Position control systems with friction compensation for servo pneumatic actuators

This work is devoted to the development of control systems for a tracking pneumatic actuator, taking into account the current position of the working body of the actuator and the amount of friction in the friction pairs of the actuator. Implementing the positioning of a pneumatic actuator is a complex technical task, but at the same time extremely relevant, since industrial systems of modern production require the performance of technological operations not only with high speed but also with high accuracy of positioning the working body of the actuator. The paper also considers control systems for pneumatic actuators based on the position of the working body, taking into account the nonlinearity of motion caused by friction forces in the pneumatic actuator. Friction in the contact pairs of pneumatic actuators adversely affects the operation of the actuators, especially taking into account the dependence of friction on ambient temperature, the surface condition of the contact pairs, the availability and quality of lubricants, etc. The study demonstrates existing control systems and implemented static and dynamic models of friction compensation and the impact of such models on the accuracy and controllability of systems with different types of regulators and implementation schemes, including proportional distributors with analog control and high-speed direct-acting distributors. The paper analyzes positioning systems with the ability to regulate the inlet pressure and the impact of such system solutions on the system rigidity and its performance. The paper formulates a goal for further research and identifies a list of tasks necessary to achieve the goal set in the paper. The paper also presents a design solution for a test bench with the ability to implement adaptive control of the actuator force depending on changes in the operating parameters of the technological operation and changes in the parameters of the pneumatic system as a whole.