SIL's (Safety Integrity Levels) are used by IEC 61508:1998 [1] to characterise the required functional safety of computer control systems. For example, SIL 4, the highest rating is for fly by wire aircraft and wea...
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ISBN:
(纸本)9781920682156
SIL's (Safety Integrity Levels) are used by IEC 61508:1998 [1] to characterise the required functional safety of computer control systems. For example, SIL 4, the highest rating is for fly by wire aircraft and weapons systems and track circuited train signalling systems while SIL 2 is typical of certain programmable logic controllers (PLC). Fire control panels have not been SIL rated to date even though certification organisations like Factory Mutual provide SIL for various PLCs in their approvals guides. This paper addresses SIL' derivation/allocation to fire systems and fire control panels in particular.
Platelets induce chronic inflammation which is a key step in atherosclerosis and may be involved in the progression of neurodegenerative diseases (NDD). We aimed to measure the mean platelet volume (MPV) and platelet ...
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A new DSP-based design of flight control computer (FCC) hardware system is presented according to the design principle of high performance and miniaturization. Using the TMS320LF240x DSP as the core processor, a compl...
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A new DSP-based design of flight control computer (FCC) hardware system is presented according to the design principle of high performance and miniaturization. Using the TMS320LF240x DSP as the core processor, a complex programmablelogic device (CPLD) is used to accomplish the chip-selection and interrupt-control for external extension circuits (A/D, D/A, asynchronous-communication element 16C554 and external memories). Consequently, the FCC offers a great number of interfaces including analog interfaces, flexible digital interfaces and serial communicating interfaces. In addition to the specifications of the pivotal components and their characteristics, the hardware connection and software programming are also presented.
The control of accurate axle position is discussed in this paper. The pulse output function and highspeed count function of PLC (programmablelogical Controller) are used to realize the purpose of the study. The main ...
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The control of accurate axle position is discussed in this paper. The pulse output function and highspeed count function of PLC (programmablelogical Controller) are used to realize the purpose of the study. The main principle of this control and its practical application are discussed. The systematic composition of such control system model is given. Several key problems are discussed. The principle obtained in this study has got very good application in the real work. The usage of this principle in automatic equipment controlling or in transformation from manual equipment to automatic ones has certain theoretical and actual directive significance.
A controller for the on-line tuning of PID (Proportional-Integral-Derivative) parameters based on the satisfactory degree and genetic algorithm is proposed. With the theory of satisfactory solution, the satisfactory f...
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A controller for the on-line tuning of PID (Proportional-Integral-Derivative) parameters based on the satisfactory degree and genetic algorithm is proposed. With the theory of satisfactory solution, the satisfactory functions of over-shoot, rise time and setting time of the system response are designed, and the three parameters kp, ki and kd of the PID controller are obtained by means of genetic algorithm. These three parameters are used as the base values for the on-line tuning of PID parameters. Then, by designing the nexus functions between the tracking error and kp, ki, kd, the PID controller parameters are adjusted online, thus improving the static performance, dynamic performance and robust performance of the control system. The results of Matlab simulation show that the proposed PID controller is valid.
A new method for position control of motor was discussed, in which PLC is used as controller, RS485 is used for motor driver port and high-speed-counter is used for feedback. The method for the tuning parameters of po...
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A new method for position control of motor was discussed, in which PLC is used as controller, RS485 is used for motor driver port and high-speed-counter is used for feedback. The method for the tuning parameters of position control algorithm and the compensation system dead-zone was given. The problem of nonlinear saturation was analyzed also. In the end, a successful sample of this method used in the reciprocating type bale plucker in a textile mill was given.
This paper presents an introduction of the MMS protocol, especially the description of the VMD model, in the application layer of MAP 3.0. The strategy of PC's connecting to network the mapping of PC/PC functions ...
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This paper presents an introduction of the MMS protocol, especially the description of the VMD model, in the application layer of MAP 3.0. The strategy of PC's connecting to network the mapping of PC/PC functions to the VMD model are studied. An instance of prototype implementation guided by this strategy is given
The article introduces a closely-designed programmable sample and coding set according to the sampling and coding technique employed in the testing of spacecrafts. And it gives a detailed introduction to the critical ...
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The article introduces a closely-designed programmable sample and coding set according to the sampling and coding technique employed in the testing of spacecrafts. And it gives a detailed introduction to the critical techniques involved as the table-driving-technique, the automatic-generation of the distribution table of wave channels, and the online programming of memory, etc., it covers the multi-step switch timing which present an effective means of implementation to improve the switching speed of analog switches and the overall sampling rate of the equipments.
The intelligent analogue operation and fault detection for PLC logic circuits are implemented in expert system technology, and special circuits and their application are introduced in this paper. The designation resol...
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The intelligent analogue operation and fault detection for PLC logic circuits are implemented in expert system technology, and special circuits and their application are introduced in this paper. The designation resolves the contradiction between fewer PLC programming panels and more users. The practicability and the efficiency of the means mentioned in the paper have been proved by the results of simulated operation.
Due to the increasing in technological development and modernization of industrial process, control techniques to address high performance are being developed. These not only solve new problems in more complicated pla...
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ISBN:
(纸本)9781467346214
Due to the increasing in technological development and modernization of industrial process, control techniques to address high performance are being developed. These not only solve new problems in more complicated plants, but also improve the performance of existing controllers. To improve the control performance of electrical distribution substations, embedded optimization techniques have been developed utilizing the programmable logic controllers (PLC). In this work an industrial artificial neural controller, that is the union between industrial controller and neural network, in associated with an intelligent electronic device (IED) for data acquisition is developed. The PLC execute operational tasks. The neural network controller performs data processing in a MATLAB environment that communicates with the PLC, to receive and to send data, via OPC protocol. The proposed methodology is evaluated in virtual electrical power substations, where the automation devices are: 1) Smart Relays, Remote Transmission Units (RTU) and PLC are real devices and 2) transformers, circuit breakers and capacitor banks simulated with software or hardware.
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