scholarly journals Research on Trajectory Planning and Tracking of Hexa-copter

2018 ◽  
Vol 173 ◽  
pp. 02008
Author(s):  
Qiyu Wang ◽  
Huijie Zhang ◽  
Jinrong Han
Keyword(s):  
Trajectory Planning ◽  
Flight Control ◽  
Attitude Control ◽  
Control Method ◽  
Sliding Mode ◽  
Interpolation Method ◽  
Spline Interpolation ◽  
Variable Structure ◽  
Flight Trajectory ◽  
Attitude Stability

In this paper, the flight control problem of hexa-copter is studied in detail from threedimensional trajectory planning to tracking. Then the cubic spline interpolation method is used to generate the trajectory by using these time marked waypoints. The flight trajectory curve produced by this method is smooth, twice differentiable, and it is easy to control implementation. The flight dynamics model of the UAV has the characteristics of multi-input multi-output, strong coupling, under-actuation, severe nonlinearity and external environmental disturbance. In order to improve the accuracy of flight trajectory and the stability of attitude control, a multi-loop sliding mode variable structure control method is proposed to achieve the hexa-copter flight trajectory tracking. The simulation results show that this method can track the predetermined flight trajectory and keep the attitude stability of the UAV normally.

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

Terminal Sliding Mode Control of a Lunar Lander with Electric Propulsion

2014 ◽  
Vol 494-495 ◽  
pp. 1195-1201
Author(s):  
Bo Yang ◽  
Jun Miao ◽  
Yong Yang
Keyword(s):  
Attitude Control ◽  
Electric Propulsion ◽  
Control Method ◽  
Sliding Mode ◽  
Variable Structure ◽  
Control Force ◽  
Terminal Sliding Mode ◽  
Control Precision ◽  
Sliding Mode Variable Structure ◽  
Lunar Lander

This paper presents an attitude control method based on electric propulsion systems for the lunar lander that considers the important characteristics of nonlinearity and uncertainty of lunar soft landing maneuvers with large attitudes. The attitude control law is designed according to the terminal sliding mode variable structure control method. A soft lunar landing utilizing the proposed control method is simulated, and the results show that this attitude control system demonstrates superior global robustness, consumes less propellant, and can achieve higher precision than a conventional chemical propulsion-based control system. For a lunar lander with a pulse plasma thruster as the propulsion system, the attitude control precision of the system is 0.002 degrees when the attitude control force is 0.1 Newtons. When a conventional chemical, not electric, propulsion thruster is used, if the attitude control force decreases by one order of magnitude, then the control precision of the lunar lander decreases 10-fold. This study demonstrates that a terminal sliding mode variable structure control method combined with low level thrust electric propulsion can improve the precision of lunar soft landings.

Aircraft Controller Flight Control System Design

2014 ◽  
Vol 602-605 ◽  
pp. 1291-1294
Author(s):  
Hong Cheng Zhou ◽  
Dao Bao Wang
Keyword(s):  
Control System ◽  
Flight Control ◽  
Control Method ◽  
Sliding Mode ◽  
Variable Structure ◽  
Control Law ◽  
Low Velocity ◽  
Structure Control ◽  
Sliding Mode Variable Structure ◽  
And Control

The servo control methods of motion configuration are researched. Based on analysis for characteristic of the motion configuration, the control strategy and control law used on the motion control system are presented. The controllers are respectively designed by frequency correcting method and normal control method which belongs to classical control theory. Sliding mode variable structure control method is presented for location control law designing, so that the problem of location control loop low velocity creeping is solved, and a simulating experimentation demonstrate the effectiveness of the proposed approach.

scholarly journals Dynamic Sliding Mode Controller with Variable Structure for Fast Satellite Attitude Maneuver

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Gao Shan ◽  
Li You ◽  
Xue Huifeng ◽  
Yao ShuYue
Keyword(s):  
Convergence Rate ◽  
Attitude Control ◽  
Sliding Mode ◽  
Variable Structure ◽  
System Stability ◽  
System State ◽  
Satellite Attitude ◽  
Satellite Attitude Control ◽  
Attitude Maneuver ◽  
Mode Parameter

In order to deal with the low convergence rate of the standard sliding mode in satellite attitude control, a novel variable structure sliding mode is constructed in this paper by designing the update law of the sliding mode parameter. By implementing this method, the advantage such as simple structure and strong robustness of the standard sliding mode are maintained and the system convergence rate is largely improved. The fixed sliding mode parameter is modified, and the update law is designed. When the system state is away from the sliding mode surface, the parameter is fixed, and when the system state approaches the sliding mode surface, the parameter begins to update. The constraint on control torque and angular velocity is taken into consideration, and the constraint on control parameters is given to ensure that the system state do not exceed its upper bound. System stability is proved by the Lyapunov stability theorem, and the superiority of the proposed controller is demonstrated by numerical simulation.

scholarly journals Variable Structure Compensation PID Control of Asymmetrical Hydraulic Cylinder Trajectory Tracking

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Difei Liu ◽  
Zhiyong Tang ◽  
Zhongcai Pei
Keyword(s):  
Trajectory Tracking ◽  
Pid Control ◽  
Control Method ◽  
Sliding Mode ◽  
Variable Structure ◽  
Hydraulic Cylinder ◽  
Control Value ◽  
Equivalent Control ◽  
Asymmetrical Hydraulic Cylinder ◽  
The Stability

A novel variable structure compensation PID control, VSCPID in short, is proposed for trajectory tracking of asymmetrical hydraulic cylinder systems. This new control method improves the system robustness by adding a variable structure compensation term to the conventional PID control. The variable structure term is designed according to sliding mode control method and therefore could compensate the disturbance and uncertainty. Meanwhile, the proposed control method avoids the requirements for exact knowledge of the systems associated with equivalent control value in SMC that means the controller is simple and easy to design. The stability analysis of this approach is conducted with Lyapunov function, and the global stability condition applied to choose control parameters is provided. Simulation results show the VSCPID control can achieve good tracking performances and high robustness compared with the other control methods under the uncertainties and varying load conditions.

scholarly journals A Speed Control Method for Underwater Vehicle under Hydraulic Flexible Traction

2015 ◽  
Vol 2015 ◽  
pp. 1-16
Author(s):  
Yin Zhao ◽  
Ying-kai Xia ◽  
Ying Chen ◽  
Guo-Hua Xu
Keyword(s):  
Control System ◽  
Control Theory ◽  
Control Method ◽  
Sliding Mode ◽  
Variable Structure ◽  
Speed Control ◽  
Underwater Vehicle ◽  
Vehicle Speed ◽  
Sliding Mode Variable Structure ◽  
Traction System

Underwater vehicle speed control methodology method is the focus of research in this study. Driven by a hydraulic flexible traction system, the underwater vehicle advances steadily on underwater guide rails, simulating an underwater environment for the carried device. Considering the influence of steel rope viscoelasticity and the control system traction structure feature, a mathematical model of the underwater vehicle driven by hydraulic flexible traction system is established. A speed control strategy is then proposed based on the sliding mode variable structure of fuzzy reaching law, according to nonlinearity and external variable load of the vehicle speed control system. Sliding mode variable structure control theory for the nonlinear system allows an improved control effect for movements in “sliding mode” when compared with conventional control. The fuzzy control theory is also introduced, weakening output chattering caused by the sliding mode control switchover while producing high output stability. Matlab mathematical simulation and practical test verification indicate the speed control method as effective in obtaining accurate control results, thus inferring strong practical significance for engineering applications.

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.

Robust motion control for multi-split transmission line four-wheel driven mobile operation robot in extreme power environment

2020 ◽  
Vol 47 (2) ◽  
pp. 219-229 ◽  
Author(s):  
Hong Jun Li ◽  
Wei Jiang ◽  
Dehua Zou ◽  
Yu Yan ◽  
An Zhang ◽  
...  
Keyword(s):  
Motion Control ◽  
Trajectory Tracking ◽  
Control Method ◽  
Sliding Mode ◽  
Variable Structure ◽  
Control Model ◽  
Joint Motion ◽  
Content Type ◽  
Structure Control ◽  
Sliding Mode Variable Structure

Purpose In the multi-splitting transmission lines extreme power environment of ultra-high voltage and strong electromagnetic interference, to improve the trajectory tracking and stability control performance of the robot manipulator when conduct electric power operation, and effectively reduce the influence of disturbance factors on the robot motion control, this paper aims to presents a robust trajectory tracking motion control method for power cable robot manipulators based on sliding mode variable structure control theory. Design/methodology/approach Through the layering of aerial-online-ground robot three-dimensional control architecture, the robot joint motion dynamic model has been built, and the motion control model of the N-degrees of freedom robot system has also been obtained. On this basis, the state space expression of joint motion control under disturbance and uncertainty has been also derived, and the manipulator sliding mode variable structure trajectory tracking control model has also been established. The influence of the perturbation control parameters on the robot motion control can be compensated by the back propagation neural network learning, the stability of the controller has been analyzed by using Lyapunov theory. Findings The robot has been tested on a analog line in the lab, the effectiveness of sliding mode variable structure control is verified by trajectory tracking simulation experiments of different typical signals with different methods. The field operation experiment further verifies the engineering practicability of the control method. At the same time, the control method has the remarkable characteristics of sound versatility, strong adaptability and easy expansion. Originality/value Three-dimensional control architecture of underground-online-aerial robots has been proposed for industrial field applications in the ubiquitous power internet of things environment (UPIOT). Starting from the robot joint motion, the dynamic equation of the robot joint motion and the state space expression of the robot control system have been established. Based on this, a robot closed-loop trajectory tracking control system has been designed. A robust trajectory tracking motion control method for robots based on sliding mode variable structure theory has been proposed, and a sliding mode control model for the robot has been constructed. The uncertain parameters in the control model have been compensated by the neural network in real-time, and the sliding mode robust control law of the robot manipulator has been solved and obtained. A suitable Lyapunov function has been selected to prove the stability of the system. This method enhances the expansibility of the robot control system and shortens the development cycle of the controller. The trajectory tracking simulation experiment of the robot manipulator proves that the sliding mode variable structure control can effectively restrain the influence of disturbance and uncertainty on the robot motion stability, and meet the design requirements of the control system with fast response, high tracking accuracy and sound stability. Finally, the engineering practicability and superiority of sliding mode variable structure control have been further verified by field operation experiments.

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.

Sign in / Sign up

Export Citation Format

Share Document