Papers by Keyword: Synchronisation

Abstract: In a stroboscopic imaging system, in order to make images to be correctly captured the synchronization must be strictly satisfied. Direct digital synthesizer (DDS) is a new frequency synthesizing technique used for creating arbitrary waveforms from a single, fixed-frequency reference clock. It has many advantages such as fast frequency conversion, high resolution of frequency and keeping phase continuous while frequency switches. By applying the DDS technique, this paper presents a method to generate the illumination signal of light source and the drive signal of device, and more attention is paid to how to perform the precise synchronization between the two signals. By adjusting the relative delay of the illumination and the drive signals, the phase can be changed. Allowing a sequence of images depicting the motion over the interval studied to be captured, which yields a complete picture of the vibration of a specimen or the surface structure of a MEMS device. Experimental results show that the high frequency of a signal could be up to 120 MHz with frequency resolution 4μHz. The phase resolution of 2^-16 can be achieved by the proposed method. The relative phase error between illumination and driven signals could be down to 2^-16. It is relatively easy to a synchronization illumination signal of light source and drive signal of MEMS accurately. However, as the two signals' transmission paths are different, their transmission delays are different also. Accordingly, a phase error would be caused and it would change as the signal frequency changes. Moreover, if the drive signal of external objects is used, the phase error, which is introduced via inaccuracy synchronizing the frequency of signal, would be superposed, indeed. These phase errors would affect the quality of imaging and the accuracy of measurement. In this paper, an effective method to adjust the errors is proposed. By means of specially designed hardware circuit, the error of phase and frequency synchronization between illumination signal of light source and drive signal of MEMS can be adjusted automatically. The proposed method improves the accuracy in synchronism and reduces the impact of the error of signal synchronization in the system. It is proved that the minimum relative phase error between illumination signal of light source and drive signal of MEMS can be reduced by more than 10 times using this method.

Abstract: The background of this paper is Rotary Screen Printing Machine(RSPM),and the paper need to resolve the printing flower dislocation phenomenon caused by synchronization between each motor, and by the synchronization between rotary screen motor and the conduction band. The paper presented overall scheme, and analyzed, designed and realized synchronous control arithmetic design based on system hardware platform. Through some related experimental results proved that the distributed system based on CAN bus(CANOpen protocol) worked stably, each motor transmitted independently and could run synchronously , and the results verified the correctness and feasibility of distributed structure scheme used for RSPM system.

Abstract: In this paper, a cross-coupling synchronization controller is proposed to achieve a synchronous motion for high-precision positioning systems with uncertainties and disturbances, where an additional P controller is equipped to generate cross-coupling control action. Tuning procedure of the control parameters is also provided, so that improved tracking and synchronization performance can be obtained. The key to the success of the new design is to ensure that each motor tracks its desired trajectory while synchronizing motion with others. Experiments on a positioning system with two permanent-magnet linear motors demonstrate the effectiveness of the proposed control method.

Abstract: Based on the dynamic model of the nonlinear vibration system which driven by double exciting motors, the rotate speed difference and phase difference state space equations have been deduced. According to the design feature of the nonlinear vibration system and the vibration synchronization requirement of double exciting motors, the approach control synchronization strategy has been deduced with sliding mode reaching law. The practical examples and tests shows that the reaching law synchronization controller can effectively control the double exciting motors to realize the synchronization movement, and the synchronization controller has stronger robustness. The analysis result can provide the theoretical and test basis for the further exploitation of synchronization vibrating machine.

Abstract: The principle of inking system in sheet-feed printing press is introduced. Some tests on ink thickness are performed and the experiment results shows that in the traditional press, some inherent defects cause serious quality problems. The application of shaft-less drive technology to printing press is introduced and the drive principle of inking rollers of printing press and is explained. Synchronization control method of rollers is put forward, and the shaft-less technology is applied to the inking roller. Control system of shaft-less roller press is constructed for four color printing. Mechanical zero and electrical zero can be reset and corrected. Slight asynchrony is allowed between inking rollers and cylinders for normal printing, and the speed difference between them can eliminate a kind of printing troublesome of ghosting when needed. Analysis shows that with this technology, the functions of press are extended. Furthermore, the results of calculation indicated that when printing the special products, the make-ready time for inking is shorten about 50% and the power consumption is decreased about 19.8 to 21.5%, so the efficiency of machine can be increased by a big margin and the power cost can be cut down obviously.

Abstract: The process of integration in the global economy driven by foreign business cycle fluctuations on China's economy has become increasingly evident. United States as the world's largest economy, the world economy has a significant impact, while the United States is China's most important trading partner, the most important foreign export market. From the close trade links between the two countries on the run, U.S. economic growth has an important role in China's economic development. Articles by examined the 1979-2010 China-US previous years, the operation of law of economic cycles and volatility characteristics of China and the U.S. business cycle synchronization features. Came to the conclusion, fluctuations in business cycle synchronization between the two countries occurred mainly after 2000 results.

Abstract: Most properties of Super Chen’s chaotic system satisfy with the requirements of secure communication and cryptography. Implusive stabilzation for control and synchronization of Super Chen’s chaotic systems can be applied in secure communication. Super Chen’s Chaotic synchronization control can be the kernel technology in chaos-based secure commu-nication. In this paper we propose a hybrid Super Chen chaotic synchronization scheme control which contains both continuous chaotic system with a sort of oscillating parameters and discrete chaotic system. If oscillating parameters approach to 0, we proved that two systems can get synchronized without control signal transmitting.

Abstract: The control of chaotic synchronization is the kernel technology in chaos-based secure communication. Those control methods have to transmitting control signal which increase the security risks of the communication system. Attacker can reconstruct the chaotic system or estimate parameters by using the information of the chaotic system. In this paper we propose a hybrid Super Chen chaotic synchronization scheme control which contains both continuous chaotic system with oscillating parameters and discrete chaotic system. If oscillating parameters satisfyingwhen , we proved that two systems can get synchronized without control signal transmitting.

Abstract: The control of chaotic synchronization is the kernel technology in chaos-based secure communication. Those control methods have to transmitting control signal which increase the security risks of the communication system. Attacker can reconstruct the chaotic system or estimate parameters by using the information of the chaotic system. In this paper we propose a hybrid Liu chaotic synchronization control scheme which contains both continuous chaotic system with oscillating parameters approach to 0 and discrete chaotic system. By theory of impulsive differential equations, we proved a theorem that two continuous Liu chaotic systems can get synchronized without control signal transmitting which has reduced the risk of the security.

Abstract: This paper introduces a modified financial chaotic system. Some basic dynamical properties are studied. Based on Lyapunov stability theory and LMI (linear matrix inequality), sufficient condition for the synchronization has been analyzed theoretically. Numerical simulations are given to show the effectiveness of this method.