A fractional-order control strategy for a pneumatic position servo-system is presented in this paper. The idea of the fractional calculus application to control theory was introduced in many works, and its advantages were proved. This paper deals with the design of fractional order PIλDµ controllers, in which the orders of the integral and derivative parts, λ and µ, respectively, are fractional. Experiments with fractional-order controller are performed under various conditions, which include position signal with different frequencies and amplitudes or a step position signal. The results show the effectiveness of the proposed schemes and verify their fine control performance for a pneumatic position servo-system.
Contemporary research on mobile robotics aims at designing robots that will be able to traverse an extremely varied environment. One of the most universal modes of locomotion is the serpentine movement. A majority of modern snake-like robots use electric drives. This study presents a snake-like robot made out of McKibben muscles. Using a pneumatic cable with muscles arranged in series, it is possible to create a robot of any length, limited only by the length of the muscle cables. Because the control system and the body of the robot are separate, the robot can be used for rescue missions involving high risk of explosion of flammable substances and for missions taking place on extremely difficult terrain.