Research On Programmable Pneumatic Servo DSP Controller

Pneumatic servo systems have many advantages such as low cost,clean and easy to work with and so on.However,as pneumatic systems are highly nonlinear and exist rather serve parametric variety,which bring difficulty to control when implementing the trajectory tracking with high precision.This paper is based on the existing adaptive robust control algorithm,the embedded controller and trajectory programming software operating on PC are developed,trajectory tracking control and positioning control with high precision of pneumatic system are studied.Firstly,the research background related to the model and control strategy of pneumatic systems is reviewed.And the application status of embedded pneumatic servo controller and programmable controller is introduced.The hardware of the controller is based on DSP28335,and data acquisition and processing,control signal output,communication with computer,data storage are introduced respectively in hardware circuit design part.In software design part,using Qt as PC software development platform to realize third-order S curve planning by G instruction,the derivation of the third-order S curve and the functions of G instructions are explained.The peripheral driver software of A/D conversion chip,D/A conversion chip,Flash chip,and the serial port communication and timer on the DSP chip are introduced in the DSP peripheral driver software section.To improve the transferability and applicability of the existing algorithm,a dead-zone identification method of proportional directional valve based on the change of cylinder cavity pressure is put forward,and the identification method is verified stable and accurate through the experiment.In order to use the accurate LuGre friction model to describe the friction of cylinder,cylinder friction identification method based on genetic algorithm is put forward,and the Kalman filter and nonlinear differential tracker are applied in the signal processing.The method of self-adjustment on adaptive robust control parameters based on RBF neural network is introduced to replace the tedious and time-consuming artificial adjustment on these parameters.Finally,the experiment equipment of the pneumatic servo control system is introduced.Some experiments are conducted including controller parameters self-tuning experiments,the different frequency sine tracking experiments and S curve trajectory tracking experiments and positioning control experiment.