The Research Of Hardware In The Loop Simulation Of The Process Control Experimental Device

Process control in petroleum processing,chemical production,metallurgy and other industries is the control of certain objects in the production process.Its universal practical application has great significance for a country's economic development and social progress.Specific to an industrial process,it has its own control requirements and control objects.Different controlled quantities have different characteristics,so finding a suitable control method can achieve better control effects.In the industrial process,there are always many difficult to build model,such as nonlinearity,timedelay and uncertainty,which bring a lot of difficulties to the establishment of the model,and the control effect of the control method does not match the actual.Another kind of semi-physical simulation is hardware-in-the-loop simulation,which replaces part of the pure digital simulation with the actual physical object,adds the actual physical object to the simulation loop,and makes some approximations in the modeling process.Ignoring the problem of the distortion caused by the processing is reduced,and the ignored interference is also brought into the simulation loop,so that the control result is closer to the actual situation.In this paper,the hardware of the process control experimental device and the real-time simulator are first described.The controlled object with time-delay or coupling characteristics in the process control device is selected.and the control methods are adopted for the problems of time-delay and coupling respectively,so as to obtain the system without time-delay or coupling.The liquid level in the upper tank is used as the control object.When the liquid level of the water tank is controlled,due to the existence of the time lag in the system due to the existence of the coil,the Smith predictor is designed to deal with time lag problem which based on the PID control as the controller.The experimental results show that the Smith predictor can improve the control effect;The upper tank and the middle tank are connected in series.The liquid level in the middle water tank is selected as the controlled object.By comparing the PID control,the cascade PID control,and the fuzzy control result of the PID cascade control can be seen that the designed fuzzy PID cascade control performance is better;The hot water and cold water are simultaneously introduced into the upper water tank to construct a temperature liquid level coupling system,due to the existence of coupling,the choice of parameters in the control scheme is quite difficult,so the decoupling must be carried out first,so the diagonal matrix decoupling method is selected to achieve the purpose of decoupling.Then the single neuron PID control strategy is applied to the decoupled temperature and liquid level.Individual control of temperature and liquid level settings is achieved in systems that do not interfere with each other.The above three control systems are first simulated and parameterized on MATLAB/Simulink to obtain the control results.According to the needs of the hardware-in-the-loop simulation system,the channels on the board in the target machine are configured,and then the target code generation technology is used.Generate the code file that the target machine can run.Finally,download the code file to the target machine through RT-Sim main control software,and then monitor the process control system running in the target machine in real time through RT-Sim software and LabVIEW software.It can intuitively observe the control effect of the control strategy and provide simulation ideas for the actual process control.