An adaptive variable structure position control for induction motors using field oriented control theory is presented. The proposed sliding-mode control law incorporates an adaptive switching gain to avoid calculating an upper limit of the system uncertainties. The design incorporates a flux estimator that operates on the principle of flux and current observer. The proposed observer is basicall...

This paper develops a high dynamic and robust speed-torque control system for servo drives based on adaptive observer and self-tuning techniques with on-line inertia identification. Only the rotor position is measured even for a low precision shaft encoder. The instantaneous speed and the disturbance torque are accurately estimated by an extended Luenberger observer inertia adaptive. A current ...

This paper proposes an observer-based indirect adaptive fuzzy sliding mode controller with state variable filters for a certain class of unknown nonlinear dynamic systems in which not all the states are available for measurement. To design the proposed controller, we first construct the fuzzy models to describe the input/output behavior of the nonlinear dynamic system.Then, an observer is emplo...

For a class of uncertain nonlinear systems with actuator faults, robust active fault-tolerant control is investigated based on the adaptive observer, feedback linearization, and backstepping design theory. Time-varying faults and bounded uncertainty are simultaneously considered in the paper. An adaptive observer is firstly constructed to estimate the faults and then a backstepping-based active...

1This paper presents a new speed observer for high performance FOC (Field Oriented Control) and DTC (Direct Torque Control) induction motor drives. It is an MRAS (Model Reference Adaptive Systems) observer which employs a linear ANN (Artificial Neural Network) for the estimation of both the rotor speed and the flux-linkage. The training of the ANN based adaptive model of the MRAS observer is pe...

This paper investigates an improved stator flux linkage observer for sensorless permanent magnet synchronous motor (PMSM) drives using a voltage-based flux linkage model and an adaptive sliding mode variable structure. We propose a new observer design that employs an improved sliding mode reaching law to achieve better estimation accuracy. The design includes two models and two adaptive estimat...

This paper addresses adaptive observer design problem for joint estimation of the states and unknown parameters for a class of nonlinear systems which satisfying one-sided Lipschitz and quadratic inner bounded conditions. It’s shown that the stability of the proposed observer is related to finding solutions to a quadratic inequality consists of state and parameter errors. A coordinate transform...

Model Reference Adaptive System (MRAS) based techniques are one of the best methods to estimate the rotor speed and position due to its performances and straight forward stability approach. In this paper, we propose a new robust MRAS scheme based on sliding mode techniques to estimated the rotor speed of a Surface Permanent Magnet Synchronous Motor (SPMSM). Furthermore, an Estimator/Observer sw...

This paper presents a novel disturbance observer-based adaptive neural network control for hydraulic knee exoskeleton with valve deadband and output constraint. Adaptive networks are employed to approximate the unknown nonlinearities of actuator, i.e., unmodeled dynamics caused by leakage. A observer is designed integrated into controller compensate external equivalent interactive force acted o...