Modeling and simulated control of non-linear switching actuation systems

Pneumatic actuation systems have great advantages like power-to-weight ratio and low cost that make them challenging to automation applications. To control the position of the piston of a pneumatic actuator has always been an attractive field for research and there is still area for deeper investigation. The main reason for this is the compressibility of air and the friction force inside the cylinder body. These two factors make the system highly non-linear and its controllability difficult. In this work presented here an effort to model mathematically the pneumatic system, which consists of a controller a pneumatic proportional servo-valve and a double acting cylinder, is provided. The switching dynamics of the system are discussed in details as well as all forces affecting the piston displacement. Since MatLab® Simulink ® is considered to be the most appropriate simulation environment for controlling tasks, the pneumatic system was designed there based on its mathematical model. A classical three-term (P-I-D) controller and its variations (P-PD-PID) were implemented also in the simulation model and all performance results were recorded and illustrated in this research paper.