Dynamic Modeling and Sliding Mode Control of a 2-DOF Spherical Parallel Mechanism With a Passive Branch

2014 ◽  
Author(s):  
Bin Chen ◽  
Jingjun Yu ◽  
Guanghua Zong ◽  
Jing Kuang
Keyword(s):  
Sliding Mode Control ◽  
Tracking Control ◽  
Parallel Mechanism ◽  
High Speed ◽  
Controller Design ◽  
Sliding Mode ◽  
Lyapunov Theory ◽  
Control Approach ◽  
Mode Control ◽  
Spherical Parallel Mechanism

This paper presents a dynamic analysis and a sliding mode control approach for high speed tracking control of a 2-DOF spherical parallel mechanism with a redundant branch. The kinematics of this mechanism is briefly introduced, two of three branches are actuated and the rest one is a passive branch. The dynamic model is built based on Lagrange method and simplified to develop a real-time controller. The control scheme is designed given that only the angle and angular velocity of actuators are measureable. First a Quasi-sliding mode control algorithm is proposed to compensate the parameter perturbation and reduce the chattering phenomenon, and then the trending law is introduced to decrease the regulation time of tracking control. Lyapunov theory is performed to guarantee that the controller design is stable. Finally, experiment based on a prototype of SPM is carried out to verify the effectiveness of the proposed method.

scholarly journals Fractional-Order Sliding Mode Control of Overhead Cranes   

2020 ◽  
Vol 31 (1) ◽  
pp. 68-76
Keyword(s):  
Sliding Mode Control ◽  
Fractional Order ◽  
Closed Loop ◽  
Control Structure ◽  
Adaptive System ◽  
Sliding Mode ◽  
Lyapunov Theory ◽  
Closed Loop System ◽  
Control Approach ◽  
Mode Control

We constitute a control system for overhead crane with simultaneous motion of trolley and payload hoist to destinations and suppression of payload swing. Controller core made by sliding mode control (SMC) assures the robustness. This control structure is inflexible since using fixed gains. For overcoming this weakness, we integrate variable fractional-order derivative into SMC that leads to an adaptive system with adjustable parameters. We use Mittag–Leffler stability, an enhanced version of Lyapunov theory, to analyze the convergence of closed-loop system. Applying the controller to a practical crane shows the efficiency of proposed control approach. The controller works well and keeps the output responses consistent despite the large variation of crane parameters.

scholarly journals Synchronization of Lorenz System Based on Fast Stabilization Sliding Mode Control

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Xu Guowei ◽  
Wan Zhenkai ◽  
Li Chunqing
Keyword(s):  
Sliding Mode Control ◽  
Finite Time ◽  
Lorenz System ◽  
Sliding Mode ◽  
External Perturbation ◽  
Lyapunov Theory ◽  
Continuous Control ◽  
Integral Sliding Mode ◽  
Control Approach ◽  
Mode Control

A sliding mode control approach is achieved for Lorenz system based on optimal finite time convergent and integral sliding mode surface. The system perturbation is divided into two parts: the unmatched and the matched parts. Firstly, we design a discontinuous control for the unmatched part which will not be amplified. Secondly, we design a continuous control, that is, the ideal control to stabilize the Lorenz system error states in finite time stabilization. Then the controller based on integral sliding mode is constructed to ensure the robustness. The proposed method is proven to guarantee the stability and the robustness using the Lyapunov theory in the system uncertainties and external perturbation. Finally, the numerical simulations demonstrate that the proposed controller is effective and robust with respect to the perturbation.

Sliding Mode Variable Structure Control of Active Magnetic Bearings Using Boundary Layer Approach

2011 ◽  
Vol 411 ◽  
pp. 213-217
Author(s):  
Yan Li Yang ◽  
Zhen Xing Zhang
Keyword(s):  
Boundary Layer ◽  
Sliding Mode Control ◽  
Controller Design ◽  
Sliding Mode ◽  
Variable Structure ◽  
Magnetic Bearing ◽  
Lyapunov Theory ◽  
Active Magnetic Bearing ◽  
Mode Control ◽  
Finite Gain

To solve the chattering problem caused by the general sliding mode control in the active magnetic bearing control, a boundary layer approach is used in the controller design in this paper. The dynamic model of the active magnetic bearing is built firstly, and then a saturation function is employed to substitute for the sign function in the controller based on the Lyapunov theory to approximately realize infinite gain with finite gain. Finally, the performance of the controller is simulated, and compared with the general sliding mode control. The results show that the disadvantage of chattering can be effectively reduced by using the boundary layer approach, the rotor-s quick adjusting and steady levitation are achieved, and the controller has high tracking precision and good robustness.

Robust integral sliding mode control of tower cranes

2020 ◽  
pp. 107754632093818
Author(s):  
Lobna T Aboserre ◽  
Ayman A El-Badawy
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
Lyapunov Theory ◽  
Control Effort ◽  
Nonlinear Dynamical ◽  
Integral Sliding Mode Control ◽  
Integral Sliding Mode ◽  
Control Approach ◽  
Mode Control ◽  
Error Dynamics

In this study, integral sliding mode control is proposed for tower cranes to ensure precise tracking of the desired position while reducing the oscillations of the payload. The nonlinear robust controller is designed based on high fidelity nonlinear dynamical model, unlike the decoupled or linearized models used in the literature. The advantage of this approach is reducing the model uncertainties resulting in a lower control effort demand that would be required by the sliding mode controller. Moreover, the stability of the under-actuated tower crane system is analyzed using Lyapunov theory to guarantee the practical stability of error dynamics. Experimental results of the proposed control approach are compared with conventional sliding mode control to show its effectiveness and robustness against real system uncertainties.

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