Disturbance Observer-based Backstepping Control Research Articles

Disturbance Observer–Based Backstepping Control for Hypersonic Vehicles with Input Constraints

Disturbance Observer–Based Backstepping Control for Hypersonic Vehicles with Input Constraints

Experimental Verification of Disturbance Observer-Based Backstepping Control for DC–DC Boost Converter

Experimental Verification of Disturbance Observer-Based Backstepping Control for DC–DC Boost Converter

Disturbance Observer based Backstepping Control for Electro-hydraulic Position Servo System of the Projectile Coordination Arm

Due to the existence of unmodeled friction and unknown load disturbance, the position tracking control of electro-hydraulic position servo system of projectile coordination arm becomes an important problem to be solved urgently. In this paper, a dynamic surface backstepping control strategy is proposed based on the disturbance observer(DOB). To be specific, the disturbance observer is applied to estimate the unknown disturbance force, and the backstepping controller realizes the position tracking control. In order to improve the position tracking performance, The estimated value of the observer output is brought into the backstepping controller to realize the model compensation of the disturbance. Meanwhile, the dynamic surface method is utilized to handle the differential explosion problem in the backstepping method. The global stability of the closed-loop system is verified by Lyapunov stability theory. The co-simulation results show that the proposed method can effectively compensate the unknown disturbance in the electro-hydraulic position servo system, and has better tracking performance and strong robustness.

Disturbance observer-based backstepping control for leader–follower ships with disturbances

ABSTRACT This paper studies leader–follower cooperative control with the slowly-varying environment disturbances of the surface ships, which are mainly caused by wind, wave and current. A disturbance observer is constructed to estimate the slowly-varying environmental disturbances. Based on disturbance observer, the control law of the follower ship is designed by backstepping technique. The disturbance observer-based leader–follower cooperative control scheme is carried out via employing stochastic control theory to analyse the close-loop system. The scheme achieves the follower ship track the leader ship with a certain error range for cooperative movement and all signals are bounded in the mean square. Finally, the results of simulation are listed to verify the scheme.

Disturbance observer-based backstepping control for hypersonic flight vehicles without use of measured flight path angle

In this paper a nonlinear control method is proposed for the tracking control of hypersonic flight vehicles. The designed control laws do not utilize the measured flight path angle due to its inferior accuracy in practical engineering. For this, an estimated flight path angle is designed via the measurements of the altitude and velocity. A tracking differentiator is designed for constructing nonlinear disturbance observer which is used to estimate the model uncertainties including the parameter indeterminacies and external disturbances in the channels of velocity and pitch rate. A robust high-order differentiator is introduced to avoid the employment of the measured flight path angle and estimate the lumped disturbance in dynamics of flight path angle. Meanwhile, the possible saturation of the control inputs is considered and compensated by the auxiliary states. The boundness of closed-loop signals is proved through the Lyapunov theory. Comparative simulations are carried out and the results demonstrate the effectiveness of the proposed method.

Robust trajectory tracking control for a quadrotor subject to disturbances and model uncertainties

ABSTRACTIn this paper, a robust hierarchical controller is proposed for trajectory tracking of a quadrotor in the presence of disturbances and parametric uncertainties. The hierarchical controller has an outer-inner loop structure. The outer loop controls the position of the quadrotor and generates desired roll and pitch angles for the inner loop corresponding to desired position, velocity and heading angle. The inner loop controls the attitude of the quadrotor. A disturbance observer based backstepping controller is designed for the outer loop to compensate for disturbances and guarantee robust position tracking. An adaptive non-singular terminal sliding mode controller is designed for the inner loop to ensure the attitude angles converge to their desired values in finite time and deal with the parametric uncertainties. The stability and online estimating capability of the proposed controller are proved by using Lyapunov theory. Finally, numerical simulation results are presented to validate the effectiveness of the proposed controller.

Robust path-following control of a container ship based on Serret–Frenet frame transformation

A novel disturbance observer-based backstepping controller (DOBBC) is developed and applied to the path-following system of a container ship. Our control objective is to enable the ships to follow a desired path despite the presence of environmental disturbances caused by current, wind, and wave actions. It is particularly challenging to achieve such an objective due to the underactuation and nonlinearity of container ships. To simplify controller design, a tracking error model is developed based on Serret–Frenet frame transformation. The proposed path-following control system is constructed on the model. In DOBBC, the disturbance observer estimates both constant and time-variant environmental disturbances. The backstepping controller compensates the nonlinearity and underactuation of the container ship. A feedback-dominance technique is utilized to design the controller parameters. The stability and robustness of the control system are successfully justified through Lyapunov approach. Simulation results demonstrate that the DOBBC effectively drives the ship to follow a desired trajectory in spite of the existence of time-varying environmental disturbances.

Disturbance Observer-Based Backstepping Control of PMSM for the Mine Traction Electric Locomotive

For the Permanent Magnet Synchronous Motor (PMSM) control system of the Mine Traction Electric Locomotive (MTEL), the fluctuation of the load will lead to the resonance of the velocity of the MTEL. In addition, the speed sensor is easy to be damaged due to the moisture, dust, and vibration. To solve the above problems, a disturbance observer-based (DOB) backstepping control of PMSM for the MTEL is proposed in this paper. First, a full-dimensional Luenberger observer for PMSM is designed and the asymptotically stability of the observer is proved. Next, through the designing of the virtual control input that includes the reconstruction disturbances and using backstepping control strategy, the DOB controller is proposed. The obtained controller can achieve high precision speed tracking and disturbance rejection. Finally, the effectiveness and feasibility of the designed system are verified by Matlab simulation and experiment results.

A novel disturbance observer-based backstepping controller with command filtered compensation for a MIMO system

This paper presents a novel disturbance observer-based trajectory tracking controller based on the integral backstepping approach. To avoid the complexity of analytically calculating derivatives of virtual control signals in the standard backstepping technique, a command filtered backstepping approach is utilized. The proposed control approach is formulated for a class of nonlinear MIMO systems and provides robustness against external disturbances. This approach is applied on an aerodynamic laboratory setup known as the twin rotor MIMO system (TRMS). Stability analysis of the proposed controller is presented using Lyapunov stability arguments and singular perturbation theory. Simulation studies show that the proposed controller successfully allows the system outputs to track arbitrary reference trajectories and reject arbitrary constant disturbances that may occur due to partial actuator failure. The reliability and effectiveness of the approach is validated experimentally by implementation of the proposed controller on a hardware-in-the-loop system.

Sliding mode disturbance observer-based backstepping control for a transport aircraft

This paper presents a novel control method by integrating the sliding mode disturbance observer-based control and the backstepping control technique, and successfully applies it to a flight control system for heavy cargo airdrop operations. The super-twisting second order sliding mode disturbance observer (SOSMDO) is employed to estimate bounded but otherwise arbitrary disturbances, thus ensuring asymptotic convergence of the estimation error to zero in a finite time. Besides, the integrated controller can significantly improve the robustness of the flight control system to modeling uncertainty and external disturbance in the presence of state/control constraints. The closed-loop stability is guaranteed in the sense of Lyapunov. In addition, the proposed approach can considerably reduce design cycles. The performance of the proposed control method is demonstrated in a very low altitude extraction airdrop simulation with a high-fidelity six-degree-of-freedom transport aircraft model.