FAULT DIAGNOSIS IN A PROCESS EXPERIMENTAL CONTROL SYSTEM WITH UNKNOWN FACTORS

2008 ◽  
Vol 07 (01) ◽  
pp. 151-155 ◽  
Author(s):  
AKIRA INOUE ◽  
MINGCONG DENG

A fault detection problem in a process control experimental system with unknown factors is presented in this paper. The fault detecting method is based on blind system identification approach. The experimental system actuator output includes unknown dynamics and unknown fault signal. By using the fault detecting method, the fault signal is detected. Simulation results for the experimental process are presented to show the effectiveness.

2016 ◽  
Vol 693 ◽  
pp. 1826-1833
Author(s):  
Ai Wu Yu ◽  
Chuan Min Zhu

Motor synchronous control technology has been widely used in lifting device. The effect of Synchronous control technology to improve the precision is becoming more and more attention both at home and abroad. Based on the four channels winding ascension, we design a deviation coupling based on principle of displacement compensation control system, and use Matlab/Simulink for simulation, and research the influence law of different parameters on synchronization control accuracy. The simulation results confirmed that the strategy can satisfy the control precision. Finally, we set up the experimental system to verify the feasibility and practicability of the synchronous control system.


2011 ◽  
Vol 65 ◽  
pp. 199-203
Author(s):  
Sheng Wu Wang ◽  
Xiu Hua Shi ◽  
Hui Xu ◽  
Zhao Jing Tong

Wavelet Analysis extracts the main feature from the fault signal through wavelet transformation, so it is advantageous to withdraw fault characteristic for fault diagnosis. Support Vector Machine (SVM) has shown its good classification performance in fault diagnosis. A new method of fault diagnosis for UV control system based on WAVELET-SVM is raised. The sensor output is sampled in frequency domain and it is preprocessed by wavelet to extract main vectors of the fault features. Fault patterns under various states are classified using multi-class SVM, and fault diagnosis is realized. The simulation results show that WAVELET-SVM is feasible to detect and locate faults quickly and exactly and has high robustness.


2013 ◽  
Vol 846-847 ◽  
pp. 799-803
Author(s):  
Lei Han ◽  
Qi Hua Xu ◽  
Rui Ming Liu

This paper constructs a sliding mode observer of fixed long delay network control system with an augmented modeling method, and then proves the feasibility of system residuals converging to zero by Lyapunov stability theorem. The network control system fault diagnosis is discussed in depth by detecting changes in the residuals. In addition, this paper takes Gradient faults and mutation faults of actuator as examples to conduct fault diagnosis simulation, and the simulation results show that this method can detect the system faults effectively.


Author(s):  
Neng Wan ◽  
Guangping Zeng ◽  
Chunguang Zhang ◽  
Dingqi Pan ◽  
Songtao Cai

This paper deals with a new state-constrained control (SCC) system of vehicle, which includes a multi-layer controller, in order to ensure the vehicle’s lateral stability and steering performance under complex environment. In this system, a new constraint control strategy with input and state constraints is applied to calculate the steady-state yaw moment. It ensures the vehicle lateral stability by tracking the desired yaw rate value and limiting the allowable range of the side slip. Through the linkage of the three-layer controller, the tire load is optimized and achieve minimal vehicle velocity reduction. The seven-degree-of-freedom (7-DOF) simulation model was established and simulated in MATLAB to evaluate the effect of the proposed controller. Through the analysis of the simulation results, compared with the traditional ESC and integrated control, it not only solves the problem of obvious velocity reduction, but also solves the problem of high cost and high hardware requirements in integrated control. The simulation results show that designed control system has better performance of path tracking and driving state, which is closer to the desired value. Through hardware-in-the-loop (HIL) practical experiments in two typical driving conditions, the effectiveness of the above proposed control system is further verified, which can improve the lateral stability and maneuverability of the vehicle.


2012 ◽  
Vol 262 ◽  
pp. 361-366
Author(s):  
Zhuo Fei Xu ◽  
Hai Yan Zhang ◽  
Ling Hui Ren

Roller-mark is a common problem in offset printing and its solution method is important for printing. A new detecting method of texture analysis was given in this paper. In this study, printing image was acquired with high-speed CCD. Compared the difference between printing image and standard image, a defective image was obtained. Then the reason of roller-marks was given by the texture recognition of defect image. Finally, experiments were taken to prove the feasibility and effectiveness of this new method for the roller-marks diagnosis in the offset printing machine.


Author(s):  
Lei Si ◽  
Zhongbin Wang ◽  
Xinhua Liu

In order to accurately and conveniently identify the shearer running status, a novel approach based on the integration of rough sets (RS) and improved wavelet neural network (WNN) was proposed. The decision table of RS was discretized through genetic algorithm and the attribution reduction was realized by MIBARK algorithm to simply the samples of WNN. Furthermore, an improved particle swarm optimization algorithm was proposed to optimize the parameters of WNN and the flowchart of proposed approach was designed. Then, a simulation example was provided and some comparisons with other methods were carried out. The simulation results indicated that the proposed approach was feasible and outperforming others. Finally, an industrial application example of mining automation production was demonstrated to verify the effect of proposed system.


2013 ◽  
Vol 846-847 ◽  
pp. 313-316 ◽  
Author(s):  
Xiao Yun Zhang

This paper presented a new method based on the Fuzzy self - adaptive PID for BLDCM. This method overcomes some defects of the traditional PID control. Such as lower control precision and worse anti - jamming performance. It dynamic model of BLDCM was built, and then design method for TS fuzzy PID model is given, At last, it compared simulation results of PID control method with TS Fuzzy PID control method. The results show that the TS Fuzzy PID control method has more excellent dynamic antistatic performances, as well as anti-jamming performance. The experiment shows that TS fuzzy PID control has the stronger adaptability robustness and transplant.


2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Manop Yingram ◽  
Suttichai Premrudeepreechacharn

The mainly used local islanding detection methods may be classified as active and passive methods. Passive methods do not perturb the system but they have larger nondetection zones, whereas active methods have smaller nondetection zones but they perturb the system. In this paper, a new hybrid method is proposed to solve this problem. An over/undervoltage (passive method) has been used to initiate an undervoltage shift (active method), which changes the undervoltage shift of inverter, when the passive method cannot have a clear discrimination between islanding and other events in the system. Simulation results on MATLAB/SIMULINK show that over/undervoltage and undervoltage shifts of hybrid islanding detection method are very effective because they can determine anti-islanding condition very fast.ΔP/P>38.41% could determine anti-islanding condition within 0.04 s;ΔP/P<-24.39% could determine anti-islanding condition within 0.04 s;-24.39%≤ΔP/P≤ 38.41% could determine anti-islanding condition within 0.08 s. This method perturbed the system, only in the case of-24.39% ≤ΔP/P ≤38.41% at which the control system of inverter injected a signal of undervoltage shift as necessary to check if the occurrence condition was an islanding condition or not.


Author(s):  
Takanori Emaru ◽  
Kazuo Imagawa ◽  
Yohei Hoshino ◽  
Yukinori Kobayashi

Proportional-Integral-Derivative (PID) control has been most commonly used to operate mechanical systems. In PID control, however, there are limits to the accuracy of the resulting movement because of the influence of gravity, friction, and interaction of joints. We have proposed a digital acceleration control (DAC) that is robust over these modeling errors. One of the most practicable advantages of DAC is robustness against modeling errors. However, it does not always work effectively. If there are modeling errors in the inertia term of the model, the DAC controller cannot control a mechanical system properly. Generally an inertia term is easily modeled in advance, but it has a possibility to change. Therefore, we propose an online estimation method of an inertia term by using a system identification method. By using the proposed method, the robustness of DAC is considerably improved. This paper shows the simulation results of the proposed method using 2-link manipulator.


2013 ◽  
Vol 846-847 ◽  
pp. 795-798
Author(s):  
Jiao Meng ◽  
Qi Hua Xu ◽  
Xiao Xiao

Improving network control system---NCS reliability and safety has important practical significance because NCS is a hot research subject in these years. Fault diagnosis methods are researched in this paper according to NCS with long-time delay and data packet loss. Firstly, given a NCS with long-time delay, a state observer is structured. Secondly, make the state estimation error equation equivalent to an asynchronous dynamical system having event incidence constraint according to whether the system having data packets loss. The problem of fault diagnosis is converted to filtering problem through structuring filtering residual system based on the observer, then giving a corresponding filter designing algorithm. The designed fault diagnosis filter system not only make sure the stability of the closed loop system but also make the residual systems norm less than given reduction level. Finally, the simulation results prove that the algorithm can diagnose faults effectively.


Sign in / Sign up

Export Citation Format

Share Document