Research On Gradient Control System Of Trenchless Pipe Laying Machine Based On RTK-BDS

The technology of control salt by concealed drainage in farmland is one of the main measures for the treatment of saline-alkali land.The core is to lay the drainage pipe underground according to a certain slope,and discharge the groundwater containing the saline-alkali component through the drainage pipe.The V-shaped plow-type trenchless pipelayer is an engineering equipment that supports the laying of hidden pipes.Compared with other types of pipelaying machines,it has the advantages of high pipelaying efficiency,manpower saving and no damage to the soil structure.the slope control system of the trenchless pipelayer is the core system for the quality of pipelaying operations.At present,the laser principle is generally used for slope control,However,the laser signal has a short transmission distance,is easily blocked,and is more sensitive to weather such as heavy fog.Therefore,this research takes the V-type plough-type trenchless pipelayer as the object,aiming at the high-precision pipelaying slope control requirements and the problems of the laser system,the Beidou satellite positioning system(RTK-BDS)based on the carrier phase real-time dynamic difference,The slope control system for the trenchless pipelayer was developed.The main research contents and conclusions are as follows:1.Through the analysis of the slope control structure and construction conditions of the trenchless pipelayer,two key parameters of pipelay slope control,horizontal control and elevation control,are determined.The horizontal control ensures that the four directions of the front,rear,left and right of the rear lower control arm of the trenchless pipelayer are kept level,so that the vertical distance between the plowshare and the Beidou antenna is always the same;Elevation control ensures that the plowshare of the trenchless pipelayer can control the height of the plowshare according to the specified slope coefficient,thereby controlling the altitude of the laying of the pipeline.2.By analyzing the detection principle of sensors and related filtering algorithms,the multi-sensor information fusion technology based on the multi-model adaptive UKF algorithm is studied,which improves the detection accuracy of elevation and horizontal inclination.The test results show that the left and right tilt angle detection error of the fusion algorithm is ±0.43°;the front and back tilt angle detection error is ±0.33°;the elevation detection error is±0.56cm,which is better than the detection accuracy of other algorithms such as UKF.3.the slope control technology of the trenchless pipelayer based on multi-modal fuzzy PID control is studied.a multi-modal fuzzy PID control adopts three modes:acceleration mode,transition mode and stable mode.The cylinder system is controlled in sections to improve Non-linear control capability of the system.4.The system has been tested and verified through field tests.The level control test results show that the front and rear level control and the left and right level control can effectively control the rear lower control arm to maintain the level;Elevation control test results show that the system can control the elevation error within±2cm when there is no slope or slope control;Practical engineering application tests show that the fluctuation range of slope control at different slopes is within±2cm,and the average control accuracy is within±1cm,which meets the slope control requirements of trenchless pipelayers.