Variable Structure Hybrid Control of Manipulators in Unconstrained and Constrained Motion

1996 ◽  
Vol 118 (2) ◽  
pp. 327-332 ◽  
Author(s):  
Robert R. Y. Zhen ◽  
Andrew A. Goldenberg
Keyword(s):  
Control Method ◽  
Hybrid Control ◽  
Sliding Mode ◽  
Robot Manipulators ◽  
Hierarchical Control ◽  
Variable Structure Control ◽  
Variable Structure ◽  
Control Algorithms ◽  
Constrained Motion ◽  
Structure Control

This paper addresses the problem of robust hybrid position and force control of robot manipulators. Variable structure control with sliding mode is used to implement the hybrid control strategy. Two variable structure control algorithms are developed in task space. One of the algorithms is based on hierarchical control method, and the other is developed for control of robot manipulators used to carried out both unconstrained and constrained tasks.

scholarly journals Experimental study on sliding mode variable structure control of active vibration isolation system of floating raft under multiple excitations

2018 ◽  
Vol 37 (4) ◽  
pp. 1176-1187
Author(s):  
Xianglong Wen ◽  
Kang Yi ◽  
Chunsheng Song ◽  
Jinguang Zhang
Keyword(s):  
Vibration Isolation ◽  
Control Method ◽  
Sliding Mode ◽  
Reference Signal ◽  
Variable Structure Control ◽  
Variable Structure ◽  
Vibration Signal ◽  
Isolation System ◽  
Structure Control ◽  
Sliding Mode Variable Structure

The frequency components of vibration signal in vibration isolation system under multiple excitations are quite complex.Self-adaptive feedforward control method based on Least Mean Square algorithm has strict requirements for reference signal, which results in a certain restriction on its practical application. Sliding mode variable structure control method needs neither complicated reference signal nor accurate mathematical model. It has the strong robustness for external disturbance and system parameter perturbation, and the physical implementation is simple. To this end, application of sliding mode variable structure control method is studied. First, mathematical model of the control channel through system is established for identification. Second, the discrete sliding mode variable structure controller based on state-space model is designed to carry out simulation and experiment. The experimental result indicates that root mean square value of vibration signal after control is decreased by 57.90%, of which the amplitudes of two main frequency components 17 and 25 Hz reduce by 42.66 and 72.71%, respectively. This shows that sliding mode variable structure control is an effective control method for active vibration isolation of floating raft under multiple excitations.

scholarly journals AUTO LOAD-LEVELLING CONTROL OF A LARGE SPRAYER CHASSIS USING THE SLIDING MODE METHOD

2021 ◽  
pp. 65-80
Author(s):  
Chen Yu ◽  
Wu Jun ◽  
Zhang Shuo ◽  
Chen Jun ◽  
Xia Hui ◽  
...  
Keyword(s):  
Working Conditions ◽  
Control Method ◽  
Sliding Mode ◽  
Variable Structure Control ◽  
Good Control ◽  
Variable Structure ◽  
Wheel Load ◽  
Structure Control ◽  
Air Suspension ◽  
Sliding Mode Variable Structure

When a sprayer travels on a ramp or a rough road, the load exerted on each wheel changes. If an unbalanced wheel load is maintained for long periods of time, the wheels may slip, the sprayer’s manoeuvrability is affected, and a rollover accident may occur. In this study, the air suspension of a self-propelled sprayer chassis was investigated, and the potential load imbalance conditions of the sprayer suspension were analysed. A mathematical model of the inflation/deflation of the suspension was established based on air nonlinear thermodynamics and vertical dynamics theory and a ¼-scale vertical dynamics model of the sprayer chassis was developed. A control strategy to balance the sprayer’s wheel load was developed. Considering the nonlinear characteristics of the air suspension, a sliding mode variable structure control method was used to balance the wheel load. Simulation experiments were conducted under different working conditions. The simulation results showed that the sliding mode variable structure control provided good control response and precision. The proposed auto load-levelling controller was tested under different working conditions, including different roll and pitch angles and navigating a rough road; the controller successfully changed the load on each spring to ensure that the sprung mass of the suspension was equal and the wheel load was balanced. The results of this study provide reference information for auto load-levelling control of large sprayers.

Study on the Control of Fuzzy Sliding Mode Variable Structure of Aerospace Vehicle’s Attitude

2014 ◽  
Vol 912-914 ◽  
pp. 1412-1415
Author(s):  
Bin Li
Keyword(s):  
Feedback Linearization ◽  
Control Method ◽  
Sliding Mode ◽  
Adaptive Fuzzy Control ◽  
Fuzzy Variable ◽  
Variable Structure Control ◽  
Variable Structure ◽  
Strongly Coupled ◽  
Structure Control ◽  
Unknown Disturbance

Based on the nonlinear, strongly coupled and uncertain model of the aerocraft vehicles attitude system, a fuzzy variable structure control method is proposed. Based on the feedback-linearization technique, the system was firstly decoupled into three independent SISO subsystems, and then controllers for each subsystem were designed. Modeling error and unknown disturbance is effectively restrained with the proposed adaptive fuzzy control with variable structure control. Theoretical analysis and simulation results show that the proposed method has high control accuracy, high robust and easy realization.

Fractional Variable Structure Control

2011 ◽  
Author(s):  
J. A. Tenreiro Machado
Keyword(s):  
Fractional Order ◽  
Sliding Mode ◽  
Variable Structure Control ◽  
Variable Structure ◽  
Control Algorithms ◽  
System Response ◽  
Test Bed ◽  
Control Effort ◽  
Structure Control ◽  
Order Variable

This paper studies fractional order variable structure control algorithms. For that purpose the fractional order of the sliding mode is varied and its effect upon the system performance is evaluated. The test bed is constituted by a simple mechanical manipulator. Both the system response and the control effort are analysed. The results show that the fractional order provides an extra method for adjusting the closed loop system response.

Sliding Mode Control of a Non-Collocated Flexible System

2003 ◽  
Author(s):  
Aimee M. Frame ◽  
Wayne J. Book
Keyword(s):  
Control Method ◽  
Sliding Mode ◽  
Variable Structure Control ◽  
Variable Structure ◽  
Flexible Beam ◽  
Actual System ◽  
Structure Control ◽  
Control Techniques ◽  
Flexible System ◽  
Position Tracking Control

A new control method is developed for position tracking control of a flexible, non-collocated system. The desired trajectory is specified for the free end of a flexible beam that moves along a horizontal track actuated by a linear motor. First, a system model is reformulated based on a pendulum with stiffness and dampening. Small angle approximations are used so that a linear model can be obtained. Next, variable structure control is chosen as the control method due to its seemingly robust nature. The sliding surface and feedback gains are designed using the developed model based on literature describing various variable structure control techniques. Simulations are then conducted to verify the control method and examine its robustness. Finally, the method is implemented on an actual system using a Kalman filter to estimate the states.

scholarly journals A Novel Sliding Mode Controller for Underactuated Vertical Takeoff and Landing Aircraft

2020 ◽  
Vol 14 ◽  
Keyword(s):  
Flight Control ◽  
Degrees Of Freedom ◽  
Control Method ◽  
Sliding Mode ◽  
Variable Structure Control ◽  
Variable Structure ◽  
Superior Performance ◽  
Sliding Mode Controller ◽  
Structure Control ◽  
Sliding Mode Variable Structure

Compared with other control methods, the biggest advantage of using sliding mode variable structure control method lies in its strong robustness which could be used to directly handle the strong nonlinear flight control system. However, this control method requires switching between different switching surfaces, which will inevitably cause buffeting problems, so that the energy consumption increases. Therefore, how to overcome this disadvantage to achieve the superior performance of sliding mode variable structure control method is the current research focus. This paper studies the trajectory tracking of under-actuated VTOL aircraft with three degrees of freedom and two control inputs under various coupling effects. By the input and coordinate transformation, the dynamic equation of the system is transformed into decoupled standard under-actuated form and the sliding mode controller is designed. Then Lyapunov stability theorem is used to derive sliding mode control law which could ensure that the system asymptotically converges to the given trajectory. The simulation has demonstrated the effectiveness of this method

Control of chaos in vehicle lateral motion using the sliding mode variable structure control

2018 ◽  
Vol 233 (4) ◽  
pp. 776-789 ◽  
Author(s):  
Wuwei Chen ◽  
Rongyun Zhang ◽  
Linfeng Zhao ◽  
Hongbo Wang ◽  
Zhenya Wei
Keyword(s):  
Control Method ◽  
Sliding Mode ◽  
Chaotic Behavior ◽  
Variable Structure Control ◽  
Variable Structure ◽  
Operating Conditions ◽  
Lateral Motion ◽  
Lateral Stability ◽  
Structure Control ◽  
Sliding Mode Variable Structure

A 3-degree of freedom (DOF) nonlinear model including yaw, lateral, and roll motions was constructed, and a numerical simulation of chaotic behavior was performed using the Lyapunov exponent method. The vehicle motion is complex, manifesting double-periodic, quasi-periodic, and chaotic phases, which negatively affects the vehicle lateral stability. To control this chaotic behavior, a controller was designed based on the sliding mode variable structure control (SM-VSC) method. To decrease chattering and further improve lateral stability of the vehicle under extreme operating conditions, the adaptive power reaching law was realized by using a fuzzy control method. The performance of the SM-VSC system was simulated by using Matlab/simulink. The simulation results including the uncontrol, SM-VSC control, and adaptive-reaching SM-VSC control were compared, which demonstrated that the adaptive-reaching SM-VSC control method is more effective in suppressing the chaotic phase of the vehicle lateral motion. The approach proposed in this paper can significantly improve a vehicle’s lateral stability under extreme operating conditions.

Decentralized Variable Structure Control Design in Perturbed Nonlinear Systems

1993 ◽  
Vol 115 (3) ◽  
pp. 551-554 ◽  
Author(s):  
Wen-June Wang ◽  
Jia-Ling Lee
Keyword(s):  
Large Scale ◽  
Sliding Mode ◽  
Design Method ◽  
Hierarchical Control ◽  
Variable Structure Control ◽  
Variable Structure ◽  
Lyapunov Theory ◽  
Pendulum System ◽  
Large Scale Systems ◽  
Structure Control

This paper presents a new robust decentralized variable structure control (DVSC) to stabilize a class of perturbed nonlinear large-scale systems. Only the bounds of perturbations, disturbances and interconnections of the system are needed. Based on Lyapunov theory, the DVSC is designed such that a Lyapunov function converges to a composite switching hyperplane in finite time, at least with an exponential rate. Our design method need not use the dynamic compensation or the integral of interconnections in the sliding mode definition, or the hierarchical control. Furthermore, both the convergence rate and the hitting time can be assigned. Finally, a two-pendulum system is given to illustrate the design method.

Modeling and Variable Structure Control of Autonomous Underwater Vehicles with Moving Mass

2011 ◽  
Vol 130-134 ◽  
pp. 1963-1967 ◽  
Author(s):  
E Zhao ◽  
Bao Wei Song
Keyword(s):  
Control System ◽  
Control Method ◽  
Sliding Mode ◽  
Autonomous Underwater Vehicles ◽  
Tracking Error ◽  
Variable Structure Control ◽  
Variable Structure ◽  
Moving Mass ◽  
Structure Control ◽  
Moving Mass Control

In order to solve the problem of general fins and rudders being lower at low moving speed, the moving mass technical is applied onto AUV, thus to radically solve the weakness of control method with fin and rudder. The space dynamics model of moving mass control is created for AUV. And based on this, the moving mass control system is designed with the sliding mode variable structure control method so as to ensure system tracking error zero convergence. By controlling the moving mass movement with moving mass control system, the attitude of AVU is previously controlled. And simulation result proves that moving mass control system will control the AUV attitude angle precisely and rapidly.

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