Development Of An Environment Adaptive Control System For The Wheeled Robot For In-situ Detection In Loess Boreholes

The vast and endless Loess Plateau in the northwest region has given birth to the splendid Chinese civilization and nurtured hundreds of millions of Chinese.However,affected by the structural complexity and disaster-prone nature of the loess itself,especially by engineering disturbances,and superimposed on the northward shift of the rainfall belt,a large number of recent geological disasters,landslides,cave-ins,wet sinking and other phenomena are particularly prominent,seriously affecting people’s production and life,and even threaten life safety.In order to prevent the occurrence of subsequent geological disasters,it is necessary to obtain in situ geological information of loess and reveal the disaster-causing mechanism.For this purpose,pipeline robotics and machine vision technology are combined to perform in-situ detection of geological information.The test results found that the stability of robot walking operation and the quality of information acquisition were affected to a certain extent when the hole diameter or attachment performance of the local location in the hole changed.In this thesis,the environmental adaptive control performance is developed on the basis of the original robot control system,and the main research contents are as follows:Firstly,the principle of robot variation diameter and support force measurement is analyzed,and the function relationship between the support force of different apertures and the detection value of force sensor,the position of the nut in the robot support mechanism and the size of the aperture is established.These works are to provide a theoretical model for real-time acquisition of the support force of the robot in the process of running up and down the hole.On this basis,based on the support force sensor,variable-diameter motor,variable-diameter motor encoder,and robot main controller,related algorithms are developed to improve the environment adaptive ability of the robot under the condition of variable aperture in loess holes.Secondly,the robot is prone to slipping when detecting geological information in loess holes.Based on the in-depth analysis of the slipping mechanism and adhesion performance,based on the principle of laser ranging,a high-precision laser rangefinder is selected,and the wireless communication module between the ranging sensor and the main robot is designed.These works realize real-time positioning during robot operation.On this basis,the calculation model of the slip rate of the robot roller and the related dynamic PID control model of the support force is established to realize the adaptive control of the robot walking in the complex environment in the hole.Finally,an indoor variable diameter test platform and a Plexiglass tube test platform were built to debug the robot.After the indoor debugging,the environmental adaptive capability of the robot was tested by field loess hole experiments,and the robot’s operation status in the loess hole was analyzed by the support force and slip rotation rate of the robot walking in the hole recorded during the test.The field test results verified the effectiveness of the environmental adaptive control system.