The Delta-modulated feedback control of a linear system introduces nonlinearity into the system through switchings between two input values. It has been found that Delta-modulation gives rise to periodic orbits. The e...The Delta-modulated feedback control of a linear system introduces nonlinearity into the system through switchings between two input values. It has been found that Delta-modulation gives rise to periodic orbits. The existence of periodic points of all orders of Sigma-Delta modulation with ＂leaky＂ integration is completely characterized by some interesting groups of polynomials with ＂sign＂ coefficients. The results are naturally generalized to Sigma-Delta modulations with multiple delays, Delta-modulations in the ＂downlink＂, unbalanced Delta-modulations and systems with two-level quantized feedback. Further extensions relate to the existence of periodic points arising from Delta-modulated feedback control of a stable linear system in an arbitrary direction, for which some necessary and sufficient conditions are given.展开更多
An inductive digital voice communication system used in shaft is studied. This system digitizes the voice signal by using CVSD (continuously varying slop delta), scramble/unscramble technology and partial response cod...An inductive digital voice communication system used in shaft is studied. This system digitizes the voice signal by using CVSD (continuously varying slop delta), scramble/unscramble technology and partial response coding technology. By using these technology, the anti-jamming ability of the system and the communicatiou quality can be improved.This system adapts to the worst conditions of the shaft.展开更多
A new digital audio processing system based on Nonuniform Sampling Delta Mod-ulation (NSDM) technique is presented in this paper. The performance of NSDM system is analysed. Theoretical analysis and experimental resul...A new digital audio processing system based on Nonuniform Sampling Delta Mod-ulation (NSDM) technique is presented in this paper. The performance of NSDM system is analysed. Theoretical analysis and experimental results have demonstrated that the perfor-manc e of NSDM system used in digital audio is better than that of conventional Linear Delta Modulation (LDM) in terms of coding efficiency, Signal to Quantization-Noise Ratio and dy-namic range.展开更多
The paper discusses the application of PWM delta modulation with PI controller as an alternative to the standard PWM techniques for providing gating signals to the voltage source inverters. Its inherent characteristic...The paper discusses the application of PWM delta modulation with PI controller as an alternative to the standard PWM techniques for providing gating signals to the voltage source inverters. Its inherent characteristics of constant volts/Hertz control without feedback complexity and boosting of the fundamental voltage makes it an excellent choice for motor drive applications. This paper discusses the comparison between a basic delta modulation, the advanced Delta modulation with PI controller and an optimized DMPI. It is shown that in addition to the aforementioned advantages, VSI with optimized DMPI produces superior load current/voltage waveforms compared to simple DMPI, when IGBT is employed as a switching device for the inverter. Since the tacho feedback or other traditional speed sensing means is not permissible in sealed motor or the pump, a novel method is used to monitor the motor speed from the terminal quantities like voltage, current, and motor input power factor.展开更多
基金the National Natural Science Foundation of China (No.60674113)
文摘The Delta-modulated feedback control of a linear system introduces nonlinearity into the system through switchings between two input values. It has been found that Delta-modulation gives rise to periodic orbits. The existence of periodic points of all orders of Sigma-Delta modulation with ＂leaky＂ integration is completely characterized by some interesting groups of polynomials with ＂sign＂ coefficients. The results are naturally generalized to Sigma-Delta modulations with multiple delays, Delta-modulations in the ＂downlink＂, unbalanced Delta-modulations and systems with two-level quantized feedback. Further extensions relate to the existence of periodic points arising from Delta-modulated feedback control of a stable linear system in an arbitrary direction, for which some necessary and sufficient conditions are given.
文摘An inductive digital voice communication system used in shaft is studied. This system digitizes the voice signal by using CVSD (continuously varying slop delta), scramble/unscramble technology and partial response coding technology. By using these technology, the anti-jamming ability of the system and the communicatiou quality can be improved.This system adapts to the worst conditions of the shaft.
文摘A new digital audio processing system based on Nonuniform Sampling Delta Mod-ulation (NSDM) technique is presented in this paper. The performance of NSDM system is analysed. Theoretical analysis and experimental results have demonstrated that the perfor-manc e of NSDM system used in digital audio is better than that of conventional Linear Delta Modulation (LDM) in terms of coding efficiency, Signal to Quantization-Noise Ratio and dy-namic range.
文摘The paper discusses the application of PWM delta modulation with PI controller as an alternative to the standard PWM techniques for providing gating signals to the voltage source inverters. Its inherent characteristics of constant volts/Hertz control without feedback complexity and boosting of the fundamental voltage makes it an excellent choice for motor drive applications. This paper discusses the comparison between a basic delta modulation, the advanced Delta modulation with PI controller and an optimized DMPI. It is shown that in addition to the aforementioned advantages, VSI with optimized DMPI produces superior load current/voltage waveforms compared to simple DMPI, when IGBT is employed as a switching device for the inverter. Since the tacho feedback or other traditional speed sensing means is not permissible in sealed motor or the pump, a novel method is used to monitor the motor speed from the terminal quantities like voltage, current, and motor input power factor.
