| The essence of pneumatic system control is the pressure control of gas.Due to the compressibility of gas,gas leakage and frictional force,pneumatic system is complex and nonlinear.Traditional control method is not ideal for pneumatic system.Therefore,It is the focus of the research that realizing the fast response and steady state tracking of the nonlinear pneumatic system.At present,the research on pneumatic system mainly focuses on three aspects: frictionless cylinder,high-precision control valve and the control algorithm of pneumatic system.It is the key piont of this paper that the algorithm of pressure control.Main contents of this paper are as follows:(1)The modeling and simulation analysis of the pneumatic system.According to the structure principle of friction free cylinder and proportional control valve,mathematical modeling is carried out,and then the pneumatic system model is established.The simulation model is built by using MATLAB,and the influence factors of gas source pressure and temperature,volume of gas tank and length and diameter of pipeline are simulated and analyzed.(2)Build an experimental platform for pneumatic system.According to the structural principle of the pneumatic system,the experimental platform is built,including the overall design of the experimental platform,the selection of key components,the compilation of data acquisition card driver in software design,the interaction design of the host computer software user interface and the mixed programming design of CVI and MATLAB.(3)The algorithm of brain emotional learning and its improvement.It exhibits strong rapidly response and system robustness in nonlinear system control that the Brain Emotion Learning Controller(BELC).Combined with the nonlinearity of the aerodynamic system and the characteristics of BELC,The algorithm of BELC is improved.In order to overcome the effects of the time-varying and modeling uncertainties of the system parameters,The fuzzy control is used to adjust the learning rate of the weights of BELC online.The simulation of BELC and its improved algorithm are carried out.(4)Experimental research about the algorithm of pressure control.The PID,BELC,and its improved algorithm are respectively used to perform step response,step disturbance,and sinusoidal tracking experiments.The experiments show that the improved algorithm of BELC has a significant improvement in response speed and steady-state accuracy compared with PID.The steady-state error is stable between 400 Pa and 550 Pa,which is more than 70% lower than PID.In the presence of disturbances,the steady-state time is reduced by more than 30% and the improved algorithm of BELC is more robust.In dynamic tracking,the amplitude variation and phase lag are smaller,and the tracking effect is better.In summary,the research shows that the feasibility of improved BELC and the algorithm of BELC has good adaptability and the advantage of control in pneumatic control. |
