creation of effective test automation technology for industrial software projects based on a formal model of the system under test, performing its automatic symbolic verification of the model and generation of symbolic traces, then their automatic concretization, generation and execution of test suites. The technology includes means for test results analysis and tests correction and update. High quality of software products is ensured by a balance between static (verification) and dynamic (testing) analysis techniques starting from the earlier development phases and through automation of all phases of software development. Special emphasis is made on presentation of the algorithm of concretization and configuring test scenarios.     

TIME WINDOWS: AUTOMATED ABSTRACTION OF CONTINUOUS-TIME MODELS INTO DISCRETE-EVENT MODELS IN HIGH AUTONOMY SYSTEMS∗

This paper describes the automated generation of time windows from continuous system simulation models. Time windows can be used to automatically generate equivalent discrete-event models at a coarser granularity level and they are instrumental to the design of event-based control systems. The generation of time windows represents one facility in the knowledge-based multifacetted modeling and simulation environment. DEVS-Schemc. In this environment, continuous-time and discrete-event models can coexist and they can be amalgamated with AI techniques. The usefulness of these concepts will be demonstrated by means of a model of a robot controlled fluid handling laboratory for Space Station Freedom to be used for research in Life Sciences, Microgravity Sciences, and Space Medicine.     

CNG加气母站的SCADA系统设计和研究

SCADA(Supervisory Controland Data Acquisition)数据采集和监控系统技术在工程控制领域应用广泛。结合目前天然气行业需求和技术现状,利用SCADA技术来实现CNG(Compressed naturalgas压缩天然气)加气母站自动化。系统以西门子PLC(Programmable Logic Controller可编程逻辑控制器)为基础,以现场总线和局域网为通信网络,以西门子WinCC为组态软件,结合工程实际,设计具体实施方案,实现了天然气加气母站的自动控制、远程监控和管理。提高了天然气行业的自动化水平。     

Managing plans: Integrating deliberation and reactive execution schemes

In this paper, we argue that a shift is needed for plan-based architectures to support versatile, long-lived systems. Our hypothesis is that we need to integrate plan generation, plan analysis and plan adaptation within a wholesome framework that allow a seamless integration of planning and plan execution activities, i.e. that the architectural focus should move away from planning towards so-called plan management. We present, in this paper, a software framework for plan management, which is based on a novel plan representation. This representation has been designed so that the actual context of the execution is available at all times: what the robot is doing and–more importantly–why it is doing it. Our plan manager implementation is available as open source, and has already been used on three different live systems, on which it demonstrated its capabilities.     

基于物联网的室内环境监测系统的研究

针对当前监控系统在室内环境监控中存在的弊端,为实现室内环境参数监测的自动化和实时性,设计了一种基于物联网技术的室内环境参数监测系统。该系统综合运用无线传感器网络技术、嵌入式计算技术、GPRS无线通信技术。重点介绍了监控中心和终端节点的设计思路和软硬件实施方案。实验表明:该系统成本低、功耗小,使用简单,工作稳定,测量精度较高,具有较高的实用价值。     

Toward the characterization of software testing practices in South America: looking at Brazil and Uruguay

Software testing is an important activity in the software development life cycle. Several previous studies reported the results of surveys on software testing practices among practitioners from different countries. In this paper, we analyze these surveys aiming to get their main questions, and replicate a survey with practitioners from Brazil and Uruguay, two emerging South American software development scenarios. This survey was previously conducted in Manaus/Brazil in 2006 and Buenos Aires/Argentina in 2013. The replication’s scope includes three regions (Northern Brazil, Southern Brazil, and Uruguay). A total of 150 software testing practitioners responded to the survey. Its results are compared with the previous executions and other software testing surveys identified in the technical literature, strengthening previous findings. The Brazilian and Uruguayan participants indicate that: (1) documentation of test artifacts (plan, cases, procedures, results) are useful and important for software testing practitioners; (2) system and regression testing are the two test types deemed most useful and important; (3) tools for monitoring and management of test process tasks and bug reports are considered useful and important; (4) it is usual for software companies to have a definition of a testing process and to have a dedicated testing team; (5) there is a lack of measurement of test tasks and coverage in the industry; and (6) tools to support automation of test case generation and execution or code coverage are still poorly used in their organizations.     

EKL型水文缆道控制台升级设计与应用

水文缆道控制台是我国流速仪法测流的主要设备,以现有半自动水文缆道控制台作为执行单元,在此基础上进行升级,实现缆道测流的自动化。介绍四川省广安市缆道测流设备现状,根据需求制定自动化升级的总体方案,并分别从测控装置硬件和上位机软件设计2个部分叙述项目的设计思路和实现方法。从改造后的缆道测流系统现场测试结果看,改造后的系统已能实现自动流量测验,测验结果符合明渠流量测验规范的要求,达到EKL型水文缆道控制台自动化升级的目的。     

模型驱动的分布式测试执行自动化研究与实现

随着分布式应用在商业领域中的普及,对可用于有效缩短产品上市周期的分布式测试自动化技术的研究显得日益重要。本文提出了一种模型驱动的自动化测试方法,并将其应用于分布式测试中。为了能够支持分布式测试执行,本文提供了部署和调度两个测试模型,其中,部署模型描述了测试执行环境和脚本分发的情况,调度模型描述了远程测试执行机的调度运行顺序;为了能够实现测试执行的自动化,我们设计了一个分布式测试执行框架。最后,通过Web 应用测试的实例验证了该方法能有效减少测试时间。     

Finite element design of manipulator-coupled spacecraft for a research testbed

This paper describes the design and analysis of a research testbed developed to study the control of manipulator-coupled spacecraft with independent attitude control systems. This scenario could present itself in the assembly of Space Station Freedom (SSF). SSF assembly calls for a rendezvous of the Space Shuttle (SS) with SSF. Part of the assembly process requires that both spacecraft be coupled via the Space Shuttle Remote Manipulator System. An additional criterion that poses increased complexity is that the Space Shuttle controls and Space Station controls can not communicate. The technical issue involved is unwanted vibrations of the coupled-configuration that occur retraction and the complications due to non-interacting control systems. To understand these vibrations and possible complications, a research testbed has been built at the Marshall Space Flight Center in Huntsville, AL.To build the testbed, the manipulator links joints, and vehicles that represent the Space Shuttle and Space Station had to be designed. Pre-design simulation studies using ANSYS [1] (a Finite Element Computer Code) is used to size and design the manipulator links for the experimental facility. The ANSYS results were verified by the development of the Lagrangian Equations of motion. The Harmonic drives used as joints for the two link, three joint manipulator have been dissected into free body diagrams to ensure proper load paths in the ANSYS models. Accurate simulation of manipulator-coupled spacecraft is an important technology for NASA to understand. This paper outlines the methodology behind the preliminary design of a research testbed developed to help NASA gain knowledge in this area.     

Fault‐tolerant on‐board computing for robotic space missions

This paper describes an approach to providing software fault tolerance for future deep‐space robotic National Aeronautics and Space Administration missions, which will require a high degree of autonomy supported by an enhanced on‐board computational capability. We focus on introspection‐based adaptive fault tolerance guided by the specific requirements of applications. Introspection supports monitoring of the program execution with the goal of identifying, locating, and analyzing errors. Fault tolerance assertions for the introspection system can be provided by the user, domain‐specific knowledge, or via the results of static or dynamic program analysis. This work is part of an on‐going project at the Jet Propulsion Laboratory in Pasadena, California. Copyright © 2011 John Wiley & Sons, Ltd.     

Designing function blocks for distributed process planning and adaptive control

The objective of this research is to develop methodologies and a framework for distributed process planning and adaptive control using function blocks. Facilitated by a real-time monitoring system, the proposed methodologies can be applied to integrate with functions of dynamic scheduling in a distributed environment. A function block-enabled process planning approach is proposed to handle dynamic changes during process plan generation and execution. This paper focuses mainly on distributed process planning, particularly on the development of a function block designer that can encapsulate generic process plans into function blocks for runtime execution. As function blocks can sense environmental changes on a shop floor, it is expected that a so-generated process plan can adapt itself to the shop floor environment with dynamically optimized solutions for plan execution and process monitoring.     

基于Xen的工业过程综合监控平台设计与实现

随着现代工业生产自动化水平的提高,监控平台已经成为自动控制系统中必不可少的部分;近年来信息化技术的发展要求工业企业破除各装置之间存在的"自动化孤岛"壁垒,实现统一的系统监控、身份认证以及软硬件平台的高度可靠。本文基于Xen实现统一监控虚拟化软硬件平台,并在其上完成主流监控软件(Ifix/PIMS/VXSCADA)的部署,进行冗余热备机制和高度可用性等技术的试验,实现异构监控平台的统一部署、统一接入和即插即用。     

POPS: an off-peak precomputing scheme for privacy-preserving computing

Emerging privacy-preserving technologies help protect sensitive data during application executions. Recently, the secure two-party computing (TPC) scheme has demonstrated its potential, especially for the secure model inference of a deep learning application by protecting both the user input data and the model parameters. Nevertheless, existing TPC protocols incur excessive communications during the program execution, which lengthens the execution time. In this work, we propose the precomputing scheme, POPS, to address the problem, which is done by shifting the required communications from during the execution to the time prior to the execution. Particular, the multiplication triple generation is computed beforehand with POPS to remove the overhead at runtime. We have analyzed the TPC protocols to ensure that the precomputing scheme conforms the existing secure protocols. Our results show that POPS takes a step forward in the secure inference by delivering up to \(20\times \) and \(5\times \) speedups against the prior work for the microbenchmark and the convolutional neural network experiments, respectively.

     

Flight Plan Specification and Management for Unmanned Aircraft Systems

This paper presents a new concept for specifying Unmanned Aircraft Systems (UAS) flight operations that aims at improving the waypoint based approach, found in most autopilot systems, by providing higher level fligh plan specification primitives. The proposed method borrows the leg and path terminator concepts used in Area Navigation¹ (RNAV). Several RNAV leg types are adopted and extended with new ones for a better adaptation to UAS requirements. Extensions include the addition of control constructs that enable repetitive and conditional behavior, and also parametric legs that can be used to generate complex paths from a reduced number of parameters. The paper also covers the design and implementation of a software component that manages execution of the flight plan. To take advantage of current off-the-shelf flight control systems the constructs included in the flight plan are translated to waypoint navigation commands. In this way, the advanced capabilities provided by the flight plan specification language are implemented as a new layer on top of existing technologies. The benefits and the feasibility of the proposed approach for UAS flight plan management are demonstrated by means of a simulated mission that performs the flight inspection of Radio Navigation Aids.     

Archetype: a unified method for the design and implementation ofprotocol architectures

A method for the automated design, specification, and implementation of protocol architectures is introduced. A natural-language-like protocol architecture specification technique, called Archetype, is formulated. This technique aids the design by enabling an unambiguous specification of the protocol architecture on the level of the communications technologies used, without involvement in the complex implementation details of these technologies. The author defines a data-driven concurrent execution model and specifies the generation of executable specifications from abstract protocol architecture specifications. The exploitation of parallelism in the execution model enables the fulfilment of performance constraints placed on protocol architectures. An architecture based on a single X.25-level 3-like protocol is used as an illustrative example     

自动化新技术新设备在原料场中的应用

详细介绍了卸料小车自动定位系统、水分检测计算机系统、混匀配料模型、移动设备与地面通讯等各项技术开发.通过新技术应用全面提高了料场自动化水平,稳定了中和料Si02偏差,为烧结提供了精料.