The Design Of Field Control Unit Of Central Air Condition System

With the developing of Information Technology and the application of lots of Central Air Condition,it is an important subject to many researchers about how to realize more valid control of Central Air Condition.The purpose of reaching Filed Control Unit of Central Air Condition is to develop a set of control system of Central Air Condition that can apply by using the theories and technology of computer network and field bus,especially fast-developing Internet Technology. By using the system,people can monitor and control facilities expediently,flexibly and effectively so as to obtain constant of temperature and humidity and create a homefelt environment.And the system is of great importance to technology and society development.Central Air Condition syetem control is based on the principle of distributed control and centralized supervisory and the design of Field Control Unit is based on this principle .Field Contral Unit is connected with the controlled object directly by IO modules and fulfil the task of data acquisition and control.And it is the bridge between the computer which is used for monitor- control and the controlled object.A Field Control Unit of Central Air Condition based on ARM kernel is presented in this dissertation.The system adopt LPC2119 which have ARM kernel with high speed,high performance and low price.The system uses embedded Internet technology,computer network technology and field bus technology and use PID control theory that adjust temperature and humidity to monitor and control facilities of Cemtral Air Condition in real time in LAN.The structure of the system is the network structure based on the TCP/IP protocol combining with field bus structure based on CAN bus and NHB bus protocal,which is reasonable.The system can be applied to fields needed monitor ang control,such as intelligend homesteads,industry automation,environment engineering and nature ,etc.It has comprehensive application prospect..It can say that this Field Control Unit is a general controller only by amending software.This system is simple,suited,reasonable and with real time.Furthermore ,it is low cost,flexible,more reliable and steady.By applying this system,tasks are accomplished in least cost.The dissertation concectrates on eight major parts:· From the viewpoint of technical development,the technology status is analyzed and the schemes are compared.· For the application in the area of Centeral Air Condition,the principle of distributed control and centralized supervisory is presented and Field Control Unit based on ARM kernel is designed.· Researching the realization of MicroC/OS-Ⅱ The Real-Time Kernel about ARM kernel.· Researching the realization of UDP communication of TCP/IP protocol and CAN communication.· Researching the realization of 10 modules of Field Control Unit.· Reaseaching the realization of NHB bus principal.· Reaseaching the configuration of the Field Control Unit.· The applications of the system are designed out based on MicroC/OS-Ⅱ The Real-Time KernelThe end of the dissertation shows the realization of several parts. The experimens showed that the method is feasible and efficient. At last, the practice proved that the design of the software and hardware of the system are feasible, which can meet all the control targets.