The Design Of Intelligent Control System For Constant Temperature-Humidity Incubator

This paper indicates the development of incubator home and aboard and present research of intelligent control system for constant temperature-humidity. For improving of incubator, a control system with high precision and reliability is designed, including hardware and software. The major work is research and design of control algorithm.In hardware, the whole frame is first designed. Then according to precision demand of control system for constant temperature and humidity, all electric parts is selected and the circuit is designed respectively. There are six main parts:detection with sensor, controller, controlled object, human-machine interaction, MCU and power. It can perform the function of keyboard, displaying, warning by buzzer or LED, constant temperature, constant humidity and download of data. The main power supply is 220VAC. Moreover, a new approach, equipting with backup power, is put forward for practicability and reliability design. The tandem NiMH battery is used as backup power to sustain monitoring circuit. When the main power supply is present, NiMH battery is charged. And the monitoring system can be supported for 24 hours after the main power failed. In software, it realized the basic function of sampling, display, timing, interrupt, control, data communication and so on. A good control function can reflect a good incubator. So we first research intelligent control algorithm using fuzzy control as a base. It is designed by Matlab, the simulated system was realistically designed in Simulink for adjustment and a new approach was practically put forward for optimization design of stabilization using online interpolation algorithm. It meets the basic demand in lab. Then PID control is inserted and the results in dynamic and stabilization are satisfaction because of association of advantage in fuzzy control and PID control. After a large numbers of experiments, the system gives a control result of rapid response without overshooting and high precision.The design and experiment show the reasonable scheme, high reliability, high practicability, convenient debugging. It completely fits constant temperature-humidity incubator. It helps to save cost, increase heat efficiency, reduce energy consumption and improve experimental condition. Moreover, it has been fit to be put into use and be extended in biomedical labs thanks to convenience of installation and use.