Study Of PID Control Of Room Temperature Experimental System

In recent years, HVAC automatic control system developped vigorously in China, automatic control of the air-conditioning, heating system can be found everywhere in intelligent building. However, in most of the actual control system, the results are not satisfying. The main reasons for:①designers in automatic control system design usually only by virtue of experience , lack of aided-design tools;②That the control strategy & parameter value is whether proper or not be usually judged according to the running performance on the spot only after the system is finished. If some fault is found, it is only adjusted and modified locally, that made it difficult to realize optimization control.Under the guidance of the classic theory of automation, the study is the counter at room temperature PID control of air-conditioning systems. First of all analyze properties and establish simulation model for the objects of system, according to the law of conservation of energy and quality, Newton's Laws of Motion to establish model, and then establish differential equations, re-use Laplace transform and Z transform to transfer the form of function (discrete parts into a pulse transfer function form). With all sectors of that transfer function MATLAB / Simulink module environment connect all links to establish the temperature system model of PID control system.On this basis, use MATLAB to design parameters of the entire process of simulation control, and control system MATLAB simulation performance in the time-domain analysis. In order to investigate the actual performance of automatic control system under the MATLAB aided-design, by using the PID control parameters and PI control parameters to experiment, and compare to simulation performance. By examining the comparative experiment proved that the results of design-analysis by means of this approach has high practicability and referential value by using of MATLAB aided-design in automation system. Application MATLAB / Simulink to support aided-analysis and aided-design has considerable credibility and significance, in the actual project we can use it to shorten pre-test and design time, and then detect problems early and put forward reasonable automation system.