西门子S7-1200的设计与应用 第7讲 通过S7-1200与触摸屏控制工作台滑动座

运动控制被广泛应用在包装、印刷、纺织和装配工业中。S7-1200独有轴工艺对象,通过硬件组态、面板调试和诊断功能即可实现在线手动控制,最后通过调用相关指令实现自动控制。本案例介绍了通过S7-1200与触摸屏来实现工作台滑动座电机的运动控制。     

An approach towards the design of intelligent man-machine interfaces used in process control

This paper is related to improvements carried out n the field of human-machine communication in complex industrial processes, using the concept of the ‘intelligent’ interface. Following a review of literature on this subject, an ‘intelligent’ interface design based on ergonomical concepts is described. Finally, we present our approach to the design of an ‘intelligent’ interface. The Decisional Module of Imagery (D.M.I.) as it is called, is based on two models: a task model and a user model. The D.M.I.'s structure and its integration in an experimental platform are described in the last part of this paper.     

A comparison of two Petri net types

In this article we pick up a problem stated in [1], namely the question whether PNlog-nets allow to solve synchronization problems not solvable by ordinary Petri nets under certain simulation rules. We show that a slight and reasonable strengthening of the simulation rules defined in [1] enables us to answer the raised question in the positive. As will be pointed out in the introduction, with this result we “partially” solve the original problem.     

A comparison of two different types of shoreline boundary conditions

Two different types of shoreline boundary conditions which can be used in either wave-resolving or wave-averaging models of waves and currents propagation in the nearshore are compared here. The two techniques are essentially different: in the first case the velocity of the shoreline is obtained by the momentum equation and the shoreline position is tracked by changing the grid position, while in the other case the velocity of the shoreline is obtained by a modified Riemann solver and the shoreline is defined as an interface between dry and wet fixed grid points. A number of test cases are described to compare the performance of the two techniques.     

湿熄焦PLC控制系统的设计与实现

为了提高湿熄焦控制的自动化程度与精度,设计了一种以可编程逻辑控制器(PLC)为核心的湿熄焦控制系统.该系统下位机采用西门子S7-200 PLC,通过MPI通信协议与上位机监控系统建立通信连接,从而实现了对湿熄焦过程的全自动控制与实时监测,提高了熄焦工艺的质量及生产效率.经过焦化企业的实际应用证明,该系统操作简单,具有较高的精度和稳定性,能满足湿熄焦控制的实际需要.     

车载式热解炉电气控制系统的设计

为了完成对车载式热解炉工作过程的自动化控制,从车载式热解炉工艺出发,应用PLC控制器和触摸屏技术开发并设计了一套电气控制系统。该系统采用触摸屏作为人机界面,具有手动、自动两种运行模式,可实现炉况实时监测、参数设定和修改等功能,并能方便、直观地对热解炉工作过程进行监控。该系统稳定性好、可靠性高、易于维护,提高了热解炉工作效率和自动化水平。     

Investigating the effects of multimodal feedback through tracking state in pen-based interfaces

A tracking state increases the bandwidth of pen-based interfaces. However, this state is difficult to detect with default visual feedback. This paper reports on two experiments that are designed to evaluate multimodal feedback for pointing tasks (both 1D and 2D) in tracking state. In 1D pointing experiments, results show that there is a significant effect for input types on movement time while feedback type and the use of different hands for receiving feedback (i.e. the dominant or non-preferred hand) do not affect movement time significantly. We also report that there is a significant effect for feedback types and input device types on error rate while the choice of hand (used for detecting feedback vibrations) does not affect the error rate significantly. In the 2D pointing experiment, results show that there are no significant effects for either input type or the use of different hands on movement time while feedback type affects movement time significantly. Results for both the 1D and 2D pointing tasks show that tactile plus visual feedback can improve accuracy and audio is not efficient to give user feedback in tracking state. This paper proposes several guidelines for feedback design in tracking state. We believe these results can aid designers of pen-based interfaces.     

基于气压传动和触摸屏的智能烫印机研发

针对当前烫印机采用薄膜轻触面板型人机界面交互性差、无网络功能、信息化和自动化水平低等问题,设计开发了一种新型智能烫印机。采用基于T5内核的串口电容触摸屏,实现了烫印工艺多模式交叉配置,提升了设备适应当前小批量定制化生产需求的能力。基于T5触摸屏集成的网络接口,实现了远程监控、算法升级、网络化生产管理。嵌入式控制系统以STM32F10系列32位高性能微控制器为核心,集成了烫印胶头温度测控模块和伺服电机驱动模块。采用UL2068达林顿管全数字化驱动气缸,高速全自动完成移印过程。实践应用表明:所开发的烫印机性能稳定,实现了烫印工艺、烫头恒温、伺服电机、高速气缸高性能一体化全自动控制。该烫印机集成度高,触摸屏显示界面友好,能够实现网络化控制与管理,具有广阔的工程应用前景。     

便携式氮气冲洗装置控制系统设计

为了解决目前航天产品氮气冲洗工艺中存在的问题,设计了一种基于C8051F040单片机的便携式氮气冲洗装置控制系统.该系统利用触摸屏输入各项氮气冲洗工艺参数;通过Modbus通信协议将相关数据传送至单片机;最终通过单片机实现电磁阀的自动控制和过程数据的采集,完成氮气冲洗工艺.应用结果表明,该系统体积轻便、操作简单、测量数据准确、可靠性高,具有良好的推广价值.     

A comparison of voice and multifunction controls: logic design is the key

The proper design of the human-computer interface is a key feature for the optimum use of advanced manned systems. In future aircraft cockpits, one of the pilot's principle tasks will be to interact with a very sophisticated computer system—an electronic crewmember. This paper discusses the experimental comparison of two communication mechanisms: voice control and multifunction keyboards. The paper also discusses the crucial role of the software logic used with these devices.     

A comparison of model-based path control algorithms for direct-drive SCARA robots

Various advanced control strategies are applied to a direct-drive SCARA robot and studied in computer simulations. Besides computed torque control and direct adaptive control, heuristic optimal control, a new path control scheme for robotic manipulators, is included in the comparison study. PD control, the traditional robot control method, is used for generating a comparing baseline. While all schemes are applied for the same tracking task, the effect of modelling errors and measurement noise is considered in robot performance evaluation. Simulation results show that (1) without model errors, all advanced control schemes can achieve higher tracking accuracy than PD control; (2) with a random measurement error of 1%, computed torque and direct adaptive control methods are inferior to PD control; (3) heuristic control proves to be the most robust control scheme in case of mixed model and measurement errors.     

A case study on the design of learning interfaces

The design of educational software interfaces is a complex task, given its high domain dependency and multidisciplinary nature. It requires that teachers’ knowledge and pedagogical beliefs be incorporated into the interface, posing a challenge to both teachers and designers, as they have to act as partners from the earliest phases of the process, sharing their knowledge. The present work investigates the strategies designers used when paired with experienced teachers, to design two interfaces on chemistry, evaluating how designers work with subjects they know little about, in the initial phases of the design process. Our observations demonstrate that although experienced and non-experienced designers use different strategies to couple with the design task, both approached the task in a depth-first manner. These results should not be generalized, because few subjects were investigated, but point to the importance of being familiar with the knowledge domain – which poses a challenge for designers.     

A biomechanical and subjective comparison of two powered ambulance cots

This study investigated biomechanical effects of different leg folding/unfolding mechanisms used for loading/unloading two powered cots (Cots A and B) into and from a simulated ambulance. Sixteen experienced emergency medical service (EMS) workers loaded and unloaded cots with weights of 45, 68 and 91 kg placed on the cots to simulate patients. Peak back and shoulder/arm muscle activity was reduced 52–87% when using Cot A in comparison to Cot B. Peak ground reaction force (PGRF) was reduced by 74% with Cot A. Adding weight resulted in increased muscle activity and PGRF when using Cot B, but had little effect when using Cot A. Task time was longer with Cot A, though was not perceived unfavourably by participants. This study confirmed that it is possible to substantially reduce physical stress imposed on EMS workers when loading and unloading a cot to and from an ambulance through improvements in cot design.     

A comparison of task pools for dynamic load balancing of irregular algorithms

Since a static work distribution does not allow for satisfactory speed‐ups of parallel irregular algorithms, there is a need for a dynamic distribution of work and data that can be adapted to the runtime behavior of the algorithm. Task pools are data structures which can distribute tasks dynamically to different processors where each task specifies computations to be performed and provides the data for these computations. This paper discusses the characteristics of task‐based algorithms and describes the implementation of selected types of task pools for shared‐memory multiprocessors. Several task pools have been implemented in C with POSIX threads and in Java. The task pools differ in the data structures to store the tasks, the mechanism to achieve load balance, and the memory manager used to store the tasks. Runtime experiments have been performed on three different shared‐memory systems using a synthetic algorithm, the hierarchical radiosity method, and a volume rendering algorithm. Copyright © 2004 John Wiley & Sons, Ltd.     

A comparison of multiprocessor task scheduling algorithms with communication costs

Both parallel and distributed network environment systems play a vital role in the improvement of high performance computing. Of primary concern when analyzing these systems is multiprocessor task scheduling. Therefore, this paper addresses the challenge of multiprocessor task scheduling parallel programs, represented as directed acyclic task graph (DAG), for execution on multiprocessors with communication costs. Moreover, we investigate an alternative paradigm, where genetic algorithms (GAs) have recently received much attention, which is a class of robust stochastic search algorithms for various combinatorial optimization problems. We design the new encoding mechanism with a multi-functional chromosome that uses the priority representation—the so-called priority-based multi-chromosome (PMC). PMC can efficiently represent a task schedule and assign tasks to processors. The proposed priority-based GA has show effective performance in various parallel environments for scheduling methods.     

Experimental comparison of PID vs. PID plus nonlinear controller for subsea robots

This paper presents a new approach for designing simple nonlinear robust controllers for underwater vehicles. The paper presents several in-water experiments performed on the VORTEX vehicle developed by IFREMER. We first introduce some general modeling considerations of underwater vehicles, then we present the VORTEX dynamic model and some of the special features of the VORTEX vehicle that are important for control. Among these, low sampling rates for sensor and actuator nonlinearities are considered. The main aim of this paper is to experimentally investigate the benefits of adding an easy-to-tune nonlinear control loop to the actual linear compensator in order to improve the stability and the disturbance rejection properties of the closed-loop system. The advantage of this method is two-fold. First the additional nonlinear loop does not modify the original linear (PID) regulator. Second the design of this additional loop does not rely on the system model and is simple to tune. The results presented in this paper were obtained using the VORTEX vehicle both in simulation and during real experiments; they demonstrate the advantages of using a PID with this nonlinear loop over a simple PID control.     

基于S7-300 PLC辐照装置源架控制系统设计

介绍了辐照装置源架控制系统的组成,详述了其工作原理及控制过程.重点对控制系统设计中组态软件设计及对液压控制改进进行详细的介绍.     

A comparison of analytical–numerical models for nonlinear vibrations of cylindrical shells

The nonlinear flexural vibration behaviour of cylindrical shells has received considerable attention to date. It is pointed out that, although in a well-known reference case there seems to be a reasonable agreement, there are unresolved discrepancies between the results obtained by different authors. In the present paper, the problem is studied using various analytical–numerical models with different levels of accuracy and complexity. The frequency–amplitude curves from the different analysis models developed are compared both for isotropic shells and for an orthotropic composite shell. Secondary modes can play an important role. In more complicated cases modal interactions may significantly influence the nonlinear vibration behaviour, and the results obtained strongly depend on the analysis model chosen.