This paper presents the solution of regulating the wind rate automatically by means of fuzzy control technology and implementing it with PLC (programmable logical controller) under the circumstance of many influence f...This paper presents the solution of regulating the wind rate automatically by means of fuzzy control technology and implementing it with PLC (programmable logical controller) under the circumstance of many influence factors, which exists in the axial flow fans wind rate regulation system during the process of mine ventilation, and has difficulty in modifying the mathematic model to obtain the satisfied result by normal control ways. According to this analysis, the intelligent and analytic treatment of fuzzy controller has been made and fuzzy control scheme involving self regulation divisor and intelligent integral has been deeply proposed. Test result shows that this system based on the scheme above is obviously prior to others in its responsibility such as high speed, overshoot, control precision and robustness. The system furnishes the great reliability of mine working safety and fans running efficiency.展开更多
For the constant distance spacing policy,the existing researches of the string stability focus on the single-predecessor information framework（SPIF） and predecessor-successor information framework（PSIF）.The resear...For the constant distance spacing policy,the existing researches of the string stability focus on the single-predecessor information framework（SPIF） and predecessor-successor information framework（PSIF）.The research results demonstrated that the string stability could not be guaranteed with the SPIF,and then the PSIF was proposed to resolve this string instability.But the issue,whether the string stability can be guaranteed when applying the PSIF,is still controversial.Meanwhile,most of the previous researches on the string stability were conducted without consideration of the parasitic time delays and lags.In this paper,the practical longitudinal vehicle dynamics model is built with consideration of the parasitic time delays and lags existing in the actuators,sensors or the communication systems.Secondly,the detailed theoretical analysis of string stability in frequency domain is conducted to demonstrate that the classical linear control laws can not ensure the string stability when applying both the symmetrical PSIF（SPSIF） and asymmetrical PSIF（APSIF）.Thirdly,a control law,which adds the position and velocity information of the leading vehicle,is proposed to guarantee string stability for small/medium platoon,and the other control law,which adds the acceleration information of the controlled vehicle,is proposed to guarantee string stability for large platoon as well as small/medium platoon.Finally,the comparative simulation is conducted to confirm the conducted analysis and the proposed control laws.The conducted research completes the means to analyze the string stability in frequency domain,provides the parameters＇ reference for the design and implementation of the practical automatic following controllers,and improves the reliability and stability of the platoon of automatic vehicles.展开更多
The simplified transfer function diagram block for a monitor automatic gauge control （Mon-AGC） system of strip steel rolling process was investigated. The new notion of strip sample length was given. In this way, th...The simplified transfer function diagram block for a monitor automatic gauge control （Mon-AGC） system of strip steel rolling process was investigated. The new notion of strip sample length was given. In this way, the delay time varying with the rolling speed was evaded. After a Smith predictor was used to monitor the AGC system, the control laws were deduced for both proportional and integral regulators. The control strategies showed that by choosing the controller parameter P=∞ for both control algo- rithms each regulator could compensate the whole strip gage error in the first control step. The result shows that the integral algo- rithm is more controllable for the system regulating process and has a better steady-state precision than the proportional regulator. Compared with the traditional control strategy, the new control laws have a faster response speed and a hieher steadv-state precision.展开更多
Currently, the high-speed serial fiber-optic ring net communication is a main method for performing the distributed control network topology and control mode. Because of a network transmission delay inherent in the to...Currently, the high-speed serial fiber-optic ring net communication is a main method for performing the distributed control network topology and control mode. Because of a network transmission delay inherent in the topology, synchronization between nodes has become a critical issue which needs to be studied. The existing synchronization methods largely depend on the complex communication protocol. Therefore, this paper has proposed a method of automatic measurement and compensation of synchronization delay, and analyzed its operating principle and implementation procedure in detail. The results obtained from the experiments prove the proposed method to be correct, effective and practicable.展开更多
文摘This paper presents the solution of regulating the wind rate automatically by means of fuzzy control technology and implementing it with PLC (programmable logical controller) under the circumstance of many influence factors, which exists in the axial flow fans wind rate regulation system during the process of mine ventilation, and has difficulty in modifying the mathematic model to obtain the satisfied result by normal control ways. According to this analysis, the intelligent and analytic treatment of fuzzy controller has been made and fuzzy control scheme involving self regulation divisor and intelligent integral has been deeply proposed. Test result shows that this system based on the scheme above is obviously prior to others in its responsibility such as high speed, overshoot, control precision and robustness. The system furnishes the great reliability of mine working safety and fans running efficiency.
基金supported by Doctoral Foundation of Ministry of Education of China (Grant No.20070006011)
文摘For the constant distance spacing policy,the existing researches of the string stability focus on the single-predecessor information framework（SPIF） and predecessor-successor information framework（PSIF）.The research results demonstrated that the string stability could not be guaranteed with the SPIF,and then the PSIF was proposed to resolve this string instability.But the issue,whether the string stability can be guaranteed when applying the PSIF,is still controversial.Meanwhile,most of the previous researches on the string stability were conducted without consideration of the parasitic time delays and lags.In this paper,the practical longitudinal vehicle dynamics model is built with consideration of the parasitic time delays and lags existing in the actuators,sensors or the communication systems.Secondly,the detailed theoretical analysis of string stability in frequency domain is conducted to demonstrate that the classical linear control laws can not ensure the string stability when applying both the symmetrical PSIF（SPSIF） and asymmetrical PSIF（APSIF）.Thirdly,a control law,which adds the position and velocity information of the leading vehicle,is proposed to guarantee string stability for small/medium platoon,and the other control law,which adds the acceleration information of the controlled vehicle,is proposed to guarantee string stability for large platoon as well as small/medium platoon.Finally,the comparative simulation is conducted to confirm the conducted analysis and the proposed control laws.The conducted research completes the means to analyze the string stability in frequency domain,provides the parameters＇ reference for the design and implementation of the practical automatic following controllers,and improves the reliability and stability of the platoon of automatic vehicles.
基金supported by the National High-Tech Research and Development Program of China (No.2003AA33G010)
文摘The simplified transfer function diagram block for a monitor automatic gauge control （Mon-AGC） system of strip steel rolling process was investigated. The new notion of strip sample length was given. In this way, the delay time varying with the rolling speed was evaded. After a Smith predictor was used to monitor the AGC system, the control laws were deduced for both proportional and integral regulators. The control strategies showed that by choosing the controller parameter P=∞ for both control algo- rithms each regulator could compensate the whole strip gage error in the first control step. The result shows that the integral algo- rithm is more controllable for the system regulating process and has a better steady-state precision than the proportional regulator. Compared with the traditional control strategy, the new control laws have a faster response speed and a hieher steadv-state precision.
文摘Currently, the high-speed serial fiber-optic ring net communication is a main method for performing the distributed control network topology and control mode. Because of a network transmission delay inherent in the topology, synchronization between nodes has become a critical issue which needs to be studied. The existing synchronization methods largely depend on the complex communication protocol. Therefore, this paper has proposed a method of automatic measurement and compensation of synchronization delay, and analyzed its operating principle and implementation procedure in detail. The results obtained from the experiments prove the proposed method to be correct, effective and practicable.
