Resonance drilling is a new technology, still at the laboratory stage. It has great potential to improve rock fragmentation efficiency. We analyzed the amplitude-frequency characteristics of steady- state mechanical v...Resonance drilling is a new technology, still at the laboratory stage. It has great potential to improve rock fragmentation efficiency. We analyzed the amplitude-frequency characteristics of steady- state mechanical vibration excited by harmonic vibration in rocks and an apparatus was built to achieve high fi＇equency vibration of rock. The influence of rock drillability, rotary speed, excitation frequency, and other parameters on the rate of penetration （ROP） in resonance drilling was analyzed. The results show that the rock drillability decreased with an increase in excitation frequency. When drilling with a large size drill bit, the ROP increased with excitation frequency. The ROP reached a maximum value at the resonant frequency of the rock. Tile ROP of the bit increased linearly with rotary speed when no vibration was applied on the rock and increased approximately exponentially when harmonic vibration was applied. In addition, the resonant frequency of the rock was changing during the process of rock fi＇agmentation, so in order to achieve tile desired resonance of the rock, it is necessary to detemaine an appropriate hamlonic vibration excitation frequency.展开更多
In radiation measurement and digital nuclear spectrum systems,traditional nuclear signal processing circuits in nuclear electronics have been gradually replaced by digital algorithm modules with the application of hig...In radiation measurement and digital nuclear spectrum systems,traditional nuclear signal processing circuits in nuclear electronics have been gradually replaced by digital algorithm modules with the application of highperformance programmable hardware logic devices(such as FPGA or DSP).Referring to the digital realization method of inverse RC integral circuit systems,the function of the pole-zero cancellation(PZC)circuit was analyzed,a new modified cascade equivalent model of PZC was established,and the time-domain digital PZC(DPZC)recursive algorithm was derived in detail in this study.Two parameters kIand k_(D)are included in the new algorithm,where kIshould match the exponential decay time constant of the input signal to realize the pole-zero compensation,while the decay time constant of the output signal can be changed with the adjustable parameter k_(D)(which is larger than the decay time constant of the input signal).Based on the new DPZC algorithm module,two trapezoidal(triangular)shaping filters were designed and implemented.The amplitude–frequency characteristics of the output signal of the proposed trapezoidal shaping algorithm and the convolution trapezoidal shaping algorithm were compared,with fixed peaking time.The results show that the trapezoidal shaping algorithm based on DPZC can better suppress high-frequency noise.Finally,based on the Na I(Tl)scintillator(u75 mm×75 mm)detector and^(137)Cs source,the effect of the k_(D)value on the energy resolution of the DPZC trapezoidal(triangular)shaping algorithm was studied.The experimental results show that,with an increase in k_(D),the energy resolution of the system improved and reached the maximum when k_(D)was greater than 10,and the optimal energy resolution of the system was 7.72%.展开更多
基金funded by National Natural Science Foundation of China(Grant No.51274072)Youth Science Foundation of Heilongjiang Province(Grant No.QC2012C022)
文摘Resonance drilling is a new technology, still at the laboratory stage. It has great potential to improve rock fragmentation efficiency. We analyzed the amplitude-frequency characteristics of steady- state mechanical vibration excited by harmonic vibration in rocks and an apparatus was built to achieve high fi＇equency vibration of rock. The influence of rock drillability, rotary speed, excitation frequency, and other parameters on the rate of penetration （ROP） in resonance drilling was analyzed. The results show that the rock drillability decreased with an increase in excitation frequency. When drilling with a large size drill bit, the ROP increased with excitation frequency. The ROP reached a maximum value at the resonant frequency of the rock. Tile ROP of the bit increased linearly with rotary speed when no vibration was applied on the rock and increased approximately exponentially when harmonic vibration was applied. In addition, the resonant frequency of the rock was changing during the process of rock fi＇agmentation, so in order to achieve tile desired resonance of the rock, it is necessary to detemaine an appropriate hamlonic vibration excitation frequency.
基金supported by the National Natural Science Foundation of China(Nos.11975060,12005026,and 12075038)the Fund of Robot Technology Used for Special Environment Key Laboratory of Sichuan Province(No.19kftk02)。
文摘In radiation measurement and digital nuclear spectrum systems,traditional nuclear signal processing circuits in nuclear electronics have been gradually replaced by digital algorithm modules with the application of highperformance programmable hardware logic devices(such as FPGA or DSP).Referring to the digital realization method of inverse RC integral circuit systems,the function of the pole-zero cancellation(PZC)circuit was analyzed,a new modified cascade equivalent model of PZC was established,and the time-domain digital PZC(DPZC)recursive algorithm was derived in detail in this study.Two parameters kIand k_(D)are included in the new algorithm,where kIshould match the exponential decay time constant of the input signal to realize the pole-zero compensation,while the decay time constant of the output signal can be changed with the adjustable parameter k_(D)(which is larger than the decay time constant of the input signal).Based on the new DPZC algorithm module,two trapezoidal(triangular)shaping filters were designed and implemented.The amplitude–frequency characteristics of the output signal of the proposed trapezoidal shaping algorithm and the convolution trapezoidal shaping algorithm were compared,with fixed peaking time.The results show that the trapezoidal shaping algorithm based on DPZC can better suppress high-frequency noise.Finally,based on the Na I(Tl)scintillator(u75 mm×75 mm)detector and^(137)Cs source,the effect of the k_(D)value on the energy resolution of the DPZC trapezoidal(triangular)shaping algorithm was studied.The experimental results show that,with an increase in k_(D),the energy resolution of the system improved and reached the maximum when k_(D)was greater than 10,and the optimal energy resolution of the system was 7.72%.
