The LMS Time Delay Estimation Algorithm Research Based On Maximum Likelihood And The DSP Implementation

Flow rate measurement of oil-gas-water three-phase flow is a common problem inthe development of dynamic monitoring of oil-gas field, and its accuracy of measurementis important to the oil-gas field development. In recent years, the research on LMSTDE hasbeen an important research direction in the low rate measurement of oil-gas-waterthree-phase flow field. In this paper, considering the disadvantage of LMS adaptive timedelay estimation algorithm, an improved algorithm is proposed, and the hardware circuitof signal acquisition and processing system of conductance cross correlation flow meterbased on digital signal processor (DSP) are designed.Firstly, considering a great fluctuation problem will be produced to the self-adaptionsystem by the direct usage of the transient error on weight vector function iteration innoise environment, we propose to use wavelet transform for filtering error function toreduce the delay estimation error, and construct a new weighed method for correction ofweigt vector of the time delay estimation to improve the estimation precision oftime-delay.Secondly, we designed a hardware circuit of signal acquisition and processing systemof conductance cross correlation flowmeter by digtial signal processor(DSP) to face theproblem of implementation of data real-time acquisition and time delay estimationalgorithm of well downhole conductance correlation method flowmeter sensors, which canmeet the requirements of signal collection, flow rate measurement of oil-gas-waterthree-phase, data transmission between PC and DSP and real-time display of data.Finally, combining hardware circuit of signal acquisition and processing system ofconductance cross correlation flowmeter and improved time delay estimation algorithm,implement a signal acquisition and processing system of conductance cross correlationflowmeter by DSP.The experiments in Daqing oil-gas-water three-phase flow simulationdevice platform is conducted,using the measurement data of oil-gas-water three-phaseflow in different quantity of flow to make experimental validations for signal acquisitionand processing system and comparative analysis of estimation results for time delay estimation algorithm.