The Internal Model Control of Greenhouse System Based on LS_SVM

2014 ◽  
Vol 532 ◽  
pp. 200-203 ◽  
Author(s):  
Qing Ling Dai

The greenhouse environment has the characteristics of nonlinear, time-varying, large time delay, so it is difficult to obtain satisfactory result using conventional control method. The internal model control system method and the algorithm based on LS_SVM is proposed for the problem. The simulation experiment was performed on the greenhouse environment control system. Results shows that the controlled object internal mode and inverse model have very high precision and generalization ability and the control system has not only good control performance but also strong anti-interference ability and robust performance which has the great value to application and extension

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Han Yu ◽  
Hamid Reza Karimi ◽  
Xuemei Zhu

Based on analyzing principle about the smart car’s speed control system, the system mathematical model is built. Considering the control optimization, a novel control scheme is proposed based on internal model control, and the internal model controller of speed control system is established. Regarding this subject, the internal control theory is introduced to verify the control performance; the traditional PID control method is employed in the experiment. The experiment indicates that the proposed method based on internal model control is easier to determine parameter and has a well robust and good control result of smart car’s speed.


2014 ◽  
Vol 1037 ◽  
pp. 258-263
Author(s):  
Zheng Qi Wang ◽  
Xue Liang Huang

The bearingless induction motor is a nonlinear, multi-variable and strongly coupling system. In this paper, a new nonlinear internal model control (IMC) strategy based on inverse system theory is proposed to realize the decoupling control for the bearingless induction motor. The mathematical model of the motor is built and then the inverse system method is applied to decouple the original nonlinear system. Finally the internal model control method is introduced to ensure the robustness of the closed-loop system. The effectiveness of the proposed strategy are demonstrated by simulation.


2011 ◽  
Vol 311-313 ◽  
pp. 2230-2234
Author(s):  
Gui Li Yuan

The controlled object of boiler combustion system in power plant is a complex system with nonlinear, timing change, large lagging and multi-variable coupling, and does not have precise mathematical model, so it is difficult to obtain the satisfactory control effect adopting the traditional PID control. Advanced control strategies are adopted to improve the performance of the boiler combustion control system, and it has been more and more the concern of the majority of electricity production enterprises. Internal model control is a very practical control method, and its main characteristic is simple structure, intuitive design and few online adjustment parameter, and easy adjustment policy. And it is especially particularly significant to improve the control effect of large delay system. The internal model control system is used in power station boiler combustion system, it can effectively solve the large delay, large inertia and other shortcomings, but there is the contradiction between the fast response and robustness in internal model control system. The fuzzy immune control has advantages, such as, fast response, fast stable and good robust, etc. The fuzzy immune control is introduced into internal model control system, this paper designs fuzzy immune internal model controller, which integrates speed and robustness of the internal model control. The fuzzy immune internal model control is applied to combustion control system, and we compare it with ordinary internal model control method. The simulation result shows that fuzzy immune internal model control can greatly improve the characteristics of the control system with time delay. And this effectiveness of the fuzzy immune internal model controller has been verified.


2020 ◽  
Vol 42 (14) ◽  
pp. 2733-2743
Author(s):  
Jiqiang Tang ◽  
Tongkun Wei ◽  
Qichao Lv ◽  
Xu Cui

For a magnetically suspended control moment gyro (MSCMG), which is an ideal attitude actuator for its large outputting control moment and fast response, the moving-gimbal effects due to the coupling between the moving gimbal and high-speeding rotor will make the magnetically suspended rotor (MSR) unstable. To improve control precision, both the dynamic model of MSR and the feedback linearization control are done to decouple tilting motion, and poles of the system are reconfigured to reduce control error. To suppress the varying disturbance moments caused by moving-gimbal effects, an extended state observer (ESO) is originally designed to estimate and compensate them timely and accurately. To improve system robustness, a two-degree freedom internal model control (2-DOF IMC) is researched to suppress model error. Compared with existing proportional integral derivative (PID) control method, simulations done on a single gimbal MSCMG with 200 N.m.s angular momentum indicated that this presented control method with ESO and 2-DOF IMC can suppress the moving-gimbal effects more effectively and make the rotor suspension more stable.


Electronics ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 172 ◽  
Author(s):  
Zhihong Wu ◽  
Weisong Gu ◽  
Yuan Zhu ◽  
Ke Lu

Via the vector space decomposition (VSD) transformation, the currents in an asymmetric six-phase permanent magnet synchronous motor (ASP_PMSM) can be decoupled into three orthogonal subspaces. Control of α–β currents in α–β subspace is important for torque regulation, while control of x-y currents in x-y subspace can suppress the harmonics due to the dead time of converters and other nonlinear factors. The zero-sequence components in O1-O2 subspace are 0 due to isolated neutral points. In α–β subspace, a state observer is constructed by introducing the error variable between the real current and the internal model current based on the internal model control method, which can improve the current control performance compared to the traditional internal model control method. In x–y subspace, in order to suppress the current harmonics, an adaptive-linear-neuron (ADALINE)-based control algorithm is employed to generate the compensation voltage, which is self-tuned by minimizing the estimated current distortion through the least mean square (LMS) algorithm. The modulation technique to implement the four-dimensional current control based on the three-phase SVPWM is given. The experimental results validate the robustness and effectiveness of the proposed control method.


2013 ◽  
Vol 462-463 ◽  
pp. 809-814
Author(s):  
Fei Zhao ◽  
Fan Li ◽  
Jian Hui Zhao

A Multiple Independently Targeted Reentry Vehicle (MIRV) is a ballistic missile payload containing several warheads each capable of hitting one of a group of targets. In the process of missile flight control, the release of warheads brings about coupling to the missile attitude control system which will lower the flight stability. In order to solve this problem, a missile attitude controller, which combined the α-order integral inverse system with internal model principle, was presented. Firstly, determine the Post Boost Vehicle (PBV) attitude dynamics model. Then, combine the linearization of attitude dynamics equation with feed-forward decoupling method to implement the attitude decoupling. Finally, a two-degree of freedom (TOF) multivariable internal model controller was set up to optimize the control system performance. Simulation results show that the coupling of attitude control system has been eliminated. Compared with the original system, the internal model controller provides the control system better input-tracking performance, robust stability and interference suppression capacity.


2014 ◽  
Vol 556-562 ◽  
pp. 2410-2413
Author(s):  
Sheng Bo Zhang

An internal model and an inverse model of nonlinear system were established based on LS_SVM. On this basis the algorithm of internal model control for nonlinear system based on LS_SVM was put forward. The simulation results show that the internal model and the inverse model of nonlinear have high modeling precision and strong generalization. What’s more the algorithm of internal model control for nonlinear system based on LS_SVM has good control performance, strong anti-jamming ability and robustness.


2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Guohai Liu ◽  
Jun Yuan ◽  
Wenxiang Zhao ◽  
Yaojie Mi

Multimotor drive system is widely applied in industrial control system. Considering the characteristics of multi-input multioutput, nonlinear, strong-coupling, and time-varying delay in two-motor drive systems, this paper proposes a new Smith internal model (SIM) control method, which is based on neural network generalized inverse (NNGI). This control strategy adopts the NNGI system to settle the decoupling issue and utilizes the SIM control structure to solve the delay problem. The NNGI method can decouple the original system into several composite pseudolinear subsystems and also complete the pole-zero allocation of subsystems. Furthermore, based on the precise model of pseudolinear system, the proposed SIM control structure is used to compensate the network delay and enhance the interference resisting the ability of the whole system. Both simulation and experimental results are given, verifying that the proposed control strategy can effectively solve the decoupling problem and exhibits the strong robustness to load impact disturbance at various operations.


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