Event-Triggered Adaptive Control for a Class of Uncertain Nonlinear Systems

Event‐triggered adaptive backstepping control for parametric strict‐feedback nonlinear systems

“…Remark Compared with the existing traditional adaptive backstepping schemes and the traditional event‐triggered methods,() our proposed scheme has the following advantages and disadvantages. Advantages Compared with traditional backstepping schemes with a continuous transmission,() the proposed method only uses the sampling states to update the controller and the adaptive law, which can largely reduce the transmission load and the computation burden. Different from the traditional event‐triggered methods() where the controllers are given a priori, and then the ISS property is used to handle the measurement errors, both the adaptive controller and the adaptive event‐triggering condition are designed at the same time such that the ISS assumption is no longer required. The threshold of the event‐trigger condition in this paper is designed as a function of both the parameters estimates and the system state vector.…”

“…Advantages Compared with traditional backstepping schemes with a continuous transmission,() the proposed method only uses the sampling states to update the controller and the adaptive law, which can largely reduce the transmission load and the computation burden. Different from the traditional event‐triggered methods() where the controllers are given a priori, and then the ISS property is used to handle the measurement errors, both the adaptive controller and the adaptive event‐triggering condition are designed at the same time such that the ISS assumption is no longer required. The threshold of the event‐trigger condition in this paper is designed as a function of both the parameters estimates and the system state vector. Thus, the threshold becomes adaptive unlike the traditional threshold conditions,() which are the functions of system state vector or constants alone. Since we have dynamics that evolve in continuous and discrete‐time, we write the closed‐loop system as an impulsive model and prove the closed‐loop stability for both the continuous and jump dynamics. Disadvantages In order to obtain the adaptive event‐triggering condition, the global Lipschitz continuity condition of the known function is needed, which can be relaxed in our future work.…”

“…Remark In our previous works,() some traditional event‐triggered methods have been presented, where the controllers are given a priori, and then, the input‐to‐state stability (ISS) property is used to handle the measurement errors. By comparison, in Equation , since the system contains unknown parameters, it is hard to check whether the ISS condition with respect to the state or input signal measurement errors holds or not . As a result, the problem studied in this paper is quite different from and more challenging than that in our previous works.…”

“…Moreover, the obtained result in the work of Li and Yang is restricted to be local. Although a global adaptive ETC scheme was studied in the work of Xing et al for a class of parameter strict‐feedback nonlinear systems, the proposed methods are considered in the controller‐to‐actuator channels and the approaches cannot be applied to sensor‐to‐controller channels. Thus, it is meaningful to propose a novel ETC codesign scheme for parameter strict‐feedback nonlinear systems to reduce update times of the controller, which motivates our present investigation work.…”

Adaptive prescribed performance control of nonlinear output‐feedback systems with unknown control direction

“…Assumption (See Bechlioulis and Rovithakis and Xing et al) The reference trajectory r ( t ) and its derivative are bounded.…”