Temperature Control Of Autoclave Based On Model Reference Adaptive Control

Based on investigation of laminating and vacuumizing of armoured glass,it shows that temperature is the most important factor about the production's quality.In the process of laminating and vacuumizing of armoured glass,the temperature control method is known as intermittent control method.The method is aiming to control the state of relay opening or closing to let the heater heat or not by PLC's command.The process of the control method is as follows.When the temperature being lower than the set value,the relay will be closed.Then the far infra-red heater begins heating.When the temperature being higher than the set value,the relay will be opened.Then the far infra-red heater stops heating.This method may cause overshoot,shock and so on.When the situation getting worse,the reject might be produced.Because of the problems all above,the paper regards the autoclave as the study object.And study the temperature control methods.First,this paper mathematically modeling the temperature of the autoclave.It provides a theoretical basis for designing temperature control methods.Secondly,this paper presents a model reference adaptive control system(MRACS)and PID control method.The control method traces the reference model.Adjust PID parameters online via adaptive law.The result of simulation shows that this method can eliminate overshoot effectively.But it extends the adjustment time as well.In order to solve the problem of long adjusting time,this paper proposes the MRACS and fuzzy-PID control method.The adaptive law of MRACS is based on the fuzzy rules.The result of simulation shows that the MRACS and PID control method can eliminate overshoot and shorten the adjustment time.Finally,in order to verify the effectiveness of the MRACS and PID control method,design a soft switching circuit.It is consisted of the MOC3063 SCR drive circuit and bidirectional thyristor whose type is BT136-600 E.The heater heating power can be adjusted smoothly by changing the duty ratio which being calculated by arithmetic.So as to achieve the purpose of temperature control.Finally,the effectiveness of the model reference fuzzy adaptive PID control method is proved by software simulation and laboratory simulation.