最小频移键控（MSK—Minimum Frequency Shift Keying）是二进制频移键控（BINFSK—Binary Frequency Shift Kev—ing）的一种特殊形式，由于这种调制方式具有频带利用率高、带外辐射较小的优点，因此它在数字通信系统中已得到了广泛的...最小频移键控（MSK—Minimum Frequency Shift Keying）是二进制频移键控（BINFSK—Binary Frequency Shift Kev—ing）的一种特殊形式，由于这种调制方式具有频带利用率高、带外辐射较小的优点，因此它在数字通信系统中已得到了广泛的应用。本文简要介绍了MSK信号的产生原理，并在DSP＋FPGA全数字架构的平台上，采用对加权函数采样点数的控制、DSP对AD9952的控制以及FPGA对DDR的读取控制来共同实现变速率MSK调制信号。在具体实现的过程中，把复杂的计算过程交给计算功能强大的DSP，而FPGA则主要用于实现时序控制。其中DSP在对加权函数的处理中，采用了查表的方法，从而使程序能够运行得更快。最后在DSP集成开发环境CCS中分别观察到了串并转换之后以及与加权函数相乘后的I、Q两路波形．满足了设计需求。展开更多
In order to eliminate the drawbacks of conventional force feedback gloves, a new type of master fin- ger has been developed. By utilizing three ＂four-bar mechanism joint＂ in series and wire coupling mecha- nism, the...In order to eliminate the drawbacks of conventional force feedback gloves, a new type of master fin- ger has been developed. By utilizing three ＂four-bar mechanism joint＂ in series and wire coupling mecha- nism, the master finger transmission ratio is kept exactly 1：1.4：1 in the whole movement range and it can make active motions in both extension and flexion directions. Additionally, to assure faster data transmission and near zero delay in the master-slave operation, a digital signal processing/field programmable gate array （DSP/FPGA-FPGA） structure with 200μs cycle time is designed. The operating modes of the master finger can be contact or non-contact, which depends on the motion states of a slave finger, free motion or constrained motion. The position control employed in non-contact mode ensures unconstrained motion and the force control adopted in contact mode guarantees natural contact sensation. To evaluate the performances of the master finger, an experiment between the master finger and a DLR/HTT dexterous finger is conducted. The results demonstrate that this new type master finger can augment telepresence.展开更多
We designed a universal digital energy spectroscopy based on online digital signal processing. A prototype system was built and tested. Signals from radiation detectors were processed via a digital filter whose coeffi...We designed a universal digital energy spectroscopy based on online digital signal processing. A prototype system was built and tested. Signals from radiation detectors were processed via a digital filter whose coefficients could be modified without changing the hardware. The paper introduces the hardware design of the digital energy spectroscopy system as well as the full set of software consisting of the selection of the coefficients of the finite impulse response (FIR) filter and the coding in the field-programmable gate array (FPGA). The system was tested with the high purity germanium (HPGe) detector. The results showed that this prototype can achieve an energy resolution close to that of a traditional multi-channel analyzer (MCA) with a much higher counting rate.展开更多
In this paper a fast digital real-time spectrometer was developed for timing and analysis of nuclear pulse signals. The hardware system design and algorithm implementation with field-programming gate array （FPGA） an...In this paper a fast digital real-time spectrometer was developed for timing and analysis of nuclear pulse signals. The hardware system design and algorithm implementation with field-programming gate array （FPGA） and digital signal processor （DSP） were introduced. The performance of the digital constant fraction discrimination （dCFD） platform was experimentally tested with Agilent 80 MHz function/arbitrary waveform generator and LaC13：Ce3＋ scintillator detector for 22Na positron annihilation gamma spectroscopy. The amplitude and time information of ＂/photon was online obtained. The energy resolution could be 5.525% and the timing resolution 293.75 ps, the system error estimation of dCFD approach was also studied. The results showed that this spectrometer achieved a timing resolution close to that of traditional CFD timing resolution with a more sim- plified system structure.展开更多
文摘最小频移键控（MSK—Minimum Frequency Shift Keying）是二进制频移键控（BINFSK—Binary Frequency Shift Kev—ing）的一种特殊形式，由于这种调制方式具有频带利用率高、带外辐射较小的优点，因此它在数字通信系统中已得到了广泛的应用。本文简要介绍了MSK信号的产生原理，并在DSP＋FPGA全数字架构的平台上，采用对加权函数采样点数的控制、DSP对AD9952的控制以及FPGA对DDR的读取控制来共同实现变速率MSK调制信号。在具体实现的过程中，把复杂的计算过程交给计算功能强大的DSP，而FPGA则主要用于实现时序控制。其中DSP在对加权函数的处理中，采用了查表的方法，从而使程序能够运行得更快。最后在DSP集成开发环境CCS中分别观察到了串并转换之后以及与加权函数相乘后的I、Q两路波形．满足了设计需求。
文摘In order to eliminate the drawbacks of conventional force feedback gloves, a new type of master fin- ger has been developed. By utilizing three ＂four-bar mechanism joint＂ in series and wire coupling mecha- nism, the master finger transmission ratio is kept exactly 1：1.4：1 in the whole movement range and it can make active motions in both extension and flexion directions. Additionally, to assure faster data transmission and near zero delay in the master-slave operation, a digital signal processing/field programmable gate array （DSP/FPGA-FPGA） structure with 200μs cycle time is designed. The operating modes of the master finger can be contact or non-contact, which depends on the motion states of a slave finger, free motion or constrained motion. The position control employed in non-contact mode ensures unconstrained motion and the force control adopted in contact mode guarantees natural contact sensation. To evaluate the performances of the master finger, an experiment between the master finger and a DLR/HTT dexterous finger is conducted. The results demonstrate that this new type master finger can augment telepresence.
基金supported by the National Natural Science Foundation of China (Grant No.10975132)
文摘We designed a universal digital energy spectroscopy based on online digital signal processing. A prototype system was built and tested. Signals from radiation detectors were processed via a digital filter whose coefficients could be modified without changing the hardware. The paper introduces the hardware design of the digital energy spectroscopy system as well as the full set of software consisting of the selection of the coefficients of the finite impulse response (FIR) filter and the coding in the field-programmable gate array (FPGA). The system was tested with the high purity germanium (HPGe) detector. The results showed that this prototype can achieve an energy resolution close to that of a traditional multi-channel analyzer (MCA) with a much higher counting rate.
基金supported by the National Natural Science Foundation of China (Grant No. 10975132)
文摘In this paper a fast digital real-time spectrometer was developed for timing and analysis of nuclear pulse signals. The hardware system design and algorithm implementation with field-programming gate array （FPGA） and digital signal processor （DSP） were introduced. The performance of the digital constant fraction discrimination （dCFD） platform was experimentally tested with Agilent 80 MHz function/arbitrary waveform generator and LaC13：Ce3＋ scintillator detector for 22Na positron annihilation gamma spectroscopy. The amplitude and time information of ＂/photon was online obtained. The energy resolution could be 5.525% and the timing resolution 293.75 ps, the system error estimation of dCFD approach was also studied. The results showed that this spectrometer achieved a timing resolution close to that of traditional CFD timing resolution with a more sim- plified system structure.
