Decoupling Control of Three Degrees of Freedom Hybrid Magnetic Bearing Based on LS-SVM

2014 ◽  
Vol 529 ◽  
pp. 534-538
Author(s):  
Yuan Yuan Li ◽  
Huang Qiu Zhu
Keyword(s):  
Degrees Of Freedom ◽  
Control Method ◽  
Hybrid Control ◽  
Original System ◽  
Magnetic Bearing ◽  
Inverse System ◽  
Least Square ◽  
Decoupling Control ◽  
Support Vector ◽  
Three Degrees Of Freedom

In the paper, the decoupling control method based on least square support vector machine (LS-SVM) inverse system is proposed, and adopting the method realizes decoupling control of an AC-DC three degrees of freedom hybrid magnetic bearing (AC-DC-3DOF-HMB). Aimed at the complicated multivariate nonlinear, strong coupling system of the AC-DC-3DOF-HMB, the reversibility of original system was analyzed, by the ability of least square support vector machines (LS-SVM) in universal approximation and identification fitting to get inverse model of AC-DC three degrees of freedom hybrid magnetic bearing. Then according to the basic principle of inverse system method, the inverse system was connected with the original system. So the complex nonlinear multivariable system is decoupled into three independent pseudo-linear system. The simulation results show that the system was decoupled; the hybrid control method has good dynamic and static performance, verify the feasibility of the proposed control method.

scholarly journals A Decoupling Control Method for Shunt Hybrid Active Power Filter Based on Generalized Inverse System

2017 ◽  
Vol 2017 ◽  
pp. 1-6
Author(s):  
Xin Li ◽  
Bo Li
Keyword(s):  
Generalized Inverse ◽  
Control Method ◽  
Active Power Filter ◽  
Original System ◽  
Active Power ◽  
Inverse System ◽  
Decoupling Control ◽  
Power Filter ◽  
Hybrid Active Power Filter ◽  
In Series

In this paper, a novel decoupling control method based on generalized inverse system is presented to solve the problem of SHAPF (Shunt Hybrid Active Power Filter) possessing the characteristics of 2-input-2-output nonlinearity and strong coupling. Based on the analysis of operation principle, the mathematical model of SHAPF is firstly built, which is verified to be invertible using interactor algorithm; then the generalized inverse system of SHAPF is obtained to connect in series with the original system so that the composite system is decoupled under the generalized inverse system theory. The PI additional controller is finally designed to control the decoupled 1-order pseudolinear system to make it possible to adjust the performance of the subsystem. The simulation results demonstrated by MATLAB show that the presented generalized inverse system strategy can realise the dynamic decoupling of SHAPF. And the control system has fine dynamic and static performance.

Dynamic Decoupling Control of Electro-Spindle Supported by AC Hybrid Magnetic Bearings Based on Neural Network Inverse Method

2010 ◽  
Vol 97-101 ◽  
pp. 2716-2719 ◽  
Author(s):  
Wei Yu Zhang ◽  
Huang Qiu Zhu ◽  
Ze Bin Yang
Keyword(s):  
Neural Network ◽  
System Theory ◽  
Control Method ◽  
Coupled System ◽  
Original System ◽  
Rotor System ◽  
Inverse System ◽  
Decoupling Control ◽  
Magnetic Bearings ◽  
Dynamic Decoupling

A dynamic decoupling control method based on neural network inverse system theory is developed for the 5 degrees of freedom (5-DOF) rotor system. The rotor system suspended by AC hybrid magnetic bearings (HMBs) is a multivariable, nonlinear and strong coupled system. Firstly, the configuration of 5-DOF HMBs and the mathematical equations of suspension forces are set up. Secondly, it is demonstrated the system is reversible by analyzing mathematical model. On the basis, the neural network inverse system which is composed of the static neural networks and integrators, and original system are in series to constitute pseudo linear systems. Finally, linear system theory is applied to these linearization subsystems for designing close-loop controllers. The simulation results show that this kind of control strategy can realize dynamic decoupling control, and control system obtains good dynamic and static performances.

An Example of a Special Algorithm Application for Control of Aerial Guided Bomb Flight, during Guidance on the Ground Moving Target

2016 ◽  
Vol 817 ◽  
pp. 93-103
Author(s):  
Konrad Stefański
Keyword(s):  
Degrees Of Freedom ◽  
Phase Plane ◽  
Control Method ◽  
Moving Target ◽  
Control Force ◽  
Switching Algorithm ◽  
Control Forces ◽  
Positive Results ◽  
Three Degrees Of Freedom ◽  
Special Algorithm

This paper presents the analysis of the variety of methods regarding aerial guided bomb control during the ground attack on a moving target. Based on this method there was an earlier research regarding motion control of the three degrees of freedom gyroscope axis [1,2] during space exploration and discovered target tracking. Positive results obtained during that research led to conclusion that the proposed control method will be accurate to establish a control force for aerial bomb guiding. This method is based on the use of phase trajectories control deviations. Switching of the control forces in the particular phase plane points causes the deviations to decrease to zero and facilitates the proper trajectory of the bomb. This paper presents a switching algorithm, equations of kinematics and dynamics of a bomb flight-path and the variety of examples of a numerical simulations. Obtained results were presented in the graphic form.

scholarly journals Recent Developments on Modeling for a 3-DOF Micro-Hand Based on AI Methods

Micromachines ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 792
Author(s):  
Shuhei Kawamura ◽  
Mingcong Deng
Keyword(s):  
Artificial Intelligence ◽  
Degrees Of Freedom ◽  
Air Pressure ◽  
Support Vector ◽  
Input Output ◽  
Soft Actuator ◽  
Flexible Materials ◽  
Recent Developments ◽  
Soft Actuators ◽  
Three Degrees Of Freedom

Recently, soft actuators have been expected to have many applications in various fields. Most of the actuators are composed of flexible materials and driven by air pressure. The 3-DOF micro-hand, which is a kind of soft actuator, can realize a three degrees of freedom motion by changing the applied air pressure pattern. However, the input–output relation is nonlinear and complicated. In previous research, a model of the micro-hand was proposed, but an error between the model and the experimental results was large. In this paper, modeling for the micro-hand is proposed by using multi-output support vector regression (MSVR) and ant colony optimization (ACO), which is one of the artificial intelligence (AI) methods. MSVR estimates the input–output relation of the micro-hand. ACO optimizes the parameters of the MSVR model.

Integrating a Grasp Exoskeleton Into a String-Based Interface for Human-Scale Interactions

2008 ◽  
Vol 8 (4) ◽  
Author(s):  
Rasul Fesharakifard ◽  
Maryam Khalili ◽  
Laure Leroy ◽  
Alexis Paljic ◽  
Philippe Fuchs
Keyword(s):  
Virtual Environments ◽  
Degrees Of Freedom ◽  
Force Feedback ◽  
Control Method ◽  
Hybrid Control ◽  
Force Sensor ◽  
Virtual Objects ◽  
Rotary Encoder ◽  
Human Scale ◽  
Novel Design

A grasp exoskeleton actuated by a string-based platform is proposed to provide the force feedback for a user’s hand in human-scale virtual environments. The user of this interface accedes to seven active degrees of freedom in interaction with virtual objects, which comprises three degrees of translation, three degrees of rotation, and one degree of grasping. The exoskeleton has a light and ergonomic structure and provides the grasp gesture for five fingers. The actuation of the exoskeleton is performed by eight strings that are the parallel arms of the platform. Each string is connected to a block of motor, rotary encoder, and force sensor with a novel design to create the necessary force and precision for the interface. A hybrid control method based on the string’s tension measured by the force sensor is developed to resolve the ordinary problems of string-based interface. The blocks could be moved on a cubic frame around the virtual environment. Finally the results of preliminary experimentation of interface are presented to show its practical characteristics. Also the interface is mounted on an automotive model to demonstrate its industrial adaptability.

scholarly journals Efficient adaptive constrained control with time-varying predefined performance for a hypersonic flight vehicle

2017 ◽  
Vol 14 (2) ◽  
pp. 172988141668750 ◽  
Author(s):  
Caisheng Wei ◽  
Jianjun Luo ◽  
Honghua Dai ◽  
Jianping Yuan ◽  
Jianfeng Xie
Keyword(s):  
Control Method ◽  
Low Complexity ◽  
Least Square ◽  
Design Parameters ◽  
Support Vector ◽  
Time Varying ◽  
Flight Vehicle ◽  
Performance Function ◽  
Hypersonic Flight Vehicle ◽  
Hypersonic Flight

A novel low-complexity adaptive control method, capable of guaranteeing the transient and steady-state tracking performance in the presence of unknown nonlinearities and actuator saturation, is investigated for the longitudinal dynamics of a generic hypersonic flight vehicle. In order to attenuate the negative effects of classical predefined performance function for unknown initial tracking errors, a modified predefined performance function with time-varying design parameters is presented. Under the newly developed predefined performance function, two novel adaptive controllers with low-complexity computation are proposed for velocity and altitude subsystems of the hypersonic flight vehicle, respectively. Wherein, different from neural network-based approximation, a least square support vector machine with only two design parameters is utilized to approximate the unknown hypersonic dynamics. And the relevant ideal weights are obtained by solving a linear system without resorting to specialized optimization algorithms. Based on the approximation by least square support vector machine, only two adaptive scalars are required to be updated online in the parameter projection method. Besides, a new finite-time-convergent differentiator, with a quite simple structure, is proposed to estimate the unknown generated state variables in the newly established normal output-feedback formulation of altitude subsystem. Moreover, it is also employed to obtain accurate estimations for the derivatives of virtual controllers in a recursive design. This avoids the inherent drawback of backstepping — “explosion of terms” and makes the proposed control method achievable for the hypersonic flight vehicle. Further, the compensation design is employed when the saturations of the actuator occur. Finally, the numerical simulations validate the efficiency of the proposed finite-time-convergent differentiator and control method.

POSE ESTIMATION IN AUTOMATED VISUAL INSPECTION USING GENETIC ALGORITHM

2006 ◽  
Vol 16 (04) ◽  
pp. 255-269
Author(s):  
S. HATI ◽  
K. CHAUDHURY ◽  
A. IBRAHIM
Keyword(s):  
Genetic Algorithm ◽  
Degrees Of Freedom ◽  
Visual Inspection ◽  
Maximum Error ◽  
Least Square ◽  
Automated Visual Inspection ◽  
Object Space ◽  
Rotational Error ◽  
Gradient Based ◽  
Three Degrees Of Freedom

In this paper, we propose a genetic algorithm based approach to determine the pose of an object in Automated Visual Inspection having three degrees of freedom. We have investigated the effect of noise at 20 dB SNR and also mismatch resulting from incorrect correspondences between the object space points and the image space points, on the estimation of pose parameters. The maximum error in translation parameters is less than 0.45 cm and rotational error is less than 0.2 degree at 20 dB SNR. The error in parameter estimation is insignificant upto 7 pairs of mismatched points out of 24 points in object space and the results skyrockets when 8 or more pairs of points are mismatched. We have compared our result with that obtained by least square technique and it shows that GA based method outperform the gradient based technique when the number of vertices of the object to be inspected is small. These results have clearly established the robustness of GA in estimating the pose of an object with small number of vertices in automated visual inspection.

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