In this paper, the bit synchronization algorithms in GNSS receiver are introduced, including the traditional histogram method, K-P algorithm and Viterbi algorithm. The FPGA implementation is also included. A novel tim...In this paper, the bit synchronization algorithms in GNSS receiver are introduced, including the traditional histogram method, K-P algorithm and Viterbi algorithm. The FPGA implementation is also included. A novel time division multiplexing technology （TDM） based on multi-channel shared synchronizer is proposed in this paper to solve the constrained hardware resource problem of multi-system satellite navigation receiver. Through the using of control state machine and data register structure, we realize the multiplexing of bit synchronizer of navigation receiver, which saves the hardware resource. After the experiment, it can be verified that the receiver based on the bit synchronization and multiplexing technology can correctly restore the navigation information.展开更多
This paper introduced a thermo tank temperature control system based on STM32. Firstly, the temperature acquisition is real- ized by the high-lxecision electrical bridge based on constant current source. Then the augm...This paper introduced a thermo tank temperature control system based on STM32. Firstly, the temperature acquisition is real- ized by the high-lxecision electrical bridge based on constant current source. Then the augmented PID algorithm realized by software is adopteff But-terworth filter is used to convert the o.aput PWM of STM32 to current signal which is used to control the seniconductor control rectifier to adjust the temrature. Calibration check and practical application both indicated that the system was reliable, high-precision, practicable and could meet reality needs.展开更多
In order to elucidate the broadband noise of fan,the numerical simulation of fan operating at two different rotational speeds is carried out using the three-dimensional unsteady Reynolds-averaged Navier-Stokes (URANS)...In order to elucidate the broadband noise of fan,the numerical simulation of fan operating at two different rotational speeds is carried out using the three-dimensional unsteady Reynolds-averaged Navier-Stokes (URANS) equations.The computed results are compared to experiment to estimate its accuracy and are found to show good agreement with experiment.A method is proposed to evaluate the turbulent kinetic energy in the framework of the Spalart-Allmaras one equation turbulence model.From the calculation results,the turbulent kinetic energy is visualized as the turbulence of the flow which leads to generate the broadband noise,and its noise sources are identified.展开更多
基金the National Natural Science Foundation of China under Grant，the China Postdoctoral Science Foundation under Grant No.2013M530526，the Fundamental Research Funds for the Central Universities under Grant No.FRF-TP-14-046A2
文摘In this paper, the bit synchronization algorithms in GNSS receiver are introduced, including the traditional histogram method, K-P algorithm and Viterbi algorithm. The FPGA implementation is also included. A novel time division multiplexing technology （TDM） based on multi-channel shared synchronizer is proposed in this paper to solve the constrained hardware resource problem of multi-system satellite navigation receiver. Through the using of control state machine and data register structure, we realize the multiplexing of bit synchronizer of navigation receiver, which saves the hardware resource. After the experiment, it can be verified that the receiver based on the bit synchronization and multiplexing technology can correctly restore the navigation information.
文摘This paper introduced a thermo tank temperature control system based on STM32. Firstly, the temperature acquisition is real- ized by the high-lxecision electrical bridge based on constant current source. Then the augmented PID algorithm realized by software is adopteff But-terworth filter is used to convert the o.aput PWM of STM32 to current signal which is used to control the seniconductor control rectifier to adjust the temrature. Calibration check and practical application both indicated that the system was reliable, high-precision, practicable and could meet reality needs.
基金carried out by IHI Corporation under the financial support from New Energy and Industrial Technology Development Organization (NEDO) as a part of "Research and Development of Environmentally Compatible Engine for Small Aircraft" in the civil aircraft basic technology program of Ministry of Economy,Trade and Industry,Japan
文摘In order to elucidate the broadband noise of fan,the numerical simulation of fan operating at two different rotational speeds is carried out using the three-dimensional unsteady Reynolds-averaged Navier-Stokes (URANS) equations.The computed results are compared to experiment to estimate its accuracy and are found to show good agreement with experiment.A method is proposed to evaluate the turbulent kinetic energy in the framework of the Spalart-Allmaras one equation turbulence model.From the calculation results,the turbulent kinetic energy is visualized as the turbulence of the flow which leads to generate the broadband noise,and its noise sources are identified.
