## 1 Introduction
An augmented state vector composed of current state, delay state and additive fault is constructed. The extended system is described in a singular form. Then, an UIO is obtained, which can decouple some disturbances and weaken the influence of the remaining uncoupled disturbances [14]. Aiming at the vehicle steer by the wire system with actuator failure and limited uncertainty, an FTC method is proposed. A fault observer is designed to evaluate the fault information and the fault SBW system. The minimax model predictive control is deployed in the delta domain to achieve tracking performance in actuator failures, disturbances and system uncertainties [15; 16]. [PERSON] et al. also dealt with the embedded FDI/ FTC approach, and applied it to an over-actuated electric vehicle [17]. Based on the online learning ability of RBF neural networks, an adaptive fault estimation observer is designed. The adaptive algorithm of RBF networks is established by the Lyapunov theory, and the design of the observer is expressed as a set of LMIs, which can be easily solved by standard LMI tools [18]. [PERSON] et al. studied the problem of the adaptive asymptotic tracking FTC for a class of uncertain nonlinear systems with actuator faults and event-triggered inputs. Firstly, the adaptive fault-tolerant controller based on an event-triggered strategy is designed, and the adaptive control law is constructed to compensate the unknown fault of the actuator effectively. Then, the Lyapunov function is used to ensure the uniform boundedness of the closed-loop signals [19]. [PERSON] et al. used Lipschitz nonlinearity to solve the problem of fault estimation for nonlinear systems. The estimation of system fault and state is discussed. In this method, the disturbance is regarded as a nonlinear function coupled with the system state, and the fault is regarded as an additive function. In order to diagnose faults and reduce disturbance by using dissipation theory, Luenberger and two UIOs are designed, respectively [20]. Sensor fault estimation and actuator fault detection and isolation (FDI) for a class of uncertain nonlinear systems are studied. A robust sliding mode observer estimates the states and sensor faults of the original system by attenuating unknown inputs and actuator faults [21]. [PERSON] et al. proposed a new adaptive integral sliding mode based on the FTC strategy for the actuator faults and failure compensation problem of a class of Lipschitz nonlinear systems. Firstly, a nominal state feedback virtual control law is designed to stabilize the Lipschitz nonlinear system and to achieve the ideal nominal performance. Then, the nonlinear adaptive integral SMC and control allocation scheme are introduced to compensate the unknown disturbance and uncertainty caused by actuator failure and fault estimation error [22]. [PERSON] et al. proposed a scheme for accommodating faults in the rotor and generator speed sensors in wind turbine. These measurements are very important for wind turbine control and wind turbine monitoring. The basis of this scheme is to detect and isolate these faults by using an observer with unknown inputs [23]. [PERSON] et al. studied the problem of robust predictive FTC for linear discrete-time systems. The key problem is to keep the state of the system in the robust invariant feasible set, which is a group of states to ensure the stability of the proposed control strategy [24]. A new LMI condition is proposed for the problem of the stabilization of a class of discrete-time Lipschitz nonlinear systems with parameter uncertainties. By combining the Lipschitz property with [PERSON]'s relation and a non-diagonal Lyapunov matrix, a less conservative LMIs is obtained [25]. In contrast to previous publications, in this paper, the FE and FTC of the actuator in the EPS system of the forklift were studied. An integrated FE and FTC system is proposed. Compared with the separate design of observer gain and controller gain, the integrated design fault estimation is more rapid and accurate, and the fault-tolerant control effect is better.