The safety parameters monitoring system for the coal mine based on CAN bus communication and intelligent data acquisition

In this paper,a monitoring and controlling system for the safety in production and environmental parameters of a small and medium-sized coal mine has been developed after analyzing the current domestic coal production and security conditions. The client computer can convert the analog signal about the safety in production and environmental parameters detected from the monitoring terminal into digital signal,and then,send the signal to the coal mine safety monitoring centre. This information can be analyzed,judged,and diagnosed by the monitoring-management-controlling software for helping the manager and technical workers to control the actual underground production and security situations. The system has many advantages including high reliability,better performance of real-time monitoring,faster data communicating and good practicability,and it can effectively prevent the occurrence of safety incidents in coal mines.

Multi-Point Communication System Based on CAN Bus

The paper introduced CAN （Controller Area Network） bus and CAN2.0 standard, the design of hardware frame-work multi-point communication based on CAN bus, and the software design method. At the same time, the system normal communication function and stability were shown in the experiment.

Implementation of CAN-bus Intelligent Network Communication Equipment Based on PLC

The development trend of PLC is that the functions are more, the integration level is greater and the network function is greater. Nowadays, the manufacturers of PLC develop there own network. PLC technique has two development trends. On one hand, PLC network system is not a self-contained closed system any longer and develops towards open system. Various PLC not only has distinctive PLC network systems and completes device control task, but also network with the superior computer management system to realize information exchange, which makes it become one part of information management system. On the other hand, the field-bus technique is widely applied. PLC is connected with the intelligent equipments installed on site such as intelligent instrument, sensor, intelligent solenoid valve, intelligent drive actuator by a transmission media （ such as twisted pair, coaxial cable and cable）, and they transmit information mutually according to the same communication protocol, which can form a field industrial control network. Compared with single PLC remote network, the network not only has the advantages of flexible configurations, easy expansion, low cost and higher cost perfomaance, but also has opening significance.

An On-Line Scheduler over Hard Real-Time Communication System

By thorough research on the prominent periodic and aperiodic scheduling algorithms,anon-line hard real-time scheduler is presented,which is applicable to the scheduling of packets over a link.This scheduler,based on both Rate Monotonic,pinwheel scheduling algorithm Sr and Polling Serverscheduling algorithms,can rapidly judge the schedulability and then automatically generate a bus tablefor the scheduling algorithm to schedule the packets as the periodic packets.The implementation of thescheduler is simple and easy to use,and it is effective for the utilization of bus link.The orderly executionof the bus table can not only guarantee the performance of the hard real time but also avoid the blockageand interruption of the message transmission.So the scheduler perfectly meets the demand of hard real-time communication system on the field bus domain.

A multi-modular shunt active power filter system and its novel fault-tolerant strategy based on split-phase control and real-time bus communication

We first present a new multi-modular shunt active power filter system suitable for large-capacity compensation. Each module in the system has the same circuit topology, system functionality, and controller design, to achieve coordination control among the modules. The module＇s reference signals are obtained by multiplying the total reference signal by the respective distribution coefficient. Next, a novel fault-tolerant approach is proposed based on split-phase control in the a-b-c frame and real-time bus communication. When a phase fault occurs, instead of halting the whole module, the proposed strategy isolates only the faulted bridge arm, and then recalculates the distribution coefficients and transfers the compensation capacity to the same phases of the other normal modules, resulting in a continuous operation of the faulted module and optimization of the remaining usable power devices. Through steady-state analysis of the post-fault circuit, the system stability and control reliability are proven to be high enough to guarantee its engineering application value. Finally, a prototype is established and experimental results show the validity and feasibility of the proposed multi-modular system and its fault-tolerant control strategy.

STUDY OF MICRO PROCESSOR BASED DISTRIBUTED BUS PROTECTION

A new distribution principle of bus protection is presented.The protection system description,its design features,hardware structure,construction of data communication network are given.Dynamic simulation experiments show its distinguishing advantages over traditional centralized principle.

Investigation on full distribution CNC system based on SERCOS bus

A full distribution CNC system based on SERCOS bus is studied in accordance with the limitations of traditional PC-based motion card. The conventional PC-based motion control card is dispersed into several autonomous intelligent servo-control units with the function of servo driver. The autonomous intelligent servocontrol units realize the loop control of position, velocity and current. Interpolation computation is completed in PC and the computational results are transferred to every autonomous intelligent servo-control unit by high speed SERCOS bus. Software or hardware synchronization technology is used to ensure all servomotors are successive and synchronously running. The communication and synchronization technology of SERCOS are also researched and the autonomous intelligent servo-control card is developed byself. Finally, the experiment of circle contour process on a prototype system proves the feasibility.

Windows and Fieldbus Based Software Computer Numerical Control System

Computer numerical control(CNC)system is the base of modern digital and intelligent manufacturing technolo- gy.And opened its architecture and constituted based on PC and Windows operating system(OS)is the main trend of CNC sys- tem.However,even if the highest system priority is used in user mode,real-time capability of Windows(2000,NT,XP)for applications is not guaranteed.By using a device driver,which is running in kernel mode,the real time performance of Windows can be enhanced greatly.The acknowledgment performance of Windows to peripheral interrupts was evaluated.Harmonized with an intelligent real-time serial communication bus(RTSB),strict real-time performance can be achieved in Windows platform. An opened architecture software CNC system which is hardware independence is proposed based on PC and RTSB.A numerical control real time kernel(NCRTK),which is implemented as a device driver on Windows,is used to perform the NC tasks.Tasks are divided into real-time and non real-time.Real-time task is running in kernel mode and non real-time task is running in user mode.Data are exchanged between kernel and user mode by DMA and Windows Messages.

BusTechn

Introduced the characteristics of series communicat io n I 2C bus and basic communication protocol, and introduced the application of the bus I 2C according to the image sensor OV7610.The computer correspondence s tyle can be divided the parallel correspondence and the series correspondence. T he rate of series correspondence is rapid, and the property of real time is exce llent. Because the number of ports which it takes is great, it is not proper to miniaturize. Whereas the rate of series correspondence is low, but when the corr espondence of data is not great, it is simpleconvenient and agile to dispose t he circuit. Commonly series correspondence divide synchronization correspondence and asynchronies correspondence. The standard of interface RC232 is series asyn chronies correspondence. Recently the standard of bus I 2C is adopted widely in the micro-electronics correspondence realm, it is a special form of synchr onization correspondence. I 2C bus is a two-cabledouble-direction series co rrespondence bus. The address of the machine is set in hardware, and software pe rform the search of the address instead of hardware. So it reduce the number of the corresponding cable, moreover it predigest the design of the hardware. It resolve many interface problems in design of numeric circuit. More and more se miconductor manufacturer accept the standard. Its characteristics can be listed as followed. In text, the image sensor OV7610 is introduced as the example the bus I 2C appl ication.

Marketing Development and Recognition of DFH-4 Series Bus Satellites

In this paper,we examine the interrelation between innovation and commercial marketing using the DFH-4 series bus satellite as an example which customers are familiar with.Strategies in evolving satellite buses and key subsystem technologies without compromising on advanced innovations,favorable heritage and thorough verification are also discussed.Market development experiences with the DFH-4 series bus satellite are summarized and market recognition is reflected from the space insurance perspective.

Application of Serial Port in Industrial Computer System

In an industrial computer control system, if a communication with a single chip computer built with the aid of serial port I/O ports can be got easily to connect with equipment. Meanwhile, the system reliability would be improved and the system cost would be reduced.To save ±15 V power supply and electrical level convert circuit,the author provide a simple interface circuit and operational procedure between PC and the single chip computer in this paper. The application of multithread is introduced and the advantages of data acquisition and processing with multithread are also analyzed.

Design of Intelligent Fire Alarm System for Large Storage Places Based on AVRmega128 Single Chip Microcomputer

With principles of reliability, independence, practicality and economical effi- ciency, a set of intelligent fire alarm system based on AVRmega128 single chip microcomputer was designed to solve problems of fire alarm system in many large- scale warehouses. Using advanced flame sensor, 485 bus communication, computer interactive software and related peripheral devices, this intelligent fire alarm system has functions of sound-light alarm and intelligent fire extinguishing. The human-com- puter interactive software was adopted for the remote control of the alarm main control panel through the 485 bus communication. This design of intelligent fire alarm system shows high reference and practical value to the development of intel- ligent alarm products with high integration and high reliability.

ASIC Design of High-Speed Low-Power HDLC Controller

Combined with the engineering requirement, a high-speed low-power ASIC design of HDLC controller based on RS-485 bus is given in this paper. On principle of Top-Down design, this ASIC design uses multi-techniques to reduce its die area and dynamic power, and overcomes some problems appeared frequently in application systems of the RS-485 circuits formed by the Standard Interface Chips. This design also improves the system reliability and reduces the system area.

Design of Distributed Temperature Measurement System for Switchgear

This paper develops a novel distributed temperature measurement system based on DSP and DS18B20 digital thermometer. The real-time temperature of each node in the switchgear is obtained by several DS18B20s which are connected on the 1-wire bus together. RS-485 master-slave communication protocol is used to centralize monitoring temperatures of several switchgear cabinets. The system also has the function of temperature alarm. The operation of simulation experiment has showed that the system is able to complete monitoring real-time temperatures in high voltage switchgear.

IEC 61850 as Backbone for Smart PAC Systems

This paper discusses a working definition of smartness in protection,automation and control systems(PACS)in substations.A summary is given about the standard IEC 61850 features that support smartness,i.e.,the data model,the multiple communication services,and the system configuration description language(SCL).With help of known examples of application functions for control,supervision,and protection,the building of smart systems out of the modules of IEC 61850 is demonstrated.From the possible architectures,the standardized redundancy is explained.The process bus is exploited in detail since it is seen by users as the core of a smart substation.In this context,attention is given also to the time synchronization in theµs range over the communication network,a rather new part of the standard.In the last part,all features are summarized and it is concluded that IEC 61850 may really be named the backbone for smart PAC systems.

Distributed and Decentralized Control Architectures for Converter-Interfaced Microgrids

This paper gives a summary on recently available technologies for decentralized and distributed control of microgrids.They can be classified into two general categories:1)power line communication based architectures and 2)multi-agent based architectures.The essential control methods and information sharing algorithms applied in these architectures are reviewed and examined in a hierarchical manner,in order to point out benefits they will bring to future microgrid applications.The paper is concluded with a summary on existing methods and a discussion on future development trends.