Nonlinear Cutterhead Pose Control of Large-Diameter Slurry Shields in Complicated Stratum

2021 ◽  
Author(s):  
Hangjun Zhang ◽  
Jianhua Wei ◽  
Jinhui Fang ◽  
Yuzhu Yang

Abstract To replace cutterhead worn tools conveniently or get rid of shield’s jamming effectively in complicated stratum, a new nonlinear cutterhead pose control system of large-diameter slurry shields is especially designed. High precision cutterhead pose control of large-diameter slurry shields is hardly achieved due to the uncertain load force and mass. A nonlinear controller constructed by adaptive robust control based on sliding mode is designed for this parallel mechanism, which includes a special adaptation law to compensate for the uncertainties. The stability of the whole closed loop system is verified based on Lyapunov theory. And the validity of the proposed strategy is proved by Simulink and AMESim co-simulation. The simulation results show that not only in control accuracy but also in parameter uncertainty, the designed nonlinear cutterhead pose control is effective.

Author(s):  
Nasim Ullah ◽  
Irfan Sami ◽  
Wang Shaoping ◽  
Hamid Mukhtar ◽  
Xingjian Wang ◽  
...  

This article proposes a computationally efficient adaptive robust control scheme for a quad-rotor with cable-suspended payloads. Motion of payload introduces unknown disturbances that affect the performance of the quad-rotor controlled with conventional schemes, thus novel adaptive robust controllers with both integer- and fractional-order dynamics are proposed for the trajectory tracking of quad-rotor with cable-suspended payload. The disturbances acting on quad-rotor due to the payload motion are estimated by utilizing adaptive laws derived from integer- and fractional-order Lyapunov functions. The stability of the proposed control systems is guaranteed using integer- and fractional-order Lyapunov theorems. Overall, three variants of the control schemes, namely adaptive fractional-order sliding mode (AFSMC), adaptive sliding mode (ASMC), and classical Sliding mode controllers (SMC)s) are tested using processor in the loop experiments, and based on the two performance indicators, namely robustness and computational resource utilization, the best control scheme is evaluated. From the results presented, it is verified that ASMC scheme exhibits comparable robustness as of SMC and AFSMC, while it utilizes less sources as compared to AFSMC.


Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-23
Author(s):  
Haiqiang Zhang ◽  
Hairong Fang ◽  
Qi Zou ◽  
Dan Zhang

Control of parallel manipulators is very hard due to their complex dynamic formulations. If part of the complexity is resulting from uncertainties, an effective manner for coping with these problems is adaptive robust control. In this paper, we proposed three types of adaptive robust synchronous controllers to solve the trajectory tracking problem for a redundantly actuated parallel manipulator. The inverse kinematic of the parallel manipulator was firstly developed, and the dynamic formulation was further derived by mean of the principle of virtual work. Furthermore, linear parameterization regression matrix was determined by virtue of command function “equationsToMatrix” in MATLAB. Secondly, the three adaptive robust synchronous controllers (i.e., sliding mode control, high gain control, and high frequency control) are developed, by incorporating the camera sensor technique into adaptive robust synchronous control architecture. The stability of the proposed controllers was proved by utilizing Lyapunov theory. A sequence of simulation tests were implemented to prove the performance of the controllers presented in this paper. The three proposed controllers can theoretically guarantee the errors including trajectory tracking errors, synchronization errors, and cross-coupling errors asymptotically converge to zero for a given trajectory, and the estimated unknown parameters can also approximately converge to their actual values in the presence of unmodeled dynamics and external uncertainties. Moreover, all the simulation comparative results were presented to illustrate that the adaptive robust synchronous high-frequency controller possess a much superior comprehensive performance than two other controllers.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Yassine El Houm ◽  
Ahmed Abbou ◽  
Moussa Labbadi ◽  
Mohamed Cherkaoui

This paper deals with the design of a novel modified supertwisting fast nonlinear sliding mode controller (MSTFNSMC) to stabilize a quadrotor system under time-varying disturbances. The suggested control strategy is based on a modified supertwisting controller with a fast nonlinear sliding surface to improve the tracking performance. The paper suggests a simple optimization tool built-in MATLAB/Simulink to tune the proposed controller parameters. Fast convergence of state variables is established by using a nonlinear sliding surface for rotational and translational subsystems. The modified supertwisting controller is developed to suppress the effect of chattering, reject disturbances, and ensure robustness against external disturbance effect. The stability of the proposed controller (MSTFNSMC) is proved using the Lyapunov theory. The performance of the proposed MSTFNSMC approach is compared with the supertwisting sliding mode controller (STSMC) by numerical simulations to verify its effectiveness.


Author(s):  
Duc-Minh Nguyen ◽  
Van-Tiem Nguyen ◽  
Trong-Thang Nguyen

This article presents the sliding control method combined with the selfadjusting neural network to compensate for noise to improve the control system's quality for the two-wheel self-balancing robot. Firstly, the dynamic equations of the two-wheel self-balancing robot built by Euler–Lagrange is the basis for offering control laws with a neural network of noise compensation. After disturbance-compensating, the sliding mode controller is applied to control quickly the two-wheel self-balancing robot reached the desired position. The stability of the proposed system is proved based on the Lyapunov theory. Finally, the simulation results will confirm the effectiveness and correctness of the control method suggested by the authors.


2011 ◽  
Vol 14 (4) ◽  
pp. 92-105
Author(s):  
Hai Thanh Nguyen ◽  
Nghia Hoai Duong ◽  
Chuyen Quang Lam

The adaptive sliding mode control for civil structures using Magnetorheological (MR) dampers is proposed for reducing the vibration of the building in this paper. Firstly, the indirect sliding mode control of the structures using these MR dampers is designed. Therefore, in order to solve the nonlinear problem generated by the indirect control, an adaptive law for sliding mode control (SMC) is applied to take into account the controller robustness. Secondly, the adaptive SMC is calculated for the stability of the system based on the Lyapunov theory. Finally, simulation results are shown to demonstrate the effectiveness of the proposed controller.


2019 ◽  
Vol 41 (12) ◽  
pp. 3309-3320 ◽  
Author(s):  
Jianguo Guo ◽  
Yifei Li ◽  
Jun Zhou

A novel observer-based continuous adaptive sliding mode guidance (OCASMG) is proposed for homing missiles. First, a new sliding mode guidance law is derived from the nonlinear dynamics describing the pursuit situation of a missile and a target in the two-dimensional space, where a continuous adaptive function is introduced to overcome the chattering problem in sliding mode. Second, to improve the accuracy of target interception, a new nonlinear extended state observer (NESO) is presented to estimate target acceleration and compensate for the sliding mode guidance law. The stability of observer-based closed-loop system is proved by Lyapunov theory. Finally, simulations are conducted on the nonlinear longitudinal missile model and results demonstrate the effectiveness of proposed method.


2018 ◽  
Vol 15 (6) ◽  
pp. 172988141881151
Author(s):  
Zhang Wenhui ◽  
Li Hongsheng ◽  
Ye Xiaoping ◽  
Huang Jiacai ◽  
Huo Mingying

It is difficult to obtain a precise mathematical model of free-floating space robot for the uncertain factors, such as current measurement technology and external disturbance. Hence, a suitable solution would be an adaptive robust control method based on neural network is proposed for free-floating space robot. The dynamic model of free-floating space robot is established; a computed torque controller based on exact model is designed, and the controller can guarantee the stability of the system. However, in practice, the mathematical model of the system cannot be accurately obtained. Therefore, a neural network controller is proposed to approximate the unknown model in the system, so that the controller avoids dependence on mathematical models. The adaptive learning laws of weights are designed to realize online real-time adjustment. The adaptive robust controller is designed to suppress the external disturbance and compensate the approximation error and improve the robustness and control precision of the system. The stability of closed-loop system is proved based on Lyapunov theory. Simulations tests verify the effectiveness of the proposed control method and are of great significance to free-floating space robot.


Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3427 ◽  
Author(s):  
Jiucai Jin ◽  
Jie Zhang ◽  
Deqing Liu

Unmanned Surface Vehicle (USV) is a novel multifunctional platform for ocean observation, and its heading and velocity control are essential and important for autonomous operation. A coupled heading and velocity controller is designed using backstepping technology for an USV called ‘USBV’ (Unmanned Surface Bathymetry Vehicle). The USBV is an underactuated catamaran, where the heading and velocity are controlled together by two thrusters at the stern. The three degrees-of-freedom equations are used for USBV’s modeling, which is identified using experiment data. The identified model, with two inputs, induces heading and velocity tracking, which are coupled. Based on the model, a nonlinear controller for heading and velocity are acquired using backstepping technology. The stability of the controller is proved by Lyapunov theory under some assumptions. The verification is presented by lake and sea experiments.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Bao Shi ◽  
Jian Yuan ◽  
Chao Dong

This paper extends the conventional Model Reference Adaptive Control systems to fractional ones based on the theory of fractional calculus. A control law and an incommensurate fractional adaptation law are designed for the fractional plant and the fractional reference model. The stability and tracking convergence are analyzed using the frequency distributed fractional integrator model and Lyapunov theory. Moreover, numerical simulations of both linear and nonlinear systems are performed to exhibit the viability and effectiveness of the proposed methodology.


Author(s):  
Walid Alqaisi ◽  
Yassine Kali ◽  
Jawhar Ghommam ◽  
Maarouf Saad ◽  
Vahé Nerguizian

This paper proposes an improved non-singular terminal super-twisting control for the problem of position and attitude tracking of quadrotor systems suffering from uncertainties and disturbances. The super-twisting algorithm is a second-order sliding mode known to be a very effective control used to provide high precision and less chattering for uncertain nonlinear electromechanical systems. The proposed method is based on a non-singular terminal sliding surface with new exponent that solves the problem of singularity. The design procedure and the stability analysis of the closed-loop system using Lyapunov theory are detailed for the considered system. Finally, the proposed control scheme is tested in simulations and by experiments on the parrot-rolling spider quadrotor. Moreover, a comparison is made with the standard super-twisting algorithm in the simulation part. The results obtained show adequate performance in trajectory tracking and chattering reduction.


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