Research On The System Measuring Sucker Rod Displacement Of The Beam Pumping Unit

Displacement of sucker rod is a crucial parameter of the indicator diagram,and its accuracy is the premise of a favorable indicator diagram and an exact veracious analysis of oil well conditions.At present,there are two main methods of displacement measurement on sucker rod.One is based on guyed sensor;the other is based on acceleration transducer.However the guyed sensor is characterized by easily broken wire、big bull and its poor mechanical structure.And the disadvantage of the acceleration transducer is quite a few usage astriction and susceptible measurement.Thus,the traditional methods are unable to satisfy the requirements on precision,stability and micromation.Therefore,the paper designed a new measurement system combined with the technology of laser-triangular method and PSD,resulting in an impressive promotion in accuracy and significant reduction on power consumption.The main points of the paper are as follows:Firstly,a simulation mode is made by MATLAB and the motion law of suspension point on sucker rod is obtained,which is beneficial for the practical performance evaluation of the designed system.Considering project requirements and contrasting the four different theories of laser ranging,laser triangulation was select as the basis of theoretical design.Secondly,according to the project needs,put forward the system design goals.Then,elaborate from the optical system,signal processing system and communication system to meet low-dissipation requirement and to achieve design accuracy through the selection of components,the design of light path and circuit and the setting of working mode.Accordingly,the schematic design of system is determined.Thirdly,Design hardware、software and analyze the power consumption.The hardware is composed of power module,the signal processing module,the minimum system module and wireless communication module,in which the emphasis is laid on power integrity analysis,the design of I/V converting circuit and filter amplifier circuit.While,Software design consists of initial and main programdesign,focusing on the data processing.Meanwhile,the analysis of power consumption is from two aspects:a set of working mode and the calculation on each module,in which the focal point is concerning how to reduce power consumption by the choice of operation voltage 、 frequency,modes and the cooperation of different modules.Lastly,carrying on simulation analysis on circuit performance through Tina software and testing power integrity by the oscilloscope when the hardware platform is finished.Afterwards,setting up experiment platform and carrying out calibration experiment,static test,dynamic test and field experiment on the calibration and the debugging of the system and its performance to get its power consumption and measuring accuracy.According to the experiments,laser triangulation displacement system based on PSD designed in the paper not only meets the work requirements,but also operates safely and stably.Moreover,the measurement range is 2 meters that is from 1.5 to3.5 meters and the precision is up to 7 millimeters besides its full-range accuracy is10 centimeters.Importantly,the service time of battery is 134 days,which is much longer than before.