Adaptive actuator failure compensation with unknown control gain signs

International Journal of Systems Science

Shen

et al. 2014

In this paper, the problem of adaptive tracking control is addressed for a class of nonlinear systems with unknown constant parameters and unknown actuator nonlinearity. The actuator nonlinearity is modelled as the backlash-like hysteresis, which is described by a differential model. The prior knowledge on the control gain sign is not required, and only the assumption on the reference signal is made. By combining the adaptive backstepping technique with the Nussbaum gain approach, an adaptive compensation controller design approach is developed. It is proved that the proposed control approach can guarantee that all the signals in the closed-loop system are bounded, and the tracking error can converge to zero asymptotically despite the presence of the actuator hysteresis. Two simulation examples are included to illustrate the effectiveness of the proposed approach.

Section: Introductionmentioning

confidence: 99%

Zero-error tracking control of uncertain nonlinear systems in the presence of actuator hysteresis

International Journal of Systems Science

Shen

et al. 2014

“…In the subsequent two years, this approach was used to develop output-feedback controllers [4,5] in order to improve the output-feedback schemes with overparametrization in [6,7]. Recently, the tuning functions method has been extended to many control communities such as robust adaptive control [8,9,10], adaptive control with partial overparametrization [11], decentralized adaptive control [12,13,14], approximation-based adaptive control [15,16], nonlinear systems with actuator nonlinearity [17], nonlinear time-delay systems [18], actuator failure compensation [19,20], etc. In this paper, we will present a novel design approach to solve the overparametrization problem.…”

Section: Introductionmentioning

confidence: 99%

An alternative scheme for adaptive backstepping control

Cao

The 26th Chinese Control and Decision Conference (2014 CCDC)

et al. 2014

In this paper, we present a new adaptive backstepping control design method to solve the overparametrization problem in parameter estimation. Unlike the existing schemes, the concept of tuning functions is not introduced. However, the number of parameter estimates is reduced to be minimal, which is exactly the same as that of unknown parameters. The parametric strict-feedback system is employed to illustrate our design procedure.

IET Control Theory & Applications

“…So, it is necessary to consider actuator faults to maintain stability and desired performances while designing control systems [2]. Many fault-tolerant controllers have been designed to deal with actuator faults by using different theories and methods, such as linear quadratic [3,4], intelligent control [5,6], adaptive control [7][8][9][10][11][12] and methods based on combination of different approaches [13][14][15]. In addition, the fault-tolerant control has been successfully designed for different applications, especially for flight systems [16,17].…”

Section: Introductionmentioning

confidence: 99%

Adaptive fault‐tolerant robust control for a linear system with adaptive fault identification

Shen

Liu

Dowell

2013

An integrated design of the adaptive robust control and the fault identification for a linear system with actuator faults is proposed. When actuators suffer from unpredicted faults, the proposed control strategy can track the actuator fault parameters adaptively without any prior fault information, and guarantee the robustness of the faulty system. An unknown input observer is designed to decouple the disturbance and the actuator faults. Then an adaptive control law with projection is presented to track the fault parameters. A new definition of robust H ∞ -like performance is proposed to ensure that the system is robust for both exogenous disturbance and unpredicted faults. Then the adaptive robust control law is designed to guarantee the system satisfying the robust H ∞ -like performance. Finally, the effectiveness of this control strategy is illustrated through the faulttolerant longitudinal control of the simplified F-18 aircraft model.