Linear Active Disturbance Rejection Research Articles

Predictive Control of Trajectory Tracking for Flapping-Wing Aircraft Based on Linear Active Disturbance Rejection

Predictive Control of Trajectory Tracking for Flapping-Wing Aircraft Based on Linear Active Disturbance Rejection

Adaptive Optics Tip-Tilt Correction Based on Smith Predictor and Filter-Optimized Linear Active Disturbance Rejection Control Method.

A tip-tilt mirror (TTM) control method is designed to enhance the control bandwidth and ensure the rejection performance of the adaptive optics (AO) tip-tilt correction system. Optimized with the Smith predictor and filter, linear active disturbance rejection (LADRC) is adopted to achieve the tip-tilt correction. An AO tip-tilt correction experimental platform was built to validate the method. Experimental results show that the proposed method improves the control bandwidth of the system by at least 3.6 times compared with proportional-integral (PI) control. In addition, under the same control bandwidth condition, compared with the Smith predictor and proportional-integral (PI-Smith) control method, the system is more capable of rejecting internal and external disturbances, and its dynamic response performance is improved by more than 29%.

Research on a DC–DC Converter and Its Advanced Control Strategy Applied to the Integrated Energy System of Marine Breeding Platforms

The deep-sea aquaculture industry will become one of the important pillars of the future marine economy. However, the application of clean energy in the new scenario needs to be strengthened for platform operation. For this kind of renewable-energy distributed-generation system, an energy storage system is essential. A bidirectional DC–DC converter is essential for distributed power generation systems. It connects a variety of renewable energy sources with energy storage cells. A high-gain bidirectional Cuk circuit with zero ripple is proposed in the paper. It is characterized by a simple structure, zero ripple, low voltage stress of semiconductor power devices, and high voltage gain. A passivity-based control with linear active disturbance rejection is proposed to solve the problems of the large steady-state error. The zero steady-state error, strong robustness, and whole-range stability have been obtained for the proposed control strategy. Finally, a simulation was carried out. A 100 W, 48 V/400 V prototype was built to verify the validity of the theoretical analysis for the proposed circuit. The improved passivity-based control strategy was verified to solve the contradiction between rapidity and overshoot. It can be realized to improve the dynamic performance of the proposed converter and achieve robust control.

Centralised fractional order LQI controller design for quadruple tank process — An optimisation approach

In this paper, a centralised Fractional Order Linear Quadratic Integral (FOLQI) controller is proposed for highly interacting Multi Input Multi Output (MIMO) system to reject the load disturbance conditions. An optimisation problem to minimise the control effort as an objective function is formulated in addition to meet the desired time domain inequality constraints. The parameters of the FOLQI controller are obtained by using sequential quadratic programming optimisation approach. For illustration, the quadruple tank process is considered as a case study which exhibits both minimum and non-minimum phase characteristics. To show the performance of the FOLQI controller, the simulation is performed under disturbance and parameter uncertainty conditions. The performance indices such as maximum peak overshoot, settling time and steady state error are computed for FOLQI controller. To show the superiority of FOLQI controller, these indices are compared with the responses obtained using the existing Integer Order Linear Quadratic Integral (IOLQI) and Linear Active Disturbance Rejection (LADR) controllers.

Simulation of a Quadrotor under Linear Active Disturbance Rejection

The quadrotor aircraft has the characteristics of simple structure, high attitude maintenance performance and strong maneuverability, and is widely used in air surveillance, post−disaster search and rescue, target tracking and military industry. In this paper, a robust control scheme based on linear active disturbance rejection is proposed to solve the problem that the quadrotor is susceptible to various disturbances during the take−off process of non−horizontal planes and strong disturbances. Linear Active Disturbance Rejection Control (LADRC) is a product of a tracking differentiator (TD), a linear extended state observer (LESO) and an error feedback control law (PD) and is a control technique for estimating compensation for uncertainty. Radial Basis Function Neural Networks (RBFNN) is a well−performing forward network with best approximation, simple training, fast learning convergence and the ability to overcome local minima problems. Combined with the advantages and disadvantages of LADRC, Adaptive Control and Neural Network, the coupling force between each channel, gust crosswind disturbance and additional resistance of offshore platform jitter in the flight state of the quadrotor are optimized. In the control, the RBF neural network is designed, the nonlinear control signal is wirelessly approximated and the uncertain disturbance to the quadrotor is identified online. Finally, the real−time estimation and compensation are performed by LESO to realize the full−attitude take−off of the quadrotor. In addition, this paper uses adaptive control to optimize the parameters of LADRC to reduce the problem of many LADRC parameters and difficulty to integrate. Finally, the robust control system mentioned in this paper is simulated and verified, and the simulation results show that the control scheme has the advantages of simple parameter adjustment and stronger robustness.

Research on Aircraft Attitude Control Method Based on Linear Active Disturbance Rejection

In this paper, a dual-loop active disturbance rejection attitude controller design method is proposed for the attitude control of aircraft. Firstly, based on the nonlinear dynamic model of aircraft, the control system model with inner loop as angular velocity and outer loop as attitude angle is established. Secondly, the extended state observer for the inner loop is established to estimate and compensate the state of the system in real time. The controller of the compensated series integral system is designed by using the linear PD control method. Thirdly, the extended state observer and controller for the outer loop are designed by the same method. Finally, the stability proof of the dual-loop attitude control method is given based on the Lyapunov theorem of stability. Simulation results show that compared with the traditional PID attitude control method, the dual-loop ADRC attitude control method has better control quality in tracking speed, tracking error, and system anti-interference ability. The control parameters to be adjusted in this method have distinct physical significance. So this method has a wide range of engineering application prospects.

A Novel Current Control Strategy for Magnetization State Manipulation of Variable Flux Memory Machine Based on Linear Active Disturbance Rejection

In this article, a novel current control strategy is proposed to manipulate the magnetization state of the variable flux memory machine (VFMM) through a newly developed linear active-disturbance-rejection-based feedforward current controller. A linear extended state observer is designed to estimate the sum of the permanent magnet (PM) induced voltage and the disturbance voltage caused by the susceptible machine parameters to compensate for the linear state error feedback output. The voltage across the winding resistance and the cross-coupling voltage are calculated by the voltage equations and fed forward to the output of the current controller. Meanwhile, the magnetizing current pulse amplitude can be determined by the target PM flux linkage obtained by looking up the table according to the mechanical speed. Since the q -axis disturbance voltage can commonly be ignored during the steady operation, the q -axis observed voltage after low-pass filtering can be directly utilized to estimate the PM flux linkage, which is compared with the target PM flux linkage to determine whether the current manipulation is needed to achieve online remagnetization or demagnetization. Experimental measurements on a hybrid-magnetic-circuit VFMM verify the effectiveness and superiorities of the proposed current control strategy.