Provident control of an electro-hydraulic servo with experimental results

The fusion of computationally intelligent methodologies and sliding-mode control-a survey

“…By taking the time derivative of (5) and using the plant equation 13is obtained. By putting (13) into (12), the control input signal can be obtained as (14) where is the equivalent control and it is written as (15) and is the corrective control term and written as (16) Another design possibility is to ensure that (17) in which case the corrective term that adds onto is obtained as (18) It is to be noted, however, that there is no switching in this case and the approach does not result in a VSS.…”

“…The advantages of this approach as compared to conventional chattering avoidance techniques based on "hard computing" are not discussed in the paper and is open to discussion. b) Use of FL for the tuning of SMC parameters: Consider the SMC as defined by (14)- (16) or (18). The effects of the design parameters and on the system performance are shown in Fig.…”

“…This approach is based on the idea of the equivalence of the high-gain systems and the systems with sliding modes [17]. Another variation of the scheme is called provident control that combines variable-structure control (VSC) and variable-structure adaptation and performs hysteretic switching between the structures so as to avoid a sliding mode [18], [19]. Both approaches are based on the calculation of the equivalent control, requiring a good mathematical model of the plant.…”

Fuzzy boundary layer tuning for sliding mode systems as applied to the control of a direct drive robot

“…To overcome this problem, many modifications to the original sliding control law have been suggested (see Slotine and Li 1991;Elmali and Olgac 1992;Tunay 1996). The most popular modification is the boundary layer approach, which is, basically, the application of a high gain feedback when the motion of the system reaches /-vicinity of a sliding manifold (Slotine and Shastry 1983).…”

Use of adaptive fuzzy systems in parameter tuning of sliding-mode controllers

“…Another variation of the scheme is called "provident control." Provident control combines variable structure control and variable structure adaptation and performs hysteretic switching between the structures so as to avoid a sliding mode [17]. The computation of the equivalent control plays a vital role in both methodologies, requiring a good mathematical model of the plant.…”