Control (management)

Engineering

Biology

Servomotor

Control engineering

Economics

Computer science

Mathematical optimization

Integer (computer science)

Controller (irrigation)

Thermodynamics

Physics

Mathematics

Position (finance)

Differential (mechanical device)

Agronomy

Artificial intelligence

Programming language

Finance

Control theory (sociology)

Servo

Servomechanism

IEEE Transactions on Industrial Electronics

In this paper, a fractional-order model of pneumatic servo system is introduced by replacing the integer-order dynamic equation with the corresponding fractional order one. Then, a fractional-order proportional-integer-differential (FPID) controller is optimized for the servo system using an online multivariable multiobjective genetic algorithm (MMGA). The proposed MMGA searches in five-dimensional parameter space based on Pareto rank to balance multiobjectives. In order to provide a basis for comparison, the parameters of a integer order proportional-integer-differential (IPID) controller are also optimized using the same method. The performance indices defined for comparison are the steady-state tracking accuracy and the control energy consumption. Additionally, seven other methods from the literature are compared. The experimental results obtained show that the optimized FPID controller results in a better performance than the optimized IPID controller and the other existing approaches.

Optimal Design of a Fractional-Order Proportional-Integer-Differential Controller for a Pneumatic Position Servo System