Experimental validation of a resilient monitoring and control system

Complex, high performance, engineering systems have to be closely monitored and controlled to ensure safe operation and protect public from potential hazards. One of the main challenges in designing monitoring and control algorithms for these systems is that sensors and actuators may be malfunctioning due to malicious or natural causes. To address this challenge, this paper addresses a resilient monitoring and control (ReMAC) system by expanding previously developed resilient condition assessment monitoring systems and Kalman filter-based diagnostic methods and integrating them with a supervisory controller developed here. While the monitoring and diagnostic algorithms assess plant cyber and physical health conditions, the supervisory controller selects, from a set of candidates, the best controller based on the current plant health assessments. To experimentally demonstrate its enhanced performance, the developed ReMAC system is then used for monitoring and control of a chemical reactor with a water cooling system in a hardware-in-the-loop setting, where the reactor is computer simulated and the water cooling system is implemented by a machine condition monitoring testbed at Idaho National Laboratory. Results show that the ReMAC system is able to make correct plant health assessments despite sensor malfunctioning due to cyber attacks and make decisions that achieve best control actions despite possible actuator malfunctioning. Monitoring challenges caused by mismatches between assumed system component models and actual measurements are also identified for future work.     

Evaluation of the control performance of hydronic radiant heating systems based on the emulation using hardware-in-the-loop simulation

This study presents an emulation method to evaluate the control performance of a hydronic radiant heating system. Since heat output in the system is dependent on the pressure loss and flow rate in the hydronic network, the interaction between thermal and hydronic models needs to be considered in the evaluation of the control performance. For this reason, many studies apply an integrated simulation to the evaluation; however, the analysis of the hydronic network sometimes leads to unreliable results due to the improper initial values for algebraic loops or the lack of modeling information on the hydronic components. In order to deal with this problem, this study suggests an emulation method, where the hydronic network is replaced by real hardware and the building physics is analyzed by a simulation. In the emulation, the pressure loss and flow rate in the hydronic network were represented by replacing the real pipe with equivalent hydraulic resistance. In addition, by using real control systems that connect the hydronic network and building simulation, the interaction between building physics and hydronic network could be considered in the evaluation. Based on the proposed emulation method, the performance of several control strategies was evaluated in terms of the accuracy and the rise time. The result shows that the individual control needs to be combined with hydronic balancing for more accurate control. Hydronic control devices such as a flow limit valve and a pressure differential control valve also proved to be helpful to the improvement of the control performance.     

一种基于硬件在环的可重构数控系统验证方法

作为一种开放式控制器,可重构数控(Computer numerical control,CNC)系统充分利用先进的控制技术、硬件产品等有利资源,提高系统功能的自适应性与快速响应能力。针对可重构CNC系统的验证过程复杂、硬件环境依赖性强等特点,采用硬件在环的设计方法,由仿真系统模拟数控机床的加工制造过程。给出面向可重构CNC系统的硬件在环仿真环境设计方法:采用现场总线连接数控系统与仿真环境,满足实时性、动态性等测试要求;建立机床驱动设备的仿真功能单元,完成数控加工指令的控制操作;实现数控机床的加工过程仿真,采用图形方式显示工件的切削成形过程。结合S曲线插补算法以及三轴数控铣床的仿真实例,对可重构CNC系统的加工控制过程进行测试,并且与实际加工样件进行对比分析,说明硬件在环技术在可重构CNC系统测试过程中的可行性与有效性。     

A kinematically compatible framework for cooperative payload transport by nonholonomic mobile manipulators

In this paper, we examine the development of a kinematically compatible control framework for a modular system of wheeled mobile manipulators that can team up to cooperatively transport a common payload. Each individually autonomous mobile manipulator consists of a differentially-driven Wheeled Mobile Robot (WMR) with a mounted two degree-of-freedom (d.o.f) revolute-jointed, planar and passive manipulator arm. The composite wheeled vehicle, formed by placing a payload at the end-effectors of two (or more) such mobile manipulators, has the capability to accommodate, detect and correct both instantaneous and finite relative configuration errors. The kinematically-compatible motion-planning/control framework developed here is intended to facilitate maintenance of all kinematic (holonomic and nonholonomic) constraints within such systems. Given an arbitrary end-effector trajectory, each individual mobile-manipulator's bi-level hierarchical controller first generates a kinematically-feasible desired trajectory for the WMR base, which is then tracked by a suitable lower-level posture stabilizing controller. Two variants of system-level cooperative control schemes—leader-follower and decentralized control—are then created based on the individual mobile-manipulator control scheme. Both methods are evaluated within an implementation framework that emphasizes both virtual prototyping (VP) and hardware-in-the-loop (HIL) experimentation. Simulation and experimental results of an example of a two-module system are used to highlight the capabilities of a real-time local sensor-based controller for accommodation, detection and corection of relative formation errors.     

某型火箭弹半实物仿真系列方案设计－－海鹰仿真工作站的应用

主要介绍半实物仿真的意义、特点,YHSL仿真语言的特点,某型火箭弱是半实物仿真系统组成,以及为配合武器系统研制所设计的系列仿真6方案与某型火箭弹半实物住址系统软件结构及其设计。     

四轮驱动汽车牵引力控制算法

提出了实用的四轮驱动汽车牵引力控制算法。在确定控制系统结构的基础上,设计了车速估算算法、油门位置PI控制器和制动门限控制算法。为实现牵引力控制算法的快速开发,建立由传感器、执行器、工控机、采集卡和输入输出电路组成的车载快速开发平台。硬件在环试验和道路试验表明:传感器能准确检测输入信号,控制算法能根据输入信号生成控制指令,执行器能快速、准确产生动作以消除驱动轮过度滑转。     

MODEL-BASED DEVELOPMENT OF REAL-TIME SOFTWARE SYSTEM FOR ELECTRONIC UNIT PUMP SYSTEM

A real-time operating system (RTOS), also named OS, is designed based on the hardware platform of MC68376, and is implemented in the electronic control system for unit pump in diesel engine. A parallel and time-based task division method is introduced and the multi-task software architecture is built in the software system for electronic unit pump (EUP) system. The V-model software development process is used to control algorithm of each task. The simulation results of the hardware-in-the-loop simulation system (HILSS) and the engine experimental results show that the OS is an efficient real-time kernel, and can meet the real-time demands of EUP system; The built multi-task software system is real-time, determinate and reliable. V-model development is a good development process of control algorithms for EUP system, the control precision of control system can be ensured, and the development cycle and cost are also decreased.     

导弹大扇面发射自动驾驶仪半实物仿真

介绍了某型反舰导弹大扇面(±70°)自动驾驶仪的半实物仿真方案。分析了仿真中碰到的几个技术问题,并提出了解决方法。给出了仿真结果,证明由半实物仿真校验后的数学摸型是十分准确的。     

Scaling of hybrid-electric vehicle powertrain components for Hardware-in-the-loop simulation

Hardware-in-the-loop (HIL) simulation enables experimental study of prototype hardware systems or control algorithms via real time interaction between physical hardware and virtual simulations. As a result, this method is a particularly valuable tool for hybrid vehicle powertrain analysis. In the case where novel or prototype hardware is being examined, it is often necessary to scale the signals in and out of the prototype system in order to represent production-sized components. This scaling process is often done in an ad-hoc manner. In this work, a formal method is presented that derives appropriate input/output signal conditioning to correctly scale electric vehicle components, particularly the following subsystems: electric motor and battery pack.     

硬件在环测试在电动汽车驱动总成上的应用

介绍应用于电动汽车驱动总成硬件在环(HIL)测试平台的设计、实现以及验证过程.通过连接一个实时仿真系统和被测驱动控制器实现硬件在环平台,驾驶工况模拟端进行驱动循环检测并为硬件在环平台进行故障输入.利用美国环保署(EPA)制定的城市道路循环工况,说明应用于电动汽车驱动系统HIL平台的性能.与实际小型电动汽车驱动总成在各种工况及故障条件下进行实时比较,验证该实时仿真系统的精确度.