Course and Depth Control for a Biomimetic Underwater Vehicle - RobCutt-I

This paper introduces tracking control method for robot manipulator based on Active Disturbance Rejection Control technique (ADRC). The main purpose of the ADRC technique is to obtain a proper estimation, cancel the total disturbance along with the assurance of a good trajectory tracking. First, the equations of motion of the robot manipulator is rearranged to be suitable for the ADRC technique. Then, an extended model is derived from the dynamic model. This extended model has an extra state includes the total disturbances, which are estimated online through the extended state observer (ESO). Finally, this estimated disturbance is compensated through a simple PD feedback controller. This control strategy is tested on two-DOF serial link manipulator and compared by a simple PID controller. Simulation results show the advantage of the ADRC system over the PID controller.

In the practical application process of active disturbance rejection control technique, it is difficult for parameter tuning with too many parameters, different control objects and the direction and size of tuning range unknown. In this paper, through the actual simulation and analysis, some rules on parameter tuning of active disturbance rejection control (ADRC) will be given, which has a greater significance for the practical application of ADRC.

Active disturbance rejection control (ADRC) technique was applied for attitude and trajectory control of the flying-wing unmanned aerial vehicle (UAV). Considering the characteristic of static instability in longitudinal and directional, a nonlinear ADRC controller was designed for the flying-wing UAV. After tuning the parameters, altitude command with step change, and gust disturbance were given when it was in simulation at the state of a straight and level path flight. The results showed the steady-state error of altitude reduced by 0.0235m, and the setting time of altitude reduced by 8.2s. To some extent, it is because this controller can estimate and compensate for the disturbance. Comparing with proportion-integration and differentiation (PID) controller, the ADRC controller we designed can solve the problem of oscillations, and the oscillations are often generated by step change of state variable or input command. Relevant results indicate that ADRC controller can not only meet the control accuracy requirement, but also satisfy the requirement of the rapid response, robustness and insensitivity to perturbations.

Aiming at the tip trajectory tracking against system parameter uncertainty and disturbance during the painting process of the spray painting manipulator, a sliding model active disturbance rejection trajectory tracking controller is designed integrating terminal sliding mode control (SMC) approach and active disturbance rejection control (ADRC) technique. The reference curve trajectory of the tip position/velocity is planned by the kinematics equation. in which the compensation is taken into account for the deflection of the manipulator. The extended state observer (ESO) is used to estimate the total disturbance consisting of the uncertain system parameters and the uncertain interference resulting from deflection and load. Utilizing non-singular terminal sliding mode control, a feedback control law is designed to achieve fast and accurate trajectory tracking. Simultaneously, according to the actual system parameters in the engineering, the simulation validation is given to show that the proposed control strategy can guarantee good tracking performance of the closed-loop system.

PurposeThe purpose of this paper is to enhance the quadrotor’s capability of short-distance delivery to satisfy the large demand for quadrotor, which is used for goods distribution in huge warehouses, under time-varying payload and external wind disturbance.Design/methodology/approachA trajectory tracking controller design based on the combination of an adaptive sliding mode control (ASMC) method and the active disturbance rejection control (ADRC) technique is proposed. Besides, an inner–outer loop control system structure is adopted.FindingsSimulation results of different trajectory tracking verify the effectiveness and robustness of the proposed tracking control method under various conditions, including parameter uncertainty and external wind disturbance. The proposed control strategy ensures that quadrotor UAV is capable of tracking linear and spiral trajectory well whether it loads or unloads goods in the presence of the external wind disturbance.Originality/valueThe proposed method of designing a trajectory tracking controller is based on an integral ADRC and ASMC scheme so as to deal with the trajectory tracking problem for a quadrotor with payload variation.

This paper deals with the stabilization problem of an axially moving string with a tip mass attached at the free end and subject to an external disturbance. The disturbance here is not uniformly bounded, and it is assumed to be exponentially increasing. First, the tip mass equation is designed under a boundary controller. By using this equation, the active disturbance rejection control (ADRC) technique is applied to design a disturbance observer, and it is shown that the observer can be estimated exponentially. Then, the closed‐loop system is formulated and the well‐posedness of the model is proved in the framework of the semigroup theory. The stability of the closed‐loop system is then proved by means of the multiplier technique, where the energy system converges to equilibrium with an exponential manner. The efficiency of the obtained results is verified through numerical simulations.

A novel attitude control strategy based on active disturbance rejection control (ADRC) and input shaping technique was proposed for a flexible spacecraft without angular velocity sensors. Aiming at achieving high rapidity and high pointing accuracy, we focus on the suppression of vibration of flexible appendages when the spacecraft's attitude maneuvers a large angle. In the proposed scheme, a transient process which combines path planning for attitude maneuver with input shaping is designed to reduce vibration of flexible appendages. Furthermore, an extended state observer (ESO) for the flexible spacecraft is designed to estimate the immeasurable attitude angular velocity and the disturbances, which include parameter uncertainties and external disturbances. Also a nonlinear attitude feedback control law is designed to track the desired attitude and compensate the disturbances in real time way. Simulation results demonstrate the effectiveness and robustness of the proposed control strategy.

An attitude decoupling controller based on linear active disturbance rejection control (LADRC) is designed for small quadrotor aircraft, considering the problems existing in the controller based on active disturbance rejection control (ADRC), such as complicated design and parameters tuning difficulties in project implementation. First, the nonlinear and couple model of small quadrotor aircraft were established, and the LADRC was introduced, which described the principles of the ability of decoupling rejection control for multiple-input and multiple-output (MIMO) system and tuning method, then the model was decoupled. After that, the attitude controller based on second-order LADRC is designed and parameters is turned according to the desired settling time. F. Finally, the simulation test of the design was carried out. The simulation results indicate that the designed controller has strong robustness and anti-disturbance performance, and does not have accurate models. Moreover, there is only one parameter needs tuning in this controller, which makes the design easy to be realized and shows great engineering value.

Based on active disturbance rejection control technique and characteristics of electric power steering, a steering angle tracking controller is designed, which consists of an aligning moment estimator to deal with modeling error and nonlinearity of electric power steering. The aligning moment estimator is based on an extended state observer and takes steering system friction and differential drive steering torque, which is a unique phenomenon in a distributed drive electric vehicle, into consideration. According to the estimated aligning moment and tracking differentiator, the steering angle tracking controller is designed based on a nonlinear state feedback control and feedforward compensation control laws. Results of various simulations and experiments, including pivot steering, step input steering, and sinusoidal input steering, show that the proposed controller has good performance in tracking reference steering angle and is convenient to implement. With the aligning moment estimator, the proposed controller shows better results in comparative experiments than a conditional integral-based steering angle tracking controller.

With large-scale integration of wind power in power systems, the impact of wind generation on power system stability has become an important issue. In this paper, a new power oscillation damping controller based on active disturbance rejection control technique for DFIG-based wind turbine generators is presented. The proposed power oscillation damping controller utilizes the grid frequency at the point of common coupling to generate the active power modulation, so as to damp power system oscillations. The kinetic energy of the rotating masses of wind turbine generators is utilized to provide the required damping active power. Case study on a two-area system verifies the effectiveness of the proposed power oscillation damping controller.

The intelligent motion control technology of Autonomous Underwater Vehicle (AUV) is the basis of long-distance voyage for AUV. The motion control capability in vertical plane is an important technical for AUV to complete multifarious missions. So, it is important and realistic significance to research on motion control in vertical plane of AUV. Motion control problem of AUV in vertical plane, especially depth control problems is researched based on active disturbance rejection control (ADRC) method in this paper. The kinetic and dynamic model in vertical plane of AUV is established and simplified. The active disturbance rejection controller design method is introduced. Detailed algorithms of each part for active disturbance rejection controller are discussed according to separability principle of ADRC. Based on ADRC, the depth controller is designed and applied in AUV. At last, simulation results indicate that the method is feasibility and effectiveness for AUV depth control.

The performance of a higher-order power system deteriorates due to the sudden load variations, structural discrepancy, and uncertainties involved in the parameters. Thus, an effective control technique must be employed to resolve the load frequency control (LFC) related issues in such systems. For the performance analysis of a higher-order system, a reduced-order controller is used for its reduced-order model because the full-order controller meets some structural and computational complexities. This paper proposes a reduced order linear active disturbance rejection control (RDLADRC) technique to deal with the LFC issues in a single-area power system. This technique successfully combines the benefits of the model order reduction (MOR) scheme and LADRC. Merits of the proposed approach are highlighted based on a deep comparative analysis of the reduced-order LADRC (RDLADRC) technique with full-order linear active disturbance rejection control (LADRC) and pre-existing two degree of freedom-internal model control (TDF-IMC) technique. The robustness of the proposed controller is investigated via system responses under parametric variations. MATLAB and simulation results confirm the effectiveness of the proposed scheme.

Aiming at the problem that the suspension force under disturbance of the permanent magnet slice rotor is difficult to be accurately detected, a new displacement controller based on the active disturbance rejection control is proposed. Firstly, the mathematic models of torque and suspension forces of the bearingless permanent magnet slice motor (BPMSM) are deduced. Secondly, the active disturbance rejection (ADR) controller is constructed. Thirdly, the BPMSM direct control system based on the ADR controller is built and the simulation is carried out, the correctness of the mathematic model and the control algorithm are verified. Finally, the displacement controller is used for a 4 kW prototype. Compared with the traditional PI controller, the floating stability time and the disturbed recovery time of the slice rotor are both decreased, the vibration displacement of rotor in stable state is reduced by 44%.

Integrated electro-mechanical actuators (EMAs) are widely used in cooperative robots. Their control system has to be carefully designed to achieve a desirable performance. The proportional-integral (PI) control and the active disturbance rejection control (ADRC) are the two commonly used controllers. Compared with the PI, the ADRC shows better performance in terms of disturbance rejection, response speed and overshooting suppression. However, the ADRC utilises numerous parameters and the optimisation of these parameters is a challenge. In this study, the influence of the parameters of β 01 , β 02 , β 03 , β 1 , β 2 on the ADRC performance is deeply analysed. Considering the two non-linear factors of permanent magnet synchronous motor and harmonic transmission in the EMA, a simulation model of the EMA was established. An improved swarm optimisation algorithm was employed to optimise the parameters of the ADRC. A second-order ADRC in speed and position modes was designed. The parameters of the ADRC in these modes were adjusted using improved particle swarm optimisation. ADRC was applied to the EMA field-oriented control system instead of cascade PI, and the simulation and experimental results were compared using the cascade PI control method. When the target speed is to 15 rpm, the speed fluctuation range of the ADRC is about ±0.3 rpm, which is smaller than that of the PI controller’s ±0.5 rpm. Compared with the cascade PI control, ADRC affords a faster response speed, greater robustness and stronger disturbance resistance in the steady-state operation process.

This study discusses the control of parallel fractional order systems (FOSs) by the fractional-order active disturbance rejection control (FOADRC) technique. The FOADRC framework for linear FOSs and the necessary conditions for the existence of a stable controller of the system are given. The fractional-order tracking differentiator (FOTD) and the fractional-order extended state observer (FOESO) are introduced. Then, the FOADRC scheme for parallel FOSs is proposed. The effectiveness of the proposed scheme in this study paper is verified by a simulation example.