Abstract
The friction interference in the pneumatic rotary actuator is the primary factor affecting the position accuracy of a pneumatic rotary actuator servo system. The paper proposes an evolutionary algorithm-based friction-forward compensation control architecture for improving position accuracy. Firstly, the basic equations of the valve-controlled actuator are derived and linearized in the middle position, and the transfer function of the system is further obtained. Then, the evolutionary algorithm-based friction feedforward compensation control architecture is structured, including that the evolutionary algorithm is used to optimize the controller coefficients and identify the friction parameters. Finally, the contrast experiments of four control strategies (the traditional PD control, the PD control with friction feedforward compensation without evolutionary algorithm tuning, the PD control with friction feedforward compensation based on the differential evolution algorithm, and the PD control with friction feedforward compensation based on the genetic algorithm) are carried out on the experimental platform. The experimental results reveal that the evolutionary algorithm-based friction feedforward compensation greatly improves the position tracking accuracy and positioning accuracy, and that the differential evolution-based case achieves better accuracy. Also, the system with the friction feedforward compensation still maintains high accuracy and strong stability in the case of load.
Highlights
Pneumatic technology has the advantages of fire prevention, energy saving, high efficiency and no pollution [1,2,3,4]
Pneumatic servo systems have been widely used in the proportional control and program control systems in some multipipe production processes of automobile production lines, as well as the metallurgy and chemical industries [9]
The pneumatic rotary actuator can rotate in a plane, the pneumatic rotary actuator servo system is indispensable in the rotating occasions such as the pneumatic manipulator, the rotation of the platform and the rotation of the valve [10]
Summary
Pneumatic technology has the advantages of fire prevention, energy saving, high efficiency and no pollution [1,2,3,4]. The proportional–integral–derivative (PID) control is an effective method which can dynamically reduce the output deviation of a servo system, where proportional–derivative (PD) control can reduce the system delay and is suitable for high-speed control of the proportional valve [23] Evolutionary algorithms, such as differential evolution (DE) algorithm and genetic algorithm (GA), can optimize the controller parameters [24,25] and identify the friction parameters [26,27], and have been used in friction feedforward compensation. In order to improve the position accuracy of the pneumatic rotary actuator servo system, the modeling of the system and the design of the evolutionary algorithm-based friction feedforward compensation control architecture are carried out and verified by the experiments in this paper. The flow state of the gas flowing through the orifice is an isentropic adiabatic process
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
