Development Of The Temperature Regulator For Thermostat

The main function of the medical incubator is to maintain the temperature of the medical products needed in various occasions.It can be seen that the temperature change in the system is one of the important variables for investigation.The temperature of the medical incubator is slower than that of other controlled variables.At the same time,time-varying and non-linearity also exist in the temperature control system,and different interference environments possessed by various thermostats.The use of conventional control schemes such as PID controllers can only be applied to occasions where control requirements are not high.Therefore,it is necessary to design an ideal and practical fast algorithm for the temperature regulator of the constant temperature box to achieve precise control of its temperature,thereby ensuring the quality of its stored drugs.The development of medical thermostat temperature controller is mainly implemented in three steps:system identification,controller design,simulation and experimental verification.System identification is the first step to ensure the control effect of the controller.A relatively accurate transfer function allows the controller to output more accurate control signals,In this paper,after analyzing and discussing the advantages and disadvantages of various system identification methods implemented on a thermostat,it is decided to use relay feedback considering the initial state of the system to solve the problem.Its basic principle is that given the relay signal,the output of the control system will fluctuate reciprocally and regularly,and the model of the controlled variable in the system will be obtained by solving the relevant parameters in the image.This identification method is not only intuitive and clear,but also the identification speed is satisfactory.The design of the controller mainly uses the idea of predictive control.In this paper,according to the different requirements of the response speed of the incubator,the principles of DMC and GPC are designed to describe the construction of the controller.DMC itself has obvious features such as clear algorithm structure,distinct step level and high anti-interference ability,and the improved DMC fast algorithm,combined with the Lagrange multiplier method The idea avoids the iterative calculation of performance optimization indicators,thereby saving the memory occupied by the MCU of the regulator by the algorithm and reducing the control disorder caused by chip overload.GPC has inherited many advanced concepts of adaptive control and made further explorations on this basis,so that the system can maintain higher response sensitivity and processing strength of noise signals,and it also uses three major steps of predictive control to The limitation of controlled variables is realized,which also ensures the anti-interference ability of the system and strengthens the stability.In this paper,the relay feedback identification method is used to obtain the temperature transfer function of the thermostat,and the DMC controller and the GPC controller are designed respectively.After designing the controller,first use simulation software to compile the algorithm and compare the response curves,then translate the algorithm into the language on the table and write it into the chip of the thermostat regulator dedicated to the experiment.After conducting experiments on the thermostat,including the simulation,the practicability and effectiveness of the controller design are proved.